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The classification and interpretation of hardwood ecosystems on the Quinsam Flats, Elk River Tree Farm Bernardy, Pavel 1989

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THE CLASSIFICATION AND INTERPRETATION OF HARDWOOD ECOSYSTEMS ON THE QUINSAM FLATS, ELK RIVER TREE FARM By Pavel Bernardy For. Eng., The Brno Agriculture University, Czechoslovakia, 1980 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES (Department of Forestry) We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA September 1989 © Pavel Bernardy, 1989 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 The University of British Columbia Vancouver, Canada Date DE-6 (2/88) 1 1 ABSTRACT The vegetation and soils of hardwood ecosystems in the Elk River Tree Farm, near Campbell River, British Columbia, were sampled and analysed, and the ecosystems classified into a hierarchy of vegetation and site units, using the methods of biogeoclimatic ecosystem classification (BEC). Four plant and four site associations were distinguished. Site units were used as a categorical framework for selection of suitable site preparation method, tree species, and planting microsites. A key was developed to assist Fletcher Challenge Canada Ltd. foresters in site identification and regeneration of hardwood forests on a site-specific basis. A pattern of site units in the study area is demonstrated in the form of a 1:5000 map for a selected, 50 ha-segment of a hardwood forest. It is suggested that the hardwood ecosystems have developed and persisted in response to a seasonally fluctuating water table which can be attributed to poor drainage as a function of fine soil texture, flat topography, and winter-high and summer-low precipitation. The soil water table is very high in the winter but absent or very low in the summer. As a result, the rooting zone in the winter is under the influence of poorly oxygenated water. Such a soil moisture regime is not favourable for the growth of Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco]. This study makes recommendations for the management of hardwood ecosystems on a site-specific basis. i i i TABLE OF CONTENTS Page ABSTRACT ii TABLE OF CONTENTS iii LIST OF TABLES v LIST OF FIGURES vii ACKNOWLEDGMENTS x INTRODUCTION 1 MATERIALS AND METHODS 3 Sampling 3 Vegetation and Site Description .3 Soil Physical and Chemical Properties 5 Vegetation and Site Classification 6 Numerical Analysis of Vegetation and Site Units 8 Ecosystem Interpretation 9 Tree Species Trials 10 Site Mapping 12 THE STUDY AREA 14 Location . 14 Climate 15 Physiography and Soil Parent Material 16 Vegetation 17 RESULTS AND DISCUSSION 19 Soil Moisture Conditions on the Quinsam Flats 19 Vegetation Classification 21 i v Site Classification 26 Differentiation of Site Units 26 Soil Moisture Regimes . . 29 Soil Nutrient Regimes 31 Site Units 34 Numerical Analysis of Vegetation and Site Units 46 Soils 53 Classification of Early-seral Vegetation 56 Tree Species Trials 61 Recommendations for Rehabilitation of Hardwood Stands 66 Identification Key and Site Mapping 72 SUMMARY AND CONCLUSIONS .77 LITERATURE CITED 79 APPENDIX 1. List of Plant Species Occurring in the Intermediate-Serai Ecosystems on the Quinsam Flats 85 APPENDIX 2. List of Plant Species Occurring in the Early-Seral Ecosystems on the Quinsam Flats 89 APPENDIX 3. Vegetation Summary Table for Vegetation Units Distinguished in the Intermediate-Serai Ecosystems on the Quinsam Flats .92 APPENDIX 4. Vegetation Summary Table for Vegetation Units Distinguished in the Early-Seral Ecosystems on the Quinsam Flats 95 APPENDIX 5. A comparison of grand fir and Douglas-fir growth performance in the Elk River Tree Farm (Carter et al. 1988). . . : 98 LIST OF TABLES V Table Page 1 Description of vegetation strata (Brooke et al. 1979) 4 2 The Domin-Krajina species significance scale (Brooke etal. 1979) 4 3 The planting design for the species-site-microsite trial 11 4 Designs for nested ANOVA used in this study 12 5 Means and standard deviations (in parenthesis) of some climatic characteristics for the Campbell River Airport (Environment Canada 1982) 15 6 A synopsis of vegetation units distinguished in the hardwood stands on the Quinsam Flats 22 7 Diagnostic combination of species for vegetation units distinguished in hardwood ecosystems of the Quinsam Flats 23 8 Classes of differentiating and accessory characteristics used to delineate site associations on the Quinsam Flats 26 9 A synopsis of site units distinguished on the Quinsam Flats 27 10 Definitions of the diagnostic edaphic adjectives used to differentiate site types (after Klinka and Krajina 1987) 28 11 Nutrient content (kg/ha) and pH determined for three recognized site units 32 12 Mean values of selected environmental and vegetation characteristics of the distinguished site associations 35 13 Species correlations with first two components 47 v i 14 Numerical codes and names of life-form and moisture indicator species groups 51 15 The soils and humus forms associated with hardwood ecosystems on the Quinsam Flats 55 16 Means, standard deviations (S.D.), and coefficient of variations (C.V.) for some soil chemical properties of the study soils 55 17 Diagnostic combination of species for vegetation units recognized in serai ecosystems on the Quinsam Flats 57 18 Seedling mortality (%) at the end of the second growing season 62 19 Means (cm) and standard deviations (in parenthesis) of two-year height increment of coniferous seedlings on mounded and scarified sites 63 20 Means and standard deviations (in parenthesis) of two-year height increment of coniferous seedlings on natural mounds and in depressions within relatively undisturbed sites 64 21 Recommended tree species for rehabilitation of hardwood stands on the Quinsam Flats 67 v i i LIST OF FIGURES Figure Page 1 Approximate location of the study area 14 2 A typical soil profile of a Gleyed Humo-Ferric Podzol occurring on natural mounds within hardwood stands 20 3 The soil profile (Orthic Gleysol) featuring a high summer water table 21 4 Relationships among actual SMR's, the depth of summer and winter groundwater table, and distinguished site associations 30 5 Edatopic grid for site associations distinguished in hardwood ecosystems on the Quinsam Flats 33 6 A typical, Rubus spectabilis-domlnaXed understory of the Rubus-Achlys s.a 36 7 An understory vegetation of the Rubus-Achlys site dominated by Polystichum munitum, and Achlys triphylla with sporadic advance regeneration of Sitka spruce and western hemlock 36 8 A Heracleum lanatum-dominated understory of some Rubus-Achlys sites 37 9 A Polystichum munitum-tiom'mated understory of the Lonicera-Achlys site with sporadic advance regeneration of Sitka spruce 39 10 An Oplopanax horridus-dommaXed understory of the Lonicera-AcWys/Ravine s.t 39 11 A Carex obnupte-dominated understory of the Lonicera-Carex s.a 42 v i i i 12 A high summer water table occurring in the Lonicera-Carex s.a. as a result of an impermeable ortstein layer (Lonicera-Carex/Ortstein s.t.) 43 13 A typical, Spiraea douglasii-dom'mated understory of the Spiraea-Carex s.a. An open tree layer is formed by trembling aspen 45 14 The ordination of 84 sample plots along the first two PCA axes based on diagnostic species showing centroids and 95 % confidence ellipses for the Alnus-Disporum-Typic (1), Alnus-Disporum-Stachys (2), Alnus-Lonicera-Dryopteris (3), Alnus-Lonicera-Trautvetteha (4), Carex-Oenanthe (5), and Carex-Fontinalis (6) vegetation units 48 15 Life-form and soil moisture spectra for vegetation units (symbols are defined in Table 14) 50 16 The ordination of 84 sample plots along the first two PCA axes based on diagnostic species showing centroids and 95 % confidence ellipses for the Rubus-Achlys (1), Lonicera-Achlys (2), Lonicera-Carex (3), and Spiraea-Carex (4) s.a.'s 52 17 Characteristic soil profiles for the most common soil subgroups 54 18 Climatic, soil moisture, and soil nutrient spectra for plant associations distinguished in early-seral vegetation on the Quinsam Flats 60 19 A group of immature grand fir (a) showing relatively clean stems and smaller branches compared to Douglas-fir (b) within the same stand on the Rubus-Achlys site 71 i x 20 A group of mature, naturally regenerated black cottonwood showing excellent vigour and form on a Lonicera-Carex site 72 21 The map legend showing symbols and colour scheme used to designate site types and recommended tree species 74 22 , The distribution of site types in a selected hardwood area on the Quinsam Flats 75 23 The key to site identification and tree species selection for hardwood ecosystems on the Quinsam Flats 76 ACKNOWLEDGEMENTS X I would like to thank my advisor Dr. K. Klinka for his patient guidance during my studies. He was always there when I needed advice. Furthermore, it was a real pleasure and privilege to be able to witness and share some of his insight and imagination. My thanks are also due to my committee members, Mr. R.E. Carter, Dr. A.D. Chambers, Dr. H. Schrier, and Dr. R.P. Willington for their assistance during the thesis preparation and to Mr. T. Jones, and Mr. R. Slaco, foresters at the Elk River Tree Farm who were most helpful during the field work. Finally, I would like to thank my colleagues from the Faculty of Forestry, University of British Columbia, for their help during both course and thesis work. The financial support for this study provided by Fletcher Challenge Canada Ltd. is gratefully acknowledged. 1 INTRODUCTION Hardwood stands dominated mainly by red alder {Alnus rubra Bong.) and black cottonwood [Populus trichocarpa (Torr. & Gray) ex Hook.] occupy approximately 3,000 ha in the 40,000-ha Elk River Tree Farm owned by Fletcher Challenge Canada Ltd. Most of these stands are located on Quinsam Flats, west of Campbell River, B.C. The hardwood forest established naturally after harvesting of the old-growth coniferous forest and a major fire in 1938. Such a period of time is, in the coastal region more than adequate for natural regeneration of shade-tolerant conifers such as western hemlock [Tsuga heterophylla (Raf.) Sarg.], and western redcedar {Thuja plicata Don ex D. Don in Lamb.) under the hardwood canopy. However, this has not happened on the Quinsam Flats where natural regeneration of conifers is very sporadic. As a result, no considerable structural change of these forests is expected in the near future. This atypical situation suggests a unique pattern of secondary succession. Fletcher Challenge Canada Ltd. began a rehabilitation project in 1980. This program was based on the assumption that sites on the Quinsam Flats are capable of supporting productive growth of Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco]. About 400 ha of hardwood stands were rehabilitated but the survival and growth of planted Douglas-fir have not been satisfactory. The early annual height increment of surviving Douglas-fir seedlings is about 10 - 50 cm which is low in comparison to other sites in the area where the height increment ranges from 60 to 130 cm (R.E. Carter, pers.comm.). The poor growth performance of Douglas-fir seedlings on the Quinsam Flats is related to several factors. Firstly, Carter found that the root system of these seedlings was unusually poorly developed with very few fine feeder roots present. This was particularly obvious on wetter sites. Secondly, many seedlings showed disease 2 and insect damage symptoms in the stem such as open cankers, blocked resin canals, dead tops and lateral shoots. The combination of insect (Laspeyresia pseudotsugae) and pathogen {Nitschkia molnarii, Pragmophora pithia, Schlerophoma spp.) attack was a major cause of the top dieback in 1985/86. These pathogens are considered second degree fungi (Dr. A. Funk, pers. comm.) which indicates that the seedlings were already in a weakened physiological condition when infected. Apparently, the success of an intended large-scale rehabilitation project could be jeopardized under such circumstances. In addition, the unique environment of these hardwood ecosystems has not been studied enough to allow for their satisfactory manipulation. Therefore, it was suggested to carry out an ecosystem classification study which would attempt to reveal the factors likely responsible for the poor growth of Douglas-fir seedlings on the Quinsam Flats as well as to enable site-specific recommendations-mainly for tree species selection. Silvicultural decisions should be based on knowledge of the relationship between site quality and growth performance of different tree species. Using the biogeoclimatic ecosystem classification (BEC) system this study was designed to identify qualities of forest sites and to provide information which would improve the results of the rehabilitation project on the Quinsam Flats. 3 MATERIALS AND METHODS Sampling The location of 84 study plots was based on a reconnaissance survey which aimed to assess the extent of floristic and soil variation in hardwood stands. Each sample plot, approximately 400 m2, was subjectively selected to represent an area relatively uniform in topography, soils, and vegetation. All established plots were considered to represent segments of the entire vegetation and environmental gradient occurring in mid-seral hardwood ecosystems on the Quinsam Flats. To obtain information about early-seral vegetation, additional 22 study plots, each 25 m2 in size, were established on clearcuts with histories of different site preparation. Vegetation and Site Description The vegetation description was carried out according to the Braun-Blanquet method as modified by Krajina (Brooke et al. 1979). At each plot, the cover of all plant species (except for epiphytes and species growing on decaying wood and rock fragments) was estimated and recorded. Vegetation within a plot was stratified into four layers (Table 1) and percent cover for each layer was recorded (Table 2). Nomenclature followed Hitchcock et al. (1955-1969) and Taylor and McBryde (1977) for vascular plants, Ireland et al. (1980) for bryophytes, and Hale and Culberson (1970) for lichens. 4 Table 1. Description of vegetation strata (Brooke et al. 1979). Stratum Description tree layer trees over 10 m in height shrub layer all woody plants < 10 m but > 15 cm in height herb layer all herbaceous plants and small woody plants moss layer bryophytes and lichens Table 2. The Domin-Krajina species significance scale (Brooke et al. 1979). Code Mean cover value (%) Range of the cover values (%) + 0.2 0.1 - 0.3 1 0.7 0.4 - 1.0 2 1.5 1.1 - 2.0 3 3.5 2.1 - 5.0 4 7.5 5.1 - 10.0 5 15.0 10.1 - 20.0 6 26.5 20.1 - 33.0 7 41.5 33.1 - 50.0 8 62.5 50.1 - 75.0 9 87.5 75.1 - 100.0 The site description was carried out according to Walmsley et al. (1980). Each sample plot was described in terms of selected environmental factors such as slope, groundwater table, drainage, microtopography, parent material, forest floor, soil moisture and nutrient regime (Green et al. 1984), soil particle size (Canada Soil Survey Committee 1978), and ground coverage of humus, exposed mineral soil, decaying wood, rocks, and water. 5 On each plot, 2-5 trees were measured for diameter at breast height, total height, and age in order to determine site index (SI, m/50 years). Site index for Douglas-fir, and red alder was determined according to Mitchell and Polsson (1988); site index for black cottonwood was determined according to Hegyi et al. (1979). The soils and humus forms were described according to Canada Soil Survey Committee (1978) and Klinka et al. (1981), respectively. One or two soil pits were dug, depending on variation in microtopography. The soil pits were dug to an impermeable layer which, in most cases was a compacted gleyed Cg horizon. Soil Physical and Chemical Properties A limited soil sampling for physical and chemical analyses was carried out in order to verify field identification of soil moisture regimes and soil nutrient regimes. Soil samples were collected from 10 study plots thought to be the most suitable for the growth of conifers. These 10 plots were randomly chosen from 42 plots which represented a relatively drier portion of sample population. Composite mineral samples were taken at 0 - 30 cm depth from three faces of the soil pit used for description in each sample plot. All composite samples were air-dried, sieved through a # 10 (2.0 mm) sieve, and analyzed for texture and selected chemical properties. Soil bulk density samples were taken for the upper 30 cm of mineral soil at three systematically located points in each study plot and their volume was measured as the volume of water required to fill the resulting hole. Samples were 6 oven-dried for 24 hours at 105 °C and bulk densities were calculated following the procedure outlined in Klinka e ra / . (1981). Soil pH was measured with a pH meter in 0.01 M CaCl2 suspension. Mineralizable nitrogen (N) was determined by the anaerobic incubation method of Waring and Bremner (1964). Total carbon (C) was determined using a Leco Induction Furnace (Bremner and Tabatabai 1971). Total nitrogen was determined by semimicro-Kjedahl digestion followed by colorimetric estimation of NH4-N using a Technicon Autoanalyser (Anonymous 1976). Phosphorus (P) was determined by the extraction procedure of Moehlich (1978). Available calcium (Ca), potassium (K), and magnesium (Mg) were measured by extraction with Morgan's solution of sodium acetate at pH 4.8. Sulfate-S was determined by ammonium-acetate extraction (Bardsley and Lancaster 1965). Vegetation and Site Classification The biogeoclimatic ecosystem classification (BEC) was used to produce both vegetation and site classification. The BEC system is based on the polyclimax concept (Tansley 1935) and organizes ecosystems at local, regional, and chronological levels to show relationships among them in form, space, and time (Pojar e r a / . 