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Growth and development of a selectively cut hill dipterocarp forest in peninsular Malaysia Yong, Teng Koon 1996

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G R O W T H A N D D E V E L O P M E N T OF A S E L E C T I V E L Y C U T HILL D I P T E R O C A R P F O R E S T IN P E N I N S U L A R M A L A Y S I A By Teng Koon Yong B. Sc.(Forestry), University of Agriculture, Malaysia, 1984 A T H E S I S S U B M I T T E D I N P A R T I A L F U L F I L L M E N T O F T H E R E Q U I R E M E N T S F O R T H E D E G R E E O F M A S T E R O F F O R E S T R Y in T H E F A C U L T Y O F G R A D U A T E S T U D I E S D E P A R T M E N T O F F O R E S T R E S O U R C E S M A N A G E M E N T We accept this thesis as conforming to thejrequirejL-slrandard T H E U N I V E R S I T Y O F B R I T I S H C O L U M B I A August 1996 © Teng Koon Yong, 1996 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department of Forest Resources Management The University of British Columbia 2075 Wesbrook Place Vancouver, Canada V6T 1Z1 Date: Abstract A Selective Management System (SMS) which emphasizes leaving intermediate-sized trees (30 to 45 cm dbh) was strongly recommended as a viable system for management of the hill dipterocarp forests. Due to the lack of reliable and quantitative data, a growth and yield study was carried out to assess the effects of selective cutting on the growth and development of the residual stand. Prior to harvest, the stem frequency distribution of the hill dipterocarp forest exhib-ited a reverse J-shaped stand structure, with generally higher variability (coefficient of variation) being observed for trees in the higher dbh classes. The non-dipterocarps were the dominant species, and the application of the various treatments further enhanced the proportion of the non-dipterocarps, by removing a higher proportion of the diptero-carps. Forest harvesting, in general, enhances forest regeneration: five of the replicated treatments exceeded their precut number of stems/ha (5 cm dbh and larger). Results of repeated measures multivariate analysis of variance indicated that there was no evidence of different growth trends among the replicated treatments, in terms of number of stems, basal area and gross volume. The residual stands showed signs of response to the various treatments applied 14 years after harvest. However, the overall increment rates of all trees 30 cm dbh and larger were relatively low, when compared to the rates assumed under the SMS. The overall gross volume growth of all trees 30 cm dbh and larger was 0.80 m 3/ha/year, while the periodic annual diameter increment (DPAI) averaged only 0.39 cm/year when compared to 2.0 to 2.5 m 3/ha/year and 0.8 to 1.0 cm/year, respectively assumed under the SMS. Though the DPAIs of the dipterocarps were significantly higher than that of ii the non-dipterocarps, their overall contribution to forest growth was small due to their lower stocking in the residual stand. The overall mean mortality (2.73 %) of all trees 30 cm dbh and larger over the 14 year period was higher than that assumed under the SMS, while the ingrowth of trees (3.35 %) surpassed that expected under the SMS. Besides poorer than average site conditions, the low growth rates could be attributed to the lack of post-harvest silvicultural treatments. Based on these growth rates, anticipating a second cut in 25 to 30 years as stipulated under the SMS, would be overly optimistic for this study area. i n Table of Contents Abstract ii Table of Contents iv List of Tables ix List of Figures xiv Acknowledgements xvii 1 Introduction 1 1.1 Problem Statement 1 1.2 Objectives 3 1.3 Overview of Thesis 4 2 Description of Forests of Peninsular Malaysia 5 2.1 Lowland Dipterocarp Forest 6 2.2 Hil l Dipterocarp Forest 7 2.3 Upper Dipterocarp Forest 7 2.4 Management and Silviculture in Dipterocarp Forest 8 3 Literature Review 11 4 Materials and Methods 17 4.1 Study Area 17 iv 4.2 Permanent Plot Establishment Procedures 19 4.2.1 Pre-Felling Forest Inventory 19 4.2.2 Selection of Diameter Cutting Limits (Treatments) 20 4.2.3 Experimental Design 20 4.2.4 Tree Marking and Harvesting 22 4.2.5 Establishment of Permanent Sample Plot 22 4.3 Measurement Procedures 22 4.3.1 Size of Trees Measured 22 4.3.2 Remeasurement 25 4.4 Data Analysis 26 4.4.1 Data Preparation 26 4.4.2 Species Grouping 26 4.4.3 Compilation 28 4.4.3.1 Stems 28 4.4.3.2 Basal Area 28 4.4.3.3 Gross Volume 28 4.4.3.4 Stand Growth 30 4.4.3.5 Diameter Growth 30 4.4.3.6 Mortality 30 4.4.3.7 Ingrowth 31 4.4.4 Statistical Analysis 31 4.4.4.1 Prior to Harvest 31 4.4.4.2 Regression Analysis 33 4.4.4.3 Repeated Measures Analysis of Variance 34 v 5 Results 36 5.1 Stand Structure and Species Composition Before Harvest 36 5.1.1 Stand Structure 36 5.1.1.1 Stems 36 5.1.1.2 Basal Area 40 5.1.1.3 Gross Volume 44 5.1.2 Species Composition 44 5.1.2.1 Stems 44 5.1.2.2 Basal Area 48 5.1.2.3 Gross volume 51 5.2 Stems, Basal Area and Gross Volume Cut 53 5.2.1 Stems 53 5.2.2 Basal Area 55 5.2.3 Gross Volume 57 5.3 Effects of Treatments 60 5.3.1 Stem Growth 60 5.3.1.1 Trees 5 cm dbh and larger 60 5.3.1.2 Trees 30 cm dbh and larger 61 5.3.2 Basal Area Growth - . . . . 70 5.3.2.1 Trees 5 cm dbh and larger . 70 5.3.2.2 Trees 30 cm dbh and larger 74 5.3.3 Gross Volume Growth 78 5.3.3.1 Trees 15 cm dbh and larger 78 5.3.3.2 Trees 30 cm dbh and larger 82 5.3.4 Diameter Growth 86 5.3.4.1 By Diameter Class/Limit 86 vi 5.3.4.2 By Species Group 86 5.3.4.3 Over Time 91 5.3.4.4 Relationship with Cutting Intensity 91 5.3.5 Mortality 94 5.3.5.1 By Species Group 94 5.3.5.2 Over time 94 5.3.5.3 Relationship with logging damage and cutting intensity . 97 5.3.6 Ingrowth 100 6 Discussions of Results 103 6.1 Prior to Harvest 103 6.2 During Harvest 105 6.3 After Harvest 106 6.4 Implications for Forest Management I l l 7 Conclusions and Recommendations 114 Literature Cited 120 Appendices 130 A Logging Damage Assessment 130 B Stand Structure Before Harvest 134 C Effects of Treatments on Stand Growth (Figures) 141 D Effects of Treatments on Stand Growth (Tables) 154 E Diameter Growth 167 vii F Mortality 176 G Ingrowth 182 v i n List of Tables 4.1 Treatments prescribed for the study area 21 4.2 List of species groups 27 4.3 Height-diameter relationship (Source: Anon. 1985b) 29 4.4 A N O V A model for testing differences in stand structure 33 4.5 List of regression analyses 33 5.6 Mean and percent stem frequency distribution by species group and dbh class 49 5.7 Mean and percent basal area distribution by species group and dbh class. 52 5.8 Mean and percent gross volume distribution (ra3/ha) by species group and dbh class 54 5.9 Total number and percent stems cut at harvest (stems/ha), as well as stems/ha marked but left uncut 56 5.10 Total and percent basal area cut at harvest (m 2/ha), as well as basal area/ha marked but left uncut 58 5.11 Total and percent gross volume cut at harvest (m 3/ha), as well as gross volume/ha marked but left uncut 59 5.12 Mean periodic annual increment (stems/ha/year) of trees 5 cm dbh and larger by treatment and species group (1974-1988) 62 5.13 Mean periodic annual increment (stems/ha/year) of trees 30 cm dbh and larger by treatment and species group (1974-1988) 69 ix 5.14 Mean periodic annual increment (m 2/ha/year) of trees 5 cm dbh and larger by treatment and species group (1974-1988) 73 5.15 Mean periodic annual increment (m 2/ha/year) of trees 30 cm dbh and larger by species group (1974-1988) 77 5.16 Mean periodic annual increment (m 3/ha/year) of trees 15 cm dbh and larger by treatment and species group (1974-1988) 81 5.17 Mean periodic annual increment (m 3/ha/year) of trees 30 cm dbh and larger by treatment and species group (1974-1988) 85 5.18 Mean periodic annual diameter increment (cm/year) by treatment, species group and dbh class (1974-1988) 87 5.19 Mean periodic annual diameter increment (cm/year) by treatment, species group and dbh limit (1974-1988) 89 5.20 Summary of A N O V A for diameter increment 90 5.21 Mean periodic annual diameter increment (cm/year) over three growth periods by treatment, major species group and dbh limit 92 5.22 Mean annual percent mortality by treatment, species group and dbh limit (1974-1988) 95 5.23 Mean annual percent mortality of trees 5 cm dbh and larger over three successive growth periods by treatment and species group 96 5.24 Mean mortality of trees by logging damage class, cutting intensity, dbh limit and growth period 98 5.25 Mean annual percent ingrowth of trees by treatment, species group and dbh limit (1974-1988) 101 A.26 Stem damage classes 131 A.27 Crown damage classes 132 x A.28 Combined stem and crown damage classes 132 A. 29 Combined overall logging damage classes 133 B. 30 Stem frequency distribution (stems/ha) by dbh class before harvest. . . . 135 B.31 Stem frequency distribution (percent) by dbh class before harvest 136 B.32 Basal area distribution (m 2/ha) by dbh class before harvest 137 B.33 Basal area distribution (percent) by dbh class before harvest 138 B.34 Gross volume distribution (m 3/ha) by dbh class before harvest 139 B.35 Gross volume distribution (percent) by dbh class before harvest 140 D.36 Stems/ha and periodic annual increment (stems/ha/year) of trees 5 cm dbh and larger (1974-1988) 155 D.37 Periodic annual increment (stems/ha/year) of trees 5 cm dbh and larger by species group (1974-1988) 156 D.38 Stems/ha and periodic annual increment (stems/ha/year) of trees 30 cm dbh and larger (1974-1988) 157 D.39 Periodic annual increment (stem/ha/year) of trees 30 cm dbh and larger by species group (1974-1988) 158 D.40 Basal area (m 2/ha) and periodic annual increment(m2/ha/year) of trees 5 cm dbh and larger (1974-1988) 159 D.41 Periodic annual increment (m 2/ha/year) of trees 5 cm dbh and larger by species group (1974-1988) 160 D.42 Basal area (m 2/ha) and periodic annual increment (m 2/ha/year) of trees 30 cm dbh and larger (1974-1988) 161 D.43 Periodic annual increment (m 2/ha/year) of trees 30 cm dbh and larger by species group (1974-1988) 162 xi D.44 Gross volume (m 3/ha) and periodic annual increment (m 3/ha/year) of trees 15 cm dbh and larger (1974-1988) 163 D.45 Periodic annual increment (m 3/ha/year) of trees 15 cm dbh and larger by species group (1974-1988) 164 D.46 Gross volume (m 3/ha) and periodic annual increment (m 3/ha/year) of trees 30 cm dbh and larger (1974-1988) 165 D. 47 Periodic annual increment (m 3/ha/year) of trees 30 cm dbh and larger by species group (1974-1988) 166 E. 48 Periodic annual diameter increment (cm/year) for diameter class 5.0-14.9 cm (1974-1988) 168 E.49 Periodic annual diameter increment (cm/year) for diameter class 15.0-29.9 cm (1974-1988) 169 E.50 Periodic annual diameter increment (cm/year) for diameter class 30.0-44.9 cm (1974-1988) 170 E.51 Periodic annual diameter increment (cm/year) of trees 5.0 cm dbh and larger (1974-1988). 171 E.52 Periodic annual diameter increment (cm/year) of trees 15.0 cm dbh and larger (1974-1988) 172 E.53 Periodic annual diameter increment (cm/year) of trees 30.0 cm dbh and larger (1974-1988) 173 E.54 Periodic annual diameter increment (cm/year) of trees 5.0 cm dbh and larger over three growth periods 174 E. 55 Periodic annual diameter increment (cm/year) of trees 30.0 cm dbh and larger over three growth periods 175 F. 56 Mean annual percent mortality of trees 5 cm dbh and larger (1974-1988). 177 xii F.57 Mean annual percent mortality of trees 30 cm dbh and larger (1974-1988). 178 F.58 Mean annual percent mortality of trees 5 cm dbh and larger (1974-1979). 179 F.59 Mean annual percent mortality of trees 5 cm dbh and larger (1979-1984). 180 F. 60 Mean annual percent mortality of trees 5 cm dbh and larger (1984-1988). 181 G. 61 Mean annual percent ingrowth of trees into 5 cm dbh limit (1974-1988). . 183 G.62 Mean annual percent ingrowth of trees into 30 cm dbh limit (1974-1988). 184 xm List of Figures 4.1 Location of study area 18 4.2 Experimental layout of growth and yield study area 23 4.3 Layout of permanent sample plot 24 5.4 Coefficients of variation (C.V.) for stems/ha (all treatments combined) by dbh class 37 5.5 Standard deviation (stems/ha) for the replicated treatments by dbh class. 38 5.6 Mean frequency distribution (stems/ha) for the replicated treatments by dbh class 39 5.7 Coefficients of variation (C.V.) for basal area/ha (all treatments combined) by dbh class 41 5.8 Standard deviation (m 2/ha) for the replicated treatments by dbh class. . 42 5.9 Mean basal area distribution (m 2/ha) for the replicated treatments by dbh class 43 5.10 Coefficients of variation (C.V.) for gross volume/ha (all treatments com-bined) by dbh class 45 5.11 Standard deviation (m 3/ha) for the replicated treatments by dbh class. . 46 5.12 Mean gross volume distribution (m 3/ha) for the replicated treatments by dbh class 47 5.13 Mean frequency distribution of trees (stems/ha) by species group and dbh class 50 5.14 Mean basal area distribution (m 2/ha) by species group and dbh class. . . 51 xiv 5.15 Mean gross volume distribution (m 3/ha) by species group and dbh class. 53 5.16 Stems/ha of all trees 5.0 cm dbh and larger after harvest for replicated treatments 63 5.17 Stem ratios of all trees 5.0 cm dbh and larger after harvest for replicated treatments 64 5.18 Relationship between percent stem change and cutting intensity 65 5.19 Stems/ha of all trees 30.0 cm dbh and larger after harvest for replicated treatments 67 5.20 Stem ratios of all trees 30.0 cm dbh and larger after harvest for replicated treatments 68 5.21 Basal area of all trees 5.0 cm dbh and larger after harvest for replicated treatments 71 5.22 Basal area ratios of all trees 5.0 cm dbh and larger after harvest for repli-cated treatments 72 5.23 Basal area of all trees 30.0 cm dbh and larger after harvest for replicated treatments 75 5.24 Basal area ratios of all trees 30.0 cm dbh and larger after harvest for replicated treatments 76 5.25 Gross volume of all trees 15.0 cm dbh and larger after harvest for replicated treatments 79 5.26 Gross volume ratios of all trees 15.0 cm dbh and larger after harvest for replicated treatments 80 5.27 Gross volume of all trees 30.0 cm dbh and larger after harvest for replicated treatments 83 5.28 Gross volume ratios of all trees 30.0 cm dbh and larger after harvest for replicated treatments 84 xv 5.29 Mean periodic annual diameter increment (cm/year) for replicated treat-ments by major species group and dbh class (1974 - 1988) 88 5.30 Relationship between mean periodic annual diameter increment and per-cent cutting intensity by major species group (1974-1988) 93 5.31 Relationship between percent mortality and percent cutting intensity by major species group (1974-1988) 99 5.32 Relationship between percent ingrowth and percent cutting intensity by major species group (1974-1988) 102 C.33 Stems/ha of all trees 5.0 cm dbh and larger after harvest 142 C.34 Stem ratios of all trees 5.0 cm dbh and larger after harvest 143 C.35 Stems/ha of all trees 30.0 cm dbh and larger after harvest 144 C.36 Stem ratios of all trees 30.0 cm dbh and larger after harvest 145 C.37 Basal area of all trees 5.0 cm dbh and larger after harvest 146 C.38 Basal area ratios of all trees 5.0 cm dbh and larger after harvest 147 C.39 Basal area of all trees 30.0 cm dbh and larger after harvest 148 C.40 Basal area ratios of all trees 30.0 cm dbh and larger after harvest 149 C.41 Gross volume of all trees 15.0 cm dbh and larger after harvest 150 C.42 Gross volume ratios of all trees 15.0 cm dbh and larger after harvest. . . 151 C.43 Gross volume of all trees 30.0 cm dbh and larger after harvest 152 C.44 Gross volume ratios of all trees 30.0 cm dbh and larger after harvest. . . 153 x v i Acknowledgements I wish to express my sincere appreciation to the Public Service Department of Malaysia and the Director-General of Forestry, Peninsular Malaysia for making it possible for me to undertake this study at U B C . Funding for the study from the Canadian International De-velopment Agency (CIDA) through the A S E A N Institute of Forest Management (AIFM) project is also gratefully acknowledged. I am greatly indebted to my supervisor, Dr. V . LeMay for her dedication, direction and unfailing encouragement throughout the course of my studies. Sincere thanks are also extended to other members of my advisory committee, Drs. A . Kozak and P. Mar-shall from the Department of Forest Resources Management, Dr. A . Y . Omule from the Ministry of Forests, B . C . at Victoria, and Dr. M . Bonner who served in the committee prior to his retirement from Forestry Canada in Apri l 1996, for their guidance and advice at all stages of this study. I would like to thank Ms. Kathleen Mitchell, the Canadian project administrator for the A I F M project for all administrative and logistic assistance. Thanks are extended to the field staff of the Forest Management Unit, Forestry Department Headquarters who were involved in the collection of the data that formed the basis of this research. Special thanks are accorded to my church family for their love, concern, fellowship and prayer support at all times. Last but not least, sincere thanks and affection are due to my wife, Suan Kee for her love, patience and understanding, as well as my daughters: Deborah, Phoebe and Sharon for bringing me much joy and fond memories. To God be the glory! xvn Chapter 1 Introduction 1.1 Problem Statement The dipterocarp forests are of vital economic and ecological importance to Peninsular Malaysia. In 1992, they constituted about 5.55 million hectares or 93 % of the total forested area of Peninsular Malaysia (Masran, 1994) and formed the bulk of the produc-tion forest of the permanent forest reserve. They comprise the well-drained forests of the plains, undulating land and foothills up to an elevation of 1,200 m above mean sea level, and can be classified as Lowland dipterocarp, Hil l dipterocarp and Upper dipterocarp forests, according to the classification of Wyatt-Smith (1963). Despite their economic importance, the dipterocarp forests have been greatly de-pleted, particularly the Lowland dipterocarp forest. This is principally the result of large scale agricultural development through the conversion of forested land to agriculture, mainly rubber and oil palm plantations, under the various Malaysian National Devel-opment Plans since 1961. It was estimated some 2 million hectares, 15 % of the total forested area of Peninsular Malaysia, were converted over the period from 1960 to 1978 (Harun, 1981). The massive land conversion was based on the Land Capability Classifi-cation (LCC) which has been used as the basis for land use planning in Malaysia since 1964. Under the L C C , land suitable for mining (minerals) and agriculture are given development priority over forestry. Hence, only those areas that have no potential for mining and agriculture were relegated for long-term forestry use. 1 Chapter 1. Introduction 2 The fast depletion of the dipterocarp forests was also confirmed by the First National Forest Inventory of Peninsular Malaysia which was conducted from 1970 to 1972. The results of the inventory indicated that virtually all easily accessible lowland and foothill forests had been logged. About one-third (the more accessible) of hill forest reserves had been exploited, while the remaining forests were found on steeper slopes in the remote parts of the country (FAO, 1973). The depletion of the lowland forests initiated the beginning of a new era of forestry in Peninsular Malaysia, the logging of the hill forests. This has, to a great extent, been made possible through the use of mechanized logging methods. However, the harvesting of the hill forests raised a number of concerns. Firstly, no silviculture/management system was in place for management of these forests. The Malayan Uniform System (MUS), the existing forest management system devised for the lowland forests, was found to be unsuitable for the hills for many reasons, particularly because of a lack of natural regeneration (Thang, 1987). Secondly, little was known about the ecology of these forests (Burgess, 1970). There was little or no information to indicate how the hill forests could be managed in a sustained manner to produce commercial products at least equal to those of the existing forest. These factors have resulted in a strong lobby for the use of a selection felling system in Peninsular Malaysia (Tang and Wan Razali, 1980). The selection felling emphasizes leaving intermediate-sized trees (30 to 45 cm diameter outside bark at breast height (dbh), measured at 1.3 m above ground or 0.3 m above buttress) to form the next crop, instead of leaving seedlings using the MUS. Leaving intermediate-sized trees presupposes that these trees would respond vigor-ously to the release provided by partial cutting. However, no reliable, quantitative data were available to assess the response of the residual stands under the selection felling system. Hence, it was proposed that growth and yield studies be conducted to study the Chapter 1. Introduction 3 effects of selective felling on the growth and development of the residual stand. Under the assistance of the United Nations Development Program and the Food and Agriculture Organisation of the United Nations ( U N D P / F A O ) , the first of a series of growth and yield study areas was established in about 150 hectares of hill dipterocarp forest in the state of Terengganu in 1974. Since its establishment, this study area was remeasured at regular intervals. To date, a total of 10 remeasurements have been carried out over the period from 1974 to 1988. Data obtained from this study area were utilized for this research. 1.2 Objectives The objectives of this research were: 1. To study the stand structure and species composition of the forest before harvesting. 2. To study the amount of stems, basal area and gross volume per hectare cut during harvesting. 3. To study the growth and development of the forest as a result of harvesting, in terms of • stems, basal area, and gross volume per hectare; • average diameter increment in centimeter/year; • mortality rate; and • ingrowth. 4. To discuss the implications of these results on forest management. Chapter 1. Introduction 4 1.3 Overview of Thesis The second chapter of this thesis contains a description of the forest types in Peninsular Malaysia, particularly the dipterocarp forests. A brief account of the silviculture and management of the dipterocarp forest is also given. Chapter 3 is a literature review of growth and yield studies conducted and models that had been developed in Malaysia. Materials and methods used in conducting this research are included in Chapter 4. Chap-ter 5 contains results of the research. These results are discussed in Chapter 6. Chapter 7 contains conclusions and recommendations for future research. Chapter 2 Description of Forests of Peninsular Malaysia The forests of Peninsular Malaysia can be broadly classified into nine major forest types (Wyatt-Smith, 1963). They are: 1. Lowland dipterocarp forest; 2. Hi l l dipterocarp forest; 3. Upper dipterocarp forest; 4. Lower montane forest; 5. Upper montane forest; 6. Freshwater alluvial swamp forest; 7. Peat swamp forest; 8. Riparian fringes; and 9. Mangrove forest. Since this research focuses on the dipterocarp forest, only the first three,forest types will be described here. The descriptions of these three forest types are summary extracts based on the classification by Wyatt-Smith (1963). With the exception of Peat swamp and Mangrove forests, the other forest types are all 'non-productive' and are designated as protection forest. 5 Chapter 2. Description of Forests of Peninsular Malaysia 6 2.1 Lowland Dipterocarp Forest The lowland dipterocarp forests include all the well-drained forests of the plains, undu-lating land and foothills up to an elevation of about 300 m above mean sea level. The forests are usually dense and comprised of many thousands of tree species as well as shrubs, herbs and woody climbers. The upper or emergent storey is usually about 30 to 45 m high, though trees nearly 60 m in height are often present. This storey is usually characterized by a high occurence of the family Dipterocarpaceae with many of the species of the genera Anisoptera, Dipterocarpus, Dryobalanops, Hopea, Shorea and Parashorea. Other common large trees in this storey include Dyera costulata, Gluta species, Intsia palembanica, Koompassia malaccensis, Melanorrhoea species, Palaquium species, Sindora species and Tarrietia species. The main storey or second tree layer, which occupies a region of about 20 m to 30 m from the ground, forms a continuous canopy except immediately below the large emergent storey trees. This storey consists of young trees of the normally upper storey species together, predominantly, with members of the families Burseraceae, Guttiferae, Myristicaceae, Mytaceae and Sapotaceae. The understorey or third tree layer consists of saplings of the upper two storeys together, mainly with members of such families as Annonaceae, Euphorbiaceae, Flacourtiaceae and Rubiaceae. The density of the shrub layer is very variable, comprised of shrub species of An-nonaceae, Euphorbiaceae and Rubiaceae. The herb layer consists mainly of young seedlings of the other layers and lianas, with some aroids and ferns near streams and in moist valleys, while epiphytes are usually very poorly represented. Chapter 2. Description of Forests of Peninsular Malaysia 7 2.2 Hill Dipterocarp Forest The hill dipterocarp forests occur on the inland ranges between the altitudinal limits of 300 and 750 m above mean sea level. Aspect and site, however, are important factors and the forests have a tendency to be found at lower limits on exposed ridges, and at higher limits in the more sheltered valleys. On isolated mountains and on coastal ranges, the forests can be found at very low elevations and occur almost at sea level. The main difference between the lowland dipterocarp and hill dipterocarp forest is a shift in the floristic composition of the dominants in the emergent and main storeys. The most common large tree species of this forest is Shorea curtisii which tends to be gregarious and shows a distinct preference for ridge tops. The large trees in the hill forest are usually slightly smaller and shorter than those in the lowland forest, except for the big trees on the ridge tops. The density of trees on ridge tops is greater than that in the lowland forest, and there are correspondingly fewer trees in the understorey and in the lower part of the main storey. The vegetation of hill slopes, particularly steep slopes, is often poorly stocked with woody species. The understorey is usually very rich in stemmed palms such as Arenga westerhoutii, Oncosperma horrida and Orania macrocladus, and in stemless palms such as Licuala species, Eugeissona triste and rattans such as Calamus castaneus. In valley bottoms, large woody species are also poorly represented and the forest is characterized by the richness of the ground flora and shrub layer where Alocasia species, Colocasia species, Donax grandis and many other ground ferns are commonly found. 2.3 Upper Dipterocarp Forest The upper dipterocarp forests are found on the higher hills between the approximate altitudinal limits of 750 to 1,200 m above mean sea level. As in the case of the hill Chapter 2. Description of Forests of Peninsular Malaysia 8 dipterocarp forest, they may also be found in narrower and much lower belt on coastal ranges or on isolated mountains. The species are very different from those found in the hill dipterocarp forests. Although the forest structure is much the same, namely three-layered, the upper layer is less tall and varies between 25 to 30 m in height, with a more even upper canopy level. The second and emergent tree layers are frequently less distinct as separate entities. The family Dipterocarpaceae is only represented by a few species and this forest is often characterized by the presence of Shorea platyclados. The shrub layer in this forest is frequently dominated by rattans and dwarf palms, while the ground flora is comprised of species of Argostemma (Rubiaceae), Sonerila (Melastomaceae), Selaginella atroviridis, and the fern Thelypteris chalamydophora. 