1987). At the local level the ecosystems are organized according to affinities in their vegetation and site properties. This was accomplished in this study by vegetation and site classification. At the regional level, the ecosystems are organized according to their distribution in vegetation-inferred, climatic space. This is done by zonal classification producing biogeoclimatic units. Finally, at the chronological level the distinguished 7 vegetation units for a given site unit are arranged into a site-specific chronosequence according to disturbance, treatment, and successional status. Although it is recommended to use vegetation of climax or near-climax ecosystems in vegetation classification (Pojar et al. 1987), this study had to analyze vegetation in mid-seral stages as there was not any old growth forest in the study area. The vegetation classification was based on the presence and cover of plant species, using the Braun-Blanquet tabular method (Westhoff and van der Maarel 1980), diagnostic criteria proposed by Pojar et al. (1987), and a computerized tabling program (Emanuel 1989). The floristically uniform groups of study plots were obtained by reciprocal averaging analysis (Gauch 1977) performed on a correlation matrix (Noy-Meir and Whittaker 1977). The diagnostic combination of species (DCS) was used as a sole differentiating characteristic to organize plant communities into a hierarchy of vegetation units - plant subassociations, associations, alliances, and orders. Plant communities change overtime due to succession, continually dating the results of vegetation classification. Therefore, it is more meaningful to classify ecosystems on the basis of their environmental properties particularly those which are relatively stable overtime. This need is fully recognized by incorporating of site classification. Site classification is based on a concept of ecological equivalence (Cajander 1926, Bakuzis 1969). This concept assumes that sites with the same or equivalent physical properties have a potential to develop similar climax vegetation. Site association as a basic category in site classification is derived from a late-seral, near-climax, or climax plant association(s) or subassociation(s), and is characterized by combinations of climate, soil moisture and nutrient regimes, and, if appropriate, by other environmental factor(s) strongly influencing the development of parent vegetation units. Therefore, in site classification vegetation serves only as an accessory 8 characteristic by using plant species as indicators of certain environmental attributes. Because there are no old growth forests in the study area site associations were derived from mid-seral plant associations. Each site association can be divided into site series according to climate to obtain climatically more consistent units. As the entire study area occurs within the same regional climate (biogeoclimatic subzone), each site association then corresponds to a site series. The most specific category of site classification is a site type. To form edaphically more consistent classes, site series were divided into site types according to important edaphic factors thought to affect ecosystem response to management (cf. Soil Survey Staff 1975). Site type then represents an ecosystem unit uniform in the largest number of environmental properties (Pojar etal. 1987). Numerical Analysis of Vegetation and Site Units A spectral analysis (Klinka and Krajina 1987) was performed to characterize distinguished ecosystem units in terms of frequencies of indicator species groups (ISG's) for a given site attribute (e.g., soil moisture and soil nutrients regimes). These frequencies which represent relative proportion of indicator species based on species cover were used to produce spectral histograms (Emanuel 1989). Principal component analysis (PCA) (Fox and Guire 1976) was used to investigate environmental or biological factors which account for most of variation in vegetation. The PCA was performed on correlation matrix based on mean species significance. The testing of discreteness of vegetation and site units was accomplished by calculating 95 % confidence ellipses and 9 through ANOVA on the scores of the first two principal components with the subsequent use of Scheffe's multiple comparison of group means (Zar 1984). Ecosystem Interpretation The main practical purpose of the BEC is to facilitate application of our knowledge and experience about vegetation-environment relationships to forest management. Ecologically sound and economically successful forest resource management requires that (a) a forest is stratified (classified) into strata (units) each representing different site quality, different vegetation and productivity potential, and (b) a specific set of silvicultural treatments for each stratum is applied. Ecosystem interpretations can then be defined as recommendations for specific uses or manipulations of ecosystems derived from ecological reasoning (Klinka and Krajina 1986) and management objectives. After the stratification of hardwood forest it was relatively easy to interpret each stratum in terms of a rehabilitative silvicultural regime. Knowledge of site quality characteristics, the ecological characteristics of trees and the influence of the environment and biotic community on tree growth were used to recommend the most suitable tree species and planting microsites for different strata. In most cases the interpretations made are reasonable alternatives which can be supported by indirect evidence. Tree species trials and the Douglas-fir and grand fir growth performance study (Appendix 5) were used to provide direct evidence for the most important interpretation, i.e. tree species selection. Site type - the taxonomic unit homogenous in the largest number of vegetation and environmental properties was used as a basic unit for interpretation. 10 This study followed the tree species selection principles based on ecological factors, management factors, and tree species suitability criteria as outlined in Klinka and Feller (1984) for southwestern British Columbia. Tree species were selected using the following criteria: (1) maximum sustainable productivity; (2) crop reliability; and, (3) silvicultural feasibility, with timber production as the management goal. The optimization of species selection was determined subjectively, therefore all species options should be considered as approximations. Tree Species Trials Site-specific interpretations for rehabilitation of hardwood stands on the Quinsam Flats were corroborated by three tree species trials. The five species included in these trials were: black cottonwood, Douglas-fir, grand fir [Abies grandis (Dougl. ex D.Don) Lindley], western redcedar, and Sitka spruce [Picea sitchensis (Bong.) Carr.]. The trials were established on clearcuts with different histories of site preparation. Altogether 2200 seedlings were planted as bareroot, 1+1 stock except for black cottonwood which was planted as 1 m-long whips. The initial height was measured in June 1987 followed by measurements for the first and second growing season in November 1987 and 1988, respectively. Two species-site trials were set up to examine species growth performance of the five species in relation to two site preparation methods. Each trial involved two blocks with 300 seedlings, 60 of each species planted randomly in each block. The first species trial was located on sites prepared by scarification and involved two blocks, both belonging to the Lonicera-Achlys site association. 11 The second species-site trial was established on artificially mounded sites. Mounds were made as parallel ridges and seedlings were planted on the top. Two blocks were situated on sites with relatively high (> 1 m) and low (< 1 m) mounds, respectively. The third trial was established to examine the effect of site and microsite (mounds and depression) on growth performance of the five species. This trial, involving four blocks was set up on a relatively undisturbed site harvested by a cable system. Two blocks were situated within the Lonicera-Achlys and Lonicera-Carex site associations, respectively (Table 3). Table 3. The planting design for the species-site-microsite trial. Site association Lonicera-Achlys Lonicera-Carex Number of blocks 2 2 Seedlings/block 300 200 Seedlings/microsite 150 100 Seedlings/species 60 40 Seedlings/species/microsite 30 20 The initial evaluation of growth performance was based on seedling mortality and height increment for two growing seasons. The hiearchical (nested) analysis of variance (Zar 1984) was used to investigate differences in height increment. Mounded and scarified trials were analyzed together with site preparation, block, and species as factors, and total height increment for 1987 and 1988 as the dependent variable (Table 4). 12 Table 4. Designs for nested ANOVA used in this study. Source of variation Degrees of freedom Species-site trial Site preparation 1 Block 1 Species 3 Site preparation-Species 3 Species-site-microsite trialSite association 1 Block 1 Microsite 1 Species 3 Site association-Species 3 The species-site-microsite trial (Table 4) was analyzed separately using site association, block, and microsite (mound and depression) and species as factors, and total height increment for 1987 and 1988 as the dependent variable, Both models were first determined for all possible interactions but only site preparation-species and site association-species were found significant. The analyses were performed using SYSTAT statistical software (Wilkinson 1988). Site Mapping An approximately 50 ha-area on the Quinsam Flats was selected to demonstrate the feasibility of site mapping and to show the pattern of site types. Site type was used as a basic mapping unit and mapping was accomplished using the transect method. The placing of transect lines followed examination of forest cover maps and aerial photographs. All transect lines were 50 m apart and run 13 perpendicularly to the baseline established in an east-west direction through the area. The identification was done every 25 m along the transect by examining an area of about 50 m2. The number of natural mounds (microsites) suitable for conifer regeneration was recorded wherever they were present. The mapping was carried out in April 1988 with compass and measuring tape as basic tools to locate the position of each identification point. The final map was produced in a scale of 1:5,000. 14 THE STUDY AREA Location The Elk River Tree Farm is located on the east coast of Vancouver Island, British Columbia, west to southwest of Campbell River (Figure 1). The hardwood stands are concentrated in the eastern portion of the Tree Farm on the Quinsam Flats which are situated at about 50O N and 125° 20' W. Figure 1. Approximate location of the study area. 15 Climate The Quinsam Flats are located within the Very Dry Maritime Western Hemlock (CWHxm) subzone and are under the influence of a cool mesothermal climate (Cfb) characterized by cool and relatively dry summers and mild rainy winters (Table 5, Threwartha 1968). In general, southwestern coastal British Columbia is under a strong maritime influence and does not experience seasonal extremes in temperature. The weather throughout the year can be described in terms of two distinctive periods, relatively dry summer and rainy winter. Precipitation in winter is particularly high on the west coast of Vancouver Island. The east coast receives relatively less precipitation regardless of season due to a rain-shadow Table 5. Means and standard deviations (in parenthesis) of some climatic characteristics for the Campbell River Airport (Environment Canada 1982). Characteristic Value Total annual precipitation (mm) 1406.0 (214.9) Total precipitation April - September (mm) 323 (NA) Mean precipitation - driest month (mm) 37.4 (23.7) Mean precipitation - wettest month (mm) 250.5 (76.2) Mean daily temperature - warmest month (OC) 16.6 (1.1) Mean daily temperature - coldest month (OC) 0.4 (2.1) effect of the Vancouver Island Coast Mountains and, as a result it commonly experiences summer water deficit. The study area receives only 23 % of total annual precipitation during the growing season from April to September. 16 The climatic data presented in Table 5 are based on the 30-year normals recorded for the Campbell River Airport station which is located at the eastern limits of the study area. Physiography and Soil Parent Material Flat and slightly sloping terrain prevails throughout the study area with elevation ranging between 100 - 150 m above sea level. Due to a gentle relief, the Quinsam River - the major waterway - has developed a series of winding curves and cut U-shaped ravines through marine deposits. In some parts, marine sediments have been completely eroded and the river bed reached predominantly sedimentary rock formations. Most of the soils on the Quinsam River Flats were formed from silty marine deposits. These materials were deposited after the last (Fraser) glaciation during the period of isostatic rebound. Sandy glacio-fluvial materials are present to a lesser extent and occur particularly in the eastern part of the study area. These materials were deposited directly by water coming from the receding glacier. In some areas, usually in depressions, the soils have developed from organic deposits under the influence of excessive moisture. 17 Vegetation The hardwood stands on the Quinsam Flats originated from natural regeneration after a fire in 1938. The remnants of the original old growth forest -decayed stumps and logs of Douglas-fir and western redcedar within the hardwood stands - indicate an uneven spatial distribution of coniferous trees. The tree layer of these hardwood stands includes mainly red alder, black cottonwood, and bigleaf maple (Acer macrophyllum Pursh), with red alder as a constant dominant species. The vigor of red alder decreases with decreasing drainage (aeration); it grows best on coarse alluvial soils. Black cottonwood is usually found as a dominant tree and its distribution is limited to relatively wet sites. Bigleaf maple grows mainly on river benches. Trembling aspen (Populus tremuloides Michx) and lodgepole pine (Pinus contorta Dougl.) are confined to sites with very poor drainage where they form an open tree layer in otherwise shrub-dominated communities. Coniferous species do occur in the dominant canopy position in the hardwood stands. They include most frequently Douglas-fir; infrequent species are western hemlock, Sitka spruce, western redcedar, and grand fir. Advance regeneration of all coniferous species under the hardwood canopy is very low and confined mostly to natural mounds which apparently represent the most suitable microsites for conifer regeneration. Shade-intolerant Douglas-fir is practically absent, western hemlock regenerates on decaying wood and the only species with relatively higher rates of regeneration under the hardwood canopy are Sitka spruce and, to a lesser extent, western redcedar. Rubus spectabilis is the most common species in the shrub layer (mean cover = 20 %). Under favorable conditions this shrub forms a dense thicket up to 3 m high. Other species such as Lonicera involucrata, Symphoricarpos albus, 1 8 Rosa gymnocarpa, Rosa nutkana and Cornus sericea are very common. Poorly drained, wettest sites are typically inhabited by Spiraea douglasii, and Salix spp. Disturbed, open sites frequently feature Rubus parviflorus. Hardwood forests on the Quinsam Flats are characterized by a relatively large number of herbaceous species. However, the species diversity decreases sharply with increasing soil moisture. Polystichum munitum, Achlys triphylla, Osmorhiza chilensis, and Dicentra formosa typically occupy relatively drier sites while on wetter sites Stachys cooleyae, Trautvetteria caroliniensis, Carex obnupta, and Oenanthe sarmentosa are dominant. The moss layer is mostly poorly developed and consists typically of Plagiomnium insigne, Kindbergia oregana, Kindbergia praelonga, Rhytidiadelphus loreus, and Rhytidiadelphus triquetrus. The only exeption is Fontinalis howelii which is the dominant species in small, wet depressions. A number of depressions have developed into marshes with semi-terrestrial to semi-aquatic communities where the most characteristic species are: Spiraea douglasii, Juncus effusus, Juncus ensifolius, Potentilla palustris, Typha latifolia, Epilobium minutum, Galium trifidum, Carex cusickii, Carex leptalea, and Carex interior. 