2.4 Management and Silviculture in Dipterocarp Forest The lowland dipterocarp forests of Peninsular Malaysia have been managed under the M U S since the 1950s. Formulated in 1948, the MUS is basically a system for converting the virgin tropical lowland rain forest into a more or less even-aged forest, containing a greater proportion of the commercial species (Wyatt-Smith, 1961). This is achieved by removing the mature crop (all trees 45 cm dbh and above) in one single felling and through the systematic poison-girdling of defective and non-commercial species 15 cm dbh and larger. Approximately 3 to 5 years after felling, a post felling forest inventory is carried out to verify the presence and status of regeneration on the ground, and subsequently to determine suitable silvicultural treatments. The MUS has been modified to the current practice in the lowland dipterocarp forest (Thang, 1987). The modified MUS employs a more discriminating use of the poison-girdling technique and a more conservational approach in silvicultural treatments. Only Chapter 2. Description of Forests of Peninsular Malaysia 9 defective trees are being poisoned-girdled, while advanced growth of potentially mar-ketable trees is being retained. Despite its effectiveness in regenerating the lowland dipterocarp forest (Wyatt-Smith 1963, Burgess, 1970), the MUS was found to be unsuitable for the hill dipterocarp forest (Anon. 1985a, Thang 1987). This is because of comparatively more difficult terrain, uneven distribution of trees, lack of natural regeneration on the forest floor before felling, and uncertain seedling regeneration after logging due to irregular flowering of potential mother trees. The danger of soil erosion on steep slopes, the incidence of a stemless palm, Eugeissona triste, and other secondary growth, also do not encourage a drastic opening of the canopy. Consequently, the Selective Management System (SMS) was introduced for the hill forests in Peninsular Malaysia in 1978. The SMS is designed to optimize the management objective of economic and efficient forest harvesting, forest sustainability, and minimum forest development costs. The selection of management (felling) regimes is based on pre-felling forest inventory data. In practice, the common prescriptions followed are (Thang, 1987): 1. The cutting limit prescribed for the group of dipterocarp species should not be less than 50 cm dbh, except for Neobalanocarpus heimii (chengal) where the cutting limit prescribed should not be less than 60 cm dbh; 2. The cutting limit prescribed for the group of non-dipterocarp species should not be less than 45 cm dbh; 3. The difference in the cutting limits prescribed between the dipterocarp species and that of the non-dipterocarp species should be at least 5 cm; 4. The residual stocking should have at least 32 sound commercial trees per hectare Chapter 2. Description of Forests of Peninsular Malaysia 10 in the dbh class from 30 to 45 cm dbh. Substitutions using trees with dbh larger than 45 cm were given equivalent value of 2 stems/ha, while trees in the dbh class from 15 to 30 cm were given equivalent value of | stems/ha; and 5. The percentage of dipterocarp species in the residual stand for trees having dbh of 30 cm and larger should not be less than that in the stand prior to harvest. In addition, the following average growth rates were assumed for all trees 30 cm dbh and larger in determining the subsequent cuts every 25 to 30 years (Thang 1987, Apanah and Weinland 1990): 1. Mean annual dbh growth of 0.8 to 1.0 cm/year; 2. Mean annual volume growth of 2.0 to 2.5 m 3/ha/year; 3. Mean annual mortality of 0.9 %; and 4. Mean annual ingrowth of 0.6 %. These rates were assumed to remain constant over time. The SMS should offer reduced cutting cycles and total silvicultural costs (Tang, 1976). However, such a system can be effectively applied only if the residual stand contains an adequate number of undamaged trees of acceptable species, which are capable of responding to the release. C h a p t e r 3 L i t e r a t u r e R e v i e w In Peninsular Malaysia, growth plots to monitor the growth and diameter increment of trees were established as early as 1901. However, these plots were invalidated later due to non-conformity of measurements. New sample plots were established in 1915 based on guidelines formulated during the first Malayan Forestry Conference. By 1928, growth data on approximately 4,500 trees consisting of 23 major timber species were collected, compiled and analyzed by Edwards and Mead (1930). In 1937, nine plots ranging in size from 0.3 to 2 ha were laid out in Sungai Buloh Forest Reserve, Selangor to study the growth and natural regeneration of Shorea leprosula (Meranti tembaga) (Landon, 1954). In 1956, a series of 70 permanent sample plots, each measuring 20 m x 200 m (0.4 ha) in size were established in logged-over forests which had been silviculturally treated and considered sufficiently regenerated in the state of Perak (Cousens, 1958). The aim of the study was to determine the species composition and stocking of the regenerating forests. The study was subsequently extended to cover regenerated forests in the states of Johor (59 plots), Malacca (53 plots), and Negeri Sembilan (114 plots) (Sandrasegaran, 1965). However, as of 1989, only 38 plots were still being monitored (Thang and Yong, 1989a). The remaining plots have been lost, due mainly to the excision of the study areas for mining and agricultural development. Only part of the data from the Selangor plots had been analyzed by Tang (1976). He found that the dipterocarps were able to achieve a periodic mean annual diameter increment of 0.9 cm/year, with a mean annual mortality rate of 2% over a 10 year period. 11 Chapter 3. Literature Review 12 In the 1960s, a series of observation notes on the growth of various timber species were written, notably by Vincent (1961a, 1961b, 1961c, 1962a, 1962b), Vincent et al. (1964, 1965), Sandrasegaran (1966a), and Freezeilah and Sandrasegaran (1966). Over the same period, volume equations to predict yield for various timber species were also developed. A l l these equations were developed by Sandrasegaran for Fagraea fragrans (1966b), Tectona grandis Linn. F (1966c, 1969), Gmelina arborea (1966d), Eucalyptus robusta SM. (1966e), E. grandis (1967a), E. saligna SM. Crown (1967b), Pinus caribaea Mor. (1968), and P. merkusii (1970). In addition, a height-diameter regression function for P. caribaea Mor. (Sandrasegaran, 1971a) and height-diameter-age multiple regression models for Rhizophora apiculata (Sandrasegaran, 1971b) were also developed. Comparative growth rates of some 233 species of trees planted in the arboretum and plantation of the Kepong Forest Research Institute, covering up to 47 years for many species, were compiled and published by Ng and Tang (1974). They found that the Shorea and Dipterocarpus species were the fastest growers among the commercial timber species of the lowland forests. The average mean annual dbh increment at year 40 ranged from 1.5 to 2.7 cm/year for the Shorea species and 1.5 to 2.0 cm/year for the Dipterocarpus species. In Peninsular Malaysia, the systematic establishment of growth and yield study areas began in 1973. The first of a series of growth and yield study areas was set up in the state of Terengganu through the technical assistance of the FAO. Since then, many more study areas have been established using the same experimental design. A detailed description of these study areas was given by Thang and Yong (1989b). The aim was to study the growth response and development of the lowland and hill dipterocarp forests under different intensities of logging. Some preliminary results of these studies have been published by Borhan (1985), Johari and Borhan (1982), Karkee (1993), Tang (1976, 1978, 1980) and Yong (1990). Chapter 3. Literature Review 13 In addition, a total of 64 growth plots have been established in the logged-over forests of the permanent forest reserve of Peninsular Malaysia over the period from 1992 to 1994 (Masran and Yong, 1994). The aim was to study the regeneration status and potential yield of the logged-over forest. This is of vital importance as only 0.23 million hectares of the production forests of the permanent forest reserve are still unexploited and it was envisaged that they will all be logged over the next 5 years. The future timber supply will have to come from the previously logged forest. Existing growth and yield models developed in Malaysia are either the product of graduate research or of foreign experts as part of development projects in Malaysia. Unfortunately, most of these models remain in their rudimentary forms and have not been improved upon to be of any practical use. The first attempt to develop a computer simulation model was undertaken by Salleh (1977). He developed a preliminary forest stand management model (FORSTAM) in an attempt to simulate, in a simplified way, the dynamics of a managed hill dipterocarp forest in Peninsular Malaysia. The model takes into consideration the cutting regime, silvicultural system, and logging system as part of management strategy alternatives and determines their impacts on the forest stand. The manager can evaluate the acceptability of the chosen alternatives by studying the outputs of the simulation, which consist of financial returns (timber output), development of the residual stands, and impact on the environment (potential erosion). Iterative runs using different selective alternatives will allow the manager to decide on the most appropriate alternative to use. Canonizado (1978) proposed the first computer simulation scheme to study the re-sponse of forest stands managed under the selective management system (SMS) for the Jengka Company concession forest in the state of Pahang. The objectives of the simu-lation were to provide insights on: (i) species composition and structure of the residual stands, (ii) predicted yield in the second cutting cycle, (iii) economic cutting cycle, and Chapter 3. Literature Review 14 (iv) extraction limits under various stand density levels. The simulation scheme in-cluded four simulators, namely a logging damage simulator, a tree marking (allowable cut) simulator, a harvest cut simulator and a growth simulator. To run the simulation, basic inputs are needed. They include cutting intensity, stand and stock tables, logging system, growth, mortality, ingrowth and time trends. Borhan (1985) employed multiple regression techniques to predict the growth of a selectively cut hill dipterocarp forest in Labis Forest Reserve, Peninsular Malaysia. He found that the total standing basal area and volume of trees 10 cm dbh and larger immediately after harvest were the best independent variables to predict the standing basal area and volume yield four years after harvest. Individual tree distance independent models were developed by Wan Razali (1986) to model the diameter increment and mortality of the mixed tropical moist forest of Peninsular Malaysia. Linear models and non-linear models were developed to model diameter increment and mortality, respectively. Other growth models developed include that by Abdul Rahman (1989) and Yusuf (1990). Abdul Rahman developed a log production planning model for the state of Negeri Sembilan using linear programing. The structure of the initial stand is input to the model, the harvest is simulated, the development of the residual stand is simulated, and future yield is calculated. Yusuf (1990) fitted inventory data into the model developed by Abdul Rahman to indicate how cutting cycles under the SMS could be determined, and subsequently applied it to plan the sustainability of timber production in Peninsular Malaysia. Watts (1990a) employed five different modelling techniques in developing growth and yield functions to be used in an inventory projection model for the hill dipterocarp forest of Peninsular Malaysia. The main aim of the inventory projection model was to enable forest managers to simulate stand growth for forests managed under the SMS. The five Chapter 3. Literature Review 15 techniques considered were: 1. A Weibull probability density function to predict the future diameter distribution (stems) by species groups. 2. An individual tree model using the logistic function to predict tree mortality and linear regression to predict dbh growth of surviving trees by species groups over the projection period. 3. Predicting the components of stand growth (mortality, ingrowth, diameter class growth and tree movement between dbh class/limit) by dbh class and species group in a stand-level model. Components were predicted in terms of stems, basal area, gross volume and net volume per hectare. 4. A linear regression to predict periodic mean annual increment over time (stems, basal area, gross volume, net volume) by dbh class/limit and species group. 5. Predicting stems, basal area, gross volume and net volume per hectare as functions of time, cutting intensity, site quality, pre-felling and post-felling stand conditions using linear regression techniques by species groups. Three criteria were used to assess the models. They were: (i) statistical validity (based on coefficient of multiple determination, standard error of the estimate, and significance tests), (ii) accuracy in making predictions over the range of the data, and (iii) accuracy in making projections beyond the range of the data. Based on the above criteria, Model 5 was found to be most appropriate for forest inventory projection. The model provided reliable estimates for the non-dipterocarp species and all species groups combined. The projection of dipterocarps was found to be less accurate due to low number of trees in this species group. Chapter 3. Literature Review 16 In Sarawak, a stand table projection model was developed by Kofod (1982) for the se-lectively harvested mixed dipterocarp forest. The mean time of passage and de Liocourts q value were used as a basis to determine the time and rate of growth and mortality to move one tree from one dbh class to another. This model has since been improved by Korsgaard (1993) and made applicable to the forests of Peninsular Malaysia. Chai and LeMay (1993) developed tree diameter increment models for the mixed swamp forest as an initial effort towards developing a growth and yield modelling system for the forests of Sarawak. They found that linear weighted models are better predictors and modelling at the individual species level resulted in moderately better predictions than at the group level. Chapter 4 Materials arid Methods 4.1 Study Area The data used in this study were collected on a growth and yield study area established in Compartments 4, 5 and 6, Gunung Tebu Forest Reserve in the state of Terengganu. Lo-cated on the east coast of Peninsular Malaysia (Figure 4.1), the study area comprises 150 hectares of hill dipterocarp forests. The general topography of the study area is undulat-ing to hilly, having elevations between 15 m to 340 m above mean sea level. Geologically, the study area belongs to the Upper Palaezoic, comprised mainly of calcareous rocks, with the dominant soil types being lithosols and shallow lithosols, considered unsuitable for agricultural development. The climate of the study area is influenced primarily by monsoonal activity. The north-east monsoon often brings strong winds and rain across the study area between October and March. There is no pronounced dry season, but a generally drier period is experienced between Apri l and August, coinciding with the south-west monsoon season. Annual rainfall is 3824 mm, with 195 rainy days per annum, an annual mean temperature of about 23.8° C and a mean relative humidity of 80.2 % (Anon. 1986). 17 er 4. Materials and Methods 18 Figure 4.1: Location of study area. Chapter 4. Materials and Methods 19 4.2 Permanent Plot Establishment Procedures The permanent plot establishment procedures for the study were developed by the Forest Management Unit, Forestry Department Headquarters, Peninsular Malaysia, in collabo-ration with experts attached to the Forestry and Forest Industries Development project in 1973. These procedures were described in detail by Calliez (1974) and are summarized in this report. 4.2.1 Pre-Felling Forest Inventory A systematic pre-felling forest inventory covering the major sub-divisions of the study area and using a plot size of 20 m x 20 m with a distance between plot centers of 60 m was carried out in 1973. The aim of the inventory was to determine the stocking and structure of the forest by diameter class and species groups. Information obtained from this inventory was used to stratify the study area into three stocking classes, which was considered necessary in view of the heterogeneity of the composition and stocking of the forest. A l l trees 15 cm dbh and larger were identified to the species level, measured for diameter, and estimated for height class. Pre-felling sample plot data were analyzed and volumes were summarized into treatment block averages by species group and diameter class (16 variables altogether). Each variable was later ranked in ascending order, with the treatment block having the lowest value being given a rank of 1. Treatment blocks having same value were assigned an equal rank number (averaged). Based on the ranking exercise, the six treatment blocks having the highest overall ranking were considered as having superior stocking (S), followed by the next six blocks as having good stocking (G) and the last six treatment blocks as having moderate stocking (M). Details of the ranking procedures were described by Calliez (1974). In the absence of adequate knowledge of site factors, it was assumed that the stocking and composition of the undisturbed forest Chapter 4. Materials and Methods 20 is a fair expression of site condition and growth potential. 4.2.2 Selection of Diameter Cutting Limits (Treatments) Two main factors were considered in the determination of diameter cutting limits to be applied over the study area. They were: 1. Inclusion of some cutting specifications that would favour the retention and growth of Shorea and Parashorea species in the residual growing stock. This is necessary to avoid an eventual elimination of the Shorea (meranti) species from future crops, as this species group has a higher growth rate than most other economic species (Calliez, 1974). This could result by specifying a higher cutting limit for these species; and 2. Possible changes in usage practices with time. The study also includes some low cutting limits which are not currently practiced but may be economically feasible in the future. Based on the above considerations, a total of nine treatments were determined by specifying cutting limits for the meranti and non-meranti species (Table 4.1). In this study, only the six main treatments (A to F) were replicated three times. Treatments G, H and I, which represent extreme cutting limits, were not replicated and were included for demonstration and reference purposes only. 4.2.3 Experimental Design Due to the heterogeneity of the composition and stocking of the forest, and other related site factors, a completely randomised design was not attempted. Instead, the study area was stratified into three stocking classes (blocks), as described in Section 4.2.1. The three Chapter 4. Materials and Methods 21 Table 4.1: Treatments prescribed for the study area. Treatment Diameter Cutting Limit A Cut all trees 15" (38cm) dbh and above B Cut all non-meranti 15" (38cm) dbh and above Cut all meranti 18" (46cm) dbh and above C Cut all trees 18" (46cm) dbh and above D Cut all non-meranti 18" (46cm) dbh and above Cut all meranti 21" (53cm) dbh and above E Cut all trees 21" (53cm) dbh and above F Cut all trees according to logger's discretion, subject to minimum cutting limit of 18" (46cm) dbh G Cut all trees 12" (30cm) dbh and above H Cut all non-meranti 12" (30cm) dbh and above Cut all meranti 15" (38cm) dbh and above I Cut all trees 24" (61cm) dbh and above Chapter 4. Materials and Methods 22 replicates within the main treatments were then randomly assigned to the blocks, with one replicate being placed in each of the three stocking classes (Figure 4.2). 4.2.4 Tree Marking and Harvesting Following the allocation of treatments, all trees to be felled in each block, as specified by the cutting limit, were marked for felling with a painted cross and numbered on the stem at breast height (1.3 m above ground). In addition, a numbered metal tag was also nailed to the tree at one foot (0.30 m) above ground level for stump identification. The number, dbh and species of these trees were recorded on tree marking forms which were subsequently used to record the log measurements of the trees felled. The tree marking was completed by the end of 1973 and the area was logged in early 1974. 4.2.5 Establishment of Permanent Sample Plot Immediately after the completion of all logging operations, an 80 m x 80 m (0.64 ha) permanent sample plot (PSP) was laid out in each treatment block, resulting in 21 PSPs. Each PSP was divided into sixteen 20 m x 20 m subplots, one 5 m x 5 m subplot, and four 2 m x 2m subplots (Figure 4.3). 4.3 Measurement Procedures 4.3.1 Size of Trees Measured The size of trees to be measured differed among the various subplots. For the twelve 20 m x 20 m subplots located along the periphery of the PSP, all trees of 20 cm dbh and larger were painted at breast height, and numbered with a metal tag. For the four central 20 m x 20 m subplots, all trees 5 cm dbh and larger were painted at breast height and Chapter 4. Materials and Methods 23 Compartment 4 \ Compartment 6 \ \ V. . A ' TV Scale Approx. 1 cm to 130 m Forest Reserve Boundary Logging Road Compartment Boundary Block Boundary Permanent Sample Plots & Number A -1 Treatment Replication 1 Replication 2 Replication 3 Moderate stocking Good stocking Superior stocking before felling before felling before felling Note: Treatments G, H, and I are not replicated. Figure 4.2: Experimental layout of growth and yield study area. Chapter 4. Materials and Methods 24 80 m "19* 18 17 12 II 10 13 20 14 15 21 16 80 m 20 m k 20m Legend [ | 20m x 20m subplot: measure all trees 20.0 cm dbh and larger. | [ 20m x 20m subplot: measure all trees 5.0 cm dbh and larger. | | 5m x 5m subplot: count the number of saplings 1.5 m ht. to < 5.0 cm dbh. 2m x 2m subplot: count the number of seedlings 15 cm ht. to < 1.5 m ht. Figure 4.3: Layout of permanent sample plot. Chapter 4. Materials and Methods 25 numbered. The following details were recorded on all trees included in the 20 m x 20 m subplots: 1. species; 2. dbh; 3. number of 5m logs in the bole; 4. quality of the first log; 5. stem damage class; and 6. crown damage class. Details of stem and crown damage classes, as well as the overall logging damage classification based on stem and crown damage combinations, are given in Tables A.26 to 29 of Appendix A. A l l sampled trees were measured to the nearest mm in dbh and identified to the species level, if possible. For the 5 m x 5 m and 2 m x 2 m subplots, no dbh measurements were taken. Instead, a count of the number of saplings and seedlings within the subplots were recorded. 4.3.2 Remeasurement Since the establishment of the study total of 10 remeasurements have been con-ducted in 1974, 1975, 1976, 1977, 1978, 1979, 1981, 1984, 1986, and 1988. To facilitate remeasurement, a plot diagram showing the position of all enumerated trees, stumps, push-over trees, winch-lorry roads and bulldozer skidding tracks was prepared for each PSP. Chapter 4. Materials and Methods 26 4.4 Data Analysis 4.4.1 Data Preparation Data collected from the study area were entered into computers by staff of the Forestry Department Headquarters, Peninsular Malaysia and staff of the A S E A N Institute of Forest Management (AIFM) in 1989. Computer programs written in F O R T R A N were used to check the growth data for both measurement and data entry errors. Error checks included changing plot characteristics, change of species, unrealistic changes in tree measurements such as very large or negative diameter increments, missing trees, as well as trees that were recorded as dead but reappeared in later measurements. A substantial amount of time was spent in checking data entry and measurement errors through checking each error message against the tally forms. A l l of these errors were verified and corrected/adjusted, where appropriate. 4.4.2 Species Grouping The diversity of species in the tropical forests and the relatively small number of some of the species present makes it impractical to study and assess the growth response by individual species even though information at this level is available. Initially, the species were grouped into thirteen species groups based on their wood properties (i.e., colour, density and marketability). However, preliminary analysis of the data revealed that there were few to no trees in some of the species groups, particularly in some of the dipterocarp species after felling. Hence, it was decided that six species groups would be used in this study (Table 4.2). Analysis also included separation of species into dipterocarp and non-dipterocarp, as well as all species groups combined. Chapter 4. Materials and Methods Table 4.2: List of species groups. Species Group Description Abbreviation 1 Dipterocarp: Meranti M E R 2 Dipterocarp: Non-meranti N M E R 3 Non-Dipterocarp: Light Hardwoods L H W 4 Non-Dipterocarp: Medium Hardwoods M H W 5 Non-Dipterocarp: Heavy Hardwoods H H W 6 Miscellaneous species (mostly non-dipterocarp species including conifer species) MISC 7 A l l species A L L 8 A l l Dipterocarp species DIPT 9 A l l Non-Dipterocarp species NDIPT Chapter 4. Materials and Methods 28 4.4.3 Compilation Computer programs written in F O R T R A N by Watts (1990b), prepared for the A I F M were utilized to analyze various growth components as described in the following subsec-tions. 4.4.3.1 Stems Tree data from the sixteen 20 m x 20 m subplots were combined to obtain measures for the 0.64 ha area. Since trees less than 20 cm dbh were only measured in four of these 16 subplots, each tree was multiplied by 4 to get the number of trees per 0.64 ha plot. The number of trees per plot was then divided by the plot area to obtain the total number of stems on a per hectare basis (all trees 5.0 cm dbh and larger). The stems/ha was calculated by dbh class and by species group. 4.4.3.2 Basal Area The basal area for each tree (m 2) was calculated from the dbh (measured in cm) using the following equation. „ , IT x dbh2 Again, trees less than 20.0 cm dbh were multiplied by a factor of 4. The basal area was summed over all trees for the PSP and the total basal area (all trees 5.0 cm dbh and larger) was divided by the plot area to obtain basal area per hectare. The basal area was also calculated by dbh class and species group. 4.4.3.3 Gross Volume Gross volume (GV), measured in m 3 was calculated using the equation currently em-ployed by the Forestry Department, Peninsular Malaysia for conducting a pre-felling Chapter 4. Materials and Methods 29 Table 4.3: Height-diameter relationship (Source: Anon. 1985b). D B H (cm) Height (m) 15.1-30.0 5.0 30.1-60.0 10.0 60.1-75.0 15.0 > 75.0 20.0 forest inventory (Anon., 1985b). The equation applies to all species and expresses G V as a function of the tree basal area and merchantable height (H), measured in meters and a tree form factor of 0.65 as follows: GV = BAxHx0.65 (4.2) Since individual tree height was not measured, it was estimated from dbh based on a height-diameter relationship (Table 4.3). There were a number of drawbacks of using such a relationship in volume compilation. A tree can grow 15 cm in dbh before height change occurs. Also, the relationship does not take into account species differences, site and density effects. In addition, gross volume could not be compiled for trees between 5.0 and 14.9 cm dbh as the height-diameter relationship was not applicable for trees of this size. Again, trees less than 20 cm dbh were multiplied by a factor of 4 to obtain the gross volume per 0.64 ha plot. The gross volume was summed over all trees for the PSP and the total gross volume divided by the plot area to obtain gross volume per hectare by dbh class and species group. Chapter 4. Materials and Methods 30 4.4.3.4 Stand Growth Stand growth was measured as the change in the selected stand attributes (number of stems, basal area, and gross volume) over some specific time period. The growth then refers to the algebraic sum of the growth of all trees in the stand on a per unit land area basis. In this report, it was calculated by taking the difference of the stand attribute at the beginning and the end of a growth period and dividing by the number of years of between measurements (periodic annual increment or PAI). Assessments of stand growth were carried out only for trees 5.0 cm and 30.0 cm dbh and larger (stems and basal area) and for trees 15.0 cm and 30.0 cm dbh and larger (gross volume), by major species groups. Trees 30.0 cm dbh and larger were chosen as they are deemed to be the next rotation crop while trees 5.0 cm and larger were the smallest diameter-sized trees recorded and would be indicative of future rotations. 4.4.3.5 Diameter Growth Individual-tree periodic annual diameter increment (cm/year) for any growth period was only calculated for trees that were alive at the beginning and the end of a growth period. Trees that died or grew in during the period (ingrowth) were omitted. The average periodic annual diameter increment per tree was calculated by dividing the sum of total annual diameter increments by the total number of trees within that diameter class/limit. 