19 RESULTS AND DISCUSSION Soil Moisture Conditions on the Quinsam Flats High soil water holding capacity as a result of the fine soil texture and flat topography are the main reasons for poor drainage on the Quinsam Flats. Due to unequal distribution of precipitation the effect of poor drainage becomes most obvious in rainy winter season when the groundwater table generally absent in summer, frequently rises above the soil surface. It is at this time, when the combined effect of poor drainage and high water table accounts for high incidence of gleying. As a result of seasonal water table fluctuation soils on the Quinsam Flats are usually at or above field capacity for a relatively long period of time (November to March). In addition, soil water is usually poorly oxygenated due to very slow lateral movement resulting from the flat topography. Such conditions are particularly detrimental for growth of Douglas-fir which has very low flood tolerance (Krajina etal. 1982). Slowly moving, poorly oxygenated water has a negative effect on respiration of roots which, in this relatively mild climate continue growing during the wintertime. An examination of Douglas-fir seedlings revealed high mortality of fine feeder roots apparently due to excessive moisture. In winter the only seedlings relatively unaffected were those established on well-aerated soils on mounds. Furthermore, the high water table reduces potential rooting depth thus increasing susceptibility to windthrow and summer drought. Taking the above into consideration, the seasonal water table fluctuation is regarded as the main reason for the unsatisfactory growth of Douglas-fir on the Quinsam Flats. A fluctuation in the water table occurring in similar environmental conditions was described by Roemer (1972) on the Saanich Peninsula. Figures 2 and 3 show soil development under different soil moisture conditions. Gleyed Humo-Ferric Podzol (Figure 2) represents soil with well-aerated upper horizons occurring typically on natural mounds. Gleysolic soils have developed on sites strongly influenced by a fluctuating water table or under permanently wet conditions as indicated by the summer groundwater table shown in Figure 3. Figure 2. A typical soil profile of a Gleyed Humo-Ferric Podzol occurring on natural mounds within hardwood stands. Figure 3. The soil profile (Orthic Gleysol) featuring a high summer water table. Vegetation Classification A synopsis of distinguished vegetation units according to their categorical rank is given in Table 6. Two alliances (p.all.'s), four plant associations (p.a.'s), and two subassociations (p.sa.'s) were recognized. Diagnostic combinations of species for these vegetation units are presented in Table 7. The Alnus-Polystichum p.all. represents plant communities where the tree layer is dominated by red alder with frequent occurrence of black cottonwood. Rubus spectabilis is the most common shrub and the herbaceous layer features a variety of species, typically Polystichum munitum, Osmorhiza chilensis, and Achlys triphylla. 22 The Spiraea-Carex p.all. represents the wetland, marginally forested communities. These are typically dominated by shrubs such as Spiraea douglasii and Salix spp. Carex obnupta and Oenanthe sarmentosa are the diagnostic species in the herb layer. Table 6. A synopsis of vegetation units distinguished in hardwood stands on the Quinsam Flats. Alliance Association Subassociation Alnus-Polystichum Alnus-Polystichum Alnus-Disporum-Typic Alnus-Disporum-Stachys Alnus-Lonicera Alnus-Lonicera-Dryopteris Alnus-Lonicera- Trautvetteria Spiraea-Carex Carex-Oenanthe Carex-Fontinalis The BEC system allows the formation of phases within any distinguished vegetation unit. This is done to emphasize important vegetation characteristics other then those used as differentia (Pojar et al. 1987). The Heracleum (lanatum), Oplopanax (horridus), and Lysichitum (americanum) phases were recognized as floristic variations of the Alnus-Disporum-Typic p.sa., Alnus-Lonicera-Dryopteris p.sa., and Carex-Oenanthe p.a., respectively. Although these phases are considered to represent distinct plant communities, their sampling was inadequate for a sufficient diagnosis. The distinct vegetation composition is usually a reflection of specific site properties making phases Tab le 7. D i a g n o s t i c combinat ion of s p e c i e s fo r v e g e t a t i o n u n i t s d i s t i n g u i s h e d In hardwood ecosyBtems on the Quinsam F l a t s . V e g e t a t i o n u n i t Number of p l o t s V e g e t a t i o n u n i t s and s p e c i e s D l a g n o s t I c valued 20 15 17 19 9 4 Presence c l a s s 2 a n d mean s p e c i e s s i g n i f i c a n c e s A l n u s - P o l y s t l c h u m p . a l l . Achlys trlphyl1 a ( d . c ) V 4 V 5 V 4 IV 3 111 2 Alnu3 rubra (dd) . V 8 V B V 8 V 7 IV 5 5 2 Carex deweyana (d) IV 2 V 3 IV 2 IV 1 II 1 CIaytonla slblrlca ( d , c ) V 4 V 4 IV 2 IV 3 I + Galium trif1orum (d) III 3 V 4 IV 2 IV 2 III 1 2 + Osmorhtza chl1ensl3 (d) V 4 V 4 IV 3 III 3 II 1 PIaglomnlum 1nslgne (d) IV 2 IV 4 III 2 III 3 II 1 Polystichum munltum ( d . c d ) . V 5 V 5 V 5 V 3 II 2 Rubus spectabl11s ( d . c d ) V 6 V 6 IV 5 V 5 IV 2 Symphorlcarpos albus (d) III 3 III 4 IV 3 IV 4 I •f A l n u s - P o l y s t l c h u m p . a . Acer macrophyllum (d) III 5 II 3 I 1 I + Of cent ra formosa (d) IV 4 IV 4 II + II + I + 0fsporum hookerl (d) V 2 IV 2 I + I Sambucus racemosa (d) IV 3 III 3 I 1 I + I + A lnus-Dfsporum-TypIc p . s a . A c e r m a c r o p h y l l u m A1nus-D4sporum-Stachys p . s a . (dd) Equlserum arvense (d) I + III 1 IV 1 IV 1 IV 1 Lonicera Involucrata (d) I + III 2 V 3 V 4 V 4 4 Myceli3 mural 1s (d) 11 1 IV 3 IV 2 III + I I 2 Staehys cooleyae (d) I 1 IV 3 IV 3 IV 3 II 3 A1nus-Lon1cera p . a . Carex obnupta (d) I + IV 2 IV 5 V S 5 7 Lonicera Involucrata ( d . c ) I + III 2 V 3 V 4 V 4 4 1 Trautvetterla carol 1nlensls ( d . c d ) III 2 III 4 IV 5 V 5 IV 3 A l n u s - l o n i c e r a - D r y o p t e M s p . s a . D r y o p t e r f s expansa (d) Kindbergia oregana (d) A l n u s - L o n l c e r a - T r a u t v e t t e r l a p . s a . IV II IV II II I Cornus serlcea (d) I + II 2 II 2 IV 4 III 4 Oenanthe sarmentosa (d) I + II 1 II 2 IV 3 V 5 Rosa nutkana (d) I + I 1 IV 3 II 4 2 S p l r a e a - C a r e x obnupta p . a l l . Carex obnupta ( d . c d ) Sallx laslandra (d) Spiraea douglasii ( d . c d ) Carex (obnupta)-Oenanthe p . a . A c h l y s trlphylla Lyslchlturn amerlcanum Mentha arvensls Oenanthe sarmentosa Scfrpus mfcrocarpus Scutelarla IaterlfI ore Veronica amerlcana Carex ( o b n u p t a ( - F o n t t n a l I s p.a . Drepanocladus uncinatus (d) Fontlnalls hovel I f f ( d . c d ) Populus tremuloldes ( d . c d ) Sallx hookerlana ( d . c d ) Sallx sltchensl3 ( d . c ) Spiraea douglasii (dd) Trlentalls arctlca (d) Veronica scutelIata (d) IV 2 I + (d) V 4 V s V 4 IV 3 III 2 (d) I + I 3 II 2 III 5 (d) I + I + I + III 2 ( d . c d ) I + II 1 II 2 IV 3 V 5 (d) I + III 3 (d) I 1 III 3 (d) I + III 1 3 1 II + 5 8 I 2 11 4 5 7 II 1 5 5 II 3 III 4 S 4 II 1 V 5 S 8 I + 4 2 I + I + 4 2 ^Species d i a g n o s t i c v a l u e s : d - d i f f e r e n t i a l , dd - dominant d i f f e r e n t i a l , cd - constant dominant, c - c o n s t a n t , l c - Important companion (Pojar et a l . 1987). 2Presence c l a s s e s as percent of f requency: I •= 1-20, II ° 21-40, III " 41-60, IV • 61-80. V • 81-100. If S p l o t s or l e s s , presence c l a s s Is a r a b l e va lue ( 1 - 5 ) . 3Spec1es s i g n i f i c a n c e c l a s s midpoint percent cover and range: + » 0.2 (0.1 - 0 . 3 ) , 1 • 0.7 (0 .4 - 1 .0) . 2 - 1.6 (1.1 - 2 . 1 ) . 3 • 3.6 (2 .2 - 5 . 0 ) . 4 = 7.5 (5.1 - 10.0) , 5 = 15.0 ( 10.1 - 2 0 . 0 ) , 6 - 26.5 (20.1 - 3 3 . 0 ) . 7 =• 41.S (33.1 - 5 0 . 0 ) , 8 - 60 .0 (50.1 -7 0 . 0 ) , 9 - 85 .0 (70.1 - 100). 24 very useful for the identification of site units (types) in the field. Roemer (1972) described several vegetation units on Saanich Peninsula which are akin to vegetation units distinguished in this study. The Spiraea-Carex-Oenanthe p.sa. appears to be, to some extent, floristically and environmentally similar to Roemer's Populus-Pyrus vegetation unit and its Oenanthe variant. They both occur on sites with flat or depressional topography, fine textured soils, and poor drainage. In both cases, water table is very high in winter. The major floristic link between these units is the presence of Carex obnupta, and Oenanthe sarmentosa in the herbaceous layer and occurrence of shrubs such as Cornus sericea, Malus (Pyrus) fusca, Lonicera involucrata, and Symphoricarpos albus. The Oplopanax phase of the Alnus-Lonicera-Dryopteris p.a. recognized on the Quinsam Flats resembles floristically and environmentally the Alnus-Athyrium vegetation unit on Saanich Peninsula. They both occur on slopes with plenty of seepage water or on stream edges. The floristic similarity between these two units is reflected in the presence of red alder as a major species in the tree layer, and common occurrence of Rubus spectabilis in the shrub layer. There are relatively many herbaceous species common to both units such as Lysichitum americanum, Athyrium filix-femina, Polystichum munitum, Tiarella trifoliata, Streptopus amplexifolius, Equisetum telmateia and Carex deweyana. The major difference is the presence of Oplopanax horridus, and absence of western redcedar in the Oplopanax phase compared to the Alnus-Athyrium vegetation unit. There are also minor differences. Oemleria cerasiformis was not found in the Oplopanax phase of the Alnus-Lonicera-Dryopteris p.a.and herbaceous species such as Adiantum pedatum, Gymnocarpium dryopteris, Trautvetteria caroliniensis, and Osmorhiza chilensisdo not appear in the Alnus-Athyrium vegetation unit. 25 Finally, the Alnus-Disporum-Typic p.sa. of the Quinsam Flats can be compared to Roemer's Abies-Alnus vegetation unit. Both these units represent a transition between hardwood and softwood ecosystems. The tree layer is, in both cases, dominated by red alder with Douglas-fir representing the Alnus-Disporum-Typic p.sa. compared to grand fir in the Abies-Alnus vegetation unit. The shrub layer is in both units represented by Rubus spectabilis, and Sambucus racemosa. The composition of herbaceous species is very similar featuring Polystichum munitum, Tiarella trifoliata, Claytonia sibirica, Mycelis muralis, and Tellima grandiflqra. Plagiomnium insigne represents the moss layer in both units. 26 Site Classification Differentiation of Site Units No vegetation unit except for the Carex-Fontinalis p.a. was associated with an exclusive physical property. Recognizing soil moisture as the factor with the greatest influence on vegetation, the depth of gleying (cm) as a direct indication of the depth of winter water table was selected as a differentiating characteristic (Table 8 and Figure 4) to delineate site associations. The occurrence of organic soils and a summer water table were used as accessory characteristics. Table 8. Classes of differentiating and accessory characteristics used to delineate site associations on the Quinsam Flats. Depth of gleying (cm) Water table Organic soils >35 absent absent 20-35 absent absent <20 common sporadic < 20 (closed depression) common absent Four site associations (s.a.'s) and four site series (s.s.'s) were produced by regrouping the study plots. These were further divided into twelve site types (s.t.'s) (Table 9). The explanation of diagnostic edaphic adjectives is given in Table 10. 27 Table 9. A synopsis of site units distinguished on the Quinsam Flats. Site association Site series Site type Rubus-Achlys CWHxm: Rubus-Achlys CWHxm: Rubus-Achly.s/Typ\c1 CWHxm: Rubus-Achlys/Deep CWHxm: Rubus-Achlys/OrXs\e\n CWHxm: Rubus-Achlys/Sandy CWHxm: Rubus-Achlys/S\ope Lonicera-Achlys CWHxm: Lonicera-Achlys CWHxm: Lonicera-Achlys/Typ'icZ CWHxm: Lon/cera-Ac/7/ys/Gleysolic CWHxm: Lonicera-Achlys/OttsXe'm CWHxm: Lonicera-Achlys/Ravlne CWHxm: Lonicera-Achlys/Sandy CWHxm: Lon/cera-/4cft/ys/Stream-edge Lonicera-Carex CWHxm: Lonicera-Carex CWHxm: Lonicera-Carex/Typ\c3 CWHxm: Lon/cera-Carex/Organic CWHxm: Lon/'cera-Carex/Ortstein CWHxm: Lon/'cera-Carex/Stream-edge Spiraea-Carex CWHxm: Spiraea-Carex CWHxm: Sp/raea-Carex/Typic4 28 Table 10. Definitions of the diagnostic edaphic adjectives used to differentiate site types (after Klinka and Krajina 1986). Deep Gleysolic Organic Ortstein Ravine Sandy Slope Stream-edge Typicl Typic2 Typic3 Typic4 loamy, Orthic, Sombric, Gleyed or Gleyed Humo-Ferric Podzols with depth of gleying more than 50 cm a soil which belongs to Gleysolic order a soil which belongs to Organic order presence of strongly cemented Bf horizon a soil with permanent seepage usually located on slopes along streams. Slope gradient may be > 35 % sandy, Gleyed or Gleyed Sombric Humo-Ferric Podzol a soil which has a slope gradient > 35 % with no permanent seepage a soil that borders and is influenced by permanent streams but is located neither on an active alluvial floodplain nor in a ravine loamy, Gleyed or Gleyed Sombric Humo-FerricPodzols with depth of gleying between 35-50 cm loamy, Gleyed or Gleyed Sombric Humo-Ferric Podzols with depth of gleying between 20-35 cm loamy Orthic Humic and Orthic Gleysols with depth of gleying < 20 cm loamy, or loamy skeletal Orthic Humic and Orthic Gleysols which occur within small area depressions with extremely slow subsurficial drainage 29 Soil Moisture Regimes Soil moisture regime (SMR) or hygrotope is defined as the average amount of soil water available annually for evapotranspiration by vascular plants over several years (Pojar et al. 1987). SMR can be described as potential or actual where the former is dependent only on soil properties and topography and independent of climate, while the latter determines the actual capacity of soil to supply water (Klinka etal. 1984). The classification of actual SMR is more convenient because it allows comparison of different soil moisture regimes regardless of climate. The method of quantitative classification of SMR is based on the annual water balance concept (Thornthwaite 1948) which takes into account precipitation inputs and evapotranspi ration and drainage losses within the system. Klinka et al. (1984) developed a tentative classification of actual SMR's for the Vancouver Forest Region based on the ratio of actual and potential evapotranspi ration and the presence of a water table. This classification was based on rapidly to moderately well drained, coarse-textured soils usually on slopes where gleying is not common and where there is no fluctuating water table. As the Quinsam Flats are characterized by poor drainage and strong seasonal fluctuation of the water table, the actual soil moisture regime classes do not apply in the study area. For instance, the moist to wet actual SMR classes of Klinka etal. (1984) represent sites with permanent seepage, sites which are water-receiving or even water-collecting based on topography. The SMR's on the Quinsam Flats are, on the other hand determined mainly by the unequal distribution of precipitation during summer and winter season. Using the combinations of actual SMR classes defined in Klinka et al. (1984) three tentative classes of actual SMR are proposed to describe soil water dynamics as follows: 30 (1) summer fresh/winter very moist (sF/wVM); (2) summer moist/winter wet (sM/wW), and (3) summer very moist/winter very wet (sVM/wVW). The characterization of actual SMR's on the Quinsam Flats was based on the depth of winter groundwater table indicated by the incidence of gleying (Figure 4). Spiraea-Carex & Lonicera-Carex Lonicera-Achlys Rubus-Achlys sVM/wVW sM/wW sF/wVM mineral soil surface winter groundwater table summer groundwater table Figure 4. Relationships among actual SMR's, the depth of summer and winter groundwater table, and distinguished site associations. 31 Soil Nutrient Regimes Soil nutrient regime is defined as the capacity of a soil to supply nutrients necessary for plant growth (Klinka etal. 1984). Soil nutrient regimes were determined based on environmental characteristics according to Green etal. (1984). The Rubus-Achlys, Lonicera-Achlys, and Lonicera-Carex s.a.'s. were estimated as nutrient-rich to very rich. The Spiraea-Carex s.a. was estimated as nutrient-medium. Quantitative chemical analysis was carried out for the Rubus-Achlys, Lonicera-Achlys, and Lonicera-Carex s.a.''s represented by five, four, and one 0-30 cm composite sample, respectively (Table 16). The allocation into actual nutrient regimes was done according to criteria of Klinka and Carter (1989) based predominantly on mineralizable N content in kg/ha. In order to compare results, nutrient concentrations had to be recalculated as a weight per unit area (kg/ha) (Table 11). This was done using mean bulk density and coarse fragment content. Additional information about quantitative classification of SMR available from Courtin etal. (1985) and Klinka and Kabzems (1987) were also taken into consideration. The results of chemical analysis clearly support the field assessment of SNR's in the study area. The Rubus-Achlys, and Lonicera-Carex s.a.'s can be described as nutrient-rich. The Lonicera-Achlys s.a. was classified as very rich due to higher content of total N, and extractable bases. In general, all three site units can be characterized as nutritionally rich and soil nutrient regime apparently does not represent a limiting factor in terms of tree growth. 32 Table 11. Nutrient content (kg/ha) and pH determined for three recognized site units. The numbers in parentheses are standard deviations. Site association1 PH minN total N K+Ca+Mg Rubus-Achlys 4.7 54 2338 974 (5 samples) (0.20) (27) (900) (935) Lonicera-Achlys 4.7 68 4903 2217 (4 samples) (0.16) (33) (1764) (2042) Lonicera-Carex 4.8 72 1972 1783 (1 sample) NA NA NA NA Recognized site units in relation to actual SMR and SNR's are presented in the form of an edatopic grid (Figure 5). 33 SOIL N U T R I E N T R E G I M E LU O LU CC LU DC I-co o O CO o E £• CD > S c 0) E E 3 CD £ -cu > c S o E e-co > <5 E E A very poor B poor C medium D rich E very rich S P I R A E A -C A R E X RUBUS - ACHLYS L O N I C E R A - A C H L Y S LONICERA - C A R E X Figure 5. Edatopic grid for site associations distinguished in hardwood ecosystems on the Quinsam Flats. 3 4 Site Units Rubus-Achlys s.a. Reference: Tables 9 and 12; Figures 5, 6, 7 and 8. The Rubus-Achlys s.a. was derived primarily from the Alnus-Polystichum p.a. and divided into five site types. As gleying occurs deeper than 35 cm (mean depth = 49 cm, Table 12) this site association represents relatively driest, imperfectly drained sites which are least affected by fluctuating water table (summer fresh/winter very moist). Loamy Gleyed Humo-Ferric Podzols and Vermimulls are the most common soil and humus form of this association. The dense tree layer (mean cover = 81 %) is composed of red alder, occasional bigleaf maple, and frequently contains dominant Douglas-fir. The shrub layer is typically represented by a dense cover of Rubus spectabilis with common occurrence of Sambucus racemosa (Figure 6). A sporadic advance regeneration of Sitka spruce, western redcedar, and western hemlock occurs on sites with discontinuous shrub layer. The constant dominant species in a floristically very diverse herb layer are Achlys triphylla, Osmorhiza chilensis, and Polystichum munitum (Figure 7). The occurrence of vigorously growing Heracleum lanatum (Heracleum phase) on some typic sites (commonly on river benches) appears to be related to compacted upper mineral horizons (Figure 8). In the absence of a large scale disturbance, the final stage of the secondary succession on the Rubus-Achlys sites is predicted to be an open-canopy, uneven-aged, patchy forest composed of western redcedar, Douglas-fir, Sitka spruce, and western hemlock with the canopy openings occupied by shrubs (mainly Rubus spectabilis). This scenario seems to correspond to the kind and distribution pattern of decaying stumps of the original old-growth forest. The Rubus-Achlys s.a. represents productive sites suitable for timber production and growth of a variety of crop species. The comparison of indicator plants and soil properties suggested in most cases a similar growth potential on mounds as well as in depressions. The inherent growth potential can be sustained by preserving aeration and natural drainage of these sites. Due to soil instability, disturbance within the slope site type should be avoided. Table 12. Mean values of selected environmental and vegetation characteristics of the distinguished site associations. Site association1 RA Number of plots 33 SMR (summer)^ F-M SMR (winter) M-VW SNR3 R Slope gradient (%) 8 Particle s ize 4 LS,L,S,SS Parent material F,M Forest floor thickness (cm) 2 Major rooting depth (cm) 38 Groundwater table (cm) Gleyed horizon depth (cm) 49 Strata A layer 81 coverage B layer 59 (%) C layer 76 Dlayer 6 LA LC SC 21 26 4 F-VM M-W M-W VM-W W-VW W-VW VR R M 3 0 0 L,S US LS,L F,M F,M,0 M 3 6 9 19 15 14 - 44 40 28 18 13 77 60 36 59 56 90 78 80 62 8 4 73 1 RA - Rubus-Achlys, LA - Lonicera-Achlys, LC - Lonicera-Carex, SC - Spiraea-Carex 2SMR - soil moisture regime; F - fresh, M - moist, W - wet, VW - very wet 3SNR - soil nutrient regime; M - medium, R - rich, VR - very rich 4LS - loamy-skeletal, L - loamy, S - sandy, SS - sandy-skeletal 5F - fluvial, M - marine, O - organic 36 Figure 7. An understory vegetation of the Rubus-Achlys site dominated by Polystichum munitum, and Achlys thphyllamXh sporadic advance regeneration of Sitka spruce and western hemlock. Figure 8. A Heracleum /anafcvm-dominated understory of some Rubus-Achlys sites. Lonicera-Achlys s.a. Reference: Tables 9 and 12; Figures 5, 9 and 10. The Lonicera-Achlys s.a. was derived from the Alnus-Polystichum and Alnus-Lonicera p.a.'s and divided into six site types. This site association represents imperfectly to poorly drained sites under increased influence of fluctuating water table (summer moist/winter wet) which is also reflected in depth of gleying between 20-35 cm (mean depth = 28 cm). Loamy Gleyed Humo-Ferric Podzols are still the most frequent soils but soils of Gleysolic order are also present. Mullmoders and Vermimulls are the major humus forms with occasional occurrence of Hydromoders and Hydromulls reflecting increasing moisture. 38 The tree layer (mean cover = 77 %) is dominated by red alder but the cover of this species is lower then in the previous unit in favour of black cottonwood. The most common shrubs are Lonicera involucrata, Rubus spectabilis, and Symphoricarpos albus. Achlys triphylla, Carex deweyana, Polystichum munitum, and Athyrium filix-femina are the major species representing herbaceous layer (Figure 9). Shrub layer of some permanent seepage sites is dominated by vigorous Oplopanax horridus {Oplopanax phase) with the occurrence of less common herbaceous species such as Habenaha unalaschaensis, and Listera caurina (Figure 10). The current plant composition on the Lonicera-Achlys sites indicates that the final stage of secondary succession is likely to be similar to that described for the Rubus-Achlys sites. The coniferous cover composed mainly of Sitka spruce and western redcedar is predicted to be slightly lower compared to the Rubus-Achlys sites. Frequent canopy openings will be occupied by shrubs. Stability of soil as a rooting substrate is likely to decrease with increasing moisture and trees will be more susceptible to windthrow. Any such disturbance may result in the exposure of mineral soil and the establishment of red alder. The Lonicera-Achlys s.a. represents sites suitable for timber production. It is the most variable unit in terms of site properties and two of the six distinguished site types impose some management restriction. The ravine site type occasionally occurs along active streams and on slopes with permanent seepage. These sites should be managed to prevent stream pollution and maintain slope stability. The stream-edge site type can be found along river channels in the study area. The best growth of red alder was observed within this site type along the Quinsam River. However, due to the proximity of streams, the timber production management on these sites should be carried out with extreme Figure 9. A Polystichum mu/i/'/um-dominated understory of the Lonicera-Achlys site with sporadic advance regeneration of Sitka spruce. Figure 10. An Oplopanax ftom'dus-dominated understory of the Lonicera Achlys/Rav'me s.t. 40 caution without causing any major site disturbance. In order to prevent erosion it is recommended to leave a protective tree belt along the river banks. Microtopography of the Lonicera-Achlys s.a. is very diverse and strongly mounded sites are common. In contrast to the Rubus-Achlys sites, mounds and depressions represent in this case microsites of different growth potentials due to the strong influence of the fluctuating water table. Wetter and drier conditions in depressions and on mounds respectively should be taken into consideration while making decisions about tree species selection. Lonicera-Carex s.a. References: Tables 9 and 12; Figures 5, 11 and 12. The Lonicera-Carex s.a. was derived from the Alnus-Lonicera and Carex-Oenanthe p.a.'s and was divided into four site types. This site association represents relatively wet, poorly drained sites (depth of gleying within 20 cm) under strong influence of fluctuating water table (summer very moist/winter very wet). The presence of a summer groundwater table is quite common and occurs mainly in subdued areas. The associated soils belong almost entirely to the Gleysolic order and Hydromoders and Hydromulls are the most common humus forms. The tree layer (mean cover = 60 %) is formed by red alder and black cottonwood with approximately equal representation. However, while the growth of black cottonwood appears to be the best in this site unit, red alder is visibly on decline suffering presumably from poor drainage. The shrub layer is dominated by Lonicera involucrata, and Rubus spectabilis with common occurrences of 41 Cornus sericea, Symphoricarpos albus, Physocarpus capitatus, and Malus fusca. The constant dominant species represented in the herb layer are Carex obnupta, Oenanthe sarmentosa, and Trautvetteria caroliniensis (Figure 1.1). The open-canopy, uneven-aged and very patchy forest composed mainly of western redcedar and Sitka spruce is predicted as the final stage of secondary succession. Most of coniferous regeneration will likely be confined to natural mounds which, in fact do not represent the Lonicera-Carexs.a. Reduced potential rooting depth due to high water table will further increase susceptibility to windthrow particularly in winter. The exposed mineral soil resulting from such disturbance will be invaded by red alder. Large canopy openings will be occupied by shrubs such as Lonicera involucrata, Cornus sericea, Physocarpus capitatus with the herb layer dominated by Carex obnupta. Increasing mortality of shade-intolerant hardwoods will result in expansion of shrubs which may, on sites with no advance regeneration of conifers develop into "brush fields". There are four site types distinguished within this site association but only the typic site type is suitable for wood production. The ortstein site type commonly occurs on coarse-textured soils on the Quinsam Flats. The development of an ortstein layer is due to different water regimes in winter and summer. During wintertime the upper soil horizons are eluviated and the lower part of soil profile is enriched with colloids. In.summer soils dry out and colloids (mainly Fe - oxides) are precipitated in the soil profile forming a very hard and often continuous water restricting layer. Drainage, especially in flat areas, is severely reduced and the presence of a high water table is common (Figure 12). Therefore, the ortstein site type is not suitable for wood production unless drainage is improved mechanically. The organic site type is characterized by the presence of organic soils with high to moderate decomposition of organic matter. Strongly reduced "blue" marine clays are commonly found underneath the organic layer. These soils developed mainly in depressions in the process of succession from aquatic to terrestrial ecosystems. They are at or above field capacity for most of the year and as such are not suitable for wood production. The Lysichitum phase represented by Salix spp., Cornus sericea, Lysichitum americanum, Spiraea Figure 11 . A Carex obnupte-dominated understory of the Lonicera-Carex s.a. Figure 12. A high summer water table occurring in the Lonicera-Carex s.a. as a result of an impermeable, ortstein layer (Lonicera-Carex/Or\s\e\n s.t.). douglasii, and Scirpus microcarpus is frequently associated with this site type. Carex obnupta in this case may or may not be present. The stream-edge site type occurs along slowly moving streams on the Quinsam Flats and was common in the area selected for mapping. Any disturbance within this site type should be avoided. Spiraea-Carex s.a. References: Tables 9 and 12; Figures 5 and 13. The Spiraea-Carex s.a. is the only ecosystem unit which is both floristically and environmentally unique. Therefore, this site unit is delineated exclusively by the presence of the Carex-Fontinalis p.a. It represents poorly to very poorly 44 drained sites located in small depressions with gleying occurring within 20 cm of mineral soil. Due to very compacted, fine-textured soils with no natural outlets the influence of fluctuating water table on these sites is reduced and the differences between summer and winter moisture regimes (summer very moist/winter very wet) are less pronounced. Summer water table within 30 cm frequently occurs on these sites. Soils belong exclusively to the Gleysolic order and Hydromoders are the most common humus form. The coarse fragment content was found to be unusually high on some sites (up to 60 %) and the soil had a higher portion of fine sands and clays. Particle size was estimated as loamy-skeletal with a relatively high percentage (about 30 - 50 %) of cobbles. Such a particle mixture could be the result of wave action mixing marine and glacial materials during isostatic rebound. The Spiraea-Carex s.a. represents a transition between forested and non-forested ecosystems. The Spiraea-Carex sites are floristically poor compared to other units. Red alder occurs sporadically and only as a shrub. Trembling aspen and occasionally lodgepole pine are the only species forming very open (max. 50 %) tree layer. This site unit is therefore better characterized by semi-terrestrial shrub communities represented by Spiraea douglassii and Salix spp. The herbal layer is completely dominated by Carex obnupta. The moss layer, relatively unimportant in this classification study is a unique feature of this unit with a high cover of Fontinalis howelii. A shrub-dominated {Spiraea douglasii) community is predicted to be the final stage of secondary succession on the Spiraea-Carex sites. It is possible, that due to continuous input of organic material the relief and potential rooting depth of these sites would be increased. Such action would likely alter the composition of the shrub layer in favour of terrestrial species such as Symphoricarpos albus, Rosa gymnocarpa, and Rosa nutkana. 45 The Spiraea-Carex s.a. represents sites unsuitable for timber production. These sites should not be disturbed as they can provide good habitat for deer and elk populations in terms of food and shelter. Figure 13. Atypical, Spiraea doug/as/V-dominated understory of the Spiraea-Carex s.a. An open tree layer is formed by trembling aspen. 