4.4.3.6 Mortality The assessment of mortality takes into consideration all trees (both residual and in-growth) that died within the selected diameter limits (5.0 and 30.0 cm dbh and larger) over a specified growth period. It was expressed as a percent of the total stems/ha found at the beginning of the growth period. In addition, mortality of the residual trees Chapter 4. Materials and Methods 31 with logging damage was also assessed based on the overall logging damage classes (No Damage, Moderate Damage and Severe Damage) (see Appendix A) and cutting intensity classes (< 30 %, 30 to 40 % and > 40 % basal area removal). Mortality due to logging damage was expressed in terms of the number and proportion of trees that died within the selected diameter limit during the measurement period. 4.4.3.7 Ingrowth Ingrowth was defined as trees that grew into the lowest recognized diameter limit in the forest stand during a specified growth period. In this study, it was calculated as a percent of the total stems/ha within a selected diameter class/limit and by species group. Only trees that grew into two diameter limits, 5.0 cm or 30.0 cm dbh and larger were considered. 4.4.4 Statistical Analysis Unless otherwise stated, all data analyses were conducted using SAS procedures (SAS 1990, 1994). A rank or log transformation procedure was used to transform data for tests that require the assumptions of normality and equal variance to be met, if those assumptions were not met. 4.4.4.1 Prior to Harvest Pre-harvest differences in stand structure and species composition by treatment in terms of stems, basal area and gross volume were examined. For testing differences in stand structure, analysis of variance (ANOVA) was performed on all trees (all species groups combined) 5 cm dbh and larger (stems and basal area) and 15 cm dbh and larger (gross volume). The A N O V A model used is given in Table 4.4. A multivariate analysis of Chapter 4. Materials and Methods 32 variance ( M A N O V A ) procedure was used to test for differences in species composition, for individual as well as broad species groups (dipterocarp and non-dipterocarp species). For these analyses only the six treatments from A through F (Table 4.1) were used, since treatments G through I were not replicated. Treatments were considered fixed effects, whereas stocking classes were considered random effects. For M A N O V A , several test statistics can be used to test for population differences on the basis of sample data, including Wilk's Lambda, Roy's greatest root, Hotelling's trace and Pillai's trace criterion (Tabachnick and Fidell, 1989). Wilk's Lambda, Hotelling's trace and Pillai's criterion are evaluations of the null hypotheses when group differences based on more than one dimension have been pooled (e.g., a discriminant function). Roy's greatest root, on the other hand, only considers the dimension with the largest eigenvalue. To assess the statistical significance of an effect, each statistic is referred to an F-distribution with the appropriate degree of freedom. If the effect has one degree of freedom, then the tests based on the four statistics are equivalent. Otherwise the tests differ, although in many cases, they lead to similar conclusions. In situation when the tests lead to substantially different conclusions, one must consider other factors such as the selective power of the tests (i.e. the probability that departure from the null hypothesis will be detected), before arriving at a conclusion (Nemec, 1996). In general, Roy's greatest root, with only one dimension to consider, is not widely accepted as the test statistic of choice, while Pillai's criterion may be the statistic of choice under less ideal design conditions (e.g. small and unequal sample size) (Tabachnick and Fidell, 1989). The pros and cons of the four M A N O V A test statistics were described in detail by Tabachnick and Fidell (1989). Chapter 4. Materials and Methods 33 Table 4.4: A N O V A model for testing differences in stand structure. Source of Variation df MS EMS F Treatment (T) 5 MST a2 + a\s + 2</>T MST/MSe Stocking (S) 2 MSS al + 5a2s Error (T x S) 10 MS£ a2£ + a2TS Table 4.5: List of regression analyses. Dependent Variable Independent Variable Diameter Limits (cm) Species Group % Stem Change % Cutting intensity 5.0 + & 30.0 + Diameter growth % Cutting intensity 5.0 + A l l species, Dipterocarps, Non-dipterocarps % Mortality % Cutting intensity 5.0 + % Ingrowth % Cutting intensity 5.0 + 4.4.4.2 Regression Analysis Simple linear regression analysis was employed to study and test for significant relation-ships between the dependent and independent variables as listed in Table 4.5. Chapter 4. Materials and Methods 34 4.4.4 .3 Repeated Measures Analysis of Variance Repeated measures analysis is a type of analysis of variance in which the variation between experimental units ('between-subject' variation) and variation within units ('within-subjects') are examined (Nemec, 1996). Between-units variation can be attributed to the factors that differ across the treatments. Within-units variation is any change, such as an increase in basal area, that is observed in an individual experimental unit. The ob-jectives of repeated measures analysis are twofold: (i) to determine how the experimental units change over time, and (ii) to compare the changes across treatments. Kuehl (1994) found that the estimation of time trend was more precise using repeated observations. There are three types of hypotheses to be tested in a repeated measures analysis. H0i '• The growth curves or trends are parallel for all groups (i.e. there are no interactions involving time). H02 : There are no trends over time (i.e. there are no time effects). H03 : There are no overall differences among groups (i.e. the between-units factor has no effect). Meredith and Stehman (1991) categorized the methods used to analyze repeated measures experiment into four groups, namely (i) separate analyses at each time period, (ii) split-unit univariate analysis, (iii) multivariate analysis and (iv) analysis of coefficients of a function estimated from the t repeated measures on each experimental unit. The pros and cons of each technique were also discussed. In this study, multivariate repeated measures analysis (MANOVA) using a G L M procedure was used to study the time trend of all trees (all species combined) for stems/ha (5.0 and 30.0 cm dbh and larger), basal area/ha (5.0 and 30.0 cm dbh and larger) and gross volume/ha (15.0 and 30.0 cm and larger). Repeated measures M A N O V A was chosen because the t repeated measures Chapter 4. Materials and Methods 35 on each experimental unit could be correctly regarded as a t-variate response vector and hence analyzed via multivariate methods (Meredith and Stehman, 1991). In addition, the model works on a less restrictive sets of assumptions and does not require the variance of the repeated measures, or the correlation between pairs of repeated measures, to remain constant over time (Tabachnick and Fidell, 1989). It is also one of the methods recommended as most likely to be applicable to forestry data (Nemec, 1996). Four multivariate test statistics, namely Wilk's Lambda, Hotelling's trace, Pillai's trace and Roy's greatest root were used to test H0i and H02. A brief description of these four test statistics was given in Section 4.4.4.1. Chapter 5 Results 5 . 1 Stand Structure and Species Composition Before Harvest 5 . 1 . 1 Stand Structure 5 . 1 . 1 . 1 Stems There was considerable variation in the total stocking of trees 5 cm dbh and larger among the 21 PSPs before harvest. The total number of stems varied from 429.69 in plot 9 to 1579.69 in plot 4, with an overall mean of 944.05 stems/ha (Table B.30 of Appendix B). The mean number of trees by treatment varied from 740.63 in Treatment B to 1376.57 stems/ha in Treatment G. By stocking class, the number of trees ranged from 631.25 to 1198.46 stems/ha in the Superior class; 687.51 to 1579.69 stems/ha in the Good class; and from 429.69 to 1356.26 stems/ha in the Moderate class. The distribution of stems by dbh class/limit also varied considerably among the 21 PSPs before harvest. For all treatments combined, the coefficients of variation (C.V.) ranged from 17.24 % to 73.60 %, with higher C .V. values generally observed for trees in the higher dbh classes/limits (Figure 5.4). However, in terms of absolute variation, the variability was higher in the lower dbh classes, as indicated by the distribution of standard deviations by dbh class for the replicated treatments (Figure 5.5). This could be attributed to the lower number of trees at the higher dbh classes. Overall, the hill dipterocarp forests exhibited a reverse J-shaped stand structure, with the average number of stems/ha by treatment being highest in the lower dbh classes and 36 Chapter 5. Results 37 o -I 1 1 1 1 1 1 5.0-14.9 15.0-29.9 30.0-44.9 45.0-59.9 60.0-74.9 75.0-89.9 90.0+ Diameter class (cm) Figure 5.4: Coefficients of variation (C.V.) for stems/ha (all treatments combined) by dbh class. decreasing greatly with increasing dbh classes (Figure 5.6). On average, trees with dbh less than 30 cm accounted for more than 88 % of the total stocking (Table B.31). Since the stems/ha data of all trees 5 cm dbh and larger were not normally dis-tributed, the data were transformed using ranks. The ranked data were normally dis-tributed (p=0.6237) and had equal variance (p=0.9523). Results of analysis of variance (ANOVA) on the ranked data indicated that there was no evidence of differences among the treatments (p=0.9153). Differences among stocking classes could not be tested, as it was considered a random factor in the experiment. Chapter 5. Results 38 5.0-14.9 15.0-29.9 30.0-44.9 45.0-59.9 60.0-74.9 75.0-89.9 90.0+ Diameter class (cm) Figure 5.5: Standard deviation (stems/ha) for the replicated treatments by dbh class. Chapter 5. Results 39 Figure 5.6: Mean frequency distribution (stems/ha) for the replicated treatments by dbh class. Chapter 5. Results 40 5.1.1.2 Basal Area Similar to stems/ha, the basal area of all trees 5 cm dbh and larger also varied consid-erably among the 21 plots, from 25.17 ra2/ha in plot 9 to 42.00 m 2 / ha in plot 4, with a mean plot basal area of 31.96 m 2 /ha (Table B.32). The mean basal area by treatment varied from 29.62 m 2 /ha in Treatment D to 35.70 m 2 /ha in Treatment C. In terms of stocking class, the basal area varied from 28.48 to 39.92 m 2 /ha in the Superior class; 25.63 to 42.00 m 2 /ha in the Good class; and from 25.17 to 36.81 m 2 /ha in the Moderate class. By dbh class/limit, the basal area distribution of trees also varied considerably among the 21 plots, with C .V. values ranging from 15.44 % to 76.28 % for all treat-ments combined. Again, a generally higher C .V. was observed for trees in the higher dbh classes/limits (Figure 5.7). In constrast to stems/ha, higher absolute variability was observed for the intermediate and higher dbh classes as shown by the distribution of standard deviations of the replicated treatments (Figure 5.8). Trees of intermediate size (15 to 60 cm dbh) appeared to dominate the basal area distribution (Figure 5.9). They accounted for more than 58 % of the total basal area of trees 5 cm dbh and larger, with the highest mean basal area of 6.71 m 2 /ha (21 %) being recorded for trees in the 15.0 to 29.9 cm dbh class, followed by trees in the 30.0 to 44.9 cm and 45.0 to 59.9 cm diameter classes with basal areas of 6.67 m 2 / ha (20.88 %) and 5.33 m 2 /ha (16.66 %), respectively (Tables B.32 & B.33). Results of A N O V A on the ranked data of all trees 5 cm dbh and larger (normally distributed (p=0.1858) and equal variance(p=0.7523)) also indicated that there was no evidence of differences among the treatments (p=0.6018). Again, due to the random nature of stocking class in the experiment, a test for differences among stocking classes was not possible. Chapter 5. Results 41 o -I 1 1 1 1 1 1 5.0-14.9 15.0-29.9 30.0-44.9 45.0-59.9 60.0-74.9 75.0-89.9 90.0+ Diameter class (cm) Figure 5.7: Coefficients of variation (C.V.) for basal area/ha (all treatments combined) by dbh class. Chapter 5. Results 0 A 1 1 1 1 1 1 5.0-14.9 15.0-29.9 30.0-44.9 45.0-59.9 60.0-74.9 75.0-89.9 90.0+ Diameter class (cm) Figure 5.8: Standard deviation (m2/ha) for the replicated treatments by dbh class. Chapter 5. Results 43 ! _ 0 -J 1 1 1 1 1 5.0-14.9 15.0-29.9 30.0-44.9 45.0-59.9 60.0-74.9 75.0-89.9 90.0+ Diameter class (cm) Figure 5.9: Mean basal area distribution (m2/ha) for the replicated treatments by dbh class. Chapter 5. Results 44 5.1.1.3 Gross Volume The total gross volume of trees 15 cm dbh and larger varied from 155.55 m 3 /ha in plot 2 to 298.63 m 3 /ha in plot 18 with a mean plot value of 207.65 m 3 /ha (Table B.34). The mean gross volume of trees 15 cm dbh and larger varied from 183.54 m 3 / ha in Treatment G to 240.20 m 3 / ha in Treatment F. In terms of stocking class, the gross volume varied from 169.94 to 298.67 m 3 /ha in the Superior class; 155.55 to 258.08 m 3 / ha in the Good class; and from 160.83 to 207.77 m 3 / ha in the Moderate class. Considerable variation in gross volume distribution by dbh class/limit among the 21 plots was also observed. For all treatments combined, the C.V. values ranged from 19.06 % to 77.90 %, with higher C.V.'s generally observed for trees in the higher dbh classes/limits (Figure 5.10). The same trend was also observed in terms of the distribution of standard deviation by dbh class (Figure 5.11). Gross volume distribution by dbh class for the replicated treatments is shown in Figure 5.12. In contrast to stems per hectare, trees of dbh less than 30 cm accounted for only about 10 % of the total volume before harvest (Table B.35). Results of A N O V A on the ranked data of all trees 15 cm dbh and larger (normally dis-tributed (p=0.6237) and equal variance (p=0.8775)) indicated that there was no evidence of differences in gross volume among the treatments (p=0.3803). 5.1.2 Species Composition 5.1.2.1 Stems With the exception of dbh class 75.0 to 89.9 cm, the study area was dominated by the non-dipterocarp species (Table 5.6 & Figure 5.13). Non-dipterocarp species were most prevalent in the lower dbh classes, comprising 94.69 % of trees in the 5.0 to 14.9 cm dbh class and gradually decreasing to about 50 % for trees larger than 90.0 cm dbh. Chapter 5. Results 45 15.0-29.9 30.0-44.9 45.0-59.9 60.0-74.9 75.0-89.9 90.0 + Diameter class (cm) Figure 5.10: Coefficients of variation (C.V.) for gross volume/ha (all treatments com-bined) by dbh class. Chapter 5. Results 46 Figure 5.11: Standard deviation (m3/ha) for the replicated treatments by dbh class. Chapter 5. Results 47 60 0 -I 1 1 • 1 1 1 15.0-29.9 30.0-44.9 45.0-59.9 60.0-74.9 75.0-89.9 90.0 + Diameter class (cm) Figure 5.12: Mean gross volume distribution (m3/ha) for the replicated treatments by dbh class. Chapter 5. Results 48 Dipterocarps, on the other hand, were extremely low in numbers especially in the lower dbh class. On average, they accounted for only 7.67 % of all trees greater than 5 cm dbh. Within the dipterocarps, the merantis were found to be most dominant, accounting for 59.71 % of all trees 5 cm dbh and larger. As for the non-dipterocarps, M H W was found to be most abundant (39.37 %), followed by L H W (37.13 %), MISC (15.81 %) and H H W (7.69 %). A multivariate analysis of variance (MANOVA) was performed on the ranked data of all trees 5 cm dbh and larger (all ranked variables were normally distributed and had equal variance, all p values > 0.05). A l l multivariate test statistics of the M A N O V A indicated that there was no evidence of significant differences in species composition by treatment, both for individual as well as broad species groups (dipterocarp and non-dipterocarp species) at an a level of 0.05. 5.1.2.2 Basal Area Species composition in terms of basal area was found to be similar to that of the stems. Again, the non-dipterocarp species dominated all lower dbh classes (Table 5.7 & Figure 5.14). Overall, the non-dipterocarps accounted for 75.57 % of the total basal area for all trees greater than 5 cm dbh and larger. The non-merantis were found to be more dominant within the dipterocarps, account-ing for 51.52 % of the total basal area of all trees 5 cm dbh and larger. Among the non-dipterocarps, M H W continued to dominate, accounting for 42.60 % of the total basal area, followed by L H W (37.43 %), MISC (10.17 %), and H H W (9.80 %). The ranked data of all trees 5 cm dbh and larger by species groups were normally distributed and had equal variance (all p values > 0.05). Wilk's Lambda and Pillai's Trace statistics of the M A N O V A indicated there was no evidence of significant differ-ences in basal area composition by treatment for individual species groups, while all Chapter 5. Results 49 Table 5.6: Mean and percent stem frequency distribution by species group and dbh class. Species Diameter Class / Limit (cm) Group" 5.0-14.9 15.0-29.9 30.0-44.9 45.0-59.9 60.0-74.9 75.0-89.9 90.0+ 30.0+ 5.0+ MER 21.43 9.15 5.36 3.87 1.41 1.34 0.67 12.65 43.23 NMER 12.50 5.36 3.20 2.98 2.53 1.41 1.19 11.31 29.17 DIPT(D) 33.93 14.51 8.56 6.85 3.94 2.75 1.86 23.96 72.40 LHW 224.20 68.53 19.94 6.55 2.38 0.97 0.89 30.73 323.66 MHW 226.49 78.79 25.52 8.26 2.75 0.67 0.67 37.87 343.16 HHW 41.37 15.85 6.70 2.31 0.52 0.22 0.07 9.82 67.04 MISC 113.10 17.63 4.17 2.01 0.45 0.22 0.22 7.07 137.80 NDIPT(ND) 605.36 180.80 56.32 19.12 6.10 2.08 1.86 85.49 871.65 ALL 639.29 195.31 64.88 25.97 10.05 4.84 3.72 109.45 944.05 MER as % of D 63.16 63.08 62.60 56.53 35.84 48.63 36.02 52.80 59.71 MER as % of ALL 3.35 4.69 8.26 14.91 14.07 27.68 18.01 11.56 4.58 D as % of ALL 5.31 7.43 13.19 26.37 39.25 56.92 49.99 21.89 7.67 LHW as % of ND 37.07 37.90 35.41 34.25 39.01 46.44 47.98 35.95 37.13 MHW as % of ND 37.41 43.58 45.31 43.20 45.12 32.11 35.98 44.30 39.37 HHW as % of ND 6.83 8.77 11.89 12.07 8.54 10.72 3.99 11.49 7.69 MISC as % of ND 18.68 9.75 7.40 10.51 7.30 10.69 11.98 8.27 15.81 ND as % of ALL 94.69 92.57 86.81 73.63 60.75 43.08 50.01 78.11 92.33 "Species group codes used are as listed in Table 4.2. Chapter 5. Results • Dipt m Ndipt B All 5.0-14.9 15.0-29.9 30.0-44.9 45.0-59.9 60.0-74.9 75.0-89.9 90.0+ Diameter class (cm) Figure 5.13: Mean frequency distribution of trees (stems/ha) by species group and class. Chapter 5. Results 51 5.0-14.9 15.0-29.9 30.0-44.9 45.0-59.9 60.0-74.9 75.0-89.9 90.0+ Diameter class (cm) Figure 5.14: Mean basal area distribution (m2/ha) by species group and dbh class. multivariate test statistics of the MANOVA were non-significant for the dipterocarp and non-dipterocarp species groups. 5.1.2.3 Gross volume The same trend as for stems and basal area was observed for gross volume composition (Table 5.8 k, Figure 5.15). The non-diperocarps again dominated all lower dbh classes and accounted for 64.92 % of the total standing volume of all trees larger than 15 cm dbh. Dipterocarps, on the other hand, dominated the higher dbh classes, and accounted for 58.25 % and 52.59 % of the volume in the dbh class/limit 75.0-89.9 cm and 90.0 + cm, respectively. A MANOVA was performed on the ranked data of all trees 15 cm dbh and larger (all Chapter 5. Results 52 Table 5.7: Mean and percent basal area distribution by species group and dbh class. Species Diameter Class / Limit cm) Group" 5.0-14.9 15.0-29.9 30.0-44.9 45.0-59.9 60.0-74.9 75.0-89.9 90.0+ 30.0+ 5.0+ MER 0.14 0.35 0.59 0.82 0.51 0.71 0.68 3.30 3.78 NMER 0.08 0.18 0.36 0.65 0.91 0.74 1.10 3.76 4.02 DIPT(D) 0.22 0.53 0.95 1.48 1.42 1.45 1.76 7.06 7.81 LHW 1.40 2.24 2.04 1.33 0.78 0.50 0.76 5.40 9.04 MHW 1.46 2.79 2.53 1.67 0.94 0.34 0.57 6.04 10.29 HHW 0.27 0.55 0.72 0.47 0.16 0.11 0.10 1.55 2.37 MISC 0.62 0.60 0.44 0.39 0.14 0.10 0.16 1.24 2.46 NDIPT(ND) 3.75 6.19 5.72 3.85 2.01 1.05 1.59 14.22 24.16 ALL 3.97 6.71 6.67 5.33 3.43 2.50 3.35 21.28 31.96 MER as % of D 65.43 65.55 61.88 55.68 35.86 49.06 37.66 46.69 48.48 MER as % of ALL 3.59 5.16 8.83 15.43 14.85 28.46 19.80 15.49 11.84 D as % of ALL 5.48 7.87 14.26 27.72 41.42 58.00 52.59 33.17 24.43 LHW as % of ND 37.32 36.27 35.60 34.43 38.59 48.05 47.68 37.95 37.43 MHW as % of ND 38.86 45.17 44.21 43.36 46.54 32.02 35.84 42.47 42.60 HHW as % of ND 7.21 8.86 12.60 12.12 7.74 10.17 6.20 10.89 9.80 MISC as % of ND 16.57 9.69 7.61 10.09 7.15 9.99 10.28 8.69 10.17 ND as % of ALL 94.52 92.13 85.74 72.28 58.58 42.00 47.41 66.83 75.57 °Species group codes used are as listed in Tab le 4.2. Chapter 5. Results 53 45 15.0-29.9 30.0-44.9 45.0-59.9 60.0-74.9 75.0-89.9 90.0+ Diameter class (cm) Figure 5.15: Mean gross volume distribution (m3/ha) by species group and dbh class. ranked variables normally distributed and had equal variance, all p values > 0.05). All test statistics of the MANOVA except Roy's greatest root indicated that there was no evidence of significant differences in volume composition among treatments, for individual species group, while all test statistics were non-significant for broad species groups. 5.2 Stems, Basal Area and Gross Volume Cut 5.2.1 Stems The total number of stems cut varied from 1.56 stems/ha (0.12 %) in plot 17 to 89.06 stems/ha (10.31 %) in plot 19 with an overall mean cut of 39.29 stems/ha or 4.16 % of the total stocking before harvest (Table 5.9). The mean total number of stems cut by treatment varied from 5.73 stems/ha (0.55 %) in Treatment F to 89.06 stems/ha (10.31 Chapter 5. Results Table 5.8: Mean and percent gross volume distribution (m 3/ha) by species group an' dbh class. Species Diameter Class / Limit (cm) Group" 15.0-29.9 30.0-44.9 45.0-59.9 60.0-74.9 75.0-89.9 90.0+ 30.0+ 15.0+ MER 1.1.3 3.83 5.35 4.97 9.01 8.63 31.79 32.92 NMER 0.56 2.36 4.25 8.89 9.58 14.28 39.36 39.92 DIPT(D) 1.69 6.19 9.60 13.86 18.59 22.91 71.15 72.83 LHW 7.19 13.08 8.61 7.30 6.44 9.85 45.27 52.46 MHW 8.94 16.25 10.85 9.07 4.14 7.40 47.71 56.65 HHW 1.76 4.68 3.04 1.45 1.39 1.28 11.84 13.60 MISC 1.91 2.78 2.52 1.40 1.36 2.12 10.19 12.10 NDIPT(ND) 19.81 36.79 25.02 19.21 13.32 20.65 115.01 134.81 ALL 21.49 42.99 34.62 33.07 31.91 43.56 186.15 207.65 MER as % of D 66.85 61.91 55.69 35.87 48.48 37.66 44.68 45.19 MER as % of ALL 5.24 8.92 15.44 15.03 28.24 19.81 17.08 15.85 D as % of ALL 7.85 14.40 27.73 41.91 58.25 52.59 38.22 35.08 LHW as % of ND 36.31 35.54 34.41 37.97 48.33 47.68 39.36 38.91 MHW as % of ND 45.15 44.17 43.35 47.19 31.07 35.83 41.48 42.02 HHW as % of ND 8.90 12.73 12.14 7.53 10.41 6.22 10.29 10.09 MISC as % of ND 9.66 7.56 10.09 7.31 10.22 10.27 8.86 8.98 ND as % of ALL 92.15 85.60 72.27 58.09 41.75 47.41 61.78 64.92 "Species group codes used are as listed in Table 4.2. Chapter 5. Results 55 %) in Treatment H . Even though all trees having dbh larger than the cutting limits as specified by the treatments were marked for felling, it was apparent that not all marked trees were cut during the harvesting operations. The total number of stems left uncut varied from 3.13 stems/ha (2 trees) in plot 3 to 71.88 stems/ha (46 trees) in plot 21, with an overall mean of 18.01 stems/ha (11 trees/plot). Marked trees that were left uncut could be due to: (i) being located on steep slopes rendering them dangerous or impossible to be felled, (ii) possessing irritant sap (such as rengas (Melanochylla spp.), and (iii) being non-marketable and defective, and though the logging contractor was advised to fell them, it was nonetheless not made mandatory (Tang 1976, Borhan 1985, Yong 1990). As a result of this, there was no clear trend in terms of the number of stems cut by treatment. For example, one would expect Treatment G (with the lowest dbh cutting limit of 30 cm) to result in the highest number of stems/ha cut. However, the result was the contrary because 46 marked trees were left uncut in the plot. Due to the higher concentration of the dipterocarps in the larger dbh classes, the application of the various treatments resulted in a higher proportion of dipterocarps removed compared to the non-dipterocarps. The overall mean percent of dipterocarps 5 cm dbh and larger cut was 19.12 % compared to 2.92 % for the non-dipterocarps. However, the non-dipterocarps were found to comprise a higher proportion of the actual total cut, accounting for 64.77 % of all trees cut. This was not unexpected due to the higher stocking of the non-dipterocarps in the stand prior to harvest. 5.2.2 Basal Area The basal area of all trees 5 cm dbh and larger removed varied from 0.16 m 2 / ha (0.47 %) in plot 17 to 22.44 m 2 /ha (56.18 %) in plot 18 with an overall mean removal of 10.99 m 2 /ha or 34.38 % of the total basal area before harvest (Table 5.10). The mean total Chapter 5. Results 56 Table 5.9: Total number and percent stems cut at harvest (stems/ha), as well as stems/ha marked but left uncut. Plot N o . T r e a t . Stems C u t S t e m s C u t (% T o t a l ) % T o t a l C u t S t e m s U n c u t / S t o c k " ment D I P T N D I P T T o t a l D I P T N D I P T T o t a l D I P T N D I P T D I P T N D I P T T o t a l IS A 29.69 23.44 53.13 38.78 2.38 5.01 55.88 44.12 - 4.69 4.69 7 M A 28.13 37.50 65.63 36.74 3.29 5.40 42.86 57.14 - 15.63 15.63 1 0 G A 9.38 43.74 53.12 26.10 6.71 7.73 17.66 82.34 _ 6.25 6.25 M e a n A 22.40 34.89 57.29 35.54 3.77 5.80 39.10 60.90 8.86 8.86 8 G B 12.50 21.87 34.37 17.02 2.69 3.87 36.37 63.63 1.56 21.88 23.44 I S M B 6.26 32.80 39.06 10.01 6.73 7.10 16.03 83.97 • 14.06 14.06 16S B 20.31 54.69 75.00 38.23 7.48 9.56 27.08 72.92 10.94 10.94 M e a n B 13.02 36.45 49.48 20.66 5.38 6.68 26.32 73.68 0.52 15.63 16.15 4 G C 12.49 50.01 62.50 10.25 3.43 3.96 19.98 80.02 3.13 10.93 14.06 9 M C 17.19 26.56 43.75 57.90 6.64 10.18 39.29 60.71 1.56 10.94 12.50 18S C 25.01 39.05 64.06 36.37 4.81 7.27 39.04 60.96 7.81 7.81 M e a n C 18.23 38.54 56.77 24.82 4.33 5.89 32.11 67.89 1.56 9.90 11.46 2 G D 7.82 17.18 25.00 7.15 1.61 2.12 31.28 68.72 6.25 6.25 5S D 12.50 23.44 35.94 30.77 3.97 5.69 34.78 65.22 1.56 7.82 9.83 1 4 M D 12.50 6.25 18.75 15.69 0.72 1.97 66.67 33.33 9.38 9.38 M e a n D 10.94 15.62 26.56 14.29 1.85 2.89 41.18 58.82 0.52 7.82 8.34 3 M E 15.63 12.49 28.12 31.25 1.83 3.84 55.58 44.42 • 3.13 3.13 6S E 7.81 15.63 23.44 6.41 1.45 1.96 33.32 66.68 3.13 10.93 14.06 11G E 6.25 29.69 35.94 9.76 4.19 4.65 17.39 82.61 9.38 9.38 M e a n E 9.90 19.27 29.17 12.58 2.34 3.24 33.93 66.07 1.04 7.82 8.86 12G F 7.82 4.68 12.50 10.88 0.55 1.37 62.56 37.44 7.81 35.94 43.75 13S F 3.13 0.00 3.13 6.68 0.00 0.36 100.00 0.00 14.06 32.82 46.88 1 7 M F 0.00 1.56 1.56 0.00 0.12 0.12 0.00 100.00 10.94 28.12 39.06 M e a n F 3.65 2.08 5.73 5.79 0.21 0.55 63.70 36.30 10.94 32.29 43.23 21 G 12.50 26.56 39.06 11.27 2.10 2.84 32.00 68.00 3.13 68.75 71.88 19 H 34.38 54.68 89.06 41.51 7.00 10.31 38.60 61.40 9.38 9.38 20 I 9.37 12.51 21.88 12.76 1.50 2.42 42.82 57.18 6.25 6.25 O v e r a l l M e a n - 13.84 25.44 39.29 19.12 2.92 4.16 35.23 64.77 2.23 15.78 18.01 "Stock ing class identified for replicated treatments only. S=superior G = g o o d M = m o d e r a t e . Chapter 5. Results 57 basal area removed by treatment varied from 2.41 m 2 /ha (6.85 %) in Treatment F to 19.52 m2 /ha (59.64 %) in Treatment H . As a result of the uncut stems, the basal area left uncut varied from 0.82 m 2 /ha in plots 3 and 10, to 16.40 m 2 /ha in plot 13. Again, a higher proportion of the basal area of the dipterocarps was removed as compared to the non-dipterocarps. The mean percent of dipterocarps 5 cm dbh and larger removed was 66.35 % compared to 24.05 % for the non-dipterocarps. However, the non-dipterocarps comprised a higher proportion of the actual total basal area removed (52.86 %) due to its overall supremacy in terms of stocking. 