46 Numerical Analysis of Vegetation and Site Units Principal component analysis (PCA) was performed on diagnostic species for vegetation units. The first two principal components accounted for 38.8 % of total variance and the first component alone explained 27.2 %. The PCA axis scores were retained and used in correlation analysis between individual species and first two PCA components (Table 13). Species with high positive and negative correlation to the first principal component were examined in relation to the environmental characteristics of each vegetation unit. This examination indicated that the first component is related to a soil moisture gradient. This assumption is based on a strong positive correlation of Carex obnupta, Spiraea douglasii, Salix spp., and Fontinalis howelii and negative correlation of red alder, Polystichum munitum, Dicentra formosa, and Achlys triphyllato the first principal component. It was expected however, that soil moisture would explain more then 27.2 % of the total variation in vegetation. The main reason for the low explained variance may be the relatively narrow environmental gradient between the driest and wettest vegetation units which results in relatively minor floristic variation. The second principal component accounts only for 11 % of variation in vegetation and its interpretation is not clear. Positively correlated species such as Symphoricarpos albus, Mycelis muralis, Stachys cooleyae, Lonicera involucrata, Plagiomnium insigne along with negatively correlated Rubus spectabilis, Dicentra formosa, and Sambucus racemosa suggest that the second principal component represents a combined effect of nutrient-richer regime, mounding and perhaps soil disturbance. 47 Table 13. Species correlations with first two components (R@ 0.01=0.28). Variable Component 1 Component 2 Carex obnupta 0.78 0.17 Populus tremuloides 0.65 0.04 Salix sitchensis 0.62 0.03 Rosa nutkana 0.39 0.50 Lonicera involucrata 0.35 0.58 Spiraea douglasii 0.81 - 0.10 Fontinalis howelii 0.60 -0.15 Salix hookeriana 0.58 -0.13 Trientalis arctica 0.48 -0.08 Oenanthe sarmentosa 0.42 -0.07 Malus fusca 0.41 -0.07 Polystichum munitum - 0.78 -0.02 Dicentra formosa - 0.61 -0.47 Disporum hookeri - 0.56 -.0.03 Dryopteris expansa -0.54 -0.12 Sambucus racemosa -0.40 -0.48 Rubus spectabilis -0.38 -0.61 Acer macrophyllum -0.35 - 0.14 Alnus rubra -0.74 0.11 Claytonia sibirica - 0.68 0.25 Achlys triphylla -0.63 0.42 Osmorhiza chilensis - 0.67 0.18 Carex deweyana - 0.49 0.33 Plagiomnium insigne -0.42 0.50 Mycelis muralis - 0.28 0.54 Symphoricarpos albus -0.27 0.70 Stachys cooleyae - 0.06 0.40 95 % confidence ellipses were used to ordinate distinguished vegetation units (associations and subassociations) along the first two PCA axis in order to test discreteness of each unit. Although there are some overlaps, the spread of vegetation units along the first PCA axis is clearly wider than along the second axis (Figure 14). ANOVA was performed to compare component scores for each vegetation unit with significant differences found only for the first axis. Scheffe's multiple comparison of group means for component scores of the first axis 48 indicated no difference between the Alnus-Disporum-Typic and Alnus-Disporum-Stachys p.sa.'s. The remaining units are discrete from this combined group and from each other. o d CM F i r s t p r i n c i p a l ax i s s c o r e s Figure 14. The ordination of 84 sample plots along the first two PCA axes based on diagnostic species showing centroids and 95 % confidence ellipses for the Alnus-Disporum-Typic (1), Alnus-Disporum-Stachys (2), Alnus-Lonicera-Dryopteris (3), Alnus-Lonicera-Trautvetteria (4), Carex-Oenanthe (5), and Carex-Fontinalis (6) vegetation units. 4 9 Spectral analysis (Klinka and Krajina 1987) based on life-form indicator species groups revealed several patterns but no sharp differences between the first five vegetation units (Figure 15) which appear to be arranged according to decreasing cover of deciduous trees, and increasing cover of deciduous shrubs and graminoids. The Carex-Fontinalis p.a. shows a somewhat different pattern due to much higher frequency (29 %) of mosses {Fontinalis howelii). The results of spectral analysis for soil moisture regime (Figure 15) do not fully reflect an assumed gradient of increasing soil moisture from the Alnus-Disporum-Typic p.sa. to the Carex-Fontinalis p.a. Especially the grouping of the Alnus-Disporum-Typic p.sa. as relatively drier than the Alnus-Disporum-Stachys p.sa. is not clear. It is based only on the presence of wet to very wet indicators (1 %). The assumption, that this 1 % can compensate for a 6 %-increase in moderately dry to fresh indicators in the Alnus-Disporum-Stachys p. sa. can be questionable. However, the complete absence of species indicating wet moisture regimes within the Alnus-Disporum-Typic p.sa. suggests sites higher in topography, with a lower groundwater table and generally drier soil moisture regime. The relatively high incidence of species indicating moderately dry to fresh, and wet to very wet moisture regimes within the Alnus-Disporum-Stachys and the Alnus-Lonicera-Dryopteris p.sa.'s is likely caused by mounding. Results of spectral analysis suggest soil moisture regime to be the most influential factor controlling the development of ecosystems on the Quinsam Flats. Life form 50 Alnus-Dlsporunr-Typlc p.sa. 1 2 i 3 4 S 6 7 9 7% 29% IX 18% Alnus-Disporun-Stachys p.sa. 11% 3% 28X 3X 4X 24% <X 19X Alnus-Lcnlcera-Dryopterls p.sa. 12X 6X 31X 3X 32% 2X 22X Alnus-Lonlcera-Trautvetterla p.sa. 13X 5% 21X 3% 27X 28X Carex (obnupta)-Oenanthe p.a. 8% 9X 23X 2% 9 J 1% 3% 16X 2% 28X Carex (obnupta)-Fontlnalls p.a. 5% 19X 26X 1% 15% 32X 2IX 2X 29% Soil moisture regime Alnus-Disporum-Typic p.sa. 1% 5X GO% Alnus-Dlsporum-Stachys p.sa. 34% 1 6 J 1% 2 3 J 1% 11% 53X Alnus-Lcnlcera-Drycpteris p.sa. 34% 3 4 5 6 )4% 38% 42% 6% Alnus-Lonlcera-Trautvstterla p.sa. 3 4 5 6 4% 34% 45% 17% Carex (obnupta)-Oenanthe p.a. r 23 4 5 6 12% IX 34 1% 19% 31% Carex (otonLpta)-FantlnaHs p.a. 5 54% 47% 44% re 15. Life-form and soil moisture spectra for vegetation units (symbols are defined in Table 14). 51 Table 14. Numerical codes and names of life-form and moisture indicator species groups. Species group Code Name life-form 1 coniferous trees 2 broad-leaved trees 3 evergreen shrubs 4 deciduous shrubs 5 ferns and allies 6 graminoids 7 herbs 8 parasites and saprophytes 9 mosses 10 liverworts 11 lichens soil moisture 1 excessively to very dry 2 very to moderately dry 3 moderately dry to fresh 4 fresh to very moist 5 moist to wet 6 wet to very wet Principal component analysis (PCA) was performed on the correlation matrix of the diagnostic species for site units to examine differences in percentage of explained variance compared to the same procedure involving diagnostic species for vegetation units. In this case, the percentage of total variance explained by the first principal component increased to 30 %. The second principal component accounted for only 13 % of the total variance and its interpretation is not clear. The discreteness of recognized site units was tested by their ordination constructing 95 % confidence ellipses along the first two PCA axes (Figure 16). The component scores for each site unit were compared using ANOVA but the significant differences were found only for the first axis. Scheffe's multiple comparison for the component scores of the first axis shows clear difference (p < 52 0.001) between all group means. The analysis indicates that each site unit represents a floristically discrete group along the first principal component (soil moisture gradient). Compared to the same analysis of the vegetation units site units are floristically more distinct due to regrouping of study plots according to the depth of gleying. o 6~ CM Figure 16. The ordination of 84 sample plots along the first two PCA axes based on diagnostic species showing centroids and 95 % confidence ellipses for the Rubus-Achlys (1), Lonicera-Achlys (2), Lonicera-Carex (3), and Spiraea-Carex (4) s.a.'s. 53 Soils In most cases, the soil particle size was estimated as fine-loamy. This was supported by textural analysis of 10 composite samples where the mean content of sand, silt, and clay was determined as 32.1, 49.5, and 18.4 %, respectively. Sandy soils are present but less common. The average coarse fragment content within the rooting zone was determined as 17 % with a standard deviation of 12 % by volume. Coarse fragments were a mixture of cemented silts and clays, concretions (oxides) and, to a lesser extent, rock fragments (mainly gravel). The average depth of the forest floor and major rooting zone was determined as 4 and 25 cm, respectively. Fast decomposition of organic matter is reflected in well-developed Ah horizons. The structure of the Ah horizon was, in most cases described as granular or subangular blocky with friable consistency. With increasing depth the soil structure and consistence became angular blocky and firm, respectively. Very compacted Cg or cemented Bfc horizons formed the root restricting layers. The soils and humus forms present in the study area were identified at subgroup and group levels, respectively and are given in Table 15. Gleyed Humo-Ferric Podzols and Orthic Gleysols were the most common soils (Figure 17). The occurrence of Brunisolic and Organic soils was rare. Virtually all sites were mounded to some extent from slightly to severely mounded (Walmsley era/. 1980). Some physical properties of the soils were based on the analysis of ten composite samples collected within the Rubus-Achlys site association. Mean and standard deviation of bulk density for the upper 30 cm mineral soil layer was calculated as 0.662 g/cm3 and 0.165 g/cm3, respectively. The results of chemical analysis are presented in Table 16. Soils can be described as acid (pH 4.4 - 4.9) with pH being the least variable soil property. Low C/N (12-18) values indicate high rates of mineralization and thus higher nitrogen availability (Pritchett 1979, Brady 1984). Calcium, magnesium, and phosphorus were the most variable soil nutrients, respectively. GL.HFP O.G Figure 17. Characteristic soil profiles for the most common soil subgroups. 55 Table 15. The soils and humus forms associated with hardwood ecosystems on the Quinsam Flats.1 Soil subgroup (CSSC 1978) Humus form group (Klinka at. al. 1981) Gleyed Dystric Brunisol Orthic Humic Gleysol Orthic Gleysol Terric Mesisol Orthic Humo-Ferric Podzol Ortstein Humo-Ferric Podzol Sombric Humo-Ferric Podzol Gleyed Humo-Ferric Podzol Gleyed Sombric Humo-Ferric Podzol Mormoder Leptomoder Mullmoder Hydromoder Histomoder Vermimul Hvdromull Saprimull 1 Soils and humus forms with highest occurrence are underlined. Table 16. Means, standard deviations (S.D.), and coefficient of variation (C.V.) for some soil chemical properties of the study soils. Plot number pH MinN (ppm) tot.C (%) tot.N (%) Extractable S-SO4 K Ca Mg ppm > 9 4.9 50.0 0.8 0.06 1.8 0.9 85.0 750 185 15 4.8 23.3 2.7 0.15 3.0 0.7 70.0 190 35 17 4.7 31.6 6.1 0.44 1.2 0.2 41.5 1750 380 19 4.8 58.3 2.7 0.23 3.0 <0.2 38.0 1200 335 27 4.8 43.3 3.4 0.24 1.2 0.9 20.0 1650 500 32 4.9 48.3 3.5 0.21 2.4 0.7 22.5 1500 315 39 4.5 46.7 3.5 0.22 9.1 0.2 30.0 155 70 51 4.7 21.7 3.8 0.24 1.2 <0.2 18.5 245 65 52 4.6 23.3 2.9 0.17 1.2 <0.2 32.0 30 13 63 4.4 15.0 2.8 0.18 6.1 <0.2 60.0 85 60 Mean 4.7 36.1 3.2 0.21 3.0 ND 755 195.8 41.7 S.D. 0.1 14.9 1.3 0.10 2.6 704 173.4 22.7 C.V. 2 41 41 48 87 ND 54 93 88 56 Classification of Early-Seral Vegetation The Quinsam Flats ecosystems have developed under the influence of a seasonally fluctuating water table. Due to a general lack of information about both forested and non-forested ecosystems on such sites, it was decided to describe and classify vegetation on non-forested sites to obtain information about early-seral stages of secondary succession. Fletcher Challenge Canada Ltd. established a number of study plots on the Quinsam Flats to monitor various soil physical properties. These plots were encompassed within study plots used for vegetation description. The study plots represented (1) relatively undisturbed sites harvested by a cable system, (2) sites prepared by scarification, and (3) sites artificially mounded. Vegetation on these sites was described and classified into a simple hierarchy of one alliance and two plant associations (Table 17). The $Symphoricarpos {albus)-Fragaria {vesca) and $Polystichum (munitum)-Equisetum (arvense) p. a.'s represent plant communities in early-seral stages of secondary succession on disturbed sites in the study area. Due to a severe disturbance it was, in many cases, difficult to allocate early-seral sites into distinguished site associations. Based on relatively undisturbed and scarified sites no correspondence was found between the early-seral plant associations and the site associations recognized in hardwood ecosystems. Therefore it was concluded that each early-seral p.a. may develop within any of the Rubus-Achlys, Lonicera-Achlys, and Lonicera-Carex s.a.'s. Early-seral vegetation on the Quinsam Flats are characterized by a relatively large number of herbaceous species compared to forested communities. Several plant species, identified as diagnostic for the $Rubus (parviflorus)-Pteridium {aquilinum) p.all., such as Pteridium aquilinum, Rubus 57 T a b l e 17. D i a g n o s t i c c o m b i n a t i o n o f s p e c i e s f o r v e g e t a t i o n u n i t s d i s t i n g u i s h e d i n e a r l y - s e r a l e c o s y s t e m s on t h e Quinsam F l a t s . P l a n t a s s o c i a t i o n 1 2 Number o f p l o t s D i a g n o s t i c 9 13 V e g e t a t i o n u n i t s and s p e c i e s v a l u e 1 P.C? and M.5.S SRubus p a r v l f 1 o r u s - P t e r I d I u m p . a l l . Anaphalls margaritacea ( d . c ) IV 3 V 4 Cirsium arvense ( d ) IV 3 IV 3 Corntis sericea ( d ) 111 1 I I 1 Eplloblt.im angust 1 fo 1 1um ( d ) I I I 1 IV 3 Ga1 1um triflorum ( d ) 111 3 IV 3 Hypochoerl s radlcat a ( d ) IV 3 IV 3 Luplnus polyphyllus ( d ) IV 3 I I I 4 Myce11s muralis ( d ) IV 3 V 4 Ptertdlum aquilinum ( d . c ) V 4 V 4 Rubus parvlflorus ( d . c d ) V 5 V 4 Rubus urslnus ( d . c ) V 5 IV 3 $ S y m p h o r 1 c a r p o s - F r a g a r 1 a p . a . Brachytheelum sp. ( d ) I I I 4 I 3 Bromus carlnatus ( d ) I I I 2 Cornus una 1aschkens1s ' ( d ) I I I 2 I 1 Fragarla vesca ( d . c d ) V 5 11 3 Geum macrophy 1', um ( d ) IV 3 11 1 Heuchera chlorantha ( d ) I I I 1 I + Holcus lanatus ( d , c d ) V 5 I I 1 Loni cera 1nvolucrata ( d ) IV 3 11 1 Plantago major ( d ) I I I 1 I + Symphor1carpos a/bus ( d , c d ) V 5 I I 1 Taraxacum officinale (d) IV 3 I + $ P o l y s t 1 c h u m - E q u 1 s e t u m p . a . Athyrlum flllx-femina ( d ) I 4- IV 2 Carex deweyana ( d . c ) 11 1 V 3 Clrslum vulgare ( d ) 11 2 IV 4 Oeschampsia caespltosa ( d ) I 1 111 4 DIcentra formosa ( d ) I 2 IV 3 EpHoblum mlnutum ( d ) 11 1 IV 3 Equlsetum arvense ( d . c d ) I I I 3 V 5 Festuca subulata ( d ) I I I 2 Luzula parvlflora ( d ) I + IV 3 Malanthemum dllatatum ( d ) 11 1 IV 1 Potystichum munltum ( d . c ) I 1 V 3 Rubus spectabllls ( d . c d ) 11 3 V 5 Sambucus racemosa ( d ) . I 1 IV 2 Stachys cooleyae ( d ) IV 3 Trautvetterla carol 1nlens 1s ( d ) I I 2 IV 2 Veronica s c u t e l l a t a ( d ) I I I 2 ^ S p e c i e s d i a g n o s t i c v a l u e s : d - d i f f e r e n t i a l , dd - dominant d i f f e r e n t i a l , c d - c o n s t a n t d o m i n a n t , c - c o n s t a n t , Ic - I m p o r t a n t c o m p a n i o n ( P o j a r e t a l . 1987). 2 p r e s e n c e c l a s s e s a s p e r c e n t o f f r e q u e n c y : I = 1-20. I I = 21-40, I I I = 41-60. IV = G1-80, V = 81-100. I f 5 p l o t s or l e s s , p r e s e n c e c l a s s Is a r a b l e v a l u e ( 1 - 5 ) . 3 S p e c 1 e s s i g n i f i c a n c e c l a s s m i d p o i n t p e r c e n t c o v e r and r a n g e : + = 0.2 (0.1 - 0 . 3 ) , 1 = 0.7 (0.4 - 1.0). 2 = 1.6 (1.1 - 2 . 1 ) , 3 = 3.6 (2.2 - 5 . 0 ) , 4 = 7.5 (5.1 - 10.0). 5 = 15.0 (10.1 - 2 0 . 0 ) , 6 = 26.5 (20.1 - 3 3 . 0 ) , 7 = 41.5 (33.1 - 5 0 . 0 ) , 8 = 60.0 (50.1 -70.O ) , 9 = 85.0 (70.1 - 1 0 0 ) . 58 parviflorus, Mycelis muralis, Hypochaeris radicata, and Anaphalis margaritacea were included into the diagnostic combination of species for the early-seral $Epilobium-Polytrichum p.a. recognized by Klinka et al. (1985) on disturbed sites in the Malcolm Knapp Research Forest. Vegetation of disturbed plots was subjected to spectral analysis (Emanuel 1986) to infer basic site qualities from the distribution of indicator species (Figure 18). A relatively strong local climatic gradient between two plant associations was revealed by climatic spectra. The Symphoricarpos-Fragaria p.a. showed a higher frequency (53 %) of cool temperate & mesothermal indicator species (e.g. Elymus glaucus, Trientalis latifolia, Bromus carinatus compared to the Polystichum-Equisetumplant association (31 %). This is an indication that the sites of the former p.a. are influenced by higher extremes in temperature than the later p.a. This inference could provide an explanation to several unsuccessful regeneration attempts on a certain area of the Quinsam Flats commonly known as a "meadow". Excessive soil moisture does not appear to be a major cause of unsatisfactory regeneration. Gleyed horizons do occur at about 30 cm but mottling is not distinct untill approximately 50 cm. Thus based on the depth of gleying this site belongs to the Lonicera-Achlys s.a. The "meadow", originally supporting old=growth Douglas-fir has an irregular shape, flat topography, hummocky microtopography, and is surrounded by hardwood forest. A small creek dividing the "meadow" in half has eroded a gully several meters deep. Another creek parallels the forest edge at the southern margin. The vegetation description within the "meadow" revealed a relatively high cover (about 10 %) of Carex rossii. This species, although widely distributed in British Columbia, increases its occurrence with increasing continentality (Klinka et al. 1989). 59 The evidence of late frost was observed in delayed growth of Pteridium aquilinum, dieback of Lonicera involucrata, and necrosis of Vaccinium parvifolium. It is suggested, that the "meadow" represents a frost pocket. Such situation may result from the combined effect of the following environmental conditions. Firstly, the clearcuts radiate more energy upward during the clear night than the sky radiates downward which results in the net energy loss and low surface temperatures (Cochran 1969). This is unlikely to be the main reason because the "meadow" is relatively small in size and the seedlings presumably get enough protection from the adjacent forest. Furthermore, no similar regeneration difficulties have been experienced on much larger clearcuts in the area. Secondly, examination of aerial photographs revealed a slightly concave surface of the "meadow". Due to subdued topography and low air turbulence at night, the cold air generated by two creeks can accumulate near the soil surface (D. Price 1989, pers. comm.). Under such conditions, planted Douglas-fir seedlings could be suffering from both early and late frosts. If this is the case, the influence of cold air could be reduced by leaving the protective tree belt along both creeks. In any case, further research would be required to verify this hypothesis. Soil moisture spectra indicated the drier status of the $Symphoricarpos-Fragaria p.a. with a higher frequency of moderately dry to fresh soil moisture indicators (30 %) and lower frequency of very moist to wet indicators (18 %) compared to 12 %, and 37 % of the $Polystichum-Equisetum p.a. Based on soil nutrient spectra, the $Symphoricarpos-Fragaria p.a. represents nitrogen poorer sites compared to the $Polystichum-Equisetum p.a. This is reflected in the higher frequency (37 %) of nutrient-medium indicators in the former unit compared to the latter one (28 %). This trend could be the result of a more complete removal of forest floor materials on plots representing the 60 $Symphoricarpos-Fragaria p.a. This is indirectly supported by the higher frequency (45 %) of exposed mineral soil indicators in this p.a. compared to the $Polystichum-Equisetum p.a. (35 %). Higher moisture status of the Polystichum-Equisetum plant association is also reflected in higher frequency of surface water indicators (5 %) compared to the Symphoricarpus-Fragaria p.a. (1 %). Climate Symphorlcarpos-Fragarla p.a. 2 4 5 2% 45% Polystlchum-EcfJisetum p.a. 53% l 2 1 4 5 1% 68% 31% Soil moisture regime Symphorlcarpos-Fragarla p.a. 2 3 4 5 1 6 1 9% 30% 42% 18% 1 Polystlchurn-Equlsetum p.a. 2 3 4 5 6 7% 12% 42% 37% 2% Soil nutrient regime SyrrphoMcarpos-Fragaria p.a. 1 2 3 4% 37% 59% Polystichum-Equisetum p.a. 1 2 3 2% 28% 70% Figure 18. Climatic, soil moisture, and soil nutrient spectra for plant associations distinguished in early-seral vegetation on the Quinsam Flats. 61 Tree Species Trials Tree species trials were established to obtain additional growth information to support tree species selection on the Quinsam Flats. The initial height of seedlings was measured in June 1987 followed by measurements in November 1987 and 1988. Species mortality, determined at the end of the second growing season is summarized for each site preparation method in Table 18. The lowest (10 %) and highest (40 %) seedling mortality was recorded on scarified and mounded sites, respectively. Black cottonwood showed the highest mortality on all sites. This is thought to be due to late planting (end of March) followed by drought in the spring of 1987. The period between planting and drought was likely too short for the black cottonwood whips to develop a sufficient root system and sprouts dried out. In addition, high mortality of this species was to some extent caused by elk and deer browsing. Browsing damage varied with location but was especially high in the undisturbed portion of the Lonicera-Carex s.a. The evaluation of black cottonwood growth performance was based solely on mortality because of difficulties in obtaining height measurements. The species performed best on scarified sites representing the Lonicera-Achlys s.a. while the worst performance was recorded on sites with high mounds. Although all coniferous species show a similar level of seedling mortality the best overall survival rate (84 %) was recorded for grand fir followed by Douglas-fir (81 %). Douglas-fir was the species with the lowest mortality (2 %) on scarified sites. Sitka spruce, showing a relatively good survival on the undisturbed and scarified sites had the highest mortality among conifers on mounded sites (Table 18). It is possible that Sitka spruce - the prevailing species in cool, perhumid mesothermal climates - was influenced more by water deficit and exposure than the other species. 62 Table 18. Seedling mortality (%) at the end of the second growing season. Undisturbed Site preparation1 Mounded Scarified Site association2 RA LC low high LA Overall black cottonwood 22 79 73 100 28 60 Douglas-fir 10 18 33 30 2 19 grand fir 13 16 28 15 8 16 Sitka spruce 5 15 40 32 7 20 western redcedar 27 30 23 13 6 20 Overall 15 39 40 38 10 27 1 Low mounds < 1 m high, High mounds > 1 m high 2 RA - Rubus-Achlys, LA - Lonicera-Achlys, LC - Lonicera-Carex The evaluation of two-year height growth performance of coniferous species on mounded and scarified sites is summarized in Table 19. The height increment on scarified sites was significantly higher then on the mounded sites (p < 0.05). The overall height increment was calculated for mounded sites as the effect of low and high mounds was found not significant (Table 19). In contrast, the effect of blocks was found significant on the scarified sites where height increment in block #1 was higher (p < 0.05) than in block #2. The significant difference in height increment between blocks was due to heavy browsing in block #1. Species height increment was analyzed for both mounded and scarified sites together. Sitka spruce had the highest increment followed by grand fir (p < 0.05). There was no significant difference between height increment of Douglas-fir and western redcedar but both species had lower increment then Sitka spruce and grand fir (p < 0.05). The highest and second highest increment of Sitka spruce and grand fir, respectively indicate better initial growth of these two species on disturbed sites. 63 Table 19. Means (cm) and standard deviations (in parentheses) of two-year height increment of coniferous seedlings on mounded and scarified sites. Site preparation Mounded Scarified Block 1 Block 2 Douglas-fir 1 21 10 (8) (15) (14) grand fir 9 17 13 (7) (9) (8) Sitka spruce 12 21 18 (5) (8) (9) western redcedar 5 16 11 (10) (13) (13) The analysis of growth performance on relatively undisturbed sites revealed no significant effect of individual blocks, therefore height increment values were calculated for each site association (Table 20). Seedlings on the Rubus-Achlys sites had significantly higher (p < 0.05) increment than those on the Lonicera-Carex sites which are under strong influence of a fluctuating water table. It was expected that significant differences in height growth would occur between seedlings planted on natural mounds and in depressions but the analysis did not confirm this assumption. However, it would be incorrect to assume that mounds and depressions represent planting microsites of the same quality. Clearly, two growing seasons are not adequate for making valid conclusions about species growth performance. Such information could be obtained by monitoring growth of the most vigorous seedlings in the current trials for a longer period of time (perhaps 20-50 years). 64 Table 20. Means and standard deviations (in parenthesis) of two-year height increment of coniferous seedlings on natural mounds and in depressions within relatively undisturbed sites. Site association Rubus-Achlys Lonicera-Carex Microsites Mound Depression Mound Depression Douglas fir 19 18 6 10 (16) (17) (9) (8) grand fir 16 19 14 12 (8) (12) (9) (13) Sitka spruce 17 17 16 17 (8) (7) (9) (7) western redcedar"1 -1 -3 3 -12 (8) (12) (9) (13) 1 Negative values represent reduced height due to browsing. Although the microsite effect was not shown to be statistically significant it was possible to recognize certain growth trends of individual species (Table 20). Grand fir showed a higher increment in depressions then on mounds on the Rubus-Achlys sites. The depressions, in most cases, had a soil moisture regime comparable to the Lonicera-Achlys sites. In contrast, height increment of grand fir on the Lonicera-Carex sites appeared to be higher on mounds than in depressions. Douglas-fir had a higher increment on the Rubus-Achlys sites than on the Lonicera-Carex sites (p < 0.05). This indicated a sharp decrease in height growth along a soil moisture gradient. The comparison of Douglas-fir height increment for different site associations appears to be more valid at this stage then evaluation of height increment on mounds and depressions. Sitka spruce showed no differences in hight increment on mounds and in depressions in either the Rubus-Achlys or Lonicera-Carex sites. Its mortality is 65 however higher on the Lonicera-Carex sites (15 %) than on the Rubus-Achlys sites (Table 18). As in other trials, Sitka spruce appears to have the highest and most consistent height increment. A negative or very low height increment of western redcedar reflects lack of protection against browsing. Therefore, under local conditions the protection of western redcedar is necessary at the earlier stages of development. Scarified sites were found to have the lowest coniferous seedling mortality and highest two-year increment. In contrast, seedlings planted on the relatively undisturbed Lonicera-Carex and mounded sites showed the highest mortality and lowest height increment. Survival and growth performance on all sites would likely improve with control of competing vegetation. Due to the importance of mounding on the Quinsam Flats, a short discussion on this topic is included. Mounding has been frequently used, both in Europe and North America (Smith 1986), to improve regeneration on sites with a high water table. When associated with a large scale soil disturbance, mounding often had an undesirable impact on soil physical properties (Pelisek 1964). Carter and Klinka (pers. comm.) who examined the area in 1987 suggested that present mounding techniques will have an adverse, long term effect on soils for the following reasons: (1) Sensitivity of these soils to compaction especially when wet. (2) Capillary rise will likely result in the wetting front in the artificial mounds (ridges) being just as close to the surface as it is in natural mounds while summer drying could be even more severe; this will result in the same shallow root system found on natural mounds and restricted (rectangular) root distribution. 66 (3) The mounds tend to align in only one direction and are often separated by standing water for almost half a year. This will reduce possibility of rooting between the mounds and increase susceptibility to windthrow. The possibility of compaction within mounds seems to be an important factor related to seedling mortality. Soil aeration is likely to be reduced due to disturbed soil structure and removal of the organic matter important for soil aggregation (Brady 1984) from upper soil horizons. Such conditions may last until soil structure improves through the action of vegetation. Mounds are likely to be affected by intensive summer drying due to a combination of increased evaporation from the increased surface area, run off from ridges to the drainage channels, and competing vegetation most notably Lupinus polyphylla and various grasses. Although the results of species trials would seem to indicate that artificial mounding has a detrimental effect on seedling survival it is too early to make any such conclusion. However, due to the emphasis on the site-specific approach to forest management and considering very high costs involved, mounding is not recommended as a site preparation method for the Quinsam Flats. Recommendations for Rehabilitation of Hardwood Stands In view of unpredictable demands for specific timber products it is prudent to provide flexibility in tree species decision-making. Therefore, all ecologically suitable crop tree species satisfying criteria of maximum sustainable productivity, reliability, and silvicultural feasibility (Klinka and Feller 1984) were included and evaluated in relation to three site associations representing productive forest sites 67 (Table 21). Sitka spruce was not considered a reliable crop species due to its high susceptibility to white pine weevil [Pissodes strobi (Peck)]. Table 21. Recommended tree species for rehabilitation of hardwood stands on the Quinsam Flats. Site association Recommended tree species 1 Site index (m/50 years) Rubus-Achlys western redcedar grand fir Douglas-fir red alder ND ND 36 (3) 28 (2) Lonicera-Achlys western redcedar grand fir red alder black cottonwood ND ND 26 (2) 32 Lonicera-Carex black cottonwood 37 (5) Spiraea-Carex not suitable for timber production ND 1 Species are arranged according to decreasing shade tolerance. The first step in tree species selection for the Rubus-Achlys and Lonicera-Achlys sites is to decide whether to favour a short-rotation crop (approximately < 30 years) of hardwood species, or an intermediate-rotation (60-80 years) or a long-rotation (approximately > 80 years) crop of softwood species. However, such decisions are beyond the scope of this study as it requires consideration of various management factors. The Rubus-Achlys/S\ope, Lonicera-AchlyslRay'me, Lonicera-Carex/Organic, Lon/cera-Carex/Ortstein, and Lo/7/cera-Carex/Stream-edge sites are not recommended for timber production. Red alder and black cottonwood are the only species recommended for rehabilitation of the Lonicera-Achlys/SXream-edge sites. 