5.2.3 Gross Volume The total gross volume cut based on all trees 15 cm dbh and larger varied greatly from a low of 1.07 m 3 /ha (0.54 %) in plot 17 to 229.62 m 3 /ha (76.89 %) in plot 18, with an overall mean removal of 106.88 m 3 / h a or 51.47 % of the total mean gross volume before harvest (Table 5.11). In terms of treatment, the gross volume removed varied from 28.23 m 3 /ha (11.75 %) in Treatment F to 182.93 m 3 /ha (76.91 %) in Treatment H . Where the logger was allowed to make his own choice of trees to be felled subject to a minimum size of 46 cm dbh (Treatment F), the volume removed was the least. Also, given the freedom to choose any tree above a minimum cutting limit of 46 cm dbh, the logger removed more dipterocarp trees which are of higher commercial value. This was evident in this study where 91.66 % of the total removal under Treatment F was comprised of dipterocarp species. Again, due to the uncut stems, the volume left uncut varied from 4.36 m 3 /ha in plot 1 to 159.42 m 3 /ha in plot 13. Overall, the harvesting operations had removed 76.90 % of the gross volume of dipte-rocarps present and 37.73 % of the non-dipterocarps. However, in terms of actual volume removal, the dipterocarps was only slightly higher at 52.41 %. Chapter 5. Results Table 5.10: Total and percent basal area cut at harvest (m 2/ha), as well as basal area, marked but left uncut. Plot N o . T r e a t - T o t a l B A C u t B A C u t (% T o t a l % T o t a l C u t B A U n c u t / S t o c k " ment D I P T N D I P T T o t a l D I P T N D I P T T o t a l D I P T N D I P T D I P T N D I P T T o t a l IS A 7.64 5.91 13.55 93.51 29.10 47.58 56.38 43.62 0.67 0.67 7 M A 8.27 8.26 16.53 86.33 30.35 44.92 50.03 49.97 - 2.70 2.70 10G A 4.04 9.89 13.93 86.51 47.16 54.33 29.00 71.00 0.82 0.82 M e a n A 6.65 8.02 14.67 88.98 35.12 48.41 45.33 54.67 4.35 4.35 8 G B 3.04 5.90 8.94 60.68 25.49 31.75 34.00 66.00 0.26 4.03 4.29 1 5 M B 2.08 9.13 11.21 59.43 40.78 43.30 18.55 81.45 3.23 3.23 16S B 8.21 9.12 17.33 84.90 33.70 47.18 47.37 52.63 1.67 1.67 M e a n B 4.44 8.05 12.49 73.32 33.26 41.29 35.57 64.43 0.26 8.19 8.45 4 G C 3.96 9.93 13.89 49.87 29.16 33.08 28.51 71.49 0.52 2.69 3.21 9 M C 3.97 5.93 9.90 72.31 30.13 39.33 40.10 59.90 0.58 2.81 3.39 18S C 11.67 10.77 22.44 90.26 39.87 56.18 52.01 47.99 1.87 1.87 M e a n c 6.53 8.88 15.41 74.36 32.98 43.17 42.40 57.60 0.89 5.75 6.64 2 G D 2.14 4.24 6.38 31.47 16.81 19.92 33.54 66.46 - 1.71 1.71 5S D 5.55 7.83 13.38 79.86 32.68 43.29 41.48 58.52 0.50 2.72 3.22 1 4 M D 4.56 1.91 6.47 72.61 9.73 24.96 70.48 29.52 3.90 3.90 M e a n D 4.08 4.66 8.74 61.16 20.31 29.52 46.70 53.30 0.34 5.38 5.72 3 M E 6.28 3.04 9.32 80.72 16.34 35.32 67.38 32.62 0.82 0.82 6S E 3.93 2.73 6.66 51.11 9.77 18.70 59.01 40.99 1.14 5.72 6.86 11G E 3.35 10.27 13.62 61.47 40.31 44.03 24.60 75.40 2.54 2.54 M e a n E 4.52 5.35 9.87 64.82 22.27 31.85 45.81 54.19 0.73 5.63 6.36 1 2 G F 4.45 0.93 5.38 30.86 4.78 15.88 82.71 17.29 4.41 9.96 14.37 13S F 1.67 0.01 1.68 25.61 0.03 4.50 99.40 0.60 3.72 12.68 16.40 1 7 M F 0.00 0.16 0.16 0.00 0.56 0.47 0.00 100.00 2.60 10.06 12.66 M e a n F 2.04 0.37 2.41 22.77 1.40 6.85 84.76 15.24 7.22 21.67 28.89 21 G 5.96 3.79 9.75 76.80 15.11 29.69 61.13 38.87 0.56 8.94 9.50 19 H 12.08 7.44 19.52 94.08 37.41 59.64 61.89 38.11 3.29 3.29 20 I 5.94 4.79 10.73 69.31 22.74 36.21 55.36 44.64 1.98 1.98 O v e r a l l M e a n 5.18 5.81 10.99 66.35 24.05 34.38 47.14 52.86 0.68 4.04 4.72 "Stocking class identified for replicated treatments only. S=superior G = g o o d M = m o d e r a t e . Chapter 5. Results 59 Table 5.11: Total and percent gross volume cut at harvest (m 3/ha), as well as gross volume/ha marked but left uncut. Plot N o . T r e a t - T o t a l V o l u m e C u t V o l u m e C u t (% T o t a l ) % T o t a l C u t V o l u m e U n c u t / S t o c k " ment D I P T N D I P T T o t a l D I P T N D I P T T o t a l D I P T N D I P T D I P T N D I P T T o t a l IS A 71.63 52.88 124.51 98.57 54.36 73.27 57.53 42.47 - 4.36 4.36 7 M A 77.56 59.53 137.09 93.17 47.81 65.98 56.58 43.42 • 19.32 19.32 10G A 45.38 89.62 135.00 95.98 68.25 75.59 33.61 66.39 5.35 5.35 M e a n A 64.86 67.34 132.20 95.75 57.22 71.29 49.06 50.94 11.13 11.13 8 G B 24.67 53.73 78.40 69.32 42.16 48.09 31.47 68.53 1.71 32.95 34.66 1 5 M B 20.49 91.31 111.80 76.43 58.92 61.50 18.33 81.67 29.39 29.39 16S B 91.91 66.76 158.67 93.06 48.04 66.74 57.93 42.07 10.89 10.89 M e a n B 45.69 70.60 116.29 85.05 50.26 59.88 39.29 60.71 0.66 27.14 27.80 4 G C 37.79 69.65 107.44 66.99 43.86 49.92 35.17 64.83 3.40 20.93 24.33 9 M C 41.52 51.56 93.08 79.42 42.15 53.31 44.61 55.39 5.70 21.53 27.23 18S C 130.55 99.07 229.62 96.24 60.79 76.89 56.85 43.15 14.20 14.20 M e a n C 69.95 73.43 143.38 85.89 49.60 62.48 48.79 51.21 3.33 20.80 24.13 2 G D 17.52 38.45 55.97 40.83 34.14 35.98 31.30 68.70 13.32 13.32 5S D 67.93 80.49 148.42 87.06 49.92 62.03 45.77 54.23 4.86 26.46 31.32 1 4 M D 48.34 19.88 68.22 83.95 18.65 41.55 70.86 29.14 43.30 43.30 M e a n D 44.60 46.27 90.87 74.94 36.49 48.77 49.08 50.92 1.73 29.49 31.22 3 M E 63.02 23.13 86.15 89.02 25.69 53.57 73.15 26.85 - 6.83 6.83 6S E 49.09 23.96 73.05 66.57 14.87 31.10 67.20 32.80 12.09 65.06 77.15 11G E 38.38 107.80 146.18 80.28 62.30 66.20 26.26 73.74 18.09 18.09 M e a n E 50.16 51.63 101.79 78.24 36.51 49.53 49.28 50.72 4.27 31.87 36.14 12G F 55.89 5.99 61.88 35.87 5.86 23.98 90.32 9.68 55.43 88.62 144.05 13S F 21.73 0.00 21.73 41.16 0.00 8.23 100.00 0.00 26.29 133.13 159.42 1 7 M F 0.00 1.07 1.07 0.00 0.69 0.54 0.00 100.00 18.46 105.60 124.06 M e a n F 25.87 2.35 28.23 30.79 1.51 11.75 91.66 8.34 35.80 116.34 152.14 21 G 68.63 26.44 95.07 90.56 24.53 51.80 72.19 27.81 3.62 61.21 64.83 19 H 129.59 53.34 182.93 98.42 50.24 76.91 70.84 29.16 35.59 35.59 20 I 74.64 53.61 128.25 82.56 42.78 59.45 58.20 41.80 19.35 19.35 O v e r a l l M e a n 56.01 50.87 106.88 76.90 37.73 51.47 52.41 47.59 6.26 36.93 43.19 "Stocking class identified for replicated treatments only. S=superior G=good M=moderate. Chapter 5. Results 60 5.3 Effects of Treatments 5.3.1 Stem Growth 5.3.1.1 Trees 5 cm dbh and larger For all species combined, all treatments except F and G showed an increase in the mean number of stems 14 years after harvest, relative to the mean number of stems immedi-ately after harvest (Table 5.12). The mean periodic annual increment (PAI) varied from -7.70 stems/ha/year in Treatment G to 24.00 stems/ha/year in Treatment H with an overall mean of 7.17 stems/ha/year. Heavier losses appeared to have occurred during the initial first three years after harvest as was indicated by the mean number of stems per hectare over time for the replicated treatments (Figure 5.16). Of the replicated treat-ments, Treatment E resulted in the best growth of 11.50 stems/ha/year. A l l replicated treatments except F exceeded the precut mean number of stems per hectare (with stem ratios > 1), 14 years after harvest (Figure 5.17). On an individual plot basis, all plots recorded a decrease in the number of stems for a period ranging from one to seven years after harvest (Figure C.33 of Appendix C). Except for four plots (7, 12, 17 and 21), all plots showed an increase in the number of stems per hectare 14 years after harvest (Table D.36 of Appendix D). The PAI for the 14 year period ranged from -16.74 stems/ha/year in plot 17 to 24.00 stems/ha/year in plot 19. In fact, 15 of the plots were observed to have exceeded their precut number of stems per hectare, 14 years after harvest (Figure C.34). Overall, the non-dipterocarps were found to contribute to the bulk of the increase (Table 5.12), with 14 of the plots even exceeding their precut stem levels (stem ratios >1). The mean PAI for the non-dipterocarps was 6.34 stems/ha/year, with the L H W species recorded the highest mean growth rate of 5.78 stems/ha/year (19 plots with Chapter 5. Results 61 stem ratios >1), followed by the H H W species with 1.78 stems/ha/year (17 plots with stem ratios >1), M H W species (0.70 stems/ha/year, 9 plots with stem ratios >1) and a negative growth rate of 1.93 stems/ha/year for the MISC species. The overall growth rate of the dipterocarp species was much lower at 0.83 stems/ha/year, with only 8 plots attained stem ratios greater than 1. Details of stem growth by individual plot and species group are given in Table D.37. Simple linear regressions were performed to test for any significant relationships be-tween percent stem change (relative to post harvest) as the dependent variable and cut-ting intensity (% basal area removed) as independent variable over the 14 year period. Results of the analyses indicated significant positive linear relationships between the two variables for all species combined (i?2=0.2880, p=0.0121, RMSE=16.6940, n=21), and for the non-dipterocarps (i22=0.2594, p=0.0184, RMSE=17.5608, n=21). No significant relationship was detected for the dipterocarps (i?2=0.1171, p=0.1289, RMSE=43.2028, n=21) (Figure 5.18). Results of repeated measures analysis of variance indicated there was no significant treatment x time interaction (p=0.1478) for the six treatments that were replicated. There was also no significant difference in the mean number of stems among the treatments over the 14 year period (p=0.9134). However, tests for within subject differences indicated that there was an overall significant non-linear time trend (p=0.0001). 5.3.1.2 Trees 30 cm dbh and larger The growth pattern of trees 30 cm dbh and larger for all species was found to be similar to that of 5 cm dbh and larger, but at a lower rate. All treatments except E, F and G showed an increase in the number of stems with PAI varying from -0.78 stems/ha/year in Treatment G to 1.67 stems/ha/year in Treatment H (Table 5.13). A general trend of heavier losses within the first two years after harvest was observed for the replicated Chapter 5. Results 62 Table 5.12: Mean periodic annual increment (stems/ha/year) of trees 5 cm dbh and larger by treatment and species group (1974-1988). Treat-ment Dipterocarp Non-dipterocarp All species MER NMER Total LHW MHW HHW MISC Total A -0.37 0.86 0.48 9.82 1.64 1.19 -4.39 8.26 8.74 B 0.67 0.41 1.08 7.48 0.37 2.57 -2.34 8.07 9.15 C 1.53 0.60 2.12 2.01 0.89 1.15 -1.23 2.83 4.95 D 0.97 0.15 1.12 6.47 0.97 0.41 1.30 9.15 10.27 E 0.41 0.86 1.27 6.92 0.93 3.91 -1.53 10.23 11.50 F -0.30 -0.26 -0.56 -1.49 -1.38 -0.34 -3.68 -6.88 -7.44 G 0.45 -0.56 -0.11 -1.90 -3.57 -0.45 -1.67 -7.59 -7.70 H 0.67 -0.11 0.56 13.84 5.36 6.36 -2.12 23.44 24.00 I -0.67 1.23 0.56 15.85 2.68 4.80 -1.12 22.21 22.77 Overall Mean 0.44 0.40 0.83 5.78 0.70 1.78 -1.93 6.34 7.17 Chapter 5. Results 63 Figure 5.16: Stems/ha of all trees 5.0 cm dbh and larger after harvest for replicated treatments. Chapter 5. Results 64 Figure 5.17: Stem ratios of all trees 5.0 cm dbh and larger after harvest for replicated treatments. Chapter 5. Results (i) Dipterocarp species -40 -I 1 1 1 1 a—i 1 0 10 20 30 40 50 60 Cutting intensity (%) Figure 5.18: Relationship between percent stem change and cutting intensity. Chapter 5. Results 66 treatments (Figure 5.19). Among the replicated treatments, Treatment D was found to produce the highest growth rate of 1.52 stems/ha/year. In contrast to trees 5 cm dbh and larger, none of the replicated treatments attained a mean number of stems per hectare that exceeded that of the precut number of stems (Figure 5.20). On an individual plot basis, fifteen of the 21 plots recorded an increase in stems per hectare 14 years after harvest (Figure C.35). The PAIs varied from 0.11 stems/ha/year in plot 4 to 3.35 stems/ha/year in plot 2 (Table D.38). The remaining 6 plots (plots 3, 6, 7, 12, 13 and 21) recorded negative PAIs which varied from -0.78 stems/ha/year in plots 13 and 21 to -0.22 stems/ha/year in plot 3. At year 14, only two of the plots (plot 2 & 17) recorded a total number of stems that exceeded that of the precut number of stems (Figure C.36). Of the overall PAI of 0.44 stems/ha/year, 0.37 stems/ha/year or 84% was contributed by the non-dipterocarps (Table 5.13). Again, the L H W species responded better to the cutting by attaining a higher growth rate of 0.20 stem/ha/year (with 6 plots having stem ratios >1), followed by the M H W species (0.14 stem/ha/year, 4 plots with stem ratios >1), the H H W species (0.10 stem/ha/year, 9 plots with stem ratios >1) and a negative growth rate of 0.06 stem/ha/year for the MISC species. Within the dipterocarps, both the M E R and N M E R species responded to the release provided by cutting by attaining the same growth rate of 0.04 stem/ha/year (each with 4 plots having stem ratios >1). Details of stem growth over the 14 year period by individual plot and species group are given in Table D.39. Results of repeated measures analysis of variance indicated that there was no signifi-cant treatment x time interaction (p=0.2414). However, there were significant differences in the number of stems among treatments (p=0.0035) over the 14 year period. There was also a non-linear time trend in the stem measurements over time (p=0.0002), as with the analyses for all trees 5 cm dbh and larger. Chapter 5. Results 67 Figure 5.19: Stems/ha of all trees 30.0 cm dbh and larger after harvest for replicated treatments. Chapter 5. Results 68 Figure 5.20: Stem ratios of all trees 30.0 cm dbh and larger after harvest for replicated treatments. Chapter 5. Results 69 Table 5.13: Mean periodic annual increment (stems/ha/year) of trees 30 cm dbh and larger by treatment and species group (1974-1988). Treat-ment Dipterocarp Non-dipterocarp All species MER NMER Total LHW MHW HHW MISC Total A 0.04 0.04 0.07 0.34 0.00 0.00 -0.15 0.19 0.26 B 0.11 0.00 0.11 0.22 0.74 0.00 -0.15 0.82 0.93 C 0.34 -0.15 0.19 0.19 -0.41 0.26 0.00 0.04 0.22 D 0.26 0.19 0.45 0.49 0.19 0.26 0.15 1.08 1.52 E -0.15 0.19 0.04 -0.26 0.19 0.15 -0.22 -0.15 -0.11 F -0.37 0.00 -0.37 0.07 0.04 0.04 0.07 0.22 -0.15 G 0.00 0.11 0.11 -0.22 -0.34 -0.22 -0.11 -0.89 -0.78 H 0.22 0.00 0.22 0.78 0.67 0.00 0.00 1.45 1.67 I -0.11 -0.11 -0.22 0.45 0.33 0.11 -0.33 0.56 0.34 Overall Mean 0.04 0.04 0.07 0.20 0.14 0.10 -0.06 0.37 0.44 Chapter 5. Results 70 5.3.2 Basal Area Growth 5.3.2.1 Trees 5 cm dbh and larger Relative to the post felling basal area, all treatments recorded a net increase in basal area 14 years after harvest, with PAIs varying from 0.07 m 2/ha/year in Treatment G to 0.52 m 2/ha/year in Treatment I (Table 5.14). This growth pattern was similar to stem growth where heavier losses occurred within the first two years after harvest, and slow and gradual increase thereafter, as shown by the replicated treatments (Figure 5.21). Among the replicated treatments, Treatment D achieved the best growth rate of 0.41 m 2/ha/year, while only Treatment F managed to attain its precut basal area 14 years after harvest (Figure 5.13). On an individual plot basis, all except plot 17 recorded a reduction in basal area one year after harvest (Figure C.37). Nineteen of the 21 plots recorded a reduction in basal area for two consecutive years with 7 of these plots continuing to experience further losses until the third year. A l l except plot 12 recorded a net increase in basal area 14 years after harvest relative to post felling basal area, with PAIs varying from 0.01 m 2/ha/year in plot 6 to 0.52 m 2/ha/year in plot 20 (Table D.40). Four of the plots achieved basal areas that were higher than their precut basal areas (Figure C.38). The overall PAI was 0.25 m 2/ha/year. Of this, 0.22 m 2/ha/year was contributed by the non-dipterocarps (Table 5.19). Details of basal area growth by individual plot and species group are given in Table D.41. Results of repeated measures analysis of variance indicated that there was no signif-icant treatment x time interaction (p=0.5003). However, there was a significant differ-ence among treatments (p=0.0001). There was also a significant non-linear time trend (p=0.0002). Chapter 5. Results 71 40 0 1 2 3 4 5 7 10 12 14 Years after harvest Figure 5.21: Basal area of all trees 5.0 cm dbh and larger after harvest for replicated treatments. Chapter 5. Results 72 Figure 5.22: Basal area ratios of all trees 5.0 cm dbh and larger after harvest for replicated treatments. Chapter 5. Results 73 Table 5.14: Mean periodic annual increment (m2/ha/year) of trees 5 cm dbh and larger by treatment and species group (1974-1988). Treat-ment Dipterocarp Non-dipterocarp All species MER NMER Total LHW MHW HHW MISC Total A 0.00 0.01 0.01 0.19 0.09 0.03 -0.04 0.27 0.28 B 0.03 0.01 0.04 0.09 0.06 0.03 -0.03 0.16 0.20 . C 0.06 0.00 0.05 0.06 0.01 0.07 -0.01 0.13 0.18 D 0.06 0.03 0.08 0.16 0.09 0.06 0.02 0.33 0.41 E -0.01 0.03 0.02 0.09 0.10 0.05 -0.05 0.19 0.21 F -0.08 0.03 -0.05 0.11 0.10 0.02 -0.00 0.23 0.18 G 0.00 0.02 0.03 0.04 0.02 0.00 -0.01 0.05 0.07 H 0.02 0.00 0.02 0.22 -0.11 0.20 -0.01 0.19 0.21 I -0.05 0.02 -0.03 0.37 0.13 0.09 -0.04 0.55 0.52 Overall Mean 0.01 0.02 0.02 0.13 0.10 0.10 -0.02 0.22 0.25 Chapter 5. Results 74 5.3.2.2 Trees 30 cm dbh and larger In contrast to trees 5 cm dbh and larger, not all treatments recorded a net increase in basal area 14 years after harvest. Treatments E, G and H recorded negative PAIs varying from -0.02 m 2 /ha/yr in Treatment E to -0.01 m 2/ha/year in Treatments G and H (Table 5.15). The mean basal area growth of trees 30 cm dbh and larger for the replicated treatments was similar to that of 5 cm dbh and larger, with a general reduction in the basal area immediately after harvest and gradual increase thereafter (Figure 5.23). Again, Treatment D was found to attain the highest growth rate of 0.23 m 2/ha/year among the replicated treatments. However, none of the replicated treatments attained their precut basal area levels 14 years after harvest (Figure 5.24). On an individual plot basis, there was a reduction in basal area for all plots immedi-ately after harvest (Figure C.39). Relative to the post felling basal area, seventeen of the 21 plots recorded a net increase in basal area 14 years after harvest, with PAIs varying from 0.02 m 2/ha/year in plots 1 and 7 to 0.42 m 2/ha/year in plot 2 (Table D.42). The remaining 4 plots (plots 6, 12, 19 and 21) recorded negative PAIs ranging from -0.13 to -0.01 m 2/ha/year. At year 14, only one plot (plot 17) attained a basal area that was higher than its precut basal area (Figure C.40). The overall PAI for trees 30 cm dbh and larger was 0.09 m 2/ha/year of which 0.08 m 2/ha/year were contributed by the non-dipterocarps (Table 5.20). Details of basal area growth by individual plot and species group are given in Table D.43. Results of repeated measures analysis of variance indicated no significant treatment x time interaction (p=0.2414). However, there was a significant difference in basal area among treatments (p=0.0035) and an overall significant non-linear time trend (p=0.0002). Chapter 5. Results 75 0 -I H 1 1 1 1 1 1 1 1 0 1 2 3 4 5 7 10 12 14 Years after harvest Figure 5.23: Basal area of all trees 30.0 cm dbh and larger after harvest for replicated treatments. Chapter 5. Results 76 0 -I 1 1 1 1 1 1 1 1 1 0 1 2 3 4 5 7 10 12 14 Years after harvest Figure 5.24: Basal area ratios of all trees 30.0 cm dbh and larger after harvest for replicated treatments. Chapter 5. Results 77 Table 5.15: Mean periodic annual increment (ra 2/ha/year) of trees 30 cm dbh and larger by species group (1974-1988). Treat-ment Dipterocarp Non-dipterocarp All species MER NMER Total LHW MHW HHW MISC Total A 0.01 0.00 0.01 0.05 0.02 0.01 -0.01 0.06 0.07 B 0.03 0.00 0.03 0.03 0.10 0.01 -0.01 0.13 0.15 C 0.05 -0.02 0.04 0.02 -0.03 0.05 0.00 0.04 0.08 D 0.05 0.02 0.08 0.06 0.04 0.04 0.01 0.16 0.23 E -0.02 0.02 0.00 -0.05 0.05 0.02 -0.04 -0.02 -0.02 F -0.10 0.03 -0.06 0.06 0.07 0.01 0.02 0.16 0.10 G -0.01 0.02 0.01 0.01 -0.01 -0.00 -0.01 -0.02 -0.01 H 0.02 0.00 0.02 0.08 -0.12 0.00 0.00 -0.03 -0.01 I -0.04 0.00 -0.04 0.09 0.08 0.03 -0.04 0.16 0.13 Overall Mean 0.00 0.01 0.01 0.03 0.03 0.02 -0.01 0.08 0.09 Chapter 5. Results 78 5.3.3 Gross Volume Growth 5.3.3.1 Trees 15 cm dbh and larger A l l replicated treatments recorded a net increase in gross volume 14 years after harvest, with PAIs varying from 0.11 m 3/ha/year in Treatment E to 2.00 m 3/ha/year in Treatment D and an overall mean of 0.94 m 3/ha/year (Table 5.16 & Figure 5.25). However, none of the replicated treatments achieved their precut gross volume levels (Figure 5.26). On an individual plot basis, all except plots 14 and 17 recorded a reduction in total gross volume one year after harvest (Figure C.41). These reductions in gross volume persisted for many of the plots from 2 to 4 years after felling. Seventeen of the 21 plots recorded a net increase in gross volume 14 years after harvest, with PAIs varying from 0.20 m 3/ha/year in plot 7 to 3.41 m 3/ha/year in plot 17 (Table D.44). The remaining 4 plots (plots 4, 6, 12 and 19) recorded negative PAIs ranging from -1.50 m 3/ha/year in plot 6 to -0.03 m 3/ha/year in plot 4. Two of the plots were observed to have attained gross volumes per hectare that were higher than their precut levels (Figure C.42). The overall PAI for all trees 15 cm dbh and larger was 0.94 m 3/ha/year. As for stems and basal area growth, the non-dipterocarps was found to attain a better growth rate of 0.80 m 3 /ha/year as compared to 0.14 m 3/ha/year by the dipterocarps (Table 5.16). Details of gross volume growth by individual plot and species group are given in Table D.45. Results of repeated measures analysis of variance indicated that there was no signifi-cant treatment x time interaction (p=0.7782). However, there was a significant difference in gross volume among treatments (p=0.0001) and an overall significant non-linear time trend (p=0.0015). Chapter 5. Results 79 250 Figure 5.25: Gross volume of all trees 15.0 cm dbh and larger after harvest for replicated treatments. Chapter 5. Results 80 0 -I 1 1 1 1 1 1 1 1 1 0 1 2 3 4 5 7 10 12 14 Years after harvest Figure 5.26: Gross volume ratios of all trees 15.0 cm dbh and larger after harvest for replicated treatments. Chapter 5. Results 81 Table 5.16: Mean periodic annual increment (m3/ha/year) of trees 15 cm dbh and larger by treatment and species group (1974-1988). Treat-ment Dipterocarp Non-dipterocarp All species MER NMER Total LHW MHW HHW MISC Total A 0.02 0.04 0.06 0.52 0.23 0.07 -0.10 0.72 0.78 B 0.16 0.01 0.17 0.17 0.50 0.07 -0.11 0.63 0.80 C 0.42 -0.06 0.35 0.17 0.18 0.42 -0.05 0.36 0.71 D 0.34 0.19 0.54 0.62 0.42 0.38 0.03 1.46 2.00 E -0.09 0.16 0.07 -0.28 0.54 0.19 -0.40 0.05 0.11 F -0.71 0.50 -0.21 0.79 0.91 0.08 0.16 1.95 1.74 G -0.05 0.16 0.12 0.21 0.28 -0.03 0.01 0.47 0.58 H 0.11 -0.01 0.09 0.58 -1.86 0.24 -0.04 -1.08 -0.99 I -0.27 0.06 -0.22 1.12 0.72 0.37 -0.27 1.94 1.72 Overall Mean 0.01 0.13 0.14 0.38 0.31 0.20 -0.08 0.80 0.94 Chapter 5. Results 82 5.3.3.2 Trees 30 cm dbh and larger The gross volume growth of trees 30 cm dbh and larger was similar to that of trees 15 cm dbh and larger. A l l replicated treatments except E recorded a net increase in gross volume 14 years after harvest, with PAI varying from -0.20 m 3/ha/year in Treatment E to 1.78 m 3/ha/year in Treatment D (Table 5.17 Sz Figure 5.27). None of the replicated treatments attained their precut gross volume levels (Figure 5.28). In terms of individual plots, a reduction in gross volume per hectare was experienced by all except plots 14 and 17 a year immediately after harvest. This decreasing trend continued for most plots, with further losses extending from 2 to 4 years after harvest (Figure C.43). Eighteen of the 21 plots recorded a net increase in gross volume 14 years after harvest, with PAIs varying from 0.14 m 3/ha/year in plot 1 to 3.41 m 3/ha/year in plot 17 (Table D.46). Two of these plots were found to have attained gross volumes that were higher than their precut values (Figure C.44). The overall PAI was 0.80 m 3/ha/year. Again, the non-dipterocarps were found to have a better volume growth of 0.67 m 3/ha/year compared to the 0.13 m 3/ha/year by the dipterocarps (Table 5.17). Details of gross volume growth by plot and species group are given in Table D.47. Results of repeated measures analysis of variance were the same as for gross volume of trees 15 cm dbh and larger. There was no significant treatment x time interaction (p=0.7290). However, there was a significant difference in gross volume among treatments (p=0.0001) and an overall significant non-linear time trend (p=0.0047). Chapter 5. Results 83 250 0 1 2 3 4 5 7 10 12 .14 Years after harvest Figure 5.27: treatments. Gross volume of all trees 30.0 cm dbh and larger after harvest for replicated Chapter 5. Results 84 Figure 5.28: Gross volume ratios of all trees 30.0 cm dbh and larger after harvest for replicated treatments. Chapter 5. Results 85 Table 5.17: Mean periodic annual increment (m3/ha/year) of trees 30 cm dbh and larger by treatment and species group (1974-1988). Treat-ment Dipterocarp Non-dipterocarp All species MER NMER Total LHW MHW HHW MISC Total A 0.05 0.03 0.07 0.34 0.12 0.04 -0.04 0.46 0.53 B 0.18 0.01 0.19 0.19 0.66 0.06 -0.06 0.85 1.04 C 0.41 -0.11 0.31 0.19 0.20 0.36 0.00 0.35 0.66 D 0.36 0.21 0.57 0.48 0.35 0.31 0.08 1.21 1.78 E -0.11 0.15 0.04 -0.53 0.47 0.22 -0.39 -0.24 -0.20 F -0.75 0.48 -0.27 0.70 0.86 0.09 0.20 1.86 1.59 G -0.04 0.11 0.07 0.28 0.20 -0.01 -0.06 0.41 0.47 H 0.13 0.00 0.13 0.53 -1.76 0.00 0.01 -1.22 -1.09 I -0.25 0.06 -0.19 0.62 0.68 0.33 -0.24 1.39 1.20 Overall Mean 0.01 0.12 0.13 0.26 0.28 0.17 -0.04 0.67 0.80 Chapter 5. Results 86 5.3.4 Diameter Growth 5.3.4.1 By Diameter Class/Limit In general, the periodic annual diameter increment (DPAI) of all species over the 14 year period appeared to increase with increasing dbh class for the replicated treatments under study (Figure 5.29). On average, the DPAIs of all species and treatments combined increased from 0.22 to 0.33 to 0.37 cm/year for dbh classes 5.0 to 14.9 cm, 15.0 to 29.9 cm and 30.0 to 44.9 cm (Table 5.18), and from 0.25 to 0.35 to 0.39 cm/year for dbh limits 5.0 cm, 15.0 cm and 30.0 cm and larger (Table 5.19), respectively. Details of DPAIs by dbh class/limit and species groups are given in Tables E.48-53 of Appendix E. An A N O V A performed on the log transformed data (normally distributed (p=0.3107) and equal variance (p=0.4952)), indicated there was no significant dbh class x treatment interaction (p=0.3007). However, significant differences in dbh increment rates were detected among the three dbh classes (p=0.0001). These increment rates did not differ among treatments (p=0.1061). 5.3.4.2 By Species Group The DPAIs of dipterocarps were found to be consistently higher than that of the non-dipterocarps for all dbh classes/limits under study (Figure 5.29). The DPAIs of trees 5.0 cm, 15.0 cm and 30.0 cm dbh and larger were 0.43, 0.60 and 0.56 cm/year for the dipterocarps and 0.24, 0.32 and 0.37 cm/year for the non-dipterocarps, respectively. Separate ANOVAs were performed on the ranked data (all ranked variables were normally distributed and had equal variance, all p values > 0.05) by dbh limits. Except for trees 5 cm dbh and larger, there were no significant treatment x species interactions (Table 5.20). There were also no significant differences in dbh increment rates among treatments for all dbh limits. Results of the analyses indicated there were significant differences in Chapter 5. Results 87 Table 5.18: Mean periodic annual diameter increment (cm/year) by treatment, species group and dbh class (1974-1988). D i a m e t e r T r e a t - D i p t e r o c a r p N o n - d i p t e r o c a r p A l l Class ( c m ) ment M E R N M E R T o t a l L H W M H W H H W M I S C T o t a l Species A 0.31 0.30 0.30 0.28 0.26 0.32 0.23 0.26 0.26 B 0.25 0.33 0.26 0.27 0.23 0.28 0.26 0.25 0.25 C 0.41 0.37 0.39 0.23 0.22 0.37 0.22 0.23 0.24 D 0.34 0.39 0.36 0.24 0.21 0.32 0.19 0.23 0.24 5.0-14.9 E 0.40 0.41 0.40 0.23 0.25 0.25 0.16 0.23 0.24 F 0.30 0.60 0.37 0.16 0.14 0.16 0.09 0.14 0.15 G 0.22 0.30 0.26 0.17 0.11 0.12 0.11 0.13 0.14 H 0.51 0.09 0.30 0.31 0.28 0.45 0.17 0.30 0.30 I 0.55 0.25 0.40 0.28 0.22 0.36 0.24 0.26 0.27 O v e r a l l M e a n 0.34 0.35 0.34 0.23 0.21 0.27 0.18 0.22 0.22 A 1.00 0.61 0.84 0.36 0.29 0.58 0.24 0.33 0.35 B 0.78 0.39 0.66 0.35 0.29 0.19 0.32 0.31 0.33 C 0.73 0.54 0.71 0.33 0.29 0.46 0.17 0.31 0.35 D 0.63 0.64 0.63 0.34 0.27 0.50 0.30 0.32 0.34 15.0-29.9 E 0.90 0.68 .0.75 0.35 0.34 0.40 0.38 0.35 0.38 F 0.48 0.60 0.55 0.23 0.21 0.25 0.22 0.23 0.25 G 0.47 0.48 0.48 0.21 0.22 0.14 0.23 0.21 0.22 H 0.92 0.13 0.42 0.48 0.39 0.16 0.42 0.42 I 0.63 0.63 0.47 0.32 0.34 0.13 0.34 0.36 O v e r a l l M e a n 0.71 0.53 0.64 0.32 0.28 0.36 0.24 0.30 0.33 A 0.38 0.38 0.60 0.39 0.50 0.45 0.48 0.47 B 0.50 0.43 0.47 0.26 0.32 0.30 0.54 0.31 0.33 C 0.42 0.64 0.46 0.35 0.37 0.35 0.25 0.36 0.37 D 0.60 0.40 0.57 0.33 0.30 0.40 0.25 0.32 0.37 30.0-44.9 E 0.44 0.62 0.53 0.37 0.44 0.25 0.60 0.39 0.41 F 0.46 0.63 0.54 0.27 0.32 0.26 0.09 0.28 0.30 G 0.89 0.89 0.40 0.30 0.59 0.37 0.37 0.39 H 0.59 0.17 0.38 0.38 I 0.29 0.29 0.65 0.48 0.31 0.50 0.49 O v e r a l l M e a n 0.51 0.55 0.52 0.35 0.35 0.33 0.27 0.35 0.37 Chapter 5. Results 88 Treatment A 5.0-14.9 15.0-29.9 30.0-44.9 Diameter class (cm) Treatment D 1 0.8 0.6 -0.4 -0.2 -o -+- -4-5.0-14.9 15.0-29.9 30.0-44.9 Diameter Class (cm) Treatment B Treatment E 1 0.8 0.6 0.4 0.2 o -+- -+-5.0-14.9 15.0-29.9 30.0-44.9 Diameter Class (cm) 5.0-14.9 15.0-29.9 30.0-44.9 Diameter Class (cm) Treatment C • Dipt BNdipt HAII Treatment F is 1 j 0.8 --0.6 --0.4 --0.2 0 -+- -+-5.0-14.9 15.0-29.9 30.0-44.9 Diameter class (cm) 5.0-14.9 15.0-29.9 30.0-44.9 Diameter Class (cm) Figure 5.29: Mean periodic annual diameter increment (cm/year) for replicated treat-ments by major species group and dbh class (1974 - 1988). Chapter 5. Results 89 Table 5.19: Mean periodic annual diameter increment (cm/year) by treatment, species group and dbh limit (1974-1988). D i a m e t e r T r e a t - D i p t e r o c a r p N o n - d i p t e r o c a r p A l l L i m i t ( c m ) ment M E R N M E R T o t a l L H W M H W H H W M I S C T o t a l Species A 0.52 0.34 0.41 0.30 0.27 0.38 0.23 0.28 0.28 B 0.36 0.37 0.36 0.29 0.26 0.27 0.27 0.27 0.28 C 0.52 0.42 0.49 0.25 0.24 0.40 0.22 0.25 0.27 D 0.47 0.43 0.45 0.26 0.24 0.36 0.21 0.25 0.27 5.0 + E 0.45 0.49 0.47 0.27 0.28 0.28 0.17 0.26 0.28 F 0.44 0.61 0.50 0.19 0.18 0.20 0.11 0.17 0.19 G 0.24 0.35 0.29 0.18 0.14 0.15 0.12 0.15 0.16 H 0.62 0.10 0.34 0.34 0.31 0.43 0.17 0.32 0.32 I 0.56 0.29 0.43 0.31 0.26 0.36 0.23 0.29 0.30 O v e r a l l M e a n 0.44 0.41 0.43 0.25 0.24 0.29 0.19 0.24 0.25 A 1.00 0.56 0.78 0.40 0.32 0.55 0.27 0.36 0.37 B 0.65 0.41 0.57 0.33 0.30 0.24 0.35 0.31 0.33 C 0.63 0.59 0.62 0.33 0.32 0.43 0.18 0.33 0.36 D 0.61 0.51 0.59 0.34 0.29 0.46 0.29 0.33 0.36 15.0 + E 0.60 0.65 0.63 0.36 0.38 0.34 0.44 0.37 0.39 F 0.60 0.61 0.61 0.26 0.28 0.25 0.25 0.27 0.30 G 0.43 0.57 0.53 0.28 0.25 0.26 0.30 0.26 0.27 H 0.92 0.13 0.42 0.48 0.39 0.16 0.17 0.42 0.42 I 0.63 0.48 0.57 0.53 0.38 0.34 0.23 0.40 0.41 O v e r a l l M e a n 0.64 0.54 0.60 0.33 0.31 0.35 0.26 0.32 0.35 A 0.38 0.38 0.60 0.41 0.50 0.47 0.48 0.48 B 0.53 0.43 0.50 0.26 0.31 0.31 0.49 0.30 0.33 C 0.47 0.64 0.50 0.35 0.37 0.40 0.23 0.36 0.38 D 0.60 0.35 0.55 0.36 0.34 0.40 0.25 0.35 0.39 30.0 + E 0.43 0.62 0.52 0.37 0.47 0.28 0.60 0.39 0.41 F 0.66 0.62 0.65 0.33 0.36 0.25 0.32 0.33 0.38 G 0.39 0.89 0.64 0.40 0.37 0.59 0.37 0.40 0.42 H 0.59 0.17 0.38 0.38 I 0.48 0.48 0.65 0.49 0.35 0.74 0.51 0.51 O v e r a l l M e a n 0.56 0.56 0.56 0.37 0.37 0.34 0.35 0.37 0.39 Chapter 5. Results 90 Table 5.20: Summary of A N O V A for diameter increment. Source D F 5.0 + cm dbh 15.0 + cm dbh 30.0 + cm dbh F Pr.>F F Pr.>F F Pr .>F Total 35 Treat(T) 5 0.28 0.9144 0.40 0.8406 0.35 0.8729 Stock 2 1.22 0.3305 2.31 0.1452 0.95 0.4183 Error(l) 10 Species 1 124.98 0.0001 103.61 0.0001 16.80 0.0022 T x species 5 3.55 0.0333 1.99 0.1593 3.09 0.0606 Error(2) 12 the rates of dbh increment between the dipterocarps and non-dipterocarp species for trees 15 cm and 30 cm dbh and larger. Little difference in growth rates was observed between the meranti and non-meranti species within the dipterocarps. The overall DPAIs for all trees 5 cm and 30 cm dbh and larger were 0.44 and 0.56 cm/year for meranti species and 0.41 and 0.56 cm/year for the non-meranti species, respectively. It was also observed that dipterocarp trees from the dbh class 15.0 to 29.9 cm appeared to respond better to the release provided by partial cutting, by having consistently higher growth rates over the 14 year period. Among the non-dipterocarps, H H W was found to have the highest DPAI of 0.29 cm/year, followed by L H W (0.25 cm/year) and M H W (0.24 cm/year) when all trees 5 cm dbh and larger were considered. At higher the diameter limit (30 cm dbh and larger), L H W and M H W tended to have higher growth rates (0.37 cm/year), followed by H H W (0.34 cm/year). Chapter 5. Results 91 5.3.4.3 Over Time Results of the study did not indicate a distinct decrease in the rate of dbh increment over three successive growth periods (Tables 5.21). Instead, the growth rates fluctuated among the growth periods, especially for trees 30 cm dbh and larger. Details of the DPAIs over three successive growth periods by diameter limits are given in Tables E.54 and 55. Repeated measures analysis of variance were performed to test for trend in dbh in-crement over time for dipterocarps, non-dipterocarps and all species combined, and for diameter limits 5 cm and 30 cm dbh and larger (6 combinations) over all successive growth periods. Results of the analyses indicated that there were no significant time x treatment interactions (all p values > 0.05). There were also no significant differences in dbh increment among treatments for any combinations (all p values >0.05). However, significant non-linear time trends were detected for for all 6 combinations (all p values < 0.05). 5.3.4.4 Relationship with Cutting Intensity Simple linear regressions were performed to test for relationships between the DPAI of all trees 5 cm dbh and larger (over the period 1974 to 1988) as the dependent variable and percent cutting intensity as the independent variable for dipterocarps, non-dipterocarps, and all species combined (Figure 5.30). Results of the analyses indicated significant pos-itive linear relationships between the two variables for the non-dipterocarps (p=0.0003, i?2=0.5007, RMSE=0.04208, n=21) and all species combined (p=0.0011, i?2=0.4372, RMSE=0.04354, n=21). However, no significant relationship was found for the diptero-carps (p=0.6739, i22=0.0095, RMSE=0.21377, n=21). Chapter 5. Results 92 Table 5.21: Mean periodic annual diameter increment (cm/year) over three growth peri-ods by treatment, major species group and dbh limit. D i a m e t e r T r e a t - D i p t e r o c a r p N o n - d i p t e r o c a r p A l l Species L i m i t ( c m ) ment 74-79 79-84 84-88 74-79 79-84 84-88 74-79 79-84 84-88 A 0.44 0.44 0.39 0.34 0.27 0.27 0.34 0.28 0.28 B 0.31 0.47 0.42 0.29 0.26 0.30 0.29 0.28 0.31 C 0.43 0.47 0.40 0.29 0.26 0.23 0.30 0.28 0.25 D 0.49 0.47 0.42 0.29 0.23 0.24 0.30 0.24 0.26 5.0 + E 0.58 0.47 0.34 0.32 0.27 0.25 0.34 0.28 0.26 P 0.55 0.39 0.51 0.21 0.16 0.16 0.23 0.17 0.18 G 0.34 0.25 0.31 0.19 0.14 0.13 0.20 0.15 0.14 H 0.36 0.36 0.24 0.37 0.33 0.29 0.37 0.33 0.28 I 0.58 0.39 0.41 0.35 0.32 0.23 0.37 0.33 0.24 O v e r a l l M e a n 0.46 0.43 0.39 0.28 0.24 0.24 0.29 0.25 0.25 A 0.38 0.98 0.50 0.57 0.46 0.39 0.57 0.50 0.40 B 0.39 0.49 0.66 0.31 0.28 0.39 0.33 0.31 0.42 C 0.42 0.64 0.60 0.40 0.33 0.40 0.40 0.38 0.44 D 0.51 0.54 0.61 0.38 0.34 0.40 0.41 0.38 0.44 30.0 + E 0.65 0.57 0.60 0.53 0.31 0.42 0.55 0.35 0.44 F 0.70 0.41 0.90 0.36 0.24 0.41 0.44 0.27 0.49 G 0.61 0.32 0.79 0.51 0.20 0.35 0.52 0.20 0.38 H 0.67 0.41 0.55 0.55 0.41 0.55 0.56 I 0.82 0.71 0.71 0.52 0.42 0.59 0.57 0.47 0.60 O v e r a l l M e a n 0.58 0.54 0.69 0.42 0.31 0.41 0.45 0.34 0.45 Chapter 5. Results 1.2 1 8 0 8 0.6 + 2 10 (i) Dipterocarp species X X X X X X JOT" xx X $ > 20 30 40 Cutting intensity (%) 50 60 0.4 (ii) Non-dipterocarp species 10 20 30 40 Cutting intensity (%) 50 60 0.4 _ 0.3 + < Q. Q 0.1 (iii) All species 10 20 30 40 Cutting intensity (%) 50 60 Figure 5.30: Relationship between mean periodic annual diameter increment and cutting intensity by major species group (1974-1988). Chapter 5. Results 94 5.3.5 Mortality 5.3.5.1 By Species Group Overall, the non-dipterocarp MISC species suffered the highest mortality rates over the 14 year period for both dbh limits under study (Tables 5.22). The mean annual mortality rates of trees 5 cm and 30 cm dbh and larger for the MISC species were 4.48 % and 5.65 % respectively. Within the dipterocarps, M E R species appeared to have higher mortality rates compared to N M E R species for both diameter limits. Details of mean annual percent mortality by dbh limits are given in Tables F.56 and 57 of Appendix F. The overall mean annual percent mortality for the non-dipterocarps (5 cm dbh and larger) was 2.53 % compared to 2.36 % for the dipterocarps. Results of A N O V A did not indicate any significant difference in mortality rate between these two species groups (p=0.8371). 5.3.5.2 Over time Time elapsed since the logging appeared to have a marked effect on the mortality rates of trees. The mortality of trees was observed to decrease with time (Table 5.23). The first five years immediately after felling (1974 to 1979) recorded the highest mean annual mortality rates for all species groups. These mortality rates decreased and appeared to stabilize in the subsequent growth periods. By the second growth period (1979 to 1984), all species groups except the non-dipterocarps MISC had mean annual mortality rates of less than 2 %. Details of mean annual percent mortality by growth periods and species groups are given in Tables F.58 to 60. Chapter 5. Results 95 Table 5.22: Mean annual percent mortality by treatment, species group and dbh limit (1974-1988). D i a m e t e r T r e a t - D i p t e r o c a r p N o n - d i p t e r o c a r p A l l L i m i t ( c m ) ment M E R N M E R T o t a l L H W M H W H H W M I S C T o t a l Species A 4.83 3.33 4.03 2.88 2.43 2.26 5.49 3.09 3.10 B 2.82 4.19 2.65 3.09 2.37 4.27 4.96 2.94 2.90 C 1.34 3.90 2.18 2.51 3.15 1.49 5.38 2.75 2.71 D 0.95 3.16 1.89 2.54 1.85 2.64 2.68 2.17 2.12 5.0 + E 4.20 1.36 3.01 3.19 2.09 3.12 8.60 3.38 3.33 F 2.30 1.43 1.92 1.67 1.27 1.54 2.77 1.67 1.68 G 1.34 1.38 1.36 1.98 1.51 0.95 1.55 1.60 1.58 H 2.52 0.51 1.61 3.26 3.71 0.00 6.82 3.50 3.33 I 3.02 0.48 2.09 2.67 2.27 1.25 9.75 3.53 3.43 O v e r a l l M e a n 2.58 2.05 2.36 2.44 2.13 1.98 4.48 2.53 2.50 A 7.14 3.57 6.35 4.20 4.48 4.04 6.55 4.45 4.53 B 2.38 1.19 1.96 4.21 2.18 2.85 5.35 3.03 2.88 C 2.49 5.95 3.48 3.57 3.32 1.19 3.81 3.03 3.08 D 1.43 0.00 1.07 1.96 2.35 0.89 3.57 2.32 2.10 30.0 + E 2.51 0.59 2.51 3.66 2.43 0.68 5.94 3.01 2.97 F 2.99 1.43 2.46 1.98 1.73 0.74 0.00 1.51 1.70 G 3.56 3.56 3.56 2.55 2.79 2.85 10.68 3.08 3.13 H • 0.00 8.94 0.00 5.11 5.11 I 7.14 2.38 5.10 1.78 2.78 0.00 5.71 2.58 2.99 O v e r a l l M e a n 3.36 2.67 2.75 2.96 2.72 1.34 5.65 2.75 2.73 Chapter 5. Results 96 Table 5.23: Mean annual percent mortality of trees 5 cm dbh and larger over three successive growth periods by treatment and species group. G r o w t h T r e a t - D i p t e r o c a r p N o n - d i p t e r o c a r p A l l p e r i o d ment M E R N M E R T o t a l L H W M H W H H W M I S C T o t a l Species A 9.83 6.33 8.08 5.37 4.69 5.87 7.09 5.25 5.37 B 3.99 8.40 4.60 5.55 4.40 8.32 7.63 5.11 5.03 C 2.20 9.18 3.23 2.75 4.21 2.29 5.45 3.27 3.27 D 1.97 1.27 1.61 3.87 3.20 5.63 3.12 3.51 3.38 74-79 E 7.10 2.54 5.77 4.52 3.42 4.51 6.30 4.24 4.31 F 3.82 2.33 3.50 2.53 1.89 2.18 5.14 2.65 2.69 G 3.75 1.29 2.54 2.37 1.51 0.88 1.44 1.69 1.75 H 7.06 0.00 3.87 5.89 7.57 0.00 10.00 6.58 6.25 I 6.92 0.00 4.39 2.81 4.02 2.50 6.59 3.89 3.93 O v e r a l l M e a n 4.39 2.84 3.82 3.56 3.46 3.29 5.61 3.77 3.75 A 3.48 2.71 4.04 0.82 1.02 0.00 4.63 1.76 1.80 B 3.64 6.67 2.43 2.22 1.72 2.43 5.05 2.15 2.21 C 0.00 0.67 0.34 1.87 2.40 1.58 4.17 2.07 1.95 D 0.73 5.24 3.20 1.86 1.20 0.48 1.86 1.40 1.47 79-84 E 2.44 0.00 0.80 2.28 1.79 2.26 8.94 3.28 3.09 F 2.68 1.67 2.06 1.42 1.03 1.63 1.77 1.32 1.37 G 0.00 2.67 1.43 1.41 1.35 0.31 0.87 1.20 1.21 H 0.00 1.43 0.80 1.27 0.64 0.00 3.28 1.06 1.04 I 0.00 0.00 0.00 0.69 0.66 0.29 5.64 1.57 1.48 O v e r a l l M e a n 1.91 1.84 1.82 1.57 1.44 1.25 4.14 1.80 1.78 A 0.64 0.00 0.19 1.64 1.43 0.55 3.89 1.94 1.84 B 0.00 0.00 0.00 0.85 1.07 0.90 5.66 1.35 1.25 C 1.56 1.15 2.08 2.95 2.47 0.18 4.63 2.72 2.66 D 0.00 1.28 0.46 1.50 1.09 1.24 2.61 1.39 1.30 84-88 E 2.48 1.07 1.92 2.17 0.92 1.52 6.86 2.16 2.15 F 0.00 0.00 0.00 1.15 0.92 0.80 2.16 1.14 1.07 G 0.00 0.00 0.00 2.31 1.89 1.84 2.84 2.13 1.99 H 0.00 0.00 0.00 2.17 2.78 0.00 9.09 2.54 2.40 I 2.77 0.93 1.67 2.39 1.82 0.35 9.83 3.17 3.08 O v e r a l l M e a n 1.38 0.78 1.14 1.78 1.44 1.03 4.47 1.86 1.80 Chapter 5. Results 97 5.3.5.3 Relationship with logging damage and cutting intensity The overall mean total mortality of trees appeared to increase with increasing severity of logging damage and dbh limits (Table 5.24). Over the period from 1974 to 1988, the overall mean mortality of trees 5 cm dbh and larger with severe logging damage was 43.67 %, compared with 22.23 % with moderate logging damage and 18.91 % with no logging damage. These mortality rates increased to 55.76 %, 32.62 % and 24.95 % for trees 30 cm dbh and larger with severe, moderate and no logging damage classes, respectively. Also, the total mean mortality of trees with logging damage increased with increasing cutting intensity. The mean mortality of trees 5 cm dbh and larger with overall logging damage increased from 27.09 % in the <30 % to 37.78 % and 40.98 % in the 30 to 40 % and >40 % cutting intensity classes, respectively with an overall mean mortality rate of 35.85 %. This was also confirmed by the results of simple linear regressions performed to test for relationships between percent mortality as the dependent variable and percent cutting intensity as the independent variable of all trees 5 cm dbh and larger (Figure 5.31). Results of the regression analyses indicated significant positive linear relationships for the non-dipterocarps (p=0.0003, i?2=0.5032 RMSE=0.62753, n=21) and all species combined (p=0.0004, i?2=0.4877 RMSE=0.62393, n=21). However, no significant relationship was detected for the dipterocarps (p=0.0506, i?2=0.1865 RMSE=0.93519, n=21). It was also found that mortality of trees was highest during the initial first few years immediately after felling. Of the total number of trees with overall logging damage that died over the 14 year period, more than 70 % of them died within the first five years (1974 - 1988) after felling. The mean total mortality of trees 5 cm dbh and larger 5 years after felling was 25.04 % compared to 35.85 % 14 years after felling (Table 5.24). Chapter 5. Results 98 Table 5.24: Mean mortality of trees by logging damage class, cutting intensity, dbh limit and growth period. D i a m e t e r L i m i t ( c m ) 5.0 + 30.0 + P e r i o d M e a n Variable N o M o d Severe T o t a l N o M o d Severe T o t a l C u t Int. D m g D m g D m g D m g D m g D m g D m g D m g (%) (1) (2) (3) (2 + 3) (1) (2) (3) (2 + 3) 15.73 S t e m s / h a 122.99 24.11 72.33 96.44 11.61 4.47 8.04 12.51 ( < 3 0 ) % 16.47 17.42 33.23 27.09 19.70 28.58 43.37 36.62 34.88 S t e m s / h a 93.44 19.38 117.82 137.20 10.31 5.00 14.38 19.38 1974-1988 (30 - 40) % 18.48 17.97 46.15 37.78 28.20 37.20 60.54 52.11 49.17 S t e m s / h a 85.94 41.50 121.36 162.86 7.12 4.34 11.81 16.15 ( > 4 0 ) % 23.01 27.32 49.43 40.98 33.07 33.79 61.80 52.24 O v e r a l l S t e m s / h a 100.08 30.43 104.17 134.60 9.38 4.77 11.16 15.93 M e a n % 18.91 22.23 43.67 35.85 24.95 32.62 55.76 46.94 15.73 S t e m s / h a 59.15 11.39 48.22 59.61 5.58 2.23 6.48 8.81 ( < 30) % 7.92 8.23 22.16 16.74 9.47 14.29 34.94 25.50 34.88 S t e m s / h a 50.94 8.75 87.82 96.57 7.19 1.88 12.19 14.07 1974-1979 (30 - 40) % 10.07 8.12 34.40 26.59 19.66 13.96 51.32 37.83 49.17 S t e m s / h a 55.56 25.70 94.10 119.80 4.69 3.32 10.07 13.39 ( > 4 0 ) % 14.88 16.92 38.33 37.74 21.77 22.95 52.71 41.91 O v e r a l l S t e m s / h a 55.66 16.89 77.31 94.20 5.58 2.58 9.38 11.96 M e a n % 10.51 12.34 32.41 25.04 14.85 17.64 46.84 34.86 Chapter 5. Results (ii) Non-dipterocarp species ol 1— 1 1 1 1 1 0 10 20 30 40 50 60 Cutting intensity (%) Figure 5.31: Relationship between percent mortality and percent cutting intensity major species group (1974-1988). Chapter 5. Results 100 5 .3 .6 Ingrowth Ingrowth of trees varied among treatments and differed from species to species (Table 5.25). The ingrowth of trees of all species into the 5 cm dbh limit over the 14 year period varied from 1.00 % in Treatment G to 6.01 % in Treatment I, with an overall mean annual percent ingrowth of 3.30 %. The ingrowth of trees into the 30 cm dbh limit varied from 1.59 % in Treatment F to 20.41 % in Treatment H , with an overall mean annual percent ingrowth of 3.35 %. Details of mean annual percent ingrowth by dbh limit and species group are given in Tables G.61 and 62 of Appendix G. In terms of species, the highest mean annual percent ingrowth of trees into the 5 cm dbh limit was recorded by the non-dipterocarp H H W (4.71 %), followed by L H W (4.29 %), dipterocarp N M E R (3.91 %), dipterocarp M E R (3.74 %), MISC (3.07 %) and M H W (2.34 %). Overall, dipterocarps appeared to have a higher mean annual percent ingrowth (3.78 %) compared to the non-dipterocarps (3.29 %) over the 14 year period. The non-dipterocarp L H W had the highest mean annual ingrowth of 3.90 % of trees into the 30 cm dbh limit, followed by dipterocarp M E R (3.38 %), dipterocarp N M E R (3.21 %), M H W (3.20 %), MISC (3.14 %) and H H W (2.50 %). There was not much difference in the ingrowth of trees into the 30 cm dbh limit between dipterocarps (3.34 %) and non-dipterocarps (3.35 %). Simple linear regressions were performed with the percent ingrowth as the depen-dent variable and the percent cutting intensity as the independent variable for all trees 5 cm dbh and larger over the period 1974 to 1988 (Figure 5.32). Results of the anal-yses indicated significant positive linear relationships between the two variables for all species (p=0.0014, #2=0.4243, RMSE=1.59178, n=21), for the dipterocarps (p=0.0261, E2=0.2339, RMSE-2.84525, n=21), and the non-dipterocarps (p=0.0020, i?2=0.4015, RMSE=1.67748, n=21). Chapter 5. Results 101 Table 5.25: Mean annual percent ingrowth of trees by treatment, species group and dbh limit (1974-1988). D i a m e t e r T r e a t - D i p t e r o c a r p N o n - d i p t e r o c a r p A l l L i m i t ( c m ) ment M E R N M E R T o t a l L H W M H W H H W M I S C T o t a l Species A 3.49 8.05 5.03 6.59 3.18 6.58 3.65 4.25 4.27 B 4.05 8.48 4.16 7.62 2.72 12.37 2.72 4.61 4.59 C 15.50 15.33 7.44 3.21 4.08 3.64 6.03 3.39 3.58 D 9.50 3.92 5.42 4.54 2.10 3.17 3.91 3.21 3.26 5.0 + E 4.69 4.72 4.34 5.65 2.45 10.10 7.48 4.81 4.79 F 1.42 0.34 1.06 1.69 0.88 1.45 0.45 1.08 1.07 G 2.23 0.23 1.25 1.49 0.91 0.53 0.44 0.98 1.00 H 5.04 0.00 2.76 7.76 5.65 16.29 4.76 6.73 6.42 I 1.37 5.71 2.96 8.15 3.07 8.93 8.91 6.24 6.01 O v e r a l l M e a n 3.74 3.91 3.78 4.29 2.34 4.71 3.07 3.29 3.30 A 1.19 4.78 9.52 8.25 4.85 3.56 5.96 4.95 5.16 B 4.36 2.38 3.75 5.70 4.88 2.73 2.37 4.47 4.27 C 5.13 0.60 5.23 4.90 2.27 3.25 2.22 3.14 3.42 D 2.39 4.75 3.46 6.75 3.07 4.17 5.36 4.22 4.18 30.0 + E 3.25 5.36 4.03 2.62 3.28 2.56 0.79 2.75 2.87 F 0.50 2.38 0.97 2.00 1.85 1.23 4.76 1.84 1.59 G 3.56 7.14 5.35 1.53 1.86 0.00 7.12 1.79 2.09 H 0.00 24.99 19.63 0.00 0.00 18.37 20.41 I 5.35 0.00 3.06 5.35 3.97 1.43 1.43 3.57 3.49 O v e r a l l M e a n 3.38 3.21 3.34 3.90 3.20 2.50 3.14 3.35 3.35 Chapter 5. Results 102 (i) Dipterocarp species 12 -I x 10 • X 8 - x x x 6 • 4 - X II "1" ~~ X 2 -0 -v -! I — X * r — X XX x X —1 1 X—h-> 0 10 20 30 40 50 60 Cutting intensity (%) (ii) Non-dipterocarp species 0 10 20 30 40 50 60 Cutting intensity (%) (iii) All species 0 10 20 30 40 50 60 Cutting intensity (%) Figure 5.32: Relationship between percent ingrowth and percent cutting intensity by major species group (1974-1988). Chapter 6 Discussions of Results 6.1 Prior to Harvest Prior to harvest, the stem frequency distribution by dbh class of the hill dipterocarp forest was similar for the replicated treatments and exhibited a reverse J-shaped stand structure. On average, trees having dbh less than 30 cm accounted for more than 88 % of the total stocking by stems. However, the distributions of basal area and gross volume by dbh class of the replicated treatments were more variable. Trees of intermediate size (15-60 cm dbh) accounted for more than 58 % of the total basal area while trees having dbh measures larger than 30 cm accounted for more than 89 % of the total gross volume before harvest. In general, higher variability in terms of C .V. values was observed for trees at the higher dbh classes. This could be due to the relatively smaller number of trees present in the higher dbh classes. The predominance of the non-dipterocarp species before felling was evident in the study area. They dominated the lower dbh classes and accounted for 92.33 % in terms of number of stems and 75.57 % in terms of basal area (for all trees 5 cm dbh and larger), and 64.92 % in terms of gross volume of all trees 15 cm dbh and larger. Within the dipterocarps, the N M E R species were found to be more dominant in terms of basal area and gross volume while the M H W species dominated the non-dipterocarps, followed by the L H W and H H W species. Borhan (1985) also observed similar species compositions for a hill dipterocarp forest located in the Labis Forest Reserve, Johor. He found that 103 Chapter 6. Discussions of Results 104 the non-dipterocarps comprised 87.43 % in terms of number of stems, 65.94 % in terms of basal area and 60.90 % in terms of gross volume per hectare for all trees 10 cm dbh and larger before felling. This pattern of species distribution warrants special attention and is further discussed under Implications for Forest Management, presented later in this chapter. Due to the heterogeneity of the hill dipterocarp forest prior to harvest, the whole study area was stratified into three stocking classes (Superior, Good and Moderate) based on the ranked gross volume of all trees 30 cm dbh and larger by dbh class and species groups. While the stratification was reasonable for gross volume (Superior: 169.94 to 298.67 m 3 /ha, Good: 155.35 to 258.08 m 3 /ha, Moderate: 160.83 to 207.77 m3/ha), it was not suitable for stems and basal area (5 cm dbh and larger). There is an inherent variability in the terrain and stems/ha of the hill forests, with the richest stands being almost invariably found on the ridge tops, compared to hill sides and valley bottoms (Wyatt-Smith 1960, Vincent 1961d, Burgess 1968). These natural differences in total stems/ha would be a useful basis for blocking in future studies. Prior to treatment, there was no evidence of differences in stems and basal area/ha (for all trees 5 cm dbh and larger), or gross volume/ha (all trees 15 cm dbh and larger) among the replicated treatments. There was also no evidence of differences in species composition in terms of stems, basal area and gross volume among the replicated treat-ments. The homogeneity of stand structure and species composition prior to harvest is important for ensuring that any differences in actual growth detected in later stage analyses, is attributed to treatments, rather than as a result of the initial differences. Chapter 6. Discussions of Results 105 6.2 During Harvest The various treatment prescriptions (A to I) were not fully implemented during forest harvesting. This was clearly indicated by the number of stems above the prescribed cutting limits that were left uncut in the plots (3.13 stems/ha (2 trees) to 71.88 stems/ha (46 trees/plot)). It was most unfortunate that these trees were left uncut as their presence affects the growth of the residual trees due to competition. This also highlighted the difficulty of fully implementing selective cutting studies in the hill dipterocarp forest. Depending on the initial basal area and the size class distribution of the stand, the use of lower dbh cutting limits in defining treatments resulted in vastly different basal areas being removed from the plots. In this study, the basal area removed ranged from 0.16 to 22.44 m 2 /ha. This resulted in a wide range of residual basal areas left, ranging from 11.71 to 35.62 m 2 /ha. Since residual basal area is one of the most obvious controllable factors affecting the development of a stand, future treatments should consider specifying the basal area per unit area to be retained. This will have the added advantage of allowing the treatments to be repeated more precisely. The use of lower dbh cutting limits as treatments altered the reversed J-shaped stand structure by removing most trees above the cutting limit. Murphy and Shelton (1994) working with loblolly pine indicated that stand structure is an important adjunct of uneven-aged regulation, but that knowledge about its effect on growth is fragmentary. According to Adams (1976), determination of the best economic stocking in uneven-aged forest management using selection cutting requires information on the optimal dbh distribution in relation to its stand density. Distributions are optimal when they yield maximum value growth over the cutting cycle for a given stocking level. This implies that selection cutting should harvest by dbh class in order to maintain stand structures. The BDq method is a robust structural regulation method based on a negative exponential Chapter 6. Discussions of Results 106 distribution, that has been successfully applied in the temperate hardwood and conifer forests, and could be adapted for use in tropical forests. BDq refers to the stand structure that can be uniquely determined for any combination of residual basal area (B), maximum retained diameter class (D), and negative exponential constant between diameter class (q). In the United States, the BDq method has been applied to Allegheny hardwoods (Marquis, 1978), northern hardwoods (Leak and Filip 1977, Hansen and Nyland 1987), western conifers (Alexander and Edminster 1977), and loblolly-shortleaf pine (Farrar 1980, Farrar and Murphy 1988). Though this specific aspect was beyond the scope of this study, it would be desirable to specify a dbh distribution in relation to stand density for better uneven-aged stand management (Moser, 1976). In general, the various treatments resulted in the removal of a higher proportion of the dipterocarp species, which were also the more valuable species. The proportions of dipterocarp trees removed over all treatments combined were 19.12 %, 66.35 % and 76.90 %, compared to 2.92 %, 24.05 % and 37.73 % for the non-dipterocarps in terms of stems, basal area and gross volume/ha, respectively. This is attributed to the concentration of the dipterocarp species in the higher dbh classes which were subsequently removed during the felling operations. However, the non-dipterocarps formed a higher proportion of the total trees removed in terms of stems and basal area, and about the same proportion in terms of gross volume. This could be attributed to the overall higher stocking of the non-dipterocarp species in the forest stands. 6.3 After Harvest A general decline in stems per hectare was observed during the first three years after harvest, due to mortality losses immediately after harvest. The overall mean mortality of trees 5 cm dbh and larger was highest (3.75 %) during the first five years after harvest Chapter 6. Discussions of Results 107 (1974-1979). The high mortality rate in this period was related to logging damage; more than 70 % of trees 5 cm dbh and larger with logging damage (moderate and severe) died during this period. Despite the initial decrease, all replicated treatments except F showed an overall increase in the mean number of stems per hectare (5.0 cm dbh and larger) 14 years after harvest, relative to the mean number of stems immediately after harvest. In fact, all replicated treatments except F even exceeded their precut number of stems per hectare. This could only happen if there was sufficient ingrowth of trees to compensate for losses due to mortality over the 14 year period, as indicated by the overall ingrowth of trees into the 5 cm dbh limit (3.30 %) being higher than that of mortality (2.50 %). On the other hand, Treatment F recorded a higher mean mortality rate (1.68 %) than ingrowth (1.07 %) of all trees 5 cm dbh and larger over the same period, resulting in an overall decrease in stems/ha. These results indicate that the harvesting methods promote and enhance forest re-generation. This was confirmed by the significant positive linear relationship between percent stem change and percent cutting intensities of all trees 5 cm dbh and larger over the 14 year period (within cutting intensity range of 0 to 60 % basal area removal). In their studies of the population dynamics of tree seedlings in a mixed dipterocarp rain forest before and after logging, Kuusipalo et al. (1996) also found that seedling density of logged-over stands was markedly higher than that of the unlogged forest. However, a closer look at the increase in stems revealed that the bulk of the in-crease (about 88 % of trees 5 cm dbh and larger) were non-dipterocarp species. This phenomenon could be a result of the higher abundance of the non-dipterocarps in the residual stand, providing seed trees, or the failure of the dipterocarps to regenerate in openings provided by partial cutting. Results of this study seemed to indicate that the non-dipterocarps had responded better to the openings created. This was also confirmed by the significant positive relationship between percent stem change and percent cutting Chapter 6. Discussions of Results 108 intensity for the non-dipterocarps. The relationship was not significant for the diptero-carps. According to Tuomela et al. (1996), the size of forest gaps or openings (which could be a result of harvesting) had a negative effect on the height growth of dipterocarp species. They recommended a gap size of less than 500 m 2 to provide optimal light conditions for the early growth of dipterocarps. They reasoned that larger gaps would stimulate the invasion and growth of light demanding pioneer species which may also partially suppress the dipterocarps. Other studies have also shown that dipterocarps grow best in about 50 to 70 % of full sunlight (Nicholson, 1960) and need partial shade in the early stages of development (Revilla, 1976). However, these results could not be verified by this study, as the light conditions of the plots were not monitored under this study. Further research is definitely needed to study the regeneration strategy and behaviour of the dipterocarp species managed under the SMS. Similar to stems, a net loss in basal area can be expected to occur in the first two years after felling because of mortality losses. Due to the losses that occurred, the overall basal area growth over the 14 year period was low, averaging 0.25 m 2/ha/year and 0.09 m 2/ha/year for trees 5 cm dbh and 30 cm dbh and larger, respectively. A l l treatments recorded a net increase in basal area 14 years after harvest. It was interesting to note that Treatment F, which did not attain its precut stems level, managed to attain its precut basal area 14 years after harvest. This could be due to the fact that Treatment F had the least basal area removal (6.85 %) and the high residual basal area retained did not encourage forest regeneration. Of the replicated treatments, Treatment D resulted in the best basal area growth both for trees 5 cm dbh and larger (0.41 m 2/ha/year) and for trees 30 cm dbh and larger (0.23 m 2/ha/year). Results of repeated measures M A N O V A showed that there were no significant treat-ments x time interactions for the basal area growth of all trees 5 cm and 30 cm dbh Chapter 6. Discussions of Results 109 and larger. However, there were significant differences in basal area among treatments. Based on Figures 5.21 & 5.23, Treatment F, which has the least basal area removal, appeared to be different from Treatments A to E. There was also a significant non-linear time trend indicating