68 Grand fir (Figure 19) is recommended as a crop species for intermediate rotations on the Rubus-Achlys, and Lonicera-Achlys sites. It is considered a more productive species then Douglas-fir even on the Rubus-Achlys sites suitable for growing pure Douglas-fir stands. This conclusion was reached by combining local data (Carter etal. 1988), data from British yield tables (Forest Management Tables (metric) 1971), and field observations (D.E. McMullan, pers. comm.). Carter et al. (1988) examined trends in height, diameter, annual volume increment, and growth form (Figure 19) for grand fir and Douglas-fir growing in a mixed 40-year old plantation on the Quinsam Flats (Appendix 5). Although not statistically different, the height and diameter of grand fir were consistently higher during 1973-1987 period. Grand fir was found to have greater annual volume increment since 1974 and significantly higher cumulative annual volume increment (p < 0.001) since approximately 1980 compared to Douglas-fir. The analysis indicated that evaluation of growth performance of these two species prior to an age of 30 to 40 years could lead to incorrect conclusions. Because this study was carried out on the relatively drier Rubus-Achlys site, it is expected that the growth performance of grand fir will show a greater improvement on relatively wetter sites as compared to Douglas-fir. As Douglas-fir and grand fir have a similar growth pattern, the Rubus-Achlys sites are suitable for growing mixed stands of these species. Such mixture would provide for a greater flexibility in manipulating the stand composition later in rotation and in achieving full site occupancy on strongly mounded sites. Grand fir should be planted in depressions which are likely to be under the strong influence of a fluctuating groundwater table. Douglas-fir (Figure 19) is recommended as a crop species for intermediate rotations on the Rubus-Achlys sites, and possibly as a minor crop species on high mounds on the Lonicera-Achlys sites. Decision whether to favour Douglas-69 fir, grand fir, or a mixture of these species on the Rubus-Achlys sites should be based on the management requirements. Western redcedar - a major component of the original old-growth forest on the Quinsam Flats - is a suitable crop species for long rotations on the Rubus-Achlys and Lonicera-Achlys sites. Western redcedar is capable of overcoming vegetation competition on these sites due to its high tolerance to flooding, a fluctuating water table, and shade (Krajina et al. 1982). It has been suggested that western redcedar can equal and even exceed Douglas-fir and grand fir as a volume producer and will likely remain in high demand due to its special wood properties (Handley 1988). It is recommended that western redcedar be grown in a pure, even-age stands to reduce undesirable taper, fluting, and formation of large limbs commonly occurring on trees overtopped by faster growing species in mixed stands (Oliver et al. 1988). If desired as a crop western redcedar should be established at a high density of not less then 2000 seedlings/ha (Klinka and Krajina 1986, Minore 1983). As suggested by Oliver etal. (1988), the initial density of approximately 2400 seedlings/ha could provide for merchantable utilization of first thinning. It should be noted that high susceptibility to deer and elk browsing create difficulties in regeneration of this species on the Quinsam Flats. Protection of seedlings by plastic or wire mesh will greatly increase the cost of regeneration. Regarded for a long time as a weed species, red alder has been recognized as a nitrogen-fixer, colonizer of disturbed sites, and finally, as a timber producer. According to Elliot (1980), the wood of red alder can have a value equal to other commercial hardwoods in North America. Considering an increasing demand and market opportunities, red alder is recommended as a suitable crop species for short rotations on the Rubus-Achlys and Lonicera-Achlys sites. The growth potential of this species appears to decline with 70 decreasing aeration and rooting depth from the Rubus-Achlys (SI = 28 m/50 years), to Lonicera-Achlys (SI = 26 m/50 years), and Lonicera-Carex (SI = 25 m/50 years) sites. Therefore, red alder is not recommended as a viable crop species on the Lonicera-Carex sites. High flood resistance (Krajina etal. 1984) and excellent growth potential make black cottonwood (Figure 20) a suitable crop species for short rotations on the Lonicera-Achlys and Lonicera-Carex sites. The best growth performance (SI = 36 m/50 years) of this species was recorded on the Lonicera-Carex sites. Similar results were obtained by D.S. McLennan (pers. comm.) who conducted a black cottonwood productivity study on the Quinsam Flats in 1988. It is recommended that black cottonwood be planted in the early spring to allow for sufficient root development. Cuttings or whips can be used as a suitable planting stock. (a) (b) Figure 19. A group of immature grand fir (a) showing relatively clean stems and smaller branches compared to Douglas-fir (b) within the same stand on the Rubus-Achlys site. Figure 20. A group of mature, naturally regenerated black cottonwood showing excellent vigour and form on a Lonicera-Carex site. Identification Key and Site Mapping Site units must be easily recognizable in the field to allow for application of site-specific forest management. This need was recognized by developing a field key for identification of site associations including tree species recommendations (Figure 23). Diagnostic plant species combinations and depth of gleying were used as differentiating characteristics. 73 A total of six site types belonging to three site associations were identified and delineated in a selected, 50-ha area of the hardwood forests (Figures 21 and 22). The map was not intended to convey the impression of distinct and abrupt boundaries between site types. These boundaries were typically gradual with approximately 10 m-wide transition area on sites with a gentle topographic gradient. Due to difficulties in drawing the boundary between coarse- and fine-textured soils, one polygon - the Lonicera-Achlys/Jypic & Sandy s.t.'s - was shown as a complex mapping unit. The Lonicera-AchlysfTyp\c and Lonicera-Carex/Typic s.t.'s are approximately equally represented and together they occupy the major portion (approximately 64 %; 17.9 and 14.2 ha, respectively) of the mapped area. The Rubus-AchlysUyp\c s. t. occupies an area of approximately 8.4 ha (17 %). The occurrence of coarse-textured soils is reflected in the presence of the Rubus-Achlys/Sandy s. t. in the southwest corner of the area. The Lonicera-Achlys/Stream-etige and Lon/cera-Carex/Stream-edge s.t.'s form a very small portion of the total area. The former was identified along the Quinsam River and the latter was found in shallow ravines eroded by two slowly moving creeks. Due to a history of site disturbance likely caused by past road construction or logging activities one polygon was designated on the map as disturbed. The rapid changes in microtopography on these sites result in a mosaic of different microsites. However, considering the location of the disturbed areas it is reasonable to include them mainly to the Lonicera-AchlysfTyp\c s.t. The main reason for mapping was to demonstrate the geographical distribution of distinguished site units in a typical portion of the harwood forest. As demonstrated by the map the hardwood forests on the Quinsam Flats represent a mosaic of different site types. After delineation of recognized site types (units) it is possible to determine their size and to calculate the amount of planting stock 74 needed for regeneration. The key for identification of site units together with the site map represents the connection between site classification and the practical application of a site-specific approach to forest management. Field identification of site units or their delineation on the map allows access to the interpretations made for each site unit. Site mapping and subsequent site-specific interpretations could be carried out in advance for segments of the hardwood forests scheduled for rehabilitation. Site type Symbol Recommended tree species 1 Rubus-AchlysfTyplc Rubus-Achlys/Sandy Lonicera-AchlysfTyplc Lonicera-Achlys/Typlc&Sandy Lonicera-Achlys/Stream-edge Lonicera-CarexfTyplc Lon/cera-Carex/Stream-edge RAt RAs mm LAt-s LAse LCt LCse grand fir > Douglas-fir Douglas-fir > grand fir grand fir grand fir red alder, black cottonwood black cottonwood not suitable for wood production 10ther suitable tree species are listed in Table 22. Figure 21. The map legend showing symbols and colour scheme used to designate site types and recommended tree species. Figure 22. The distribution of site types in a selected hardwood area on the Quinsam Flats. — i 76 Dilterenllatlng criteria1 Site association Recommended tree species^i3 START gleysolic soils In depressions gleyed horizon at 0 - 20 cm trembling aspen > 33 % slough sedge > 33 % Fontinalis (moss) > 2 % hardhack > 10 % willows > 10 % yes Spiraea-Carex unsuitable tor wood production no gleysolic or organic soils gleyed horizon at 0 - 20 cm yes Lon/cera -Carex black cottonwood Pacllic oenanthe > 2 % slough sedge > 3 % sword tern < 10 % no podzollc or (gleysolic) soils gleyed horizons at 20 - 35 cm yes black cottonwood red alder grand fir western redcedar common horsetail > 1 % black twinberry > 2 % Cooley's hedge-nettle > 2 % Lonicera-Achlys no podzollc soils gleyed horizon at > 35 cm yes red alder Douglas-tlr grand tir western redcedar Hooker's talrybells > 1 % red-osier dogwood absent 1 vanilla leal > 10 % * Rubus-Achlys *> 1 Numerical values that follow plant species names designate percent cover as the proportion of an area which Is covered by projection through the crown foliage onto the ground surface for all Individuals ol a species 2Recommended tree species are listed In order of Increasing shade tolerance 3Conilerous species are considered lor a longer rotation period Figure 23. The key to site identification and tree species selection for hardwood ecosystems on the Quinsam Flats. 77 SUMMARY AND CONCLUSIONS Hardwood forests on the Quinsam Flats were found to be associated with poorly drained, gleyed or gleysolic soil and a seasonal fluctuating water table. Four site associations and twelve site types were distinguished in the sampled population of the hardwood stands after the vegetation and site analysis using methods of the biogeoclimatic ecosystem classification. The influence of a fluctuating water table increased from the Rubus-Achlys, to Lonicera-Achlys, Lonicera-Carex, and Spiraea-Carex site associations. Each site association represents a major, floristically and edaphically recognizable segment of the moisture gradient occurring in poorly drained soils. Depth of gleyed horizons indicating depth of the winter water table was used as the major characteristic for differentiation of site associations and soil moisture regimes. Douglas-fir, grand fir, western redcedar, black cottonwood, and red alder were found suitable for rehabilitation of particular site units on the Quinsam Flats. Among these, grand fir and black cottonwood are considered the most important. The results of the tree species trials for two growing seasons did not provide enough conclusive evidence for tree species and microsite selection. Grand fir was found to have the lowest overall mortality of all planted species. Sitka spruce showed the best and most consistent increment on all sites closely followed by grand fir. The growth performance of Douglas-fir was more variable. Some Douglas-fir seedlings, especially on the undisturbed Rubus-Achlys sites were found to have the highest increment (up to 85 cm) of all conifers. However, growth of Douglas-fir particularly in trials established on mounded sites was very disappointing. The growth performance of western redcedar was greatly obscured because of heavy browsing. Due to high mortality, further monitoring of species trials is not recommended except for two blocks on scarified sites. 78 A field key combining identification of site quality and tree species recommendations was developed and tested to assist foresters in site-specific management. The complex pattern of site types on a 50-ha area was shown on a 1:5,000 map. The understanding of the spatial distribution of each site association is considered necessary for a sound site-specific silvicultural management. 79 LITERATURE CITED Anonymous. 1974. Technicon autoanalyzer II. Methodology: individual/simultaneous determination of nitrogen and/or phosphorus in BD acid digest. Industrial method No. 329-74W/A, Technicon Corp., Tarrytown, New York. Bakuzis, E.V. 1969. Forestry viewed in an ecosystemperspective. pp 189-258. In G.M. Van Dyne (ed.), The ecosystem concept in natural recource management. Academic Press, New York. Bardsley, C.E., and J.D. Lancaster. 1965. Sulphur, pp 1102-1116. In C A . 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A comparison of grand fir and Douglas-fir growth performance in the Elk River Tree Farm. Faculty of Forestry, University of British Columbia, Vancouver, B.C., (mimeographed), 4 pp. Cochran, P.H. 1969. Lodgepole pine clearcut size affects minimal temperatures near the soil surface. U.S. Department of Agriculture, For. Ser. Res. Pap. 126, PNW-86, 9 pp. Courtin, P.J., K. Klinka, M.C. Feller, and J.P. Demaerschalk. 1988. An approach to quantitative classification of nutrient regimes of forest soils. Can. J . Bot. 66: 2640-2653. Emanuel, J . 1988. A vegetation classification program (VTAB). Unpublished manuscript, Faculty of Forestry, University of British Columbia, Vancouver, B.C., (mimeographed), 26 pp. Environment Canada. 1982. Canadian climatic normals 1951-80: Temperature and Precipitation. Vol. 1. Atmospheric Environment Service, Ottawa. Elliot, D.M. 1980. Studies on early development and endogenous gibberelins in red alder (Alnus rubra Bong.). 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Prentice-Hall Inc., Englewood Cliffs, New Jersey, 718 pp. APPENDIX 1 List of Plant Species Occurring in the Intermediate-Serai Ecosystems on the Quinsam Flats. Abi es gr andi s Acer macrophyllum Ac hi ys t r i phyl I a 1 Actaea rubra Adeno caul on bi col or Adi ant um pedatum Agros tIs exarat a Agr os t i s s cabr a Alnus rubra Al nus si nuata Amelanchier al ni/ol i a AnaphalIs mar garitace a Angelica genuflexa Aquilegia formosa Asarum caudatum Aster subs pi cat us At hyri um fi I i x-femi na Aulacomnium palustre Bl echnum spi cant Botrychium multifidum Botrychium virginianum Br ac hyl he ci um sp. Brachyt heci um salebrosum Bromus cari natus Bromus sitchensis Br omus vulgaris Carex aquati I i s Carex deweyana Car ex he nde r s oni i Carex I e por i na Carex obnupt a Car ex r os s i i Carex sp. Ci nna I atif ol i a Ci rcaea alpi na Claopodium bolanderi CI ayt oni a s i bi r i ca Cornus nut t alIi i Cor nus s er i cea Cornus unal aschkensis Deschampsia caespitosa Deschampsia elongata Dicentra formosa Dicranum scoparium Disporum hookeri Di s por um smi I hi I Drepanocladus unci nat us Dryopteris expansa El eocharis palustris Elymus glaucus Epilobium an gusti folium Epi I obi um mi nut um Equi s e t um arvense Equi setum hyemale Equi s elum pal us t r e Equi setum lelmateia (Dougl. ex D. Don) Lindl Purs h (Sm.) DC. (Ait.) Willd. Hook. L. Tri n. Will d. Bong. (Kegel) Rydb. (Nutt.) Nutt . (L. ) Bent h. in Bent h. Nutt . in Torr . Gray Fi s ch. in DC. Li ndl. Nees (L.) Roth (Hedw.) Schwaegr. (L.) Roth (Gmel.) Tr evi s. (L.) Sw. (Web. Mohr) B.S.G. Hook. Am. Tri n. (Hook.) Shear Wahlenb. Schwein. BalIey L. Bat Iey Boot t in Hook. (Trev. ex Goepp.) Griseb L. Best L. Audub. ex Torr. Gray L. Ledeb. (L.) Beauv. (Hook.) Munro ex Benlh. (Haw.) Walp. Hedw. (Torr.) Ni cholson (Hook. ) Pi per (Hedw.) Warnst . (Presl) Fraser-Jenki ns (L.) R. S. Buckl . L. Li ndl . ex Hook. L. L. L. Ehrh. 86 APPENDIX 1. (continued) Erythronium revolulum Festuca ar undi nacea Fes t uca o c c i de nt ali s Festuca subuliflora Festuca s ubulat a Fonti nails ant i pyret i ca Fontinalis howellii Fr agar i a ves ca Gal i um a pari ne Gal i um t rifi dum Gal i um t r i fl orum Gaul t heria shall on Gent i ana sceptrum Geranium roberlianum Geum macr ophyl I um Gl yceria el at a Gymnocarpi um dryopteris Heracleum I ana turn Hoi cus Ianat us Hoi odi scus di scol or Hypnum s ubi mpo ne ns Ilex a qui fol i um Juncus effusus Juncus ensi f ol i us Kindbergia oregana Kindbergia praelonga Lathyrus nevadensis Leucolepis menziesii Li I i um col umbi anum Li nnaea bor eal i s Li sl era cauri na Loni Cera ci I i osa Lo nicer a involucrata Lupi nus polyphyllus Luzul a tnulti flora Luzula parvifI or a Lycopus americanus Lycopus uniflorus Lysichitum ameri canum Mahoni a ne r v os a Mai ant hemum dilatatum Mai us fusca Meli ca s ubulat a Me nt ha arvensis Menyanthes trifoliata Menzi esi a f e r r ugi ne a Moehringia macrophylla Mycelis muralis My osotis Iaxa Oenanthe sarmentosa Oplopanax horridus Osmorhiza chilensis Pet asi t es pal mat us Physocarpus capitatus Pi cea sil chensis Pi nus cont orta Sm. in Rees Schreb. Hook. Scribn. in Macoun Tr i n. in Bong. Hedw. Ren. Card. L. L. L. Mi chx. Pursh Gr i s eb. in Hook. L. Wi lid. (Nash) M.E. Jones (L.) Newm. Mi chx. L. (Pursh) Maxim. Lesq. L. L. Wi kstr. (SuiI.) Ochyra (Hedw.) Ochyra Wats. (Hook.) Steere ex L. Koc Hanson ex Baker L. Piper (Pursh) DC. (Richards.) Banks ex Spr Li ndl. (Retz.) Lej . (Ehrh.) Desv. Muhl . Mi chx. Hull. St. John (Pursh) Nutt. (How.) Nels. Macbr. (Raf.) Schneid. (Griseb.) Scri bn. L. L. Sm. (Hook. ) Fenzl (L.) Dumor t. Lehm. Presl ex DC. (Sm.) Miq. Hook. Arn. (Ait .) Gray (Pursh) Ktze. (Bong.) Carr. Dougl. ex Loud. APPENDIX 1. (continued) Pi nus mont i col a PI agi omnium insigne Platanthera unal as c he e ns i s Poa mar ci da Pohl i a nut ans Polytri chum commune Polystichum muni t um Populus tremuloides