a general increase in mean basal area over time. The non-linear time trend could be attributed to the initial decline in basal area due to mortality losses and a gradual increase thereafter. A reduction in gross volume per hectare also occurred in the first three years after felling due to mortality losses. The overall gross volume growth of all species over the 14 year period were 0.94 and 0.80 m 3/ha/year for trees 15 cm dbh and 30 cm dbh and larger, respectively. These figures were much lower than the published figures of 2.20 m 3/ha/year for all marketable species and 1.75 m 3/ha/year for all species having diameter greater than 30 cm (FAO, 1978), and 2.15 m 3/ha/year for all trees 10 cm dbh and larger over a 4 year growth period (Borhan, 1985). However, some of the plots in the study area did achieve growth rates exceeding 2.00 m 3/ha/year, with the highest growth rate of 3.41 m 3/ha/year being recorded for plot 17. Of the replicated treatments, Treatment D was found to have best mean volume growth of 2.00 m 3/ha/year and 1.78 m 3/ha/year for trees 15 cm and 30 cm dbh and larger, respectively. These rates are comparable to that assumed under the SMS (2.0 to 2.5 m 3/ha/year) (Thang 1987, Apanah and Weinland 1990). The general low growth rates of the study area could be attributed to poor site conditions and the lack of post-harvest silvicultural treatments. In terms of pre-harvest gross volume, this study area was located on the poorest site when compared to the other two growth and yield study areas located at the Tekam Forest Reserve, Pahang and the Labis Forest Reserve, Johor. The total gross volume of this study area before felling varied from 155.54 m 3 /ha to 298.62 m 3 /ha as compared to 223.42 m 3 /ha to 677.42 m 3 /ha in the Tekam Forest Reserve (Watts, 1990a) and 186.70 m 3 /ha to 720.1 m 3 /ha in Chapter 6. Discussions of Results 110 the Labis Forest Reserve (Borhan, 1985). Results of repeated measures M A N O V A indicated there was no evidence of different growth trends among the treatments due to non-significant treatment x time interactions. However, there was evidence of differences in gross volume among treatments. Treatment F appeared to be somewhat different from Treatments A to E as shown in Figures 5.25 & 5.27. There was also a significant non-linear time trend indicating that the forest is growing in volume over time. Again, the non-linear trend could be due to the initial mortality losses, resulting in a decline in gross volume, and a gradual increase thereafter. Although the residual stands showed some response to release after felling, the overall mean DPAIs for all species groups, dbh classes/limits and treatments under studyWer the 14 year period were generally low. The overall mean DPAI for all species combined over the 14 year period was only 0.25 cm/year for trees 5 cm dbh and larger and increased to 0.35 and 0.39 cm/year for trees 15 cm dbh and 30 cm dbh and larger, respectively. By species groups, the overall mean DPAIs of all trees 30 cm dbh and larger varied among species and treatments, from 0.34 cm/year (HHW) to 0.56 cm/year ( M E R & N M E R ) , and from 0.33 cm/year (Treatment B) to 0.51 cm/year (Treatment I). In some of the plots, the M E R species did achieve a growth rate of over 1 cm/year. However, the overall mean DPAI of 0.39 cm/year for all trees 30 cm dbh and larger is considerably lower than the rate of 0.8 to 1.0 cm/year assumed under the SMS. This overall rate is also lower than the DPAI of 0.74 cm/year for all trees 30 cm dbh and larger over a 4 year period observed by Borhan (1985) for the hill dipterocarp forest in Johor. Though the DPAIs obtained were generally low, they are within the range (0.11 to 1.30 cm/year) reported for the humid mixed tropical forests (Rai 1989, Silva et al. 1995). Results of this study also showed that dbh growth rates fluctuate over time. In fact, studies by Tang (1976) and Silva et al. (1995) showed that the rates actually decrease over time. The generally low DPAIs for all species could be attributed to the high proportion Chapter 6. Discussions of Results 111 of the non-dipterocarps in the residual stands which were observed to grow significantly slower than the dipterocarps. The DPAIs for the non-dipterocarps were 0.25, 0.32 and 0.37 cm/year compared to 0.43, 0.60 and 0.56 cm/year for the dipterocarps over the dbh limits 5.0 +, 15.0 + and 30.0 + cm, respectively. Within the dipterocarps, both M E R and N M E R species appeared to grow at similar rates, while the growth rates for the non-dipterocarp species (all trees 30 cm dbh and larger), in general, appeared to follow the density of the wood, desending in order from the L H W to M H W and H H W species. The overall low DPAIs could also be attributed to no silvicultural treatments following harvest. Under current practice, silvicultural treatments in the form of climber cutting and poison-girdling of defective trees are carried out five years after harvesting (Thang, 1987). Studies conducted elsewhere have shown that growth rates could be distinctly increased by silvicultural treatments prescribed after felling (Alder 1983, Silva et al. 1995). Stand treatment by liberation or uniform systems may increase tree increments by 25 to 50 %, but the effect diminishes with time, due to renewed competition (Alder, 1983). As was the case for stems, there was no significant relationship between the DPAI of the dipterocarps and cutting intensity. The DPAI of the non-dipterocarps, on the other hand, was significantly related to the cutting intensity. Again, indepth studies are needed to study the regenerating strategy of the dipterocarp species. 6.4 Implications for Forest Management The general variability in the stand structure and stocking of the hill dipterocarp forest before harvest suggests that a pre-felling forest inventory is a prerequisite for the de-termination of an optimum cutting limit under the SMS. It also emphasizes the need for stratifying the forest into more homogeneous units for any experimental studies that Chapter 6. Discussions of Results 112 require replication of treatments. The current method of applying a lower diameter cutting limit is easy to implement and enforce. However, it could drastically alter the stand structures. To maintain the present uneven-aged stand structure, future manage-ment systems should consider specifying a residual dbh distribution in relation to stand density as recommended by Moser (1976). The pattern of species distribution (dominated by non-dipterocarp species) warrants special attention, particularly in the formulation of a suitable silvicultural and manage-ment system for regenerating the hill dipterocarp forest (Tang and Razali, 1980). As the tendency of any commercial logging activity is to remove the dipterocarp species, special regulations must be set to ensure that the species composition be maintained. This is vital in ensuring the sustained economic production of these forests, as well as to avoid their eventual genetic degradation. The current practice of the Forestry Departments in Peninsular Malaysia to conduct pre-felling forest inventory for all forested area due to be harvested, and to prescribe an optimum cutting limit that takes into consideration the species composition of the stand both before and after felling under the SMS, is a positive step in this direction. Under the SMS, species composition is maintained by prescribing a cut that will ensure the percentage of the dipterocarps (above 30 cm dbh) remain unchanged after harvesting (Anon. 1985b). However, pragmatic measures and steps, as well as audits are needed to ensure that such prescriptions are faithfully carried out. Diameter growth rates have a significant impact on forest management, especially in the estimation of the cutting cycle, which is diameter based. Under the SMS, the cutting cycle of 25 to 30 years is based on the assumption of a consistent diameter growth of 0.8 to 1.0 cm/year for all trees 30 cm dbh and larger over the period. In this study, it was found the diameter growth of all trees 30 cm dbh and larger was not consistent over time and averaged only 0.39 cm/year, which is about half the rate assumed under the Chapter 6. Discussions of Results 113 SMS. Based on the results of this study and assuming the same growth trend continues, anticipating a second cut 25 to 30 years after the initial harvest for this study area may be overly optimistic. However, results from other growth and yield study areas should be obtained before concluding that the rotation cycle under the SMS should be lengthened. One weakness of this experiment was the exclusion of post-harvest silvicultural treat-ment on the residual stand. As studies have shown that silvicultural treatments could enhance forest growth, they should be incorporated in future studies. This would also give more realistic results as silvicultural treatments in the forms of climber cutting and poison-girdling of defective trees are routinely carried out under the SMS. In this study, logging damage data were not fully analyzed; they were only used to study the relationship between tree mortality and logging damage. Results of this study indicated that 35.85 % of all trees 5 cm dbh and larger with logging damage died over the 14 year period. Even though logging damage to the residual stand is inevitable and can never be completely avoided during felling operations, it must be kept to a minimum if the forest is to retain its productive potential. Studies have shown that well planned and supervised harvesting operations employing tree marking for directional felling could reduce damage to residual stand by 33 % and the forest area temporarily destroyed by over 40 % (Marn and Jonkers 1980, Liew and Ong 1986). Results of all repeated measures M A N O V A did not indicate any significant interac-tions between the replicated treatments and time, meaning the treatments applied had no effect on the rate of stand growth. Despite the non-significant results, it is of interest to note that Treatment D (which is closest to the SMS in terms of cutting limit pre-scriptions) resulted in the overall best growth rates of all trees 30 cm dbh and larger in terms of basal area (0.23m2/ha/year) and gross volume (1.78m3/ha/year), and moderate growth rates in terms of stems (1.52 stems/ha/year) and dbh (0.37 cm/year). Chapter 7 Conclusions and Recommendations The study has provided useful information on the stand structure, species composition, as well as the growth response and development of the hill dipterocarp forest 14 years after felling. However, because of the great variability in the composition, structure and behaviour of the hill dipterocarp forests in the country, this information cannot be considered to have general applicability. From the results of this study, the following conclusions were drawn: 1. The stem frequency distribution of the hill dipterocarp forest prior to harvest ex-hibited a reverse J-shaped stand structure, with general higher variability (C.V.) being observed for trees at the higher dbh classes. 2. The non-dipterocarps were the dominant species in the hill dipterocarp forest, ac-counting for 92.33 % (stems) and 75.57 % (basal area) of all trees 5 cm dbh and larger, and 64.92 % (gross volume) of all trees 15 cm dbh and larger. 3. The application of treatments based on different lower dbh limit prescriptions tend to remove a higher proportion of the dipterocarp species, as they were concentrated at the higher dbh classes. Pragmatic measures are needed to maintain the forest species composition of the hill dipterocarp forest to ensure its sustained economic productivity, as well as to avoid an eventual genetic degradation of the forest. 4. Forest harvesting, in general, enhances forest regeneration. This was indicated by all replicated treatments except F, in that the number of stems 5 cm dbh and larger 114 Chapter 7. Conclusions and Recommendations 115 14 years after harvest exceeded the number of stems prior to harvest. 5. The overall DPAIs of all trees 30 cm dbh and larger were relatively low when compared to the rates assumed under the SMS, and are not encouraging. Based on these growth rates, envisaging a second cut in 25 to 30 years for this study area would be overly optimistic. 6. The DPAIs of the dipterocarps were significantly higher than that of the non-dipterocarps. However, their contribution to overall forest growth was small due to their lower stocking in the residual stand. 7. The overall low growth rates of the trees could be the result of inherent poorer site condition of the study circci, cis well as the lack of silvicultural treatment after harvest. Some forms of silvicultural treatment may be required to release the residual trees from competition and boost growth. 8. The overall mean mortality of all trees 30 cm dbh and larger over the 14 year period was higher than that assumed under the SMS. Tree mortality was related to logging damage and was highest during the first five years after harvest. 9. The overall mean ingrowth of trees into the 30 cm dbh limit was higher than that expected under the SMS, and surpassed the mortaliy rate observed over the same period. 10. Results of all repeated measures M A N O V A indicated that there was no evidence of different growth trends among the replicated treatments due to no significant treatment x time interactions. Hence, the difficulty, at this juncture, to pin-point or recommend any treatment(s) best suited for forest management purposes. However, Treatment D (with cutting prescriptions closest to that of the SMS) resulted in Chapter 7. Conclusions and Recommendations 116 higher growth rates in terms of basal area and gross volume and moderate growth rates in terms of DPAI and stems. Based on the results of this study and the experience acquired through the establish-ment and maintenance of the study area, the following recommendations are made for future studies: 1. The plot size of 0.64 hectare used in this study should be reviewed as experience in other tropical forests has shown that this size of plot does not absorb enough of the natural variability in stocking (Dawkins, 1958). Ideally, the plot size should be such that the plot is homogeneous, at least with respect to forest type and site productivity, and sufficiently large to provide a representative sample of the forest stand (Vanclay, 1994). Larger plots offer greater flexibility, and plots of one hectare are recommended for mixed forests (Tang 1976, Borhan 1985, Alder and Synnott, 1992). 2. The long-term objective of this research was to study the growth and development of the residual stand after harvesting. Hence, it may be more efficient to use a natural 'biologically-related' basis instead of a 'value-related' basis for blocking or stratification. The results of the present study have shown that the 'economic' stocking of the forest, while being a useful indication of the current value of the stand, often has no relationship to the residual stand after logging. It is suggested that ridge tops, hill sides and valley bottoms, which have been commonly observed to have natural differences in total stocking and basal area, would be a useful basis for blocking. However, care must be taken to ensure that misallocation of blocks to strata does not occur (Vincent, 1960). A preliminary pre-felling forest survey, as was done in this study, is an essential part of efficient blocking. Chapter 7. Conclusions and Recommendations 117 3. Total residual basal area is one of the most obvious controllable site factors affecting the development of a stand after harvesting. The specification of treatments by the use of lower diameter cutting limits resulted in a wide range of residual basal areas, ranging from 11.71 to 35.62 m 2 /ha. It is suggested that in future growth and yield experiments, the treatments should specify the basal area per unit area to be retained by dbh class based on the BDq method. This will have the important advantage of allowing the treatments to be repeated more precisely. Preferential treatment for the dipterocarps can then be included within the main specification based on the results of pre-felling forest inventory. It is also suggested that the number of treatments be reduced to three or a maximum of four and the number of replicates increased. This is because the differences between any two treatments should be reasonably large to avoid the treatment effects being masked by the general variability, and the additional replicates would improve the precision of the results obtained. 4. Damage assessment on the residual stand as a result of harvesting was not carried out fully in this study. It should be incorporated in all future growth and yield studies to monitor its effects on stand growth as well as its impact on the quality and quantity of future yields. 5. Even though information on seedlings was recorded in this study, it consisted of hand counts and could not be analyzed meaningfully due to drastic fluctuations over time. As seedling regeneration and growth are vital to sustaining forest growth, appropriate methodologies should be developed to capture this information for meaningful data analysis in the future. Chapter 7. Conclusions and Recommendations 118 6. Many studies have shown that the amount of sunlight received by the crown (crown illumination) has a significant effect on stand growth (e.g. Wyatt-Smith and Vin-cent 1962a, Silva et al. 1989, Alder and Synnott 1992, Silva et al. 1995). Silva et al. (1989) observed that trees with crowns receiving full over-head light grew three times faster than trees that receive only side light or which are completely shaded. It is suggested that crown characteristics of all trees on permanent plots be recorded based on the Dawkins (1958) system of classification (emergent, full overhead light, some overhead light, some sidelight, no direct light). This system is simple to use and was also used by the various authors mentioned above. 7. As the volume of the final crop trees depends on both the diameter and length of bole (merchantable height), it is suggested that 4 to 5 dominant trees within each permanent plot be measured for clear bole and top height. The heights of the rest of the trees within the plot should be estimated in the field based on the height of these dominant trees. Volume should be estimated for each tree based on the estimated height and aggregated to obtain the total plot volume. The current method of using a volume equation based on a simple diameter-height relationship for volume compilation should be reviewed. 8. 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Paper presented at 14th IUFRO Congress, 5 -11 August 1990, Montreal, Canada. 9pp. Appendix A Logging Damage Assessment An assessment of logging damage was made on all live trees immediately after felling based on predetermined stem (Table A.26) and crown (Table A.27) damage classes. However, due to the subjectivity of such damage assessment which was based on visual observations of the crew members and may vary from one member to another, the stem and crown damage classes were combined into three (3) broad logging damage classes, namely no damage, moderate and severe damage class (Table A.28). It was also found that many trees suffered both stem and crown damage. For example, a tree may have moderate stem damage but no crown damage, or moderate stem damage and severe crown damage etc. Hence, an overall logging damage classification based on the various combinations of stem and crown damage classes was also formulated (Table A.29). This classification was used in the assessment of mortality due to logging damage. 130 Appendix A. Logging Damage Assessment 131 Table A.26: Stem damage classes. Damage Class Tree Condition 0 No damage. 1 Pre-logging damage (e.g. hollow, knot, etc.). 2 Minor damage; one piece of bark, not more than 1 metre long, ripped off. 3 Moderate damage; two pieces of bark, not more than 1 metre long, or one piece of bark, 1 to 3 metres long, ripped off. 4 Severe damage; three pieces of bark, not more than 1 metre long, or two pieces of bark, 1 to 3 metres long, or one piece of bark, more than 3 metres long, ripped off. 5 Very severe damage; stem inclined or pushed over but still rooted. Appendix A. Logging Damage Assessment 132 Table A.27: Crown damage classes. Damage Class Tree Condition 0 No damage. 1 Minor damage; one branch of 7.5cm diameter or larger broken off. 2 Moderate damage; two branches of 7.5cm diameter or larger broken off. 3 Severe damage; three branches of 7.5cm diameter or larger broken off. 4 Very severe; almost all branches broken off. Table A.28: Combined stem and crown damage classes Logging Damage Class Stem Damage Class Crown Damage Class No damage 0 and 1 0 Moderate damage 2 and 3 1 and 2 Severe damage 4 and 5 3 and 4 Appendix A. Logging Damage Assessment 133 Table A.29: Combined overall logging damage classes Crown Damage Class Stem Damage class No Moderate Severe No No Moderate Severe Moderate Moderate Moderate Severe Severe Severe Severe Severe Appendix B Stand Structure Before Harvest 134 Appendix B. Stand Structure Before Harvest Table B.30: Stem frequency distribution (stems/ha) by dbh class before harvest. Plot No./ Treat- Diameter Class / Limit (cm) Stock" ment 5.0-14.9 15.0-29.9 30.0-44.9 45.0-59.9 60.0-74.9 75.0-89.9 90.0+ 30.0+ 5.0+ IS A 775.00 192.19 56.25 25.00 3.13 7.81 1.56 93.75 1060.94 7M A 843.75 251.56 60.94 43.75 12.50 1.56 1.56 120.31 1215.62 10G A 418.75 170.31 71.88 14.06 3.13 4.69 4.69 98.45 687.51 Mean A 679.17 204.69 63.02 27.60 6.25 4.69 2.60 104.17 988.02 8G B 581.25 200.00 67.19 21.88 12.50 1.56 3.13 106.26 887.51 15M B 312.50 146.88 59.38 17.19 6.25 1.56 6.25 90.63 550.01 16S B 375.00 257.81 110.94 25.00 7.81 4.69 3.13 151.57 784.38 Mean B 422.92 201.56 79.17 21.36 8.85 2.60 4.17 116.15 740.63 4G C 1106.25 325.00 73.44 62.50 10.94 0.00 1.56 148.44 1579.69 9M C 218.75 101.56 67.19 20.31 17.19 3.13 1.56 109.38 429.69 18S C 581.25 179.69 53.13 31.25 21.88 6.25 7.81 120.32 881.26 Mean C 635.42 202.08 64.59 38.02 16.67 3.13 3.64 126.04 963.54 2G D 768.75 304.69 78.13 20.31 4.69 1.56 1.56 106.25 1179.69 5S D 381.25 143.75 64.06 14.06 12.50 10.94 4.69 106.25 631.25 14M D 687.50 187.50 46.88 15.63 4.69 3.13 4.69 75.02 950.02 Mean D 612.50 211.98 63.02 16.67 7.29 5.21 3.65 95.83 920.31 3M E 500.00 134.38 50.00 31.25 15.63 0.00 1.56 98.44 732.82 6S E 837.50 246.88 73.44 21.88 4.69 9.38 4.69 114.08 1198.46 11G E 518.75 153.13 53.13 23.44 17.19 3.13 4.69 101.58 773.46 Mean E 618.75 178.13 58.86 25.52 12.50 4.17 3.65 104.69 901.56 12G F 675.00 134.38 48.44 29.69 10.94 12.50 4.69 106.26 915.64 13S F 543.75 182.81 82.81 37.50 6.25 6.25 6.25 139.06 865.62 17M F 1018.75 223.44 73.44 26.56 4.69 6.25 3.13 114.07 1356.26 Mean F 745.83 180.21 68.23 31.25 7.29 8.33 4.69 119.79 1045.84 21 G 1018.75 246.88 70.31 26.56 9.38 3.13 1.56 110.94 1376.57 19 H 581.25 184.38 56.25 18.75 12.50 4.69 6.25 98.44 864.07 20 I 681.25 134.38 45.31 18.75 12.50 9.38 3.13 89.07 904.70 Overall Mean S . D 6 C . V C - 639.29 239.74 37.50 195.31 59.12 30.27 64.88 15.16 23.37 25.97 11.25 43.33 10.05 5.24 52.18 4.84 3.56 73.60 3.72 1.94 52.26 109.45 18.87 17.24 944.05 289.26 30.64 "Stock ing class identified for replicated treatments only. S=superior G = g o o d M = m o d e r a t e . b S tandard Dev ia t ion Coe f f i c ien t of Var ia t ion Appendix B. Stand Structure Before Harvest Table B.31: Stem frequency distribution (percent) by dbh class before harvest. Plot No./ Treat- Diameter Class / Limit cm) stock" ment 5.0-14.9 15.0-29.9 30.0-44.9 45.0-59.9 60.0-74.9 75.0-89.9 90.0 + 30.0+ 5.0+ IS A 73.05 18.12 5.30 2.36 0.30 0.74 0.15 8.84 100.00 7M A 69.41 20.69 5.01 3.60 1.03 0.13 0.13 9.90 100.00 10G A 60.91 24.77 10.46 2.05 0.46 0.68 0.68 14.32 100.00 Mean A 68.74 20.72 6.38 2.79 0.63 0.47 0.26 10.54 100.00 8G B 65.49 22.53 7.57 2.47 1.41 0.18 0.35 11.97 100.00 15M B 56.82 26.70 10.80 3.13 1.14 0.28 1.14 16.48 100.00 16S B 47.81 32.87 14.14 3.19 1.00 0.60 0.40 19.32 100.00 Mean B 57.10 27.21 10.69 2.88 1.19 0.35 0.56 15.68 100.00 4G C 70.03 20.57 4.65 3.96 0.69 0.00 0.10 9.40 100.00 9M C 50.91 23.64 15.64 4.73 4.00 0.73 0.36 25.46 100.00 18S C 65.96 20.39 6.03 3.55 2.48 0.71 0.89 13.65 100.00 Mean C 65.95 20.97 6.70 3.95 1.73 0.32 0.38 13.08 100.00 2G D 65.17 25.83 6.62 1.72 0.40 0.13 0.13 9.01 100.00 5S D 60.40 22.77 10.15 2.23 1.98 1.73 0.74 16.83 100.00 14M D 72.37 19.74 4.93 1.65 0.49 0.33 0.49 7.89 100.00 Mean D 66.55 23.03 6.85 1.81 0.79 0.57 0.40 10.41 100.00 3M E 68.23 18.34 6.82 4.26 2.13 0.00 0.21 13.43 100.00 6S E 69.88 20.60 6.13 1.83 0.39 0.78 0.39 9.52 100.00 U G E 67.07 19.80 6.87 3.03 2.22 0.40 0.61 13.13 100.00 Mean E 68.63 19.76 6.53 2.83 1.39 0.46 0.40 11.61 100.00 12G F 73.72 14.68 5.29 3.24 1.19 1.37 0.51 11.60 100.00 13S F 62.82 21.12 9.57 4.33 0.72 0.72 0.72 16.06 100.00 17M F 75.11 16.47 5.41 1.96 0.35 0.46 0.23 8.41 100.00 Mean F 71.31 17.23 6.52 2.99 0.70 0.80 0.45 11.45 100.00 21 G 74.01 17.93 5.11 1.93 0.68 0.23 0.11 8.06 100.00 19 H 67.27 21.34 6.51 2.17 1.45 0.54 0.72 11.39 100.00 20 I 75.30 14.85 5.01 2.07 1.38 1.04 0.35 9.84 100.00 Overall Mean - 67.72 20.69 6.87 2.75 1.06 0.51 0.39 11.59 100.00 "Stocking class identified for replicated treatments only. S=superior G=good M=moderate. Appendix B. Stand Structure Before Harvest Table B.32: Basal area distribution (m2/ha) by dbh class before harvest. Plot N o . / Treat - D i a m e t e r Class / L i m i t ( c m ) s tock 1 1 ment 5.0-14.9 15.0-29.9 30.0-44.9 45.0-59.9 60.0-74.9 75.0-89.9 90.0 + 30.0+ 5.0+ IS A 4.63 6.29 5.80 5.60 0.98 4.18 1.00 17.56 28.48 7 M A 5.38 8.56 6.35 9.17 4.49 0.79 2.07 22.87 36.81 10G A 2.30 5.19 7.46 2.77 1.02 2.16 4.73 18.14 25.63 M e a n A 4.10 6.68 6.54 5.85 2.16 2.38 2.60 19.52 30.31 8 G B 3.69 7.00 6.67 4.07 4.00 0.69 2.04 17.47 28.16 1 5 M B 2.38 5.64 6.22 3.35 2.05 0.73 5.53 17.88 25.90 16S B 2.45 9.44 11.08 5.34 2.48 2.19 3.75 24.84 36.73 M e a n B 2.84 7.36 7.99 4.25 2.84 1.20 3.77 20.06 30.26 4 G C 6.45 11.04 7.46 11.84 4.02 0.00 1.19 24.51 42.00 9 M C 1.60 3.86 7.29 4.10 5.52 1.62 1.18 19.71 25.17 18S C 3.86 6.55 5.48 6.09 8.01 3.00 6.93 29.51 39.92 M e a n C 3.97 7.15 6.74 7.34 5.85 1.54 3.10 24.58 35.70 2 G D 5.18 10.76 8.33 4.24 1.79 0.71 1.03 16.10 32.04 5S D 2.37 5.49 6.58 3.03 4.31 5.72 3.42 23.06 30.92 1 4 M D 4.35 6.09 4.92 2.87 1.79 1.74 4.16 15.48 25.92 M e a n D 3.97 7.45 6.61 3.38 2.63 2.72 2.87 18.21 29.62 3 M E 3.15 5.09 4.85 6.34 5.57 0.00 1.38 18.14 26.38 6S B 4.81 8.48 7.16 4.68 1.62 4.77 4.10 22.33 35.62 U G E 3.56 5.00 5.42 4.79 5.57 1.74 4.86 22.38 30.94 M e a n E 3.84 6.19 5.81 5.27 4.25 2.17 3.45 20.95 30.98 12G F 3.68 4.86 5.34 6.13 3.84 6.84 3.18 25.33 33.87 13S F 3.24 6.29 8.69 8.08 2.38 3.29 5.31 27.75 37.28 1 7 M F 6.26 7.31 7.79 5.72 1.52 3.13 2.53 20.69 34.26 M e a n F 4.39 6.15 7.27 6.64 2.58 4.42 3.67 24.60 35.15 21 G 6.20 7.33 6.75 5.52 3.04 1.69 2.32 19.32 32.85 19 H 3.75 6.12 5.54 4.12 4.06 2.44 6.71 22.87 32.74 20 I 4.08 4.59 4.96 3.99 4.05 5.00 2.97 20.97 29.64 Overa l l M e a n S.D*> C . V C - 3.97 1.39 34.96 6.71 1.97 29.35 6.67 1.51 22.68 5.33 2.21 41.41 3.43 1.82 52.98 2.50 1.90 76.28 3.35 1.84 54.88 21.28 3.78 17.78 31.96 4.93 15.44 "Stock ing class identified for replicated treatments only. S=superior G = g o o d M = m o d e r a t e . ' S t a n d a r d Dev ia t ion c Coeff ic ient of Var ia t ion Appendix B. Stand Structure Before Harvest Table B.33: Basal area distribution (percent) by dbh class before harvest. Plot No./ stock" Treat. Diameter Class / Limit (cm) ment 5.0-14.9 15.0-29.9 30.0-44.9 45.0-59.9 60.0-74.9 75.0-89.9 90.0+ 30.0+ 5.0 + IS A 16.26 22.09 20.37 19.66 3.44 14.68 3.51 61.62 100.00 7M A 14.62 23.25 17.25 24.91 12.20 2.15 5.62 62.12 100.00 10G A 8.97 20.25 29.11 10.81 3.98 8.43 18.45 70.79 100.00 Mean A 13.53 22.04 21.58 19.30 7.13 7.85 8.58 64.40 100.00 8G B 13.10 24.86 23.69 14.45 14.20 2.45 7.24 62.04 100.00 15M B 9.19 21.78 24.02 12.93 7.92 2.82 21.35 69.02 100.00 16S B 6.67 25.70 30.17 14.54 6.75 5.96 10.21 67.63 100.00 Mean B 9.39 24.32 26.40 14.04 9.39 3.97 12.46 66.29 100.00 4G C 15.36 26.29 17.76 28.19 9.57 0.00 2.83 58.35 100.00 9M C 6.36 15.34 28.96 16.29 21.93 6.44 4.69 78.31 100.00 18S C 9.67 16.41 13.73 15.26 20.07 7.52 17.36 73.94 100.00 Mean C 11.12 20.03 18.88 20.56 16.39 4.31 8.68 68.85 100.00 2G D 16.17 33.58 26.00 13.23 5.59 2.22 3.21 50.23 100.00 5S D 7.66 17.76 21.28 9.80 13.94 18.50 11.06 74.57 100.00 14M D 16.78 23.50 18.98 11.07 6.91 6.71 16.05 59.72 100.00 Mean D 13.40 25.15 22.32 11.41 8.88 9.18 9.69 61.48 100.00 3M E 11.94 19.29 18.39 24.03 21.11 0.00 5.23 68.78 100.00 6S E 13.50 23.81 20.10 13.14 4.55 13.39 11.51 62.69 100.00 11G E 11.51 16.16 17.52 15.48 18.00 5.62 15.71 72.36 100.00 Mean E 12.40 19.98 18.75 17.01 13.72 7.00 11.14 67.62 100.00 12G F 10.87 14.35 15.77 18.10 11.34 20.19 9.39 74.79 100.00 13S F 8.69 16.87 23.31 21.67 6.38 8.83 14.24 74.45 100.00 17M F 18.27 21.34 22.74 16.70 4.44 9.14 7.38 60.40 100.00 Mean F 12.49 17.50 20.68 18.89 7.34 12.57 10.44 69.99 100.00 21 G 18.87 22.31 20.55 16.80 9.25 5.14 7.06 58.83 100.00 19 H 11.45 18.69 16.92 12.58 12.40 7.45 20.49 69.87 100.00 20 I 13.77 15.49 16.73 13.46 13.66 16.87 10.02 70.74 100.00 Overall Mean - 12.42 21.00 20.88 16.66 10.74 7.81 10.49 66.58 100.00 "Stocking class identified for replicated treatments only. S=superior G = g o o d M = m o d e r a t e . Appendix B. Stand Structure Before Harvest Table B.34: Gross volume distribution (m3/ha) by dbh class before harvest. Plot No./ Treat- Diameter Class / Limit (cm) Stock" ment 15.0-29.9 30.0-44.9 45.0-59.9 60.0-74.9 75.0-89.9 90.0+ 30.0+ 15.0 + IS A 19.73 37.00 36.38 9.54 54.31 12.98 150.21 169.94 7M A 27.84 40.90 59.61 42.33 10.21 26.88 179.93 207.77 10G A 16.49 48.14 18.00 8.54 25.90 61.52 162.10 178.59 Mean A 21.35 42.01 38.00 20.14 30.14 33.79 164.08 185.43 8G B 22.74 42.99 26.47 37.56 6.73 26.54 140.29 163.03 15M B 18.33 40.41 21.76 20.00 9.46 71.83 163.46 181.79 16S B 30.33 71.29 34.74 24.20 28.46 48.72 207.41 237.74 Mean B 23.80 51.56 27.66 27.25 14.88 49.03 170.39 194.19 4G C 35.15 48.46 76.98 39.15 0.00 15.48 180.07 215.22 9M C 12.56 46.65 26.65 52.42 21.01 15.32 162.05 174.61 18S C 20.94 35.29 39.62 78.12 34.57 90.09 277.69 298.63 Mean C 22.88 43.47 47.75 56.56 18.53 40.30 206.60 229.48 2G D 34.24 53.78 27.58 17.45 9.17 13.33 121.31 155.55 5S D 17.48 42.75 19.71 40.55 74.30 44.48 221.79 239.27 14M D 19.42 32.01 18.64 17.42 22.59 54.08 144.74 164.16 Mean D 23.71 42.85 21.98 25.14 35.35 37.30 162.61 186.33 3M E 16.18 31.19 41.24 54.29 0.00 17.93 144.65 160.83 6S E 27.57 45.84 30.40 15.82 62.01 53.24 207.31 234.88 11G E 16.24 34.90 31.13 52.87 22.57 63.12 204.59 220.83 Mean E 20.00 37.31 34.26 41.00 28.19 44.76 185.52 205.51 12G F 15.80 34.73 39.86 37.46 88.88 41.35 242.28 258.08 13S F 20.08 56.14 52.55 23.24 42.78 69.09 243.80 263.88 17M F 23.41 49.56 37.20 14.86 40.72 32.90 175.24 198.65 Mean F 19.76 46.81 43.20 25.19 57.46 47.78 220.44 240.20 21 G 23.09 42.79 35.88 29.63 21.99 30.16 160.45 183.54 19 H 18.80 36.00 26.79 39.59 29.43 87.24 219.05 237.85 20 I 14.91 31.88 25.92 39.44 65.02 38.56 200.82 215.73 Overall Mean S . D 6 C . V C - 21.49 6.29 29.27 42.99 9.70 22.58 34.62 14.34 41.42 33.07 17.58 53.15 31.91 24.86 77.90 43.56 23.92 54.91 186.15 40.14 21.56 207.65 39.57 19.06 "Stock ing class identified for replicated treatments only. S=superior G = g o o d M = m o d e r a t e . ' S t a n d a r d Dev ia t ion Coe f f i c ien t of Var ia t ion Appendix B. Stand Structure Before Harvest Table B.35: Gross volume distribution (percent) by dbh class before harvest. Plot No./ Treat- Diameter Class / Limit (cm) Stock" ment 15.0-29.9 30.0-44.9 45.0-59.9 60.0-74.9 75.0-89.9 90.0+ 30.0 + 15.0 + IS A 11.61 21.77 21.41 5.61 31.96 7.64 88.39 100.00 7M A 13.40 19.69 28.69 20.37 4.91 12.94 86.60 100.00 10G A 9.23 26.96 10.08 4.78 14.50 34.45 90.77 100.00 Mean A 11.51 22.66 20.49 10.86 16.25 18.22 88.49 100.00 8G B 13.95 26.37 16.24 23.04 4.13 16.28 86.05 100.00 15M B 10.08 22.23 11.97 11.00 5.20 39.51 89.92 100.00 16S B 12.76 29.99 14.61 10.18 11.97 20.49 87.24 100.00 Mean B 12.26 26.55 14.24 14.03 7.66 25.25 87.74 100.00 4G C 16.33 22.52 35.77 18.19 0.00 7.19 83.67 100.00 9M C 7.19 26.72 15.26 30.02 12.03 8.77 92.81 100.00 18S C 7.01 11.82 13.27 26.16 11.58 30.17 92.99 100.00 Mean C 9.97 18.94 20.81 24.65 8.07 17.56 90.03 100.00 2G D 22.01 34.57 17.73 11.22 5.90 8.57 77.99 100.00 5S D 7.31 17.87 8.24 16.95 31.05 18.59 92.69 100.00 14M D 11.83 19.50 11.35 10.61 13.76 32.94 88.17 100.00 Mean D 12.72 23.00 11.80 13.49 18.97 20.02 87.27 100.00 3M E 10.06 19.39 25.64 33.76 0.00 11.15 89.94 100.00 6S E 11.74 19.52 12.94 6.74 26.40 22.67 88.26 100.00 11G E 7.35 15.80 14.10 23.94 10.22 28.58 92.65 100.00 Mean E 9.73 18.15 16.67 19.95 13.72 21.78 90.27 100.00 12G F 6.12 13.46 15.44 14.51 34.44 16.02 93.88 100.00 13S F 7.61 21.27 19.91 8.81 16.21 26.18 92.39 100.00 17M F 11.78 24.95 18.73 7.48 20.50 16.56 88.22 100.00 Mean F 8.23 19.49 17.99 10.49 23.92 19.89 91.77 100.00 21 G 12.58 23.31 19.55 16.14 11.98 16.43 87.41 100.00 19 H 7.90 15.14 11.26 16.64 12.37 36.68 92.10 100.00 20 I 6.91 14.78 12.02 18.28 30.14 17.87 93.09 100.00 Overall Mean 10.35 20.70 16.67 15.93 15.37 20.98 86.95 100.00 "Stocking class identified for replicated treatments only. S=superior G = g o o d M = m o d e r a t e . Appendix C Effects of Treatments on Stand Growth (Figu 141 Appendix C. Effects of Treatments on Stand Growth (Figures) 142 1600 1400 1200 1000 "55 E <L> W 800 600 400 200 3 4 5 7 Years after harvest 10 12 14 Figure C.33: Stems/ha of all trees 5.0 cm dbh and larger after harvest. Appendix C. Effects of Treatments on Stand Growth (Figures) 143 o CD w E CO Treatment/ stock - -x - AG - - -x- - - AM — X —A S - -X - BG --•K---BM —x—BS CG •- + - -CM —I—C S - -A — DG • A — -o — • o-— -a • - a — B -DM | DS EG EM ES FG FM FS • — G 0 1 3 4 5 7 Years after harvest 10 12 14 Figure C.34: Stem ratios of all trees 5.0 cm dbh and larger after harvest. Appendix C. Effects of Treatments on Stand Growth (Figures) 144 140 120 4 100 Treatment/ stock I — -X — AG • -X- - - AM — X — A S - -* - BG • * - - B M — X — B S - + - CG • + - - C M — I —C S I - - A - DG • - * - • DM — A — DS I - - * - EG -•©•--EM — o — E S I - - Q - FG - o - - F M — H — F S — • — G — • — H —A— I 3 4 5 7 Years after harvest 10 12 14 Figure C.35: Stems/ha of all trees 30.0 cm dbh and larger after harvest. Appendix C. Effects of Treatments on Stand Growth (Figures) 145 1.4 1.2 4--3 4 5 7 Years after harvest 10 12 14 Treatment/ stock — -X — AG — - -X- - - AM — X — A S — -x — BG - - • X - - - B M — x — B S - - f - C G - - + - - C M — I — C S — -A — DG - - -A - - DM — A — DS EG EM ES FG FM FS • — G - -o - - o-- -a - - o B-Figure C.36: Stem ratios of all trees 30.0 cm dbh and larger after harvest. Appendix C. Effects of Treatments on Stand Growth (Figures) 146 45 Treatment/ stock - -X - AG - - -x- - - AM —x—AS - -x — BG - - * - - B M — x—B S CG -- + - - C M — I — C S — -A — DG — - *• - - DM —A—DS — -o — EG --•©•--EM — © — E S — — FG — - o • - FM — H — F S — • — G • H 0 1 3 4 5 Years after harvest 10 12 14 Figure C.37: Basal area of all trees 5.0 cm dbh and larger after harvest. Appendix C. Effects of Treatments on Stand Growth (Figures) 1.1 147 Treatment/ stock - -X - AG -- X - - -AM — X — A S - * — BG BM — X — B S - + - C G --H - -CM — I CS — -A — DG - - A- - DM — A — D S — -©• — EG - - « - - - EM - ^ E S — o — FG - - Q - - - F M • FS — • — G • H —A—I 3 4 5 7 Years after harvest 12 14 Figure C.38: Basal area ratios of all trees 5.0 cm dbh and larger after harvest. Appendix C. Effects of Treatments on Stand Growth (Figures) 148 30 3 4 5 7 Years after harvest 10 12 14 Figure C.39: Basal area of all trees 30.0 cm dbh and larger after harvest. Appendix C. Effects of Treatments on Stand Growth (Figures) 149 2 3 4 5 7 Years after harvest 10 12 14 Treatment/ stock - -X — AG • - -X - - AM I — X — A S - -X - BG -•X---BM I — x — B S CG - + - - C M — I—C S • -A - DG ••A--DM - A — D S -o — EG •-0---EM - o — E S •n — FG • o - - F M - a — F S Figure C.40: Basal area ratios of all trees 30.0 cm dbh and larger after harvest. Appendix C. Effects of Treatments on Stand Growth (Figures) 150 300 Treatment/ stock — -X — AG — - -X- - - AM — X — A S — -X — BG - - * - - B M — X — B S - • + - CG - - + - - C M — I — C S — -A — DG •••A--DM — A — D S - - © - EG - - •©• - -EM — o — E S - • a - FG - - 0 - - F M a FS — • — G • H A I 3 4 5 7 Years after harvest 10 12 14 Figure C.41: Gross volume of all trees 15.0 cm dbh and larger after harvest. Appendix C. Effects of Treatments on Stand Growth (Figures) 151 1.4 1.2 . J3" C3 i— OJ E o > CO o * 0.6 4 i -G ° B " \ / *\ / \ CD 5 * —-4 Treatment/ stock - -x - AG - - -X - - AM — X — A S - -X — BG - - •K- - -BM — x — B S CG - - + - -CMJ — I — C S — -o - - -o - -A - DG - - -A - - DM — A — D S EG EM ES FG FM FS • — G H 3 4 5 7 Years after harvest Figure C.42: Gross volume ratios of all trees 15.0 cm dbh and larger after harvest. Appendix C. Effects of Treatments on Stand Growth (Figures) 152 300 Treatment/ stock - -x - AG - - -x - - AM — x—A S - — BG - - « - - B M —x—BS --+•- CG -- + --CMI — I —C S — -A — DG ---A--DM — A — D S - - © - EG --•©•--EM — © — E S FG - - 0 - - F M D FS — • — G — • — H 3 4 5 7 Years after harvest 10 12 14 Figure C.43: Gross volume of all trees 30.0 cm dbh and larger after harvest. Appendix C. Effects of Treatments on Stand Growth (Figures) 153 1.4 Treatment/ stock - -x - AG - - x - - AM I — x — A S • -x — BG - * - - B M |—X—BS • -+ — C G - + - - C M | —I—cs DG! - -o • . .©.. - o • •DM I •DS E G •EM - E S FG •FM •FS •G •H 3 4 5 7 Years after harvest 10 12 14 Figure C.44: Gross volume ratios of all trees 30.0 cm dbh and larger after harvest. Appendix D Effects of Treatments on Stand Growth (Tabl 154 Appendix D. Effects of Treatments on Stand Growth (Tables) 155 Table D.36: Stems/ha and periodic annual increment (stems/ha/year) of trees 5 cm dbh and larger (1974-1988). Plot Treat- Remciiuremen Year No. ment Pre-cut 1974 1975 1976 1977 1978 1979 1961 1984 1986 1988 PAI 1 A 1060.94 1007.81 909.38 921.88 931.25 1071.88 1057.81 1159.38 1195.31 1216.75 1185.94 12.72 7 A 1215.63 1150.00 1045.31 968.75 901.56 870.31 823.44 618.75 904.69 1031.25 1129.69 • 1.45 10 A 687.50 634.38 595.31 557.81 509.38 551.56 579.69 631.25 828.13 857.81 843.75 14.96 Mean A 988.02 930.73 850.00 616.15 780.73 831.25 820.31 869.79 976.04 1035.94 1053.13 8.74 8 B 887.50 853.13 812.50 759.38 734.38 720.31 775.00 826.56 887.50 875.00 915.63 4.46 15 B 550.00 510.94 473.44 432.81 421.88 468.75 504.69 687.50 751.56 790.63 823.44 22.32 16 B 784.38 709.38 628.13 600.00 560.94 542.19 529.69 571.88 643.75 679.69 718.75 0.67 Mem B 740.63 691.15 638.02 597.40 572.40 577.08 603.13 695.31 760.94 781.77 819.27 9.15 4 C 1579.69 1517.19 1448.44 1361.25 1345.31 1315.63 1545.31 1526.56 1578.13 1571.88 1554.69 2.68 9 C 429.69 385.94 356.25 353.13 351.56 335.94 371.88 407.61 465.63 450.00 479.69 6.70 18 c 881.25 817.19 773.44 732.81 742.19 854.69 842.19 871.88 832.61 837.50 893.75 5.47 Mean c 963.54 906.77 859.38 822.40 813.02 835.42 919.79 935.42 958.86 953.13 976.04 4.95 2 D 1179.69 1154.69 1114.06 1087.50 1096.88 1109.38 1200.00 1209.36 1329.69 1282.61 1393.75 17.07 5 D 631.25 595.31 564.06 518.75 545.31 512.50 504.69 568.75 631.25 675.00 698.44 7.37 14 D 950.00 931.25 909.36 854.69 834.38 981.25 975.00 1090.63 1045.31 1053.13 1020.31 6.36 Mean D 920.31 893.75 862.50 820.31 625.52 867.71 893.23 956.25 1002.08 1003.65 1037.50 10.27 3 E 732.81 704.69 653.13 596.88 595.31 607.81 643.75 939.06 878.13 910.94 950.00 17.52 6 E 1198.44 1175.00 1146.88 1092.19 1126.56 1164.06 1142.19 1248.44 1276.56 1289.06 1285.94 7.92 11 E 773.44 737.50 685.94 626.13 679.69 667.50 767.19 896.88 826.56 814.06 664.06 9.04 Mean E 901.56 872.40 828.65 772.40 800.52 619.79 851.04 1028.13 993.75 1004.69 1033.33 11.50 12 F 915.63 903.13 859.38 817.19 796.88 771.68 756.25 793.75 784.38 779.69 796.88 -7.59 13 F 865.63 862.50 851.56 779.69 790.63 789.06 793.75 634.38 832.81 859.38 890.63 2.01 17 F 1356.25 1354.69 1342.19 1321.88 1328.13 1301.56 1306.25 1275.00 1168.75 1132.81 1120.31 -16.74 Mean F 1045.64 1040.11 1017.71 972.92 971.SB 954.17 952.06 967.71 928.65 923.96 935.94 -7.44 21 G 1376.56 1337.50 1321.68 1323.44 1323.44 1314.06 1287.50 1267.19 1254.69 1206.25 1229.69 -7.70 19 H 864.06 775.00 721.88 629.69 603.13 573.44 750.00 662.50 629.69 931.25 1110.94 24.00 20 I 904.69 882.81 854.69 796.88 809.38 1092.19 12S5.94 1300.00 1254.69 1240.63 1201.56 22.77 Overall Mean 944.05 904.76 660.34 816.69 810.86 639.81 878.20 942.26 961.91 975.60 1005.13 7.17 j Appendix D. Effects of Treatments on Stand Growth (Tables) Table D.37: Periodic annual increment (stems/ha/year) of trees 5 cm dbh and larger species group (1974-1988). Plot Treat- Dipterocarp Non-dipterocarp All No. ment M E R N M E R Total LHW MHW HHW MISC Total species 1 A 0.45 1.90 2.34 12.83 5.13 0.89 -8.48 10.38 12.72 7 A -1.00 0.22 -0.78 5.36 -2.34 2.79 -6.47 -0.67 -1.45 10 A -0.56 0.45 -0.11 11.27 2.12 -0.11 1.79 15.07 14.96 Mean A -0.37 0.86 0.48 9.82 1.64 1.19 -4.39 8.26 8.74 8 B 1.34 0.33 1.67 2.90 0.45 1.34 -1.90 2.79 4.46 15 B 1.12 1.23 2.34 13.5 1.90 5.80 -1.23 19.98 22.32 16 B -0.45 -0.34 -0.78 6.03 -1.23 0.56 -3.91 1.45 0.67 Mean B 0.67 0.41 1.08 7.48 0.37 2.57 -2.34 8.07 9.15 4 C 1.23 1.12 2.34 2.57 2.34 0.89 -5.47 0.34 2.68 9 C 0.45 0.34 0.78 1.45 3.24 0.67 0.56 5.92 6.70 18 C 2.90 0.34 3.24 2.01 -2.90 1.90 1.23 2.23 5.47 Mean C 1.53 0.60 2.12 2.01 0.89 1.15 -1.23 2.83 4.95 2 D -0.33 0.67 0.34 9.15 4.91 0.11 2.57 16.74 17.07 5 D 2.68 0.11 2.79 4.58 -0.56 0.34 0.22 4.58 7.37 14 D 0.56 -0.33 0.22 5.69 -1.45 0.78 1.12 6.14 6.36 Mean D 0.97 0.15 1.12 6.47 0.97 0.41 1.30 9.15 10.27 3 E -0.45 0.45 0.00 13.06 2.01 5.36 -2.90 17.52 17.52 6 E 1.23 1.79 3.01 4.91 0.67 0.34 -1.00 4.91 7.92 11 E 0.45 0.34 0.78 2.79 0.11 6.03 -0.67 8.26 9.04 Mean E 0.41 0.86 1.27 6.92 0.93 3.91 -1.53 10.23 11.50 12 F -0.67 -0.67 -1.34 2.68 -3.68 -0.11 -5.13 -6.25 -7.59 13 F -0.11 0.11 0.00 2.34 -0.33 0.78 -0.78 2.01 2.01 17 F -0.11 -0.22 -0.33 -9.49 -0.11 -1.67 -5.13 -16.41 -16.74 Mean F -0.30 -0.26 -0.56 -1.49 -1.38 -0.34 -3.68 -6.88 -7.44 21 G 0.45 -0.56 -0.11 -1.90 -3.57 -0.45 -1.67 -7.59 -7.70 19 H 0.67 -0.11 0.56 13.84 5.36 6.36 -2.12 23.44 24.00 20 I -0.67 1.23 0.56 15.85 2.68 4.80 -1.12 22.21 22.77 Overall Mean . 0.44 0.40 0.83 5.78 0.70 1.78 -1.93 6.34 7.17 Appendix D. Effects of Treatments on Stand Growth (Tables) 157 Table D.38: Stems/ha and periodic annual increment (stems/ha/year) of trees 30 cm dbh and larger (1974-1988). Remeasurement Year Plot No. Treat-ment Pre-cut 1974 1975 1976 1977 1978 1979 1981 1984 1986 1988 PAI 1 A 93.75 42.19 21.88 20.31 21.88 23.44 28.13 34.38 39.06 45.31 45.31 0.22 7 A 120.31 56.25 40.63 34.38 34.38 32.81 32.81 42.19 45.31 45.31 . 51.56 -0.34 10 A 98.44 45.31 40.63 32.81 35.94 39.06 39.06 43.75 42.19 48.44 57.81 0.89 Mean A 104.17 47.92 34.38 29.17 30.73 31.77 33.33 40.11 42.19 46.35 51.56 0.26 8 B 106.25 71.88 68.75 65.63 68.75 67.19 71.88 75.00 73.44 75.00 81.25 0.67 15 B 90.63 51.56 50.00 45.31 45.31 43.75 42.19 46.88 53.13 54.69 62.50 0.78 16 B 151.56 78.13 64.06 62.50 59.38 65.63 67.19 73.44 81.25 85.94 96.88 1.34 Mean B 116.15 67.19 60.94 57.81 57.81 58.86 60.42 65.11 69.27 71.88 80.21 0.93 4 C 148.44 87.50 81.25 71.88 73.44 70.31 71.88 75.00 81.25 62.81 89.06 0.11 9 C 109.38 71.88 62.50 64.06 60.94 59.38 57.81 60.94 67.19 67.19 75.00 0.22 18 C 120.31 57.81 48.44 46.88 48.44 48.44 51.56 54.69 54.69 59.38 62.50 0.34 Mean C 126.04 72.40 64.06 60.94 60.94 59.38 60.42 63.54 67.71 69.79 75.52 0.22 2 D 106.25 81.25 78.13 68.75 73.44 76.56 81.25 89.06 115.63 121.88 128.13 3.35 5 D 106.25 71.88 70.31 67.19 67.19 67.19 62.50 68.75 68.75 76.56 75.00 0.22 14 D 75.00 56.25 54.69 51.56 50.00 51.56 53.13 54.69 57.81 60.94 70.31 1.00 Mean D 95.83 69.79 67.71 62.50 63.54 65.10 65.63 70.83 80.73 86.46 91.15 1.52 3 E 98.44 70.31 64.06 54.69 53.13 51.56 54.69 62.50 65.63 65.63 67.19 -0.22 6 E 114.06 96.88 92.19 85.94 85.94 87.50 89.06 90.63 85.94 87.50 92.19 -0.34 11 E 101.56 67.19 60.94 53.13 57.81 59.38 64.06 60.94 65.63 67.19 70.31 0.22 Mean E 104.69 78.13 72.40 64.59 65.63 66.15 69.27 71.36 72.40 73.44 76.56 -0.11 12 F 106.25 93.75 89.06 89.06 92.19 96.88 98.44 98.44 89.06 87.50 89.06 -0.34 13 F . 139.06 135.94 125.00 121.88 123.44 118.75 118.75 125.00 123.44 121.88 125.00 -0.78 17 F 114.06 112.50 109.38 114.06 117.19 121.88 118.75 120.31 117.19 117.19 121.88 0.67 Mean F 119.79 114.06 107.81 108.33 110.94 112.50 111.98 114.58 109.90 108.86 111.98 -0.15 21 G 110.94 75.00 75.00 70.31 68.75 67.19 67.19 70.31 68.75 65.63 64.06 -0.78 19 H 98.44 10.94 7.81 7.81 10.94 10.94 12.50 17.19 28.13 29.69 34.38 1.67 20 I 89.06 67.19 62.50 60.94 64.06 65.63 67.19 70.31 75.00 73.44 71.88 0.34 Overall Mean 109.45 71.50 65.11 61.38 62.50 63.10 64.29 68.30 71.36 73.29 77.68 0.44 Appendix D. Effects of Treatments on Stand Growth (Tables) 158 Table D.39: Periodic annual increment (stem/ha/year) of trees 30 cm dbh and larger by species group (1974-1988). Plot Treat- Dipterocar 3 Non-dipterocarp All No. ment M E R N M E R Total LHW MHW HHW MISC Total species 1 A -0.11 0.00 -0.11 0.78 0.11 -0.11 -0.45 0.33 0.22 7 A -0.11 0.22 0.11 0.34 -0.56 -0.11 -0.11 -0.45 -0.34 10 A 0.34 -0.11 0.22 -0.11 0.45 0.22 0.11 0.67 0.89 Mean A 0.04 0.04 0.07 0.34 0.00 0.00 -0.15 0.19 0.26 8 B 0.11 -0.11 0.00 0.45 0.45 0.11 -0.34 0.67 0.67 15 B 0.00 0.00 0.00 0.11 0.89 -0.11 -0.11 0.78 0.78 16 B 0.22 0.11 0.34 0.11 0.89 0.00 0.00 1.00 1.34 Mean B 0.11 0.00 0.11 0.22 0.74 0.00 -0.15 0.82 0.93 4 C 0.56 -0.22 0.33 0.56 -0.89 0.00 0.11 -0.22 0.11 9 C 0.34 -0.11 0.22 0.11 -0.67 0.67 -0.11 0.00 0.22 18 C 0.11 -0.11 0.00 -0.11 0.34 0.11 0.00 0.34 0.34 Mean C 0.34 -0.15 0.19 0.19 -0.41 0.26 0.00 0.04 0.22 2 D 1.00 0.33 1.34 1.45 0.22 0.00 0.34 2.01 3.35 5 D -0.11 0.11 0.00 -0.45 0.22 0.45 0.00 0.22 0.22 14 D -0.11 0.11 0.00 0.45 0.11 0.34 0.11 1.01 1.00 Mean D 0.26 0.19 0.45 0.49 0.19 0.26 0.15 1.08 1.52 3 E -0.11 0.11 0.00 -0.22 0.11 0.22 -0.34 -0.22 -0.22 6 E -0.45 0.00 0.11 0.11 0.11 0.11 -0.22 0.11 -0.34 11 E 0.11 0.45 0.56 -0.67 0.34 0.11 -0.11 -0.34 0.22 Mean E -0.15 0.19 0.04 -0.26 0.19 0.15 -0.22 -0.15 -0.11 12 F -0.45 -0.11 -0.56 -0.22 0.34 0.11 0.00 0.22 -0.34 13 F -0.34 0.11 -0.22 0.11 -0.56 -0.11 0.00 -0.56 -0.78 17 F -0.34 0.00 -0.34 0.34 0.33 0.11 0.22 1.01 0.67 Mean F -0.37 0.00 -0.37 0.07 0.04 0.04 0.07 0.22 -0.15 21 G 0.00 0.11 0.11 -0.22 -0.34 -0.22 -0.11 -0.89 -0.78 19 H 0.22 0.00 0.22 0.78 0.67 0.00 0.00 1.45 1.67 20 , -0.11 -0.11 -0.22 0.45 0.33 0.11 -0.33 0.56 0.34 Overall Mean 0.04 0.04 0.07 0.20 0.14 0.10 -0.06 0.37 0.44 Appendix D. Effects of Treatments on Stand Growth (Tables) 159 Table D.40: Basal area (m 2/ha) and periodic annual increment(m2/ha/year) of trees 5 cm dbh and larger (1974-1988). Remeasurement Year Plot No. Treat-ment Pre-cut 1974 1975 1976 1977 1978 1979 1981 1984 1986 1988 PA I 1 A 28.48 14.93 12.02 12.61 12.97 13.79 14.53 16.29 18.10 18.80 19.07 0.30 7 A 36.80 20.27 18.28 15.87 15.22 14.83 15.03 15.91 16.83 18.68 21.04 0.06 10 A 25.64 11.71 11.70 10.79 10.26 10.67 11.37 13.35 15.99 18.11 18.70 0.50 Mean A 30.31 15.64 14.00 13.09 12.82 13.10 13.64 15.18 16.97 18.53 19.60 0.28 8 B 28.16 19.22 18.31 16.65 16.91 16.76 17.57 18.80 19.36 19.26 21.50 0.16 15 B 25.89 14.68 13.94 13.19 13.03 13.08 13.21 15.43 16.76 17.88 19.72 0.36 16 B 36.73 19.40 17.20 16.84 16.51 16.29 16.52 17.21 18.06 18.56 20.51 0.08 Mean B 30.26 17.77 16.48 15.56 15.48 15.38 15.77 17.15 18.06 18.57 20.58 0.20 4 C 41.99 28.10 25.59 24.23 24.54 24.02 25.36 26.48 27.88 27.87 29.11 0.07 9 C 25.17 15.27 14.11 14.09 14.06 14.19 14.55 15.32 16.62 16.97 19.06 0.27 18 C 39.94 17.50 16.59 16.03 16.20 16.75 17.19 18.50 17.75 18.40 20.24 0.20 Mean C 35.70 20.29 18.76 18.12 18.27 18.32 19.03 20.10 20.75 21.08 22.80 0.18 2 D 32.03 25.65 24.52 23.49 23.54 23.76 24.87 26.39 29.08 29.66 32.59 0.50 5 D 30.91 17.53 17.10 15.47 16.87 16.57 16.44 18.01 19.10 20.60 20.89 0.24 14 D 25.92 19.45 19.28 18.87 18.79 19.49 20.17 21.66 23.20 24.99 26.50 0.50 Mean D 29.62 20.88 20.30 19.28 19.73 19.94 20.49 22.02 23.79 25.08 26.66 0.41 3 E 26.39 17.07 16.23 14.95 14.62 14.63 15.35 18.75 19.66 21.18 22.67 0.40 6 E 35.62 28.96 27.83 26.48 26.60 27.25 27.65 29.09 29.39 29.83 29.02 0.01 11 E 30.93 17.31 16.11 14.72 15.60 15.92 17.36 18.79 19.33 19.92 20:52 0.23 Mean E 30.98 21.11 20.06 18.72 18.94 19.27 20.12 22.21 22.79 23.64 24.07 0.21 12 F 33.88 28.50 27.68 27.81 28.30 28.73 29.50 30.23 26.71 27.18 28.11 -0.03 13 F 37.30 35.62 34.87 32.77 33.43 33.23 33.39 35.16 36.96 38.24 40.50 0.35 17 F 34.27 34.11 34.31 34.28 35.32 35.46 36.25 35.93 35.11 35.36 37.01 0.21 Mean F 35.15 32.74 32.29 31.62 32.35 32.47 33.05 33.77 32.93 33.59 35.21 0.18 21 G 32.84 23.09 22.92 22.73 23.22 23.15 22.83 23.44 23.79 22.93 24.13 0.07 19 H 32.73 13.21 12.36 10.39 10.77 10.82 11.76 13.19 14.24 15.82 16.19 0.21 20 I 29.63 18.90 18.65 17.91 18.64 20.34 21.99 24.42 25.89 26.05 26.15 0.52 Overall Mean _ 31.96 20.98 19.98 19.10 19.30 19.51 20.14 21.54 22.37 23.16 24.44 0.25 Appendix D. Effects of Treatments on Stand Growth (Tables) Table D.41: Periodic annual increment (m2/ha/year) of trees 5 cm dbh and larger species group (1974-1988). Plot Treat- Dipterocarp Non-dipterocarp All No. ment MER NMER Total LHW MHW HHW MISC Total species 1 A 0.00 0.02 0.02 0.25 0.17 -0.02 0.13 0.27 0.30 7 A -0.03 0.01 -0.02 0.06 0.00 0.04 -0.03 0.07 0.06 10 A 0.03 0.00 0.03 0.27 0.09 0.06 0.05 0.47 0.50 Mean A 0.00 0.01 0.01 0.19 0.09 0.03 -0.04 0.27 0.28 8 B 0.05 -0.01 0.04 0.09 0.04 0.03 -0.04 0.12 0.16 15 B 0.04 0.03 0.07 0.16 0.07 0.06 -0.01 0.29 0.36 16 B 0.01 0.00 0.00 0.02 0.08 0.00 -0.03 0.08 0.08 Mean B 0.03 0.01 0.04 0.09 0.06 0.03 -0.03 0.16 0.20 4 C 0.07 -0.02 0.05 0.08 -0.05 0.02 -0.03 0.02 0.07 9 C 0.06 -0.02 0.05 0.04 0.06 0.13 -0.01 0.23 0.27 18 C 0.05 0.02 0.07 0.05 0.00 0.07 0.01 0.13 0.20 Mean C 0.06 0.00 0.05 0.06 0.01 0.07 -0.01 0.13 0.18 2 D 0.11 0.03 0.14 0.18 0.12 0.01 0.05 0.36 0.50 5 D 0.02 0.03 0.05 0.06 0.05 0.08 0.00 0.19 0.24 14 D 0.05 0.02 0.07 0.23 0.10 0.09 0.02 0.44 0.50 Mean D 0.06 0.03 0.08 0.16 8.09 0.06 0.02 0.33 0.41 3 E -0.02 0.01 -0.01 0.26 0.12 0.09 -0.06 0.41 0.40 6 E -0.04 0.05 0.01 0.00 0.08 0.01 -0.08 0.00 0.00 11 E 0.02 0.04 0.06 0.02 0.11 0.06 -0.01 0.17 0.23 Mean E -0.01 0.03 0.02 0.09 0.10 0.05 -0.05 0.19 0.21 12 F -0.21 0.04 0.16 0.09 0.08 0.00 -0.05 0.13 -0.03 13 F -0.05 0.03 -0.02 0.21 0.09 0.03 0.04 0.37 0.35 17 F 0.00 0.02 0.02 0.04 0.12 0.03 -0.01 0.18 0.21 Mean F -0.08 0.03 -0.05 0.11 0.10 0.02 -0.00 0.23 0.18 21 G 0.00 0.02 0.03 0.04 0.02 0.00 -0.01 0.05 0.07 19 H 0.02 0.00 0.02 0.22 -0.11 0.20 -0.01 0.19 0.21 20 I -0.05 0.02 -0.03 0.37 0.13 0.09 -0.04 0.55 0.52 Overall Mean . 0.01 0.02 0.02 0.13 0.10 0.10 -0.02 0.22 0.25 Appendix D. Effects of Treatments on Stand Growth (Tables) Table D.42: Basal area (m2/ha) and periodic annual increment (m2/ha/year) cm dbh and larger (1974-1988). Remeasurement Year Plot No. Treat-ment Pre-cut 1974 1975 1976 1977 1978 1979 1981 1984 1986 1988 PA I 1 A 17.55 4.12 2.09 2.02 2.15 2.29 2.68 3.21 3.73 4.25 4.42 0.02 7 A 22.86 6.42 5.03 4.26 4.32 4.29 4.40 5.30 5.79 5.92 6.74 0.02 10 A 18.15 4.22 3.97 3.43 3.68 3.89 4.12 4.75 4.90 5.59 6.52 0.16 Mean A 19.52 4.92 3.70 3.24 3.38 3.49 3.73 4.42 4.81 5.25 5.89 0.07 8 B 17.47 8.53 8.44 8.00 8.39 8.18 8.81 9.30 9.26 9.37 10.30 0.13 15 B 17.87 6.66 6.56 6.21 6.30 6.02 5.99 6.57 7.35 7.57 8.58 0.14 16 B 24.84 7.60 6.40 6.33 6.23 6.73 7.00 7.71 8.58 9.09 10.36 0.18 Mean B 20.06 7.60 7.13 6.85 6.97 6.98 7.27 7.86 8.40 8.68 9.75 0.15 4 C 24.50 10.66 9.64 8.94 9.22 8.78 9.03 9.48 10.14 10.48 11.21 0.04 9 C 19.71 9.93 9.10 9.13 8.83 8.93 8.82 9.30 10.27 10.60 11.72 0.13 18 C 29.53 7.18 6.37 6.32 6.57 6.53 6.90 7.41 6.79 7.45 7.99 0.06 Mean C 24.58 9.26 8.37 8.13 8.21 8.08 8.25 8.73 9.07 9.51 10.31 0.08 2 D 16.09 9.71 9.38 8.54 8.94 9.31 9.89 10.79 13.51 14.42 15.61 0.42 5 D 23.05 9.71 9.39 8.59 8.84 8.92 8.49 9.20 9.46 10.37 10.50 0.06 14 D 15.48 9.01 8.87 8.77 8.78 9.15 9.52 9.49 10.33 11.18 12.14 0.22 Mean D 18.21 9.48 9.21 8.63 8.85 9.13 9.30 9.83 11.10 11.99 12.75 0.23 3 E 18.15 8.82 8.31 7.42 7.07 6.87 7.43 8.27 8.69 8.91 9.32 0.04 6 E 22.33 15.76 14.73 14.40 13.93 14.31 14.68 15.13 14.89 15.00 14.00 -0.13 11 E 22.38 8.83 7.95 7.24 7.89 8.01 8.68 8.52 9.14 9.53 9.35 0.04 Mean E 20.95 11.14 10.33 9.69 9.63 9.73 10.26 10.64 10.91 11.15 10.89 -0.02 12 F 25.34 19.96 19.45 19.80 20.31 21.17 21.87 21.83 18.01 18.36 18.79 -0.08 13 F 27.77 26.09 24.90 23.38 23.73 23.56 23.62 24.65 25.62 26.27 27.57 0.11 17 F 20.70 20.54 20.51 20.99 21.65 22.43 22.65 22.33 22.01 22.69 24.22 0.26 Mean F 24.60 22.20 21.62 21.39 21.90 22.39 22.71 22.94 21.88 22.44 23.53 0.10 21 G 19.32 9.73 9.56 9.22 9.32 9.21 9.29 9.74 9.69 9.30 9.63 -0.01 19 H 22.87 3.41 2.72 2.38 2.66 2.71 2.85 3.33 4.31 4.61 3.24 -0.01 20 I 20.96 10.23 9.47 9.45 9.90 10.14 10.53 11.30 12.09 12.13 12.00 0.13 Overall Mean 21.28 10.34 9.66 9.28 9.46 9.59 9.89 10.36 10.70 11.10 11.63 0.09 Appendix D. Effects of Treatments on Stand Growth (Tables) Table D.43: Periodic annual increment (m2/ha/year) of trees 30 cm dbh and larger species group (1974-1988). Plot Treat. Dipterocarp Non-dipterocarp All No. ment MER NMER Total LHW MHW HHW MISC Total species 1 A -0.01 0.00 -0.01 0.07 0.03 -0.02 -0.04 0.03 0.02 7 A -0.01 0.02 0.01 0.04 -0.04 0.01 0.00 0.02 0.02 10 A 0.04 -0.01 0.04 0.04 0.05 0.03 0.00 0.13 0.16 Mean A 0.01 0.00 0.01 0.05 0.02 0.01 -0.01 0.06 0.07 8 B 0.04 -0.02 0.02 0.07 0.05 0.03 -0.03 0.11 0.13 15 B 0.02 0.01 0.03 0.01 0.10 0.00 0.00 0.11 0.14 16 B 0.03 0.01 0.04 0.01 0.15 0.00 0.00 0.16 0.20 Mean B 0.03 0.00 0.03 0.03 0.10 0.01 -0.01 0.13 0.15 4 C 0.07 -0.02 0.05 0.06 -0.10 0.01 0.02 -0.01 0.04 9 C 0.08 -0.02 0.05 0.00 -0.03 0.12 -0.01 0.07 0.13 18 C 0.01 0.00 0.01 0.00 0.03 0.02 0.00 0.05 0.06 Mean C 0.05 -0.02 0.04 0.02 -0.03 0.05 0.00 0.04 0.08 2 D 0.15 0.04 0.19 0.15 0.05 0.00 0.03 0.23 0.42 5 D -0.01 0.02 0.01 -0.05 0.05 0.04 0.00 0.04 0.06 14 D 0.02 0.01 0.03 0.08 0.03 0.08 0.01 0.19 0.22 Mean D 0.05 0.02 0.08 0.06 0.04 0.04 0.01 0.16 0.23 3 E -0.01 0.01 0.00 0.00 0.04 0.03 -0.04 0.04 0.04 6 E -0.07 0.01 -0.06 -0.05 0.04 0.02 -0.08 -0.07 -0.13 11 E 0.02 0.05 0.07 -0.11 0.07 0.01 -0.01 -0.04 0.04 Mean E -0.02 0.02 0.00 -0.05 0.05 0.02 -0.04 -0.02 -0.02 12 F -0.20 0.04 -0.16 -0.01 0.08 0.00 0.00 0.08 -0.08 13 F -0.06 0.02 -0.03 0.08 0.01 0.01 0.04 0.14 0.11 17 F -0.03 0.03 0.01 0.10 0.11 0.03 0.02 0.26 0.26 Mean F -0.10 0.03 -0.06 0.06 0.07 0.01 0.02 0.16 0.10 21 G -0.01 0.02 0.01 0.01 -0.01 -0.00 -0.01 -0.02 -0.01 19 H 0.02 0.00 0.02 0.08 -0.12 0.00 0.00 -0.03 -0.01 20 I -0.04 0.00 -0.04 0.09 0.08 0.03 -0.04 0.16 0.13 Overall Mean - 0.00 0.01 0.01 0.03 0.03 0.02 -0.01 0.08 0.09 Appendix D. Effects of Treatments on Stand Growth (Tables) 163 Table D.44: Gross volume (m3/ha) and periodic annual increment (m3/ha/year) of trees 15 cm dbh and larger (1974-1988). Remeasurement Year Plot No. Treat-ment Pre-cut 1974 1975 1976 1977 1978 1979 1981 1984 1986 1988 PAI 1 A 169.94 45.43 31.45 32.02 31.57 34.30 36.97 42.11 45.87 47.50 50.78 0.38 7 A 207.77 70.68 60.22 51.43 49.91 50.06 52.77 57.11 59.64 63.46 73.47 0.20 10 A 178.59 43.59 42.24 37.19 35.07 36.79 37.85 45.51 53.36 62.48 68.23 1.76 Mean A 185.43 53.23 44.64 40.21 38.85 40.38 42.53 48.24 52.96 57.81 64.16 0.78 8 B 163.04 84.64 80.07 75.01 76.81 76.09 80.02 85.19 84.55 84.66 94.50 0.70 15 B 181.79 69.99 67.54 64.84 64.59 63.07 63.30 68.37 71.79 76.62 85.60 1.11 16 B 237.74 79.07 68.50 67.37 66.57 66.02 68.91 71.96 77.17 78.53 87.34 0.59 Mean B 194.19 77.90 72.04 69.07 69.32 68.39 70.74 75.17 77.81 79.94 89.15 0.80 4 C 215.22 107.78 98.78 93.30 94.52 91.60 94.14 97.59 101.38 101.72 107.35 -0.03 9 C 174.61 81.53 75.46 75.56 74.40 76.12 77.54 83.20 88.95 91.86 102.70 1.51 18 C 298.62 69.00 64.38 62.91 65.23 64.61 67.43 73.92 65.23 70.62 77.94 0.64 Mean C 229.48 86.10 79.54 77.26 78.05 77.44 79.70 84.90 85.19 88.07 96.00 0.71 2 D 155.54 99.57 93.60 86.82 90.88 93.08 96.53 102.90 118.83 124.27 136.09 2.61 5 D 239.27 90.85 88.99 81.71 87.39 87.09 84.87 90.78 93.65 101.38 101.61 0.77 14 D 164.17 95.95 96.12 95.37 96.71 100.15 104.75 104.64 114.44 124.64 132.49 2.61 Mean D 186.33 95.46 92.90 87.97 91.66 93.44 95.38 99.44 108.97 116.76 123.40 2.00 3 £ 160.83 74.68 71.11 63.79 62.26 60.69 65.66 74.67 78.57 83.36 88.78 1.01 6 £ 234.88 161.83 155.03 151.32 143.13 149.41 151.19 156.75 156.81 155.89 140.81 -1.50 11 E 220.83 74.65 72.64 67.44 71.48 70.58 76.90 78.37 83.39 89.05 86.30 0.83 Mean E 205.51 103.72 99.59 94.18 92.29 93.56 97.92 103.26 106.26 109.43 105.30 0.11 12 F 258.08 196.20 193.12 197.20 199.12 206.46 212.71 214.66 167.84 175.87 181.58 -1.04 13 F 263.88 242.15 240.86 224.85 227.53 226.99 230.74 241.50 256.32 266.46 282.04 2.85 17 F 198.65 197.58 199.93 204.95 210.80 215.89 224.68 216.74 218.40 232.33 245.30 3.41 Mean F 240.20 211.98 211.30 209.00 212.48 216.45 222.71 224.30 214.19 224.89 236.31 1.74 21 G 183.55 88.48 86.91 85.91 87.76 86.94 87.55 92.71 93.07 91.57 96.65 0.58 19 H 237.85 54.92 50.25 43.04 45.56 46.71 46.76 52.23 56.87 62.15 41.06 -0.99 20 I 215.72 87.47 83.84 82.87 87.38 90.10 93.20 101.24 108.75 109.58 111.61 1.72 Overall Mean 207.65 100.76 96.24 92.61 93.75 94.89 97.83 102.48 104.52 109.24 113.92 0.94 Appendix D. Effects of Treatments on Stand Growth (Tables) 164 Table D.45: Periodic annual increment (m3/ha/year) of trees 15 cm dbh and larger by species group (1974-1988). Plot Treat- Dipterocarp Nor -dipterocarp All No. ment MER NMER Total LHW MHW HHW MISC Total species 1 A -0.04 0.05 0.01 0.53 0.45 -0.16 -0.44 0.38 0.38 7 A -0.16 0.10 -0.06 0.17 -0.12 0.11 0.09 0.26 0.20 10 A 0.27 -0.03 0.24 0.86 0.36 0.26 0.04 1.52 1.76 Mean A 0.02 0.04 0.06 0.52 0.23 0.07 -0.10 0.72 0.78 8 B 0.22 -0.10 0.12 0.44 0.25 0.16 -0.27 0.58 0.70 15 B 0.17 0.09 0.26 0.19 0.59 0.07 0.01 0.86 1.12 16 B 0.10 0.03 0.13 -0.14 0.68 -0.01 -0.07 0.46 0.59 Mean B 0.16 0.01 0.17 0.17 0.50 0.07 -0.11 0.63 0.80 4 C 0.47 -0.15 0.31 0.29 -0.64 0.07 -0.06 -0.34 -0.03 9 C 0.66 0.15 0.51 0.13 0.03 0.93 -0.10 1.00 1.51 18 C 0.12 0.11 0.23 0.09 0.08 0.24 -0.01 0.41 0.64 Mean C 0.42 -0.06 0.35 0.17 0.18 0.42 -0.05 0.36 0.71 2 D 0.80 0.38 1.19 0.87 0.37 0.05 0.13 1.42 2.61 5 D 0.03 0.12 0.15 -0.14 0.35 0.43 -0.03 0.62 0.77 14 D 0.20 0.08 0.28 1.13 0.55 0.66 -0.01 2.33 2.61 Mean D 0.34 0.19 0.54 0.62 0.42 0.38 0.03 1.46 2.00 3 E -0.10 0.04 -0.05 0.64 0.45 0.24 -0.27 1.06 1.01 6 E -0.32 0.17 -0.15 -1.01 0.43 0.14 -0.91 -1.35 -1.50 11 E 0.14 0.26 0.40 -0.47 0.73 0.19 -0.02 0.43 0.83 Mean E -0.09 0.16 0.07 -0.28 0.54 0.19 -0.40 0.05 0.11 12 F -2.54 0.88 -1.66 0.25 0.44 -0.01 -0.07 0.62 -1.04 13 F 0.11 0.22 0.33 1.35 0.67 0.06 0.44 2.52 2.85 17 F 0.32 0.39 0.71 0.77 1.63 0.20 0.10 2.70 3.41 Mean F -0.71 0.50 -0.21 0.79 0.91 0.08 0.16 1.95 1.74 21 G -0.05 0.16 0.12 0.21 0.28 -0.03 0.01 0.47 0.58 19 H 0.11 -0.01 0.09 0.58 -1.86 0.24 -0.04 -1.08 -0.99 20 I -0.27 0.06 -0.22 1.12 0.72 0.37 -0.27 1.94 1.72 Overall Mean - 0.01 0.13 0.14 0.38 0.31 0.20 -0.08 0.80 0.94 Appendix D. Effects of Treatments on Stand Growth (Tables) 165 Table D.46: Gross volume (m3/ha) and periodic annual increment (m3/ha/year) of trees 30 cm dbh and larger (1974-1988). Remeasurement Year Plot No. Treat-ment Pre-cut 1974 1975 1976 1977 1978 1979 1981 1984 1986 1988 PAI 1 A 150.21 26.05 13.23 12.76 13.24 14.52 17.07 20.52 23.20 26.52 28.01 0.14 7 A 179.93 43.14 33.73 28.76 29.53 30.82 31.95 37.11 40.67 41.19 46.66 0.25 10 A 162.10 27.10 25.42 22.27 22.85 24.95 26.76 30.88 31.83 37.51 43.72 1.19 Mean A 164.08 32.10 24.13 21.26 21.87 23.43 25.26 29.50 31.90 35.07 39.46 0.53 8 B 140.30 61.89 60.59 58.56 60.43 59.80 64.25 67.44 66.50 67.94 73.52 0.83 15 B 163.46 51.66 50.80 48.99 49.27 47.57 47.85 51.80 56.13 58.42 65.40 0.98 16 B 207.41 49.06 41.63 40.77 40.51 42.64 45.13 49.06 55.77 58.76 67.36 1.31 Mean B 170.39 54.20 51.01 49.44 50.07 50.00 52.41 56.10 59.47 61.71 68.76 1.04 4 C 180.07 72.79 67.28 62.78 65.04 62.21 63.83 66.80 71.15 73.42 78.36 0.40 9 C 162.06 69.41 64.42 64.81 63.11 63.81 64.73 70.43 76.55 79.29 86.45 1.22 18 c 277.68 48.35 43.49 43.20 44.85 44.68 47.12 52.37 43.80 50.02 53.54 0.37 Mean c 206.60 63.52 58.40 56.93 57.67 56.90 58.56 63.20 63.83 67.58 72.78 0.66 2 D 121.30 65.34 62.85 57.01 62.30 65.08 68.52 73.66 92.45 98.37 107.39 3.00 5 D 221.79 73.53 71.25 66.18 68.29 69.24 66.60 70.91 73.33 79.64 80.95 0.53 14 D 144.75 76.53 76.54 77.03 78.26 81.59 85.13 82.83 88.64 96.75 102.00 1.82 Mean D 162.61 71.80 70.21 66.74 69.62 71.97 73.42 75.80 84.81 91.59 96.78 1.78 3 E 144.65 58.49 55.58 49.10 47.54 46.26 51.14 57.12 59.50 61.01 64.03 0.40 6 E 207.31 134.26 128.36 128.51 118.37 124.34 126.97 129.71 129.27 128.33 112.93 -1.52 11 E 204.59 58.64 56.41 52.10 56.54 55.78 61.37 60.79 66.33 70.69 66.02 0.53 Mean E 185.52 83.80 80.12 76.57 74.15 75.46 79.83 82.54 85.03 86.68 80.99 -0.20 12 F 242.28 180.40 178.15 182.81 185.19 193.72 200.17 201.64 155.45 163.42 166.63 -0.98 13 F 243.80 222.07 219.04 204.73 207.49 207.11 210.59 219.06 231.69 241.04 254.70 2.33 17 F 175.24 174.18 176.38 182.67 188.01 194.76 201.09 193.35 193.50 208.99 221.93 3.41 Mean F 220.44 192.22 191.19 190.07 193.56 198.53 203.95 204.68 193.55 204.48 214.42 1.59 21 G 160.45 65.92 64.89 64.28 65.47 64.56 65.68 70.16 70.32 70.04 72.54 0.47 19 H 219.05 36.32 29.99 27.50 29.75 30.21 30.86 34.74 40.37 43.10 21.06 -1.09 20 I 200.82 72.56 68.20 69.15 72.52 74.49 78.53 83.72 89.50 90.06 89.29 1.20 Overall Mean 186.15 79.41 75.63 73.52 74.69 76.10 78.83 82.10 83.62 87.83 90.59 0.80 Appendix D. Effects of Treatments on Stand Growth (Tables) 166 Table D.47: Periodic annual increment (m3/ha/year) of trees 30 cm dbh and larger by species group (1974-1988). Plot Treat- Dipterocarp Non-dipterocarp All No. ment MER NMER Total LHW MHW HHW MISC Total species 1 A -0.06 0.00 -0.06 0.39 0.21 -0.14 -0.26 0.20 0.14 7 A -0.09 0.14 0.04 0.24 -0.21 0.07 0.11 0.21 0.25 10 A 0.29 -0.06 0.23 0.39 0.35 0.20 0.02 0.96 1.19 Mean A 0.05 0.03 0.07 0.34 0.12 0.04 -0.04 0.46 0.53 8 B 0.24 -0.10 0.14 0.43 0.31 0.16 -0.21 0.69 0.83 15 B 0.11 0.07 0.17 0.08 0.67 0.02 0.04 0.81 0.98 16 B 0.18 0.07 0.25 0.05 1.02 0.01 -0.02 1.06 1.31 Mean B 0.18 0.01 0.19 0.19 0.66 0.06 -0.06 0.85 1.04 4 C 0.45 -0.15 0.30 0.53 -0.57 0.04 0.10 0.10 0.40 9 C 0.72 -0.15 0.57 0.02 -0.18 0.89 -0.09 0.64 1.22 18 C 0.07 -0.02 0.05 0.01 0.14 0.16 0.00 0.32 0.37 Mean C 0.41 -0.11 0.31 0.19 0.20 0.36 0.00 0.35 0.66 2 D 0.96 0.45 1.40 1.07 0.32 0.02 0.20 1.60 3.00 5 D 0.00 0.13 0.13 -0.34 0.45 0.29 0.00 0.40 0.53 14 D 0.12 0.07 0.19 0.71 0.28 0.62 0.03 1.63 1.82 Mean D 0.36 0.21 0.57 0.48 0.35 0.31 0.08 1.21 1.78 3 E -0.09 0.06 -0.03 0.15 0.35 0.21 -0.29 0.43 0.40 6 E -0.40 0.07 -0.33 -1.04 0.46 0.25 -0.86 -1.19 -1.52 11 E 0.16 0.32 0.47 -0.71 0.60 0.19 -0.03 0.06 0.53 Mean E -0.11 0.15 0.04 -0.53 0.47 0.22 -0.39 -0.24 -0.20 12 F -2.54 0.87 -1.67 0.07 0.58 0.03 0.01 0.69 -0.98 13 F 0.10 0.14 0.24 1.17 0.41 0.06 0.46 2.09 2.33 17 F 0.19 0.43 0.62 0.87 1.59 0.20 0.14 2.79 3.41 Mean F -0.75 0.48 -0.27 0.70 0.86 0.09 0.20 1.86 1.59 21 G -0.04 0.11 0.07 0.28 0.20 -0.01 -0.06 0.41 0.47 19 H 0.13 0.00 0.13 0.53 -1.76 0.00 0.01 -1.22 -1.09 20 I -0.25 0.06 -0.19 0.62 0.68 0.33 -0.24 1.39 1.20 Overall Mean 0.01 0.12 0.13 0.26 0.28 0.17 -0.04 0.67 0.80 Appendix E Diameter Growth 167 Appendix E. Diameter Growth 168 Table E.48: Periodic annual diameter increment (cm/year) for diameter class 5.0-14.9 cm (1974-1988). Plot Treat- Dipterocar 5 Non-dipterocarp All No. ment MER NMER Total LHW MHW HHW MISC Total Species 1 A 0.11 0.33 0.28 0.25 0.26 0.25 0.32 0.26 0.26 7 A 0.36 0.18 0.27 0.30 0.25 0.31 0.14 0.24 0.25 10 A 0.84 0.84 0.33 0.28 0.39 0.23 0.29 0.29 Mean A 0.31 0.30 0.30 0.28 0.26 0.32 0.23 0.26 0.26 8 B 0.19 0.19 0.28 0.20 0.23 0.20 0.23 0.22 15 B 0.46 0.33 0.40 0.26 0.24 0.49 0.31 0.28 0.30 16 B 0.21 0.21 0.24 0.27 0.45 0.28 0.28 Mean B 0.25 0.33 0.26 0.27 0.23 0.28 0.26 0.25 0.25 4 C 0.38 0.21 0.35 0.20 0.21 0.34 0.21 0.21 0.22 9 C 0.29 0.36 0.37 0.16 0.30 0.30 18 C 0.55 0.43 0.46 0.26 0.22 0.39 0.29 0.26 0.27 Mean C 0.41 0.37 0.39 0.23 0.22 0.37 0.22 0.23 0.24 2 D 0.31 0.20 0.28 0.22 0.19 0.24 0.23 0.22 0.22 5 D 0.06 0.58 0.32 0.29 0.26 0.35 0.10 0.27 0.27 14 D 0.44 0.47 0.45 0.23 0.21 0.33 0.17 0.22 0.24 Mean D 0.34 0.39 0.36 0.24 0.21 0.32 0.19 0.23 0.24 3 E 0.59 ~ 0.14 0.36 0.38 0.32 0.32 0.18 0.30 0.30 6 E 0.42 0.43 0.43 0.21 0.19 0.17 0.11 0.18 0.21 11 E 0.13 0.54 0.33 0.19 0.26 0.27 0.26 0.23 0.24 Mean E 0.40 0.41 0.40 0.23 0.25 0.25 0.16 0.23 0.24 12 F 0.33 0.72 0.46 0.18 0.18 0.16 0.06 0.17 0.18 13 F 0.49 0.49 0.23 0.15 0.30 0.16 0.20 0.20 17 F 0.29 0.29 0.10 0.10 0.11 0.09 0.10 0.11 Mean F 0.30 0.60 0.37 0.16 0.14 0.16 0.09 0.14 0.15 21 G 0.22 0.30 0.26 0.17 0.11 0.12 0.11 0.13 0.14 19 H 0.51 0.09 0.30 0.31 0.28 0.45 0.17 0.30 0.30 20 I 0.55 0.25 0.40 0.28 0.22 0.36 0.24 0.26 0.27 Overall Mean . 0.34 0.35 0.34 0.23 0.21 0.27 0.18 0.22 0.22 Appendix E. Diameter Growth 169 Table E.49: Periodic annual diameter increment (cm/year) for diameter class 15.0-29.9 cm (1974-1988). Plot Treat. Dipterocarp Non-dipterocarp All No. ment MER NMER Total LHW MHW HHW MISC Total Species 1 A 0.36 0.38 0.33 0.11 0.34 0.34 7 A 0.65 0.41 0.49 0.39 0.21 0.36 0.26 0.27 10 A 1.12 1.01 1.09 0.31 0.47 0.66 0.32 0.43 0.50 Mean A 1.00 0.61 0.84 0.36 0.29 0.58 0.24 0.33 0.35 8 B 1.04 1.04 0.32 0.35 0.16 0.32 0.31 0.34 15 B 0.79 0.79 0.43 0.27 0.22 0.32 0.33 16 B 0.51 0.39 0.45 0.35 0.28 0.35 0.34 0.30 0.31 Mean B 0.78 0.39 0.66 0.35 0.29 0.19 0.32 0.31 0.33 4 C 0.58 0.58 0.28 0.23 0.16 0.24 0.28 9 C 1.16 1.16 0.46 0.38 0.54 0.40 0.47 0.56 18 C 0.66 0.54 0.58 0.32 0.38 0.39 0.15 0.34 0.35 Mean C 0.73 0.54 0.71 0.33 0.29 0.46 0.17 0.31 0.35 2 D 0.63 0.52 0.61 0.39 0.29 0.33 0.40 0.35 0.39 5 D 0.74 0.74 0.28 0.22 0.34 0.38 0.26 0.27 14 D 0.92 0.92 0.29 0.29 0.72 0.13 0.32 0.33 Mean D 0.63 0.64 0.63 0.34 0.27 0.50 0.30 0.32 0.34 3 E 0.93 0.34 0.54 0.53 0.35 0.42 0.44 0.44 0.45 6 E 0.98 0.53 0.75 0.29 0.27 0.30 0.35 0.29 0.30 11 E 0.84 0.85 0.84 0.31 0.44 0.51 0.42 0.49 Mean E 0.90 0.68 0.75 0.35 0.34 0.40 0.38 0.35 0.38 12 F 0.39 1.46 0.75 0.31 0.22 0.55 0.13 0.28 0.30 13 F 0.59 0.35 0.44 0.23 0.18 0.24 0.24 0.21 0.23 17 F 0.43 0.74 0.58 0.20 0.26 0.20 0.24 0.22 0.24 Mean F 0.48 0.60 0.55 0.23 0.21 0.25 0.22 0.23 0.25 21 G 0.47 0.48 0.48 0.21 0.22 0.14 0.23 0.21 0.22 19 H 0.92 0.13 0.42 0.48 0.39 0.16 0.42 0.42 20 I 0.63 0.63 0.47 0.32 0.34 0.13 0.34 0.36 Overall Mean 0.71 0.53 0.64 0.32 0.28 0.36 0.24 0.30 0.33 Appendix E. Diameter Growth 170 Table E.50: Periodic annual diameter increment (cm/year) for diameter class 30.0-44.9 cm (1974-1988). Plot Treat- Dipterocarp Non-dipterocarp All No. ment MER NMER Total LHW MHW HHW MISC Total Species 1 A 0.27 0.40 0.37 0.37 7 A 0.38 0.38 0.52 0.32 0.58 0.45 0.47 0.46 10 A 0.81 0.43 0.36 0.56 0.56 Mean A 0.38 0.38 0.60 0.39 0.50 0.45 0.48 0.47 8 B 0.49 0.43 0.47 0.30 0.30 0.40 0.54 0.33 0.35 15 B 0.62 0.54 0.58 0.25 0.20 0.26 0.23 0.31 16 B 0.39 0.21 0.33 0.21 0.38 0.09 0.33 0.33 Mean B 0.50 0.43 0.47 0.26 0.32 0.30 0.54 0.31 0.33 4 C 0.34 0.34 0.31 0.28 0.07 0.15 0.27 0.29 9 C 1.00 1.00 0.54 0.47 0.39 0.44 0.46 0.48 18 C 0.64 0.64 0.28 0.37 0.35 0.33 0.36 Mean C 0.42 0.64 0.46 0.35 0.37 0.35 0.25 0.36 0.37 2 D 0.53 0.31 0.50 0.32 0.30 0.31 0.28 0.31 0.36 5 D 0.63 0.44 0.50 0.34 0.27 0.35 0.32 0.34 14 D 0.77 0.77 0.30 0.31 0.43 0.19 0.34 0.41 Mean D 0.60 0.40 0.57 0.33 0.30 0.40 0.25 0.32 0.37 3 E 0.36 0.06 0.21 0.47 0.51 0.26 0.45 0.42 6 E 0.26 0.50 0.35 0.38 0.36 0.28 0.36 0.36 11 E 1.06 0.88 0.92 0.28 0.56 0.21 0.60 0.38 0.48 Mean E 0.44 0.62 0.53 0.37 0.44 0.25 0.60 0.39 0.41 12 F 0.53 0.68 0.56 0.20 0.34 0.34 0.08 0.28 0.34 13 F 0.57 0.57 0.30 0.36 0.27 0.16 0.31 0.32 17 F 0.39 0.67 0.50 0.25 0.25 0.21 0.05 0.24 0.27 Mean F 0.46 0.63 0.54 0.27 0.32 0.26 0.09 0.28 0.30 21 G 0.89 0.89 0.40 0.30 0.59 0.37 0.37 0.39 19 H 0.59 0.17 0.38 0.38 20 0.29 0.29 0.65 0.48 0.31 0.50 0.49 Overall Mean 0.51 0.55 0.52 0.35 0.35 0.33 0.27 0.35 0.37 Appendix E. Diameter Growth 171 Table E.51: Periodic annual diameter increment (cm/year) of trees 5.0 cm dbh and larger (1974-1988). Plot Treat. Dipterocar] > Non-dipterocarp All No. ment MER NMER Total LHW MHW HHW MISC Total Species 1 A 0.11 0.33 0.28 0.26 0.28 0.26 0.30 0.27 0.27 7 A 0.42 0.27 0.34 0.33 0.25 0.40 0.15 0.26 0.26 10 A 1.05 1.01 1.04 0.36 0.32 0.45 0.24 0.32 0.34 Mean A 0.52 0.34 0.41 0.30 0.27 0.38 0.23 0.28 0.28 8 B 0.30 0.43 0.31 0.29 0.23 0.23 0.21 0.25 0.25 15 B 0.52 0.37 0.45 0.30 0.25 0.45 0.31 0.29 0.31 16 B 0.35 0.35 0.35 0.27 0.28 0.26 0.43 0.29 0.29 Mean B 0.36 0.37 0.36 0.29 0.26 0.27 0.27 0.27 0.28 4 C 0.43 0.21 0.41 0.21 0.22 0.32 0.21 0.22 0.23 9 C 1.06 1.06 0.33 0.40 0.44 0.21 0.37 0.39 18 C 0.57 0.47 0.49 0.27 0.26 0.38 0.26 0.28 0.29 Mean C 0.52 0.42 0.49 0.25 0.24 0.40 0.22 0.25 0.27 2 D 0.48 0.28 0.43 0.25 0.22 0.25 0.26 0.24 0.26 5 D 0.26 0.56 0.42 0.29 0.26 0.35 0.12 0.28 0.28 14 D 0.51 0.51 0.51 0.25 0.24 0.44 0.17 0.25 0.27 Mean D 0.47 0.43 0.45 0.26 0.24 0.36 0.21 0.25 0.27 3 E 0.58 0.19 0.38 0.42 0.34 0.31 0.19 0.33 0.33 6 E 0.42 0.44 0.43 0.24 0.22 0.21 0.12 0.21 0.23 11 E 0.46 0.75 0.65 0.21 0.32 0.32 0.27 0.27 0.29 Mean E 0.45 0.49 0.47 0.27 0.28 0.28 0.17 0.26 0.28 12 F 0.45 0.67 0.56 0.21 0.20 0.21 0.07 0.19 0.21 13 F 0.62 0.44 0.52 0.25 0.18 0.27 0.21 0.23 0.24 17 F 0.38 0.81 0.45 0.13 0.16 0.15 0.10 0.13 0.15 Mean F 0.44 0.61 0.50 0.19 0.18 0.20 0.11 0.17 0.19 21 G 0.24 0.35 0.29 0.18 0.14 0.15 0.12 0.15 0.16 19 H 0.62 0.10 0.34 0.34 0.31 0.43 0.17 0.32 0.32 20 I 0.56 0.29 0.43 0.31 0.26 0.36 0.23 0.29 0.30 Overall Mean 0.44 0.41 0.43 0.25 0.24 0.29 0.19 0.24 0.25 Appendix E. Diameter Growth 172 Table E.52: Periodic annual diameter increment (cm/year) of trees 15.0 cm dbh and larger (1974-1988). Plot Treat- Dipterocar > Non-dipterocarp All No. ment MER NMER Total LHW MHW HHW MISC Total Species 1 A 0.35 0.39 0.33 0.11 0.35 0.35 7 A 0.65 0.40 0.46 0.41 0.23 0.58 0.44 0.31 0.31 10 A 1.12 1.01 1.09 0.47 0.45 0.59 0.32 0.46 0.51 Mean A 1.00 0.56 0.78 0.40 0.32 0.55 0.27 0.36 0.37 8 B 0.76 0.43 0.72 0.32 0.33 0.23 0.38 0.31 0.34 15 B 0.68 0.54 0.62 0.38 0.25 0.26 0.32 0.30 0.32 16 B 0.46 0.35 0.41 0.31 0.31 0.26 0.34 0.31 0.32 Mean B 0.65 0.41 0.57 0.33 0.30 0.24 0.35 0.31 0.33 4 C 0.49 0.49 0.29 0.25 0.26 0.16 0.25 0.29 9 C 1.06 1.06 0.48 0.44 0.51 0.42 0.48 0.54 18 c 0.66 0.59 0.61 0.31 0.38 0.37 0.15 0.34 0.35 Mean c 0.63 0.59 0.62 0.33 0.32 0.43 0.18 0.33 0.36 2 D 0.59 0.41 0.56 0.38 0.29 0.33 0.38 0.34 0.38 5 D 0.65 0.54 0.58 0.31 0.25 0.34 0.38 0.28 0.30 14 D 0.71 0.92 0.74 0.32 0.31 0.58 0.14 0.35 0.37 Mean D 0.61 0.51 0.59 0.34 0.29 0.46 0.29 0.33 0.36 3 E 0.57 0.25 0.41 0.50 0.40 0.30 0.44 0.43 0.43 6 E 0.43 0.51 0.46 0.31 0.31 0.29 0.35 0.31 0.32 11 E 0.91 0.86 0.87 0.29 0.48 0.43 0.60 0.42 0.50 Mean E 0.60 0.65 0.63 0.36 0.38 0.34 0.44 0.37 0.39 12 F 0.62 0.64 0.63 0.30 0.26 0.35 0.10 0.28 0.33 13 F 0.62 0.41 0.53 0.29 0.25 0.25 0.47 0.28 0.30 17 F 0.58 0.81 0.67 0.22 0.31 0.22 0.22 0.25 0.29 Mean F 0.60 0.61 0.61 0.26 0.28 0.25 0.25 0.27 0.30 21 G 0.43 0.57 0.53 0.28 0.25 0.26 0.30 0.26 0.27 19 H 0.92 0.13 0.42 0.48 0.39 0.16 0.17 0.42 0.42 20 ! 0.63 0.48 0.57 0.53 0.38 0.34 0.23 0.40 0.41 Overall Mean , 0.64 0.54 0.60 0.33 0.31 0.35 0.26 0.32 0.35 Appendix E. Diameter Growth 173 Table E.53: Periodic annual diameter increment (cm/year) of trees 30.0 cm dbh and larger (1974-1988). Plot Treat- Dipterocar 3 Non-dipterocarp All No. ment MER NMER Total LHW MHW HHW MISC Total Species 1 A 0.27 0.40 0.37 0.37 7 A 0.38 0.38 0.52 0.41 0.58 0.47 0.49 0.48 10 A 0.81 0.43 0.36 0.56 0.56 Mean A 0.38 0.38 0.60 0.41 0.50 0.47 0.48 0.48 8 B 0.55 0.43 0.53 0.30 0.29 0.39 0.54 0.32 0.36 15 B 0.62 0.54 0.58 0.25 0.20 0.26 0.43 0.23 0.30 16 B 0.39 0.21 0.33 0.21 0.36 0.09 0.32 0.32 Mean B 0.53 0.43 0.50 0.26 0.31 0.31 0.49 0.30 0.33 4 C 0.37 0.37 0.31 0.28 0.26 0.17 0.27 0.30 9 C 0.86 0.86 0.54 0.46 0.47 0.44 0.48 0.51 18 C 0.64 0.64 0.26 0.38 0.32 0.33 0.35 Mean C 0.47 0.64 0.50 0.35 0.37 0.40 0.23 0.36 0.38 2 D 0:53 0.25 0.48 0.34 0.29 0.31 0.28 0.31 . 0.35 5 D 0.65 0.44 0.54 0.33 0.33 0.35 0.33 0.36 14 D 0.71 0.71 0.50 0.41 0.43 0.19 0.42 0.47 Mean D 0.60 0.35 0.55 0.36 0.34 0.40 0.25 0.35 0.39 3 E 0.39 0.06 0.28 0.42 0.50 0.22 0.41 0.39 6 E 0.30 0.50 0.36 0.37 0.39 0.27 0.37 0.37 11 E 1.06 0.88 0.92 0.28 0.59 0.34 0.60 0.43 0.51 Mean E 0.43 0.62 0.52 0.37 0.47 0.28 0.60 0.39 0.41 12 F 0.73 0.54 0.60 0.27 0.32 0.22 0.08 0.28 0.37 13 F 0.63 . 0.57 0.62 0.36 0.40 0.26 0.70 0.36 0.39 17 F 0.65 0.88 0.72 0.30 0.36 0.24 0.05 0.31 0.38 Mean F 0.66 0.62 0.65 0.33 0.36 0.25 0.32 0.33 0.38 21 G 0.39 0.89 0.64 0.40 0.37 0.59 0.37 0.40 0.42 19 H 0.59 0.17 0.38 0.38 20 I 0.48 0.48 0.65 0.49 0.35 0.74 0.51 0.51 Overall Mean . 0.56 0.56 0.56 0.37 0.37 0.34 0.35 0.37 0.39 Appendix E. Diameter Growth 174 Table E.54: Periodic annual diameter increment (cm/year) of trees 5.0 cm dbh and larger over three growth periods. Plot Treat- Dipterocarp Non-dipterocarp All Species No. ment 74-79 79-84 84-88 74-79 79-84 84-88 74-79 79-84 84-88 1 A 0.30 0.35 0.29 0.34 0.27 0.25 0.34 0.28 0.26 7 A 0.33 0.40 0.38 0.26 0.25 0.30 0.26 0.26 0.30 10 A 1.31 1.18 0.67 0.50 0.29 0.27 0.52 0.30 0.29 Mean A 0.44 0.44 0.39 0.34 0.27 0.27 0.34 0.28 0.28 8 B 0.24 0.29 0.41 0.25 0.23 0.25 0.25 0.24 ' 0.26 15 B 0.37 0.68 0.44 0.33 0.30 0.32 0.33 0.37 0.34 16 B 0.39 0.29 0.36 0.30 0.26 0.33 0.31 0.26 0.34 Mean B 0.31 0.47 0.42 0.29 0.26 0.30 0.29 0.28 0.31 4 C 0.40 0.45 0.31 0.22 0.24 0.19 0.23 0.25 0.20 9 C 0.96 1.17 0.90 0.51 0.37 0.35 0.53 0.40 0.38 18 C 0.38 0.40 0.41 0.31 0.26 0.25 0.32 0.27 0.26 Mean C 0.43 0.47 0.40 0.29 0.26 0.23 0.30 0.28 0.25 2 D 0.45 0.42 0.44 0.27 0.22 0.25 0.29 0.24 0.27 5 D 0.67 0.42 0.49 0.34 0.26 0.23 0.36 0.27 0.26 14 D 0.46 0.55 0.34 0.28 0.22 0.23 0.29 0.24 0.24 Mean D 0.49 0.47 0.42 0.29 0.23 0.24 0.30 0.24 0.26 3 E 0.40 0.36 0.39 0.38 0.36 0.34 0.39 0.36 0.34 6 E 0.53 0.46 0.30 0.25 0.23 0.19 0.28 0.25 0.20 11 E 0.79 0.56 0.41 0.39 0.24 0.25 0.42 0.27 0.27 Mean E 0.58 0.47 0.34 0.32 0.27 0.25 0.34 0.28 0.26 12 F 0.69 0.31 0.53 0.26 0.17 0.15 0.30 0.18 0.17 13 F 0.43 0.50 0.56 0.26 0.21 0.21 0.27 0.22 0.22 17 F 0.46 0.38 0.47 0.16 0.12 0.14 0.17 0.13 0.16 Mean F 0.55 0.39 0.51 0.21 0.16 0.16 0.23 0.17 0.18 21 G 0.34 0.25 0.31 0.19 0.14 0.13 0.20 0.15 0.14 19 H 0.36 0.36 0.24 0.37 0.33 0.29 0.37 0.33 0.28 20 I 0.58 0.39 0.41 0.35 0.32 0.23 0.37 0.33 0.24 Overall Mean . 0.46 0.43 0.39 0.28 0.24 0.24 0.29 0.25 0.25 Appendix E. Diameter Growth 175 Table E.55: Periodic annual diameter increment (cm/year) of trees 30.0 cm dbh and larger over three growth periods. Plot Treat- Dipterocar P Non-dipterocarp All Species No. ment 74-79 79-84 84-88 74-79 79-84 84-88 74-79 79-84 84-88 1 A 0.36 0.39 0.35 0.36 0.39 0.35 7 A 0.38 0.52 0.24 0.57 0.39 0.44 0.56 0.39 0.42 10 A 1.13 0.68 0.74 0.61 0.38 0.74 0.69 0.42 Mean A 0.38 0.98 0.50 0.57 0.46 0.39 0.57 0.50 0.40 8 8 0.33 0.43 0.99 0.34 0.31 0.45 0.34 0.33 0.53 15 B 0.56 0.60 0.65 0.23 0.17 0.32 0.28 0.26 0.37 16 B 0.35 0.45 0.28 0.34 0.31 0.38 0.35 0.33 0.37 Mean B 0.39 0.49 0.66 0.31 0.28 0.39 0.33 0.31 0.42 4 C 0.38 0.43 0.39 0.29 0.21 0.34 0.31 0.26 0.35 9 C 0.89 1.25 1.04 0.60 0.42 0.46 0.62 0.51 0.54 18 C 0.33 0.60 0.64 0.33 0.37 0.41 0.33 0.38 0.44 Mean C 0.42 0.64 0.60 0.40 0.33 0.40 0.40 0.38 0.44 2 D 0.40 0.51 0.57 0.35 0.30 0.34 0.36 0.37 0.41 5 D 0.48 0.43 0.80 0.33 0.30 0.34 0.35 0.31 0.40 14 D 0.78 0.74 0.58 0.47 0.44 0.56 0.52 0.49 0. 56 Mean D 0.51 0.54 0.61 0.38 0.34 0.40 0.41 0.38 0.44 3 E 0.21 0.21 0.62 0.57 0.32 0.45 0.52 0.31 0.47 6 E 0.68 0.41 0.27 0.49 0.34 0.37 0.52 0.35 0.36 11 E 0.92 1.12 0.84 0.57 0.26 0.45 0.63 0.38 0.54 Mean E 0.65 0.57 0.60 0.53 0.31 0.42 0.55 0.35 0.44 12 F 0.75 0.30 , 0.74 0.40 0.20 0.31 0.55 0.23 0.42 13 F 0.49 0.47 0.90 0.40 0.31 0.41 0.41 0.33 0.47 17 F 0.74 0.49 1.08 0.30 0.19 0.46 0.37 0.24 0.56 Mean F 0.70 0.41 0.90 0.36 0.24 0.41 0.44 0.27 0.49 21 G 0.61 0.32 0.79 0.51 0.20 0.35 0.52 0.20 0.38 19 H 0.67 0.41 0.55 0.55 0.41 0.55 0.56 20 0.82 0.71 0.71 0.52 0.42 0.59 0.57 0.47 0.60 Overall Mean 0.58 0.54 0.69 0.42 0.31 0.41 0.45 0.34 0.45 Appendix F Mortality 176 Appendix F. Mortality 177 Table F.56: Mean annual percent mortality of trees 5 cm dbh and larger (1974-1988). Plot Treat- Dipterocar Non-dipterocarp All No. ment MER NMER Total LHW MHW HHW MISC Total Species 1 A 4.95 1.68 3.10 1.74 1.95 1.30 4.46 2.37 2.38 7 A 5.36 2.60 4.38 3.25 2.66 2.10 4.27 3.05 3.11 10 A 4.17 5.72 4.62 3.65 2.69 3.39 7.74 3.84 3.82 Mean A 4.83 3.33 4.03 2.88 2.43 2.26 5.49 3.09 3.10 8 B 1.16 7.12 1.46 2.18 1.75 1.04 2.96 1.96 1.92 15 B 4.76 2.38 3.77 3.89 2.88 4.64 5.71 3.76 3.76 16 B 2.55 3.06 2.72 3.21 2.47 7.14 6.22 3.09 3.02 Mean B 2.82 4.19 2.65 3.09 2.37 4.27 4.96 2.94 2.90 4 G 3.01 2.38 2.96 2.05 2.00 1.88 3.10 2.24 2.28 9 C 1.02 7.14 1.78 3.07 4.51 0.17 9.67 3.38 3.33 18 C 0.00 2.17 1.79 2.42 2.95 2.43 3.38 2.64 2.53 Mean C 1.34 3.90 2.18 2.51 3.15 1.49 5.38 2.75 2.71 2 D 1.17 3.13 1.54 1.71 1.05 3.99 2.27 1.64 1.61 5 D 1.02 2.60 1.98 3.52 2.63 0.16 2.38 2.58 2.53 14 D 0.65 3.74 2.16 2.40 1.86 3.77 3.40 2.29 2.23 Mean D 0.95 3.16 1.89 2.54 1.85 2.64 2.68 2.17 2.12 3 E 3.81 1.02 2.92 4.00 1.68 4.08 6.07 3.60 3.55 6 E 3.00 0.00 2.06 2.17 1.89 2.54 2.98 2.18 2.14 11 E 5.80 3.06 4.05 3.39 2.69 2.74 16.77 4.35 4.30 Mean E 4.20 1.36 3.01 3.19 2.09 3.12 8.60 3.38 3.33 12 F 2.38 2.50 2.44 1.58 1.47 2.48 4.19 1.93 1.97 13 F 3.36 0.00 2.04 1.25 1.53 0.71 2.14 1.32 1.36 17 F 1.16 1.79 1.27 2.17 0.81 1.44 1.98 1.76 1.72 Mean F 2.30 1.43 1.92 1.67 1.27 1.54 2.77 1.67 1.68 21 G 1.34 1.38 1.36 1.98 1.51 0.95 1.55 1.60 1.58 19 H 2.52 0.51 1.61 3.26 3.71 0.00 6.82 3.50 3.33 20 I 3.02 0.48 2.09 2.67 2.27 1.25 9.75 3.53 3.43 Overall Mean - 2.58 2.05 2.36 2.44 2.13 1.98 4.48 2.53 2.50 Appendix F. Mortality 178 Table F.57: Mean annual percent mortality of trees 30 cm dbh and larger (1974-1988). Plot T r e a t - D i p t e r o c a r p N o n - d i p t e r o c a r p A l l N o . ment M E R N M E R T o t a l L H W M H W H H W M I S C T o t a l Species 1 A 7.14 - 7.14 4.29 3.81 7.12 8.93 4.94 5.03 7 A 7.14 0.00 4.77 4.46 5.36 1.43 3.58 4.33 4.37 10 A - 7.14 7.14 3.84 4.28 3.57 7.14 4.08 4.19 M e a n A 7.14 3.57 6.35 4.20 4.48 4.04 6.55 4.45 4.53 8 B 2.38 3.56 2.67 4.77 2.86 1.43 5.36 3.38 3.26 15 B 2.38 0.00 1.43 4.28 1.79 3.57 3.56 3.06 2.81 16 B 2.38 0.00 1.78 3.57 1.90 3.56 7.12 2.64 2.57 M e a n B 2.38 1.19 1.96 4.21 2.18 2.85 5.35 3.03 2.88 4 C 2.60 7.14 3.30 2.38 3.70 3.56 2.86 3.32 3.32 9 C 2.38 7.14 3.57 5.36 3.57 0.00 4.75 3.40 3.42 18 C - 3.57 3.57 2.98 2.68 0.00 . 2.38 2.51 M e a n C 2.49 5.95 3.48 3.57 3.32 1.19 3.81 3.03 3.08 2 D 0.71 0.00 0.59 2.60 2.08 0.00 3.58 2.32 1.92 5 D 2.38 0.00 1.43 3.28 2.74 1.78 2.97 2.80 14 D 1.19 - 1.19 0.00 2.23 0.89 3.56 1.66 1.59 M e a n D 1.43 0.00 1.07 1.96 2.35 0.89 3.57 2.32 2.10 3 E 3.57 0.00 2.85 4.13 2.19 0.00 7.13 3.21 3.18 6 E 3.97 0.00 3.25 2.38 1.79 0.00 7.13 2.24 2.42 11 E 0.00 1.78 1.43 4.47 3.30 2.04 3.56 3.57 3.32 M e a n E 2.51 0.59 2.51 3.66 2.43 0.68 5.94 3.01 2.97 12 F 3.97 1.43 2.63 3.57 1.70 1.19 0.00 2.09 2.26 13 F 2.86 0.00 2.38 1.02 2.38 1.02 0.00 1.43 1.56 17 F 2.14 2.86 2.38 1.36 1.10 0.00 0.00 1.00 1.29 M e a n F 2.99 1.43 2.46 1.98 1.73 0.74 0.00 1.51 1.70 21 G 3.56 3.56 3.56 2.55 2.79 2.85 10.68 3.08 3.13 19 H . . _ 0.00 8.94 0.00 5.11 5.11 20 I 7.14 2.38 5.10 1.78 2.78 0.00 5.71 2.58 2.99 O v e r a l l M e a n - 3.36 2.67 2.75 2.96 2.72 1.34 5.65 2.75 2.73 Appendix F. Mortality 179 Table F.58: Mean annual percent mortality of trees 5 cm dbh and larger (1974-1979). Plot Treat- Dipterocar 3 Non-dipterocarp All No. ment MER NMER Total LHW MHW HHW MISC Total Species 1 A 6.15 1.17 3.33 1.26 2.63 2.72 8.37 3.35 3.35 7 A 15.00 1.82 10.32 8.28 5.29 5.88 9.29 6.64 6.79 10 A 8.33 16.01 10.59 6.57 6.16 9.00 3.61 5.76 5.96 Mean A 9.83 6.33 8.08 5.37 4.69 5.87 7.09 5.25 5.37 8 B 0.54 9.97 1.02 5.00 2.73 1.45 7.56 4.14 3.92 15 B 5.71 6.66 6.11 4.64 6.24 6.00 7.60 5.84 5.87 16 B 5.71 8.57 6.67 7.00 4.24 17.50 7.74 5.36 5.29 Mean B 3.99 8.40 4.60 5.55 4.40 8.32 7.63 5.11 5.03 4 C 3.75 6.67 4.00 2.33 2.62 5.26 4.16 2.95 3.03 9 C 2.85 20.00 4.99 2.63 7.08 0.00 5.88 3.60 3.64 18 c 0.00 0.87 0.71 3.28 2.94 1.60 6.32 3.27 3.14 Mean c 2.20 9.18 3.23 2.75 4.21 2.29 5.45 3.27 3.27 2 D 1.23 0.00 0.92 2.68 1.55 11.16 3.29 2.88 2.71 5 D 2.85 0.00 1.11 5.63 5.53 0.44 4.17 4.68 4.51 14 D 1.82 3.81 2.79 3.30 2.53 5.28 1.91 2.97 2.92 Mean D 1.97 1.27 1.61 3.87 3.20 5.63 3.12 3.51 3.38 3 E 10.66 0.00 7.27 6.92 2.55 5.71 5.81 5.08 5.19 6 E 4.40 0.00 3.01 2.46 2.65 3.56 4.52 2.86 2.79 11 E 6.25 7.62 7.03 4.18 5.06 4.26 8.57 4.78 4.96 Mean E 7.10 2.54 5.77 4.52 3.42 4.51 6.30 4.24 4.31 12 F 0.95 7.00 3.90 2.64 2.14 4.90 9.65 3.61 3.63 13 F 9.42 0.00 5.72 2.96 3.05 0.80 4.00 2.82 2.97 17 F 1.08 0.00 0.89 1.99 0.48 0.85 1.76 1.51 1.48 Mean F 3.82 2.33 3.50 2.53 1.89 2.18 5.14 2.65 2.69 21 G 3.75 1.29 2.54 2.37 1.51 0.88 1.44 1.69 1.75 19 H 7.06 0.00 3.87 5.89 7.57 0.00 10.00 6.58 6.25 20 I 6.92 0.00 4.39 2.81 4.02 2.50 6.59 3.89 3.93 Overall Mean - 4.39 2.84 3.82 3.56 3.46 3.29 5.61 3.77 3.75 Appendix F. Mortality 180 Table F.59: Mean annual percent mortality of trees 5 cm dbh and larger (1979-1984). Plot Treat - D i p t e r o c a r 3 N o n - d i p t e r o c a r p A l l No. ment M E R N M E R T o t a l L H W M H W H H W M I S C T o t a l Species 1 A 4.71 2.14 3.11 0.72 0.46 0.00 3.11 0.85 0.97 7 A 0.00 6.00 4.00 0.79 2.11 0.00 4.66 2.11 2.16 10 A 5.72 0.00 5.01 0.95 0.49 0.00 6.13 2.31 2.26 M e a n A 3.48 2.71 4.04 0.82 1.02 0.00 4.63 1.76 1.80 8 B 2.27 20.00 2.67 0.58 1.64 0.29 0.00 0.71 0.89 15 B 6.66 0.00 3.20 3.39 1.43 2.00 5.14 2.78 2.85 16 B 2.00 0.00 1.43 2.69 2.08 4.99 10.00 2.95 2.89 M e a n B 3.64 6.67 2.43 2.22 1.72 2.43 5.05 2.15 2.21 4 C 0.00 0.00 0.00 2.31 1.69 0.00 1.96 1.88 1.70 9 C 0.00 0.00 2.04 2.86 0.00 7.50 2.16 2.10 18 C 0.00 1.34 1.03 1.26 2.64 4.73 3.05 2.16 2.04 M e a n C 0.00 0.67 0.34 1.87 2.40 1.58 4.17 2.07 1.95 2 D 2.18 2.86 2.09 0.85 0.43 0.00 1.14 0.66 0.73 5 D 0.00 7.27 4.70 3.06 1.21 0.00 1.00 1.76 1.92 14 D 0.00 5.60 2.80 1.66 1.95 1.45 3.43 1.78 1.76 M e a n D 0.73 5.24 3.20 1.86 1.20 0.48 1.86 1.40 1.47 3 E 0.00 0.00 0.00 3.12 1.85 2.50 8.38 3.52 3.35 6 E 1.86 0.00 1.14 2.58 2.35 2.27 2.83 2.48 2.35 11 E 5.46 0.00 1.25 1.15 1.18 2.00 15.61 3.83 3.58 M e a n E 2.44 0.00 0.80 2.28 1.79 2.26 8.94 3.28 3.09 12 F 6.00 0.00 3.63 1.64 0.65 2.22 2.22 1.15 1.32 13 F 0.00 0.00 0.00 0.00 1.12 0.00 0.00 0.37 0.35 17 F 2.05 5.01 2.55 2.61 1.31 2.67 3.08 2.43 2.44 M e a n F 2.68 1.67 2.06 1.42 1.03 1.63 1.77 1.32 1.37 21 G 0.00 2.67 1.43 1.41 1.35 0.31 0.87 1.20 1.21 19 H 0.00 1.43 0.80 1.27 0.64 0.00 3.28 1.06 1.04 20 I 0.00 0.00 0.00 0.69 0.66 0.29 5.64 1.57 1.48 Overa l l M e a n - 1.91 1.84 1.82 1.57 1.44 1.25 4.14 1.80 1.78 Appendix F. Mortality 181 Table F.60: Mean annual percent mortality of trees 5 cm dbh and larger (1984-1988). Plot Treat- Dipterocar 3 Non-dipterocarp All No. ment M E R N M E R Total LHW MHW HHW MISC Total Species 1 A 1.92 0.00 0.58 2.38 2.29 0.93 4.94 2.56 2.42 7 A 0.00 0.00 0.00 0.38 0.81 0.00 0.00 0.58 0.56 10 A 0.00 0.00 0.00 2.17 1.20 0.71 6.74 2.67 2.55 Mean A 0.64 0.00 0.19 1.64 1.43 0.55 3.89 1.94 1.84 g B 0.00 0.00 0.00 0.63 0.85 1.32 1.12 0.87 0.79 15 B 0.00 0.00 0.00 1.70 0.91 1.39 6.98 1.74 1.56 16 B 0.00 0.00 0.00 0.22 1.45 0.00 8.87 1.44 1.40 Mean B 0.00 0.00 0.00 0.85 1.07 0.90 5.66 1.35 1.25 4 C 4.69 0.00 3.91 1.08 1.46 0.00 3.88 1.75 1.96 9 c 0.00 0.00 0.00 4.92 2.48 0.54 10.00 3.96 3.78 18 c 0.00 3.45 2.33 2.86 3.47 0.00 0.00 2.45 2.25 Mean c 1.56 1.15 2.08 2.95 2.47 0.18 4.63 2.72 2.66 2 D 0.00 3.85 1.39 1.18 1.07 0.00 1.85 1.12 1.15 5 D 0.00 0.00 0.00 1.79 1.20 0.00 2.18 1.28 1.11 14 D 0.00 0.00 0.00 1.53 1.00 3.73 3.80 1.76 1.65 Mean D 0.00 1.28 0.46 1.50 1.09 1.24 2.61 1.39 1.30 3 E 0.00 2.08 1.09 1.26 0.31 1.67 6.65 1.72 1.69 6 E 2.24 0.00 1.42 1.08 0.40 1.60 2.03 0.99 1.04 11 E 5.21 1.14 3.26 4.17 2.06 1.29 11.91 3.78 3.73 Mean E 2.48 1.07 1.92 2.17 0.92 1.52 6.86 2.16 2.15 12 F 0.00 0.00 0.00 0.43 1.84 0.00 2.27 1.16 1.10 13 F 0.00 0.00 0.00 0.68 0.31 1.44 2.70 0.69 0.66 17 F 0.00 0.00 0.00 2.33 0.61 0.96 1.52 1.56 1.44 Mean F 0.00 0.00 0.00 1.15 0.92 0.80 2.16 1.14 1.07 21 G 0.00 0.00 0.00 2.31 1.89 1.84 2.84 2.13 1.99 19 H 0.00 0.00 0.00 2.17 2.78 0.00 9.09 2.54 2.40 20 I 2.77 0.93 1.67 2.39 1.82 0.35 9.83 3.17 3.08 Overall Mean - 1.38 0.78 1.14 1.78 1.44 1.03 4.47 1.86 1.80 Appendix G Ingrowth 182 Appendix G. Ingrowth 183 Table G.61: Mean annual percent ingrowth of trees into 5 cm dbh limit (1974-1988). Plot T r e a t - D i p t e r o c a r 3 N o n - d i p t e r o c a r p A l l N o . ment M E R N M E R T o t a l L H W M H W H H W M I S C T o t a l Species 1 A 7.14 8.82 8.10 4.98 3.61 3.90 0.61 3.45 3.64 7 A 2.14 3.89 2.77 5.62 2.30 12.61 1.01 2.99 2.98 10 A 1.19 11.43 4.21 9.16 3.62 3.22 9.33 6.32 6.18 M e a n A 3.49 8.05 5.03 6.59 3.18 6.58 3.65 4.25 4.27 8 B 3.48 17.82 4.21 3.21 1.95 2.28 1.83 2.38 2.51 IS B 8.16 7.62 7.94 11.61 4.00 23.21 4.14 8.15 8.13 16 B 0.51 0.00 0.34 8.04 2.20 11.61 2.19 3.30 3.12 M e a n B 4.05 8.48 4.16 7.62 2.72 12.37 2.72 4.61 4.59 4 C 4.24 14.28 5.10 2.54 2.47 4.89 1.55 2.27 2.46 9 C 5.10 28.62 8.03 3.89 7.69 1.16 11.77 4.96 5.06 18 C 37.15 3.10 9.18 3.19 2.07 4.86 4.76 2.94 3.21 M e a n C 15.50 15.33 7.44 3.21 4.08 3.64 6.03 3.39 3.58 2 D 0.73 5.80 1.87 3.57 2.40 4.15 4.20 3.23 3.09 5 D 25.50 3.25 11.90 5.58 2.40 0.64 2.98 3.39 3.77 14 D 2.27 2.72 2.49 4.46 1.51 4.72 4.54 3.00 2.91 M e a n D 9.50 3.92 5.42 4.54 2.10 3.17 3.91 3.21 3.26 3 E 1.90 5.10 2.92 9.25 2.54 16.33 4.07 6.21 6.03 6 E 4.57 4.97 4.70 3.30 2.07 3.02 2.48 2.65 2.82 11 E 7.59 4.08 5.41 4.40 2.73 10.94 15.89 5.57 5.52 M e a n E 4.69 4.72 4.34 5.65 2.45 10.10 7.48 4.81 4.79 12 F 0.34 0.36 0.35 2.61 0.46 2.33 0.41 1.18 1.12 13 F 2.94 0.65 2.04 1.83 1.41 1.71 0.89 1.57 1.59 17 F 0.97 0.00 0.79 0.62 0.77 0.30 0.04 0.48 0.49 M e a n F 1.42 0.34 1.06 1.69 0.88 1.45 0.45 1.08 1.07 21 G 2.23 0.23 1.25 1.49 0.91 0.53 0.44 0.98 1.00 19 H 5.04 0.00 2.76 7.76 5.65 16.29 4.76 6.73 6.42 20 I 1.37 5.71 2.96 8.15 3.07 8.93 8.91 6.24 6.01 O v e r a l l M e a n 3.74 3.91 3.78 4.29 2.34 4.71 3.07 3.29 3.30 Appendix G. Ingrowth 184 Table G.62: Mean annual percent ingrowth of trees into 30 cm dbh limit (1974-1988). Plot Treat- Dipterocarp Non-dipterocarp All No. ment M E R N M E R Total LHW MHW HHW MISC Total Species 1 A 0.00 0.00 0.00 14.30 4.28 3.56 1.78 5.77 5.56 r A 3.56 14.33 7.14 7.14 3.13 0.00 1.78 3.46 3.77 10 A 0.00 21.43 3.30 7.14 7.13 14.33 5.61 6.16 Mean A 1.19 4.78 9.52 8.25 4.85 3.56 5.96 4.95 5.16 8 B 3.56 0.00 2.67 7.94 4.29 2.86 0.00 4.51 4.19 15 B 2.38 0.00 1.43 5.00 6.55 1.78 0.00 4.85 4.33 16 B 7.14 7.14 7.14 4.16 3.81 3.56 7.12 4.04 4.29 Mean B 4.36 2.38 3.75 5.70 4.88 2.73 2.37 4.47 4.27 4 C 5.85 0.00 4.95 6.36 1.59 3.56 4.28 3.00 3.45 9 C 9.53 0.00 7.15 5.95 1.19 4.77 2.38 3.40 3.73 18 C 1.79 3.58 2.38 4.02 1.43 0.00 3.03 3.09 Mean C 5.13 0.60 5.23 4.90 2.27 3.25 2.22 3.14 3.42 2 D 7.16 10.70 7.75 11.04 2.68 0.00 8.94 5.54 6.05 5 D 0.00 3.56 1.43 2.08 3.84 8.94 0.00 3.31 3.11 14 D 0.00 1.19 7.14 2.68 3.57 7.14 3.81 3.38 Mean D 2.39 4.75 3.46 6.75 3.07 4.17 5.36 4.22 4.18 3 E 1.78 7.14 2.85 3.39 2.75 2.85 0.00 2.86 2.86 6 E 0.79 0.00 0.65 2.68 2.14 1.78 2.38 2.38 2.07 11 E 7.19 8.94 8.59 1.79 4.95 3.06 0.00 3.01 3.67 Mean E 3.25 5.36 4.03 2.62 3.28 2.56 0.79 2.75 2.87 12 F 0.79 0.72 0.75 2.39 2.72 2.38 0.00 2.44 1.90 13 F 0.72 3.56 1.19 1.23 0.90 0.51 0.00 0.96 0.99 17 F 0.00 2.87 0.96 2.38 1.93 0.79 14.29 2.13 1.89 Mean F 0.50 2.38 0.97 2.00 1.85 1.23 4.76 1.84 1.59 21 G 3.56 7.14 5.35 1.53 1.86 0.00 7.12 1.79 2.09 19 H 0.00 24.99 19.63 0.00 0.00 18.37 20.41 20 I 5.35 0.00 3.06 5.35 3.97 1.43 1.43 3.57 3.49 Overall Mean - 3.38 3.21 3.34 3.90 3.20 2.50 3.14 3.35 3.35 

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