Populus trichocarpa Prunella vulgaris Ps eudot s uga menziesii Pi eri di um aqui I i num Pyrola asari folia Ranunculus flammula Ranunculus uncinatus Rhamnus purs hi anus Rhi z omnium glabrescens Rhytidiadelphus loreus Rhytidiadelphus triquetrus Ri bes bracteosum Ri bes di var i catum Ri bes Iacus t r e Ri bes Iobbi i Rosa gymnocarpa Rosa nut kana Rubus parviflorus Rubus spectabiIis Rubus ur s i nus Salix hookeriana Sali x I as iandr a Sati x s coul er i ana Sal i x s i t c he ns i s Sambucus racemosa Sci rpus microcarpus Scut el aria lateriflora Smi I aci na s t el I at a Sol i dago canadensis Sparganium eurycarpum Spiraea douglasii St achys cool eyae St el Iar i a cr i s pa Streptopus ampl e xi fol i us Streptopus r os eus Symphoricarpos albus Taraxacum officinale Tel lima grandiflora Thai i d rum Occident ale Thuj a pi i cat a Ti arel I a trifol i at a To I mi ea me nzi es i i Torreyochloa pauciflora Trautvet t eri a carolI ni ensIs Tri ent al i s ar ct i ca Tri e nt a I i s I at ifol i a Tr i I I i um ovat um Dougl. ex D. Don in Lamb (Mitt.) Kop. (Spr e ng.) Kur t z Hi t chc. (Hedw.) Lindb. Hedw. (Kaulf.) Presl Mi chx. Torr. Gray ex Hook. L. (Mi r b. ) Franco ( I . ) Kuhn in Dec ken Mi chx. L. D. Don i n G. Don DC. (Kindb.) Kop. (Hedw.) Warnst. (Hedw.) Warnst. Dougl. ex Hook. Dougl. (Pers.) Poir. Gray Nut t . in Torr. Gray Presl Nut t . Pursh Cham. Sc hiecht . Barrat t in Hook. Bent h. Barrat t in Hook. Sans on in Bong. L. Presl L. (I .) Desf. L. Engel m. Hook. Heller Cham. Schl echt . (L.) DC. Mi chx. (L.) Blake Weber in Wi ggers (Pursh) Dougl. ex Li ndl. Gr ay Donn ex D. Don i n Lamb. L. (Pursh) Torr. Gray (Presl) Church (Walt.) Vail Fi s ch. ex Hook. Hook. Pursh 88 APPENDIX 1. (continued) Tr i s et um cer nuum Tsuga he t er ophyl I a Typha I at t f ol i a Vaccinium oval i folium Vaccinium par vi folium Veratrum vi r i de Veronica amer i cana Veronica scutellata Vi bur num edul e Vi ci a ameri cana Viola sp. Viola glabella Viola palustris Tri n. (Raf.) Sarg. L. Sm. in Rees Sm. in Rees Alt. (Raf.) Schwein. ex Benth L. (Mi chx.) Raf. Muhl enb. ex Wi 11 d. Nutt . i n Tor r . Gr ay L. APPENDIX 2 List of Plant Species Occurring in the Early-Seral Ecosystems on the Quinsam Flats. Acer macrophylIum Pursh Ac hi ys tri phyl I a (Sm.) DC. Agoseri s glauca (Pursh) Raf. Agros t i s exarat a Tr i n. Agrostis microphylla St eud. Agrostis s cabra Willd. Agrostis stolonijera L. Alnus rubra Bong. Amelanchier al ni folia (Nutt .) Nutt. Anaphal i s mar garitace a (L. ) Bent h. i n Bent h. Ant e nnar i a ne gl e ct a Greene Aquilegia formosa Fi s ch. in DC. As t er s ubspi cat us Nees Athyri um fi I i x-femina (L.) Roth Aulacomnium palustre (Hedw.) Schwaegr. Brachyt heci um sp. Bromus car i natus Hook. Arn. Bromus vulgaris (Hook.) Shear Bryum sp. Campanula scouleri Hook, ex A. DC.% Car ex aquati I i s Wahlenb. Carex deweyana Schwe i n. Car ex headersonii Bai I ey Carex i I I ot a Baile y Car ex i nt eri or Bai I ey Carex I enti culari s Mi chx. Carex muri cat a L. Carex obnupt a Bai I ey Car ex r os s i i Boot t in Hook. Car ex stipata Muhl . Car ex t racyi Mack Cer as t i um ar ve ns e L. Ci nna I atif olia (Trev. ex Goepp.) Griseb Cirsi um arvense (L.) Scop. Ci r si um edul e Nut t . Ci r s i um vulgar e (Savi) Ten. CI ayt oni a si bi r i ca L. Cornus sericea L. Cornus unalaschkensi s Ledeb. Del phi ni um menziesii DC. Deschampsia caespitosa (L.) Beauv. Deschampsia elongata (Hook.) Munro ex Benth. Dicentra formosa (Haw.) Wal p. Di spor um hooker i (Torr.) Nicholson Dryopteris expansa (Presl) Fraser-Jenkins Elymus glaucus Buckl. Epilobium angus t if ol i um L. Epilobium glandulosum Lehm. Epi I obi um mi nut um Li ndl . ex Hook. Epi I obi um pani cul at um Nut I . APPENDIX 2. (continued) 90 Equisetum ar ve ns e Equi s et um t el mat el a Er i ger on annuus Festuca subuliflora Fes t uca subulat a Fragari a v es ca Gal i um a pari ne Gal i um t r i f i dum Gal i um t r i fl or um Geranium pus 111um Geranium robertianum Geum macrophyllum Gl yceri a el at a Gnaphalium mi crocephal um Heracleum lanatum Heuchera chlorantha Hoi cus I anal us Holodiscus discolor Hypericum anagalloldes Hypochoeris radical a Juncus effusus Juncus ensifolius Juncus t enui s Kindbergia oregana Kindbergia pr a el onga Lac t uca biennis Lathyrus nevadensis Loni cera ciliosa Lonicera involucrata Lupi nus polyphyllus Luzul a par vi flora Lysichitum amerl canum Mahoni a nervosa Mai ant hemum dilatatum Mai us fusca Mel i ca s ubul at a Me nt ha ar v e ns i s Mimulus moschatus Moehringia macr ophyl I a My eel I s mur a I i s Myosotis I ax a Oenanthe sarmentosa Osmorhiza chilensis Phalaris arundinacea Phi eum pr at ens e PI agi omnium inslgne PI ant ago ma] or Poa compressa Poa pal ustri s Poa pr at ensi s Poa t ri vi al i s Pol ytri chum juniperinum Pol ysI i chum muni t um Popul us t ri cho car pa L. Ehrh. (L.) Pers. Scr i bn. in Macoun Tri n. i n Bong. L. L. L. Mi chx. Burm. L. Wi I I d. (Nash) M.E. Jones Nut t . Mi chx. Piper L. (Pursh) Maxim. Cham. Schlecht. L. L. Wi kstr. Wi 11 d. ( S u i I . ) Ochyra (Hedw.) Ochyra (Moench) (Retz.) Lej. Fe Wat s. (Pursh) DC. (Richards.) Banks ex Spr Li ndl. (Ehrh.) Desv. Hul t . St. John (Pursh) Nutt. (How.) Nels. Macbr. (Raf.) Schneid. (Griseb.) Scri bn. L. Dougl . ex Li ndl . (Hook.) Fenzl (L.) Dumort. Le hm. Presl ex DC. Hook. Arn. L. L. (Mi tt .) Kop. L. L. L. L. L. Hedw. (Kaulf.) Presl Torr. Gray ex Hook. APPENDIX 2. (continued) Prunella vulgaris Pseudotsuga menzi esi i Pt e r i di um a qui 11 num. Ranunculus repens Ranunculus unci nat us Rhyt i di ad elphus i ri que Irus Rosa gymnocarpa Ros a nut kana Rubus parviflorus Rubus spect abiIi s Rubus ursi nus Rumex acet os el I a Sal i x I asiandra Salix s c oul e r i ana Sal i x si t chensis Sambucus racemos a Scut el aria lateriflora Seneci o vulgaris Smilacina racemosa SmiI act na s t el I at a Sol i dago canadensi s Spi raea douglasi i Stachys cool eyae St el I aria cr i spa Symphori carpos albus Taraxacum officinale Tel lima grandi flora Thai i drum Occident ale Tiarella t r i f o l i a t a Torreyochloa pauci flora Traut v et teria car ol i ni ens i s Trientalis I at i folia Trifolium hybridum Tri folium prat ens e Trifolium repens Tr i I I i um ov at um Trisetum canescens Tr i s et um cer nuum Tsuga het er ophylI a Typha I at i f ol i a Vacci ni um parvifol ium Ver oni ca americana Ver oni ca s cut e11 at a Vici a ameri cana Viola gl abel I a Viola palustris L. (Mi r b.) Fr anco (I , ) Kuhn In Decken L. D. Don in G. Don (Hedw.) Warnst. Nut t. i n Torr. Gray Presl Nut t . Pur sh Cham. Sc hi e c ht . L. Bent h. Bar rat t i n Hook, Sanson in Bong. L. L. L. (I.) Desf. (I .) Desf. L. Hook. Heller Cham. Sc hi e c ht . (L.) Blake Weber in Wiggers (Pursh) Dougl. ex Li ndl . Gray L. (Presl) Church (Walt.) Vail Hook. L. L. L. Pursh Buckl . Tr i n. (Raf.) Sarg. L. Sm. in Rees (Raf.) Schwein. ex Benth L. Muhl enb. ex Wi 11 d. Nut t . in Torr . Gray L. APPENDIX 3 9 2 Vegetation Summary Table for Vegetation Units distinguished in the Intermediate-Serai Ecosystems on the Quinsam Flats.  Vegetation unlt^ ADT ADS ALD ALT CO CF Number of plots 20 15 17 19 9 4 Species Presence class and mean species s 1gn1fIcance Abies grand!3 II 3. 1 I +.0 I 1.2 I +.0 Acer macrophyllum III 5.3 II 3.3 I 1.3 I +.4 Ach1ys t r l p h y l 1 a V 4.8 V 5.7 V 4.3 IV 3.4 III 2.3 Actaea rubra I +.0 Adenocau1 on btcolor I + . 1 I 1.2 II 1.1 I +.0 Adlantum pedatum 1 +.5 I +.0 I +.5 Agrostis exarata 2 1.1 AgrostIs scabra 2 1.1 Alnus rubra V 8. 1 V 8.4 V 8.3 V 7.6 IV 5.4 5 2.5 Alnus slnuata I +.5 Amelanchler a l n l f o l t a I +.0 I +.0 II +.5 I +. 1 Anaphalls margarltacea I +.0 Angelica gcnuflexa I 12 I * .3 Aqullegla formosa I +.0 I +.0 Asarum caudatum II 1.2 I 2.9 I 1.0 II +.8 Aster subsplcatus I +.0 I * . 1 II +.8 Athyrlum f l l l x - f e m l n a V 2.8 IV 4 . 1 V 3.6 V 3. 1 V 3.5 Aulacomnlum palustre 2 2.7 Blechnum spleant I +.4 II 1.0 II 1.3 III 1.6 II 1.0 Botrychlum multlfldum I +.0 I +.0 Botrychlum vlrglnlanum I +.0 I *.0 I +.0 II *.0 I +.0 Brachythec1um sp. II 3.0 III 2.5 II 1.3 II 1.3 III 1.4 2 1.1 Brachythec1um salebrosum I +.0 I +.0 Bromus carlnatus I +.0 I +.7 I *.0 Bromus sttchensls I +.0 I +.0 I +.3 Bromus vulgaris III 3.3 IV 4.3 IV 2.5 III 1.5 II +.7 2 +.3 Carex aquat I l l s I * . o Carex deueyana IV 2.8 V 3.7 IV 2.6 IV 1.8 II 1.6 Carex hendersonl1 II 1.3 III 2.7 I +. 1 I +.0 Carex leporlna I +.0 Carex obnupta I +.2 IV 2.6 IV 5.4 V 6.6 5 7.9 Carex ross l l II 1.3 Carex sp. 2 1.8 Cinna 1 at 1 f o l l a I +.0 I +.0 II 1.0 Clrcaea alplna I * .9 I +.0 CIaopodtum bolanderl I +.0 CIaytonla s l b l r l c a V 4.6 V 4.2 IV 2.6 IV 3.2 I +.3 Cornus nuttal111 I +.4 Cornus ser1cea I +.3 II 2.5 II 2.4 IV 4 .9 III 4.4 Cornus una 1aschkens1s II 1.3 II 1.5 III 1.2 III 2.9 Deschampsia caespftoss 2 1.1 Deschamps1 a elongata I +.0 Dicentra formosa IV 4.9 IV 4.8 II +.5 II +.2 1 +.0 Dlcranum scoparlum I +.0 01sporum hooker! V 2.5 IV 2.0 I +.6 I +.0 Dlsporum smith!1 I +.0 I +.1 I +.0 Drepanoc1adus uncinatus 3 1.3 Dryopter!a expansa IV 2.5 IV 3.2 IV 2. 1 II 1.3 II +.0 E1eocharl3 p a l u s t r l s I +.3 Elymus glaucus I +.0 II 1.1 I 1.8 II 1.1 III 2.1 2 +.3 Epilobium angust1follum I +.0 II +.2 Epilobium mlnutum Equisetum arvense I +.0 III 1.5 IV 1.8 IV 1.6 IV 1.9 Eqtllsetum hyemalc I +.0 I +.0 II +,5 II 1.7 Equisetum palustre I +.0 Equlsetum telmatela I +.0 I +.0 II 1.3 I +.5 11 1.3 Erythrontum revolutum I +.0 Festuca arundlnacea I +.0 Festuca o c c l d e n t a l l s I * .o Festuca s v b u l l f l o r a I * .o Festuca subulate III 2.0 IV 3.8 III 3.3 IV 2. 1 II 1.3 2 +.3 F o n t l n a l l s a n t i p y r e t i c s I +.5 II +.7 5 8.8 FontInel1s hove I I I ! Fragarla vesca I +.0 II 1.5 II 1.0 i +. i Gallum eparlne I 2.4 I +.0 Gallum t r l f l d u m I +.3 I 1.1 2 * 3 Gallum t r l f l o r u m III 3.0 V 4 . 1 IV 2.8 IV 2.3 III 1.7 2 +.3 Gaul then!a shallon I +.2 I 2.7 I * . o III 4.0 2 1.1 Gent(ana sceptrum 2 1.1 Geranium robert1anum I 2.6 I +.0 Geum macrophyllum I +.0 1 +.2 I +.0 Glycerla elata I 1 .0 I +.0 I +. 3 Gymnocarplum dryopter!s I 1.6 I +.5 Heracleum 1anatum II 4.8 I 4.2 I + . 4 II +.0 Uolcus lanatus I +.0 I * . 1 Ho!odlsens d i s c o l o r I +.0 I +.2 I +. 1 Hypnum sub!mponens 2 +. 3 11 ex aqu1follum I + . 0 Juncus effusus I * . 3 Juncus e n s i f o l i u s I * .0 Kindbergia oregana II 1.2 II 3.1 III 1.6 I +.2 I +.3 Klndbergla praelonga III 2.1 II 1.5 II 1.7 I * . 1 III 1.7 2 1.8 APPENDIX 3. (continued) Vega tat Ion un l t 1 Number of plots Specles ADT ADS ALD ALT CO CF 20 15 17 19 9 4 Presence class and mean species significance Kindbergia praelonga tathyrus nevadensla l e u c o l e p l s menzlesll L l l l u m columblanum LInnaea boreaI Is l /3(era caurfna l o n l c e r a cl I losa l o n l c e r a Involucrata Luplnus polyphylIus l u z u l a mul11f I or a . i u z u l a p a r v l f l o r a lycopus amer t canus Lycopus u n l f l o r u s L y s l c h l t u r n amerlcanum Mahonla nervosa Maianthemum dlletatum Ma/us fusca Mel lea subulata Mentha arvensls IWenyanthes t r i f o l i a t e MenzIesla ferruglnea Moehrlngla macrophylI a Myce11s mural Is Myosotls laxa Oenanthe sarmentosa Oplopanax horrldus Osmorhlza c h l l e n s t s P e t a s l t e s palmatus Physocarpus capltatua Pfcca s l t c h e n s l s Plnus contorta Plnus montlcola Plag I omnium Inslgne Platanthera una Iaschcens/s Poa marctda Poh11 a nutans Polytrlchum commune PolystIchum munltum Populus tremuloldes Populus t r i c h o c a r p a P r u n e l l a v u l g a r i s Pseudotsuga n e n z l e s l l Pterldlum aquilinum Pyrola a s a r t f o l I a Ranunculus flammula Ranunculus uncinatus Rhemnus purshtanus Rhlzomnlum glabrescens RhytIdiadelphus loreus RhytIdiadelphus t r l q u e t r u a Rlbes bracteosum Rlbea dlvarlcetum Rlbes l e c u s t r e Rlpes l o b b l l Rlbes sp. Rosa gymnocarpa Rosa nutkana Rubus p a r v l f l o r u s Rifbus .ipect abl / /s Rubus uralnus S a l i x hooker I ana S a l i x I as Iandra S a l i x scoulerlana S a l i x sltChens Is Sambucus racemosa Sclrpus mlcrocarpus S c u t e l a r t a l a t e r i f l o r a SmlIacIna stel I at a Solldago canadensis Sparganlum eurycarpum Splraea douglas 11 Stachys cooleyae SteI IarI a c r l s p a Streptopus emplex IfolIus Streptopus roseus SympnorIcarpos albus Taraxacum o f f i c i n a l e I I I 2 1 I I 1 .5 I I I 4 0 I 4 .5 I I 4 .0 I I 4 0 I 4 .0 I I + 9 I I I 2 .3 V I I 1 2 I I I 1 .3 I I I I I + .8 I I I I 2 a I I I 3 4 I I I V 3 2 I I I 4 0 I V I + 0 11 1 9 11 I + 1 I I 1 2 I 4 0 I I 4 0 I 4 0 I I 1 e I V 3 4 I V I + 0 11 1 7 I I I I 1 2 I I 3 1 I V 4 8 V 4 7 I V I I 1 6 I I . 3 2 I I 1 ' I I I 4 0 I + 5 I I V 2 B I V 4 1 I I I I I 4 0 V 5 7 V 5 6 V I 1 1 I I 5 .0 I I I I I 4 9 I I 4 7 I I I I V 3 4 V 5 .0 I V i 4 .0 I I 4 1 I I 4 .0 I I I I 4 3 1 1 .0 I I I • 0 i 4 .5 I I 4 0 i 4 .0 I i 4 .0 I I 1 3 I I 1 . 1 I I 1 3 I I 1 .6 I I 4 7 I I 1 .2 I i 4 .2 I I I I 2 0 i n 4 .2 I I I V e 6 V 6 .0 I V I I I 2 6 I V 4 .7 I I I I 1 .2 I V 3 6 I I I 3 . 1 I I I I 1 4 11 2 .0 I I I 4 .0 I I I 1 3 I V 3 .2 I V I I I 1 .5 I I I 2 .3 I I I I + .7 I 4 .9 I I I 4 .9 I I 1 .4 I I I 3 .2 I I I 4 .7 I V 1 .7 I 4 1 III 1 7 2 1 8 4 .8 II 1 2 4 .0 I 4 0 4 .0 I 4 0 3 .6 V 4 3 V 4 0 4 1 9 I 4 5 I 4 0 1 0 III 4 6 I I 4 2 4 0 I 4 0 III 1 3 2 4 3 3 4 II 2 6 III 5 0 3 5 III 1 8 4 0 V 4 3 IV 3 3 3 1 9 1 4 III 2 0 IV 4 0 2 2 7 II 4 7 2 4 3 4 0 I 4 4 III 2 7 I 4 3 I 4 0 I 1 1 I 4 0 I 4 0 2 9 III 4 9 II 2 6 1 4 3 2 3 IV 3 8 V 5 4 3 5 I 4 0 I 4 3 3 1 III 3 1 II 1 1 2 5 II 4 6 I 1 1 2 8 II 3 6 I 4 0 2 2 7 4 9 I 4 0 2 5 III 3 2 II 1 0 4 0 I 4 0 2 4 0 2 4 3 5 3 V 3 6 II 2 0 I 2 1 II 4 0 5 7 0 5 .4 III 5 2 II 4 5 I 4 0 3 7 II 2 4 II 1 7 4 .8 IV 4 5 III 3 5 I 4 0 I 1 1 2 1 1 I 1 1 4 9 III 4 6 4 .0 I 1 1 I 4 0 4 .4 II 4 7 4 .7 I 4 0 II 4 2 4 .0 I 4 0 I 4 0 I 4 0 I 4 0 4 0 4 .0 I 4 3 4 .3 I 4 0 II 4 2 t .3 IV 3 1 I ( 4 0 2 1 8 3 .8 III 3 6 II 2 7 5 .9 V 5 4 IV 2 1 4 .7 III 3 0 IV 2 6 3 1 3 11 1 8 5 5 2 II 3 7 3 1 7 I 4 3 II 3 8 III 4 8 5 4 8 1 .5 I 4 2 I 4 0 4 .0 111 3 9 I 1 3 III 3 7 4 .9 I 4 8 4 .0 I 1 1 11 4 0 I 1 7 4 .0 II 1 2 V 5 4 5 8 1 3 .3 IV 3 9 II 3 7 1 .8 II 4 .3 II 4 5 1 .3 11 4 .3 I 4 .0 3 .7 IV 4 . 1 1 4 .0 I 4 .0 APPENDIX 3. (continued) VegetatIon u n l t 1 Number of plots Species ADT ADS ALT 20 15 17 19 9 4 Presence class and mean species signif icance Tel lima g r a n d l f l o r a 11 2 1 I 1 0 thai let rum occldentale I 4 8 I 1 4 Thuja pi 1 cat a I + 0 I I 3 4 T l a r e l l a t r l f o l l a t a III 2 3 III 3 1 III 2 1 II t 3 II 1 2 To 1 ml ea mem 1 es II I 1 9 I 2 2 Torreyochloa p a u c l f l o r a II 2 7 Trautvetterla carol 1nlens 1 a III 2 3 III 4 7 IV 5 1 V 5 5 IV 3 3 Tr1entaIIs a r c t l e a I 4 3 T r l e n t a l l s l a t l f o l l a II t 5 II 2 6 II 2 7 II 4 3 T r i I t lum ovatum III 1 3 III 1 4 II 4 2 II 4 1 Trtsetum cernuum I + 0 I 4 5 II 1 3 I 4 0 III 1 5 Tsuga heterophil1a I 1 4 I 3 3 I 1 0 I 4 0 III 2 8 Typha 1 at If o l i o I 4 0 Vaccinium o v a l l f o l l u m t • 0 I 4 0 I 4 0 Vaccinium parv1follum II 2 0 IV 3 5 IV 2 8 III 3 0 V 2 7 Veratrum v l r l d e I 1 3 I 4 0 Veronlca amer1cana I 4 0 III 1 9 Veronica scut e l l at a I 4 1 I + 0 Viburnum edule I 4 0 I 4 0 V l c l a amerlcana I 4 0 V i o l a sp. I 1 2 V i o l a glabel l a II 2 2 II 2 6 II 1 6 III 1 3 V i o l a pa 1 ustr1s 111 1 .e ADT. ..Alnus-Disporum- Typic p.sa., ADS...AInus-Disporum-Stachys p.sa. ALD...Alnus-Lonicera-Dryopteris p.sa., ALT. .Alnus-Lonicera-Trautvetteria p.sa. CO. .Carex-Oenanthe p.a., CF. .Carex-Fontinalis p.a. APPENDIX 4 Vegetation Summary Table for Vegetation Units Distinguished in the Early-Seral Ecosystems on the Quinsam Flats. Acer macrophyllum I + . 3 Achlys t r i p h y l l a I I I 2 . 5 11 1. 3 Agoserls glauca I +. 1 A g r o s t i s exarata II + . 4 A g r o s t i s microphylla II 1 . 2 II 2. 0 A g r o s t i s scabra II 2 . 9 II 2 . 6 A g r o s t i s s t o l o n i fera I + . 0 I + . 0 Alnus rubra II 1 . 8 II 3. 6 Amelanchler a l n i f o l i a II 1 . 3Anaphalis margari tacea IV 3. 9 V 4. 1 Antennaria n e g l e c t a I + . 0 I +. 3 Aquilegia formosa II 1 . 7 I +. 0 Aster subspicatus I I I 4 2 II 1 4 Athyrium f l l i x - f e m i n a I + 3 IV 2 1 Au1acomnium p a l u s t r e II 2 0 Brachytheci um sp. I I I 4 7 I 3 4 Bromus car 1natus I I I 2 3 Bromus v u l g a r i s 11 3 4 II 2 4 Bryum sp. I + 3 Campanula s c o u l e r i II 1 8 II 1 0 Carex a q u a t i l l s I + 3 II 1 6 Carex deweyana II 1 4 V 3 2 Carex hendersoni i II 2 0 Carex i1 Iota I + 8 Carex I n t e r i o r I 2 6 Carex 1enticularIs I + 3 Carex muricata I 1 4 Carex obnupta I 1 1 Carex r o s s i i I 1 7 Carex s t i p a t a I + 0 Carex t r a c y i I 1 1 II + 1 Cerastium arvense I + 0 I + 1 Clnna I at Ifol ia I 1 1 Cirsium arvense IV 3 3 IV 3 1 Cirsium edu1e I + 0 I 1 1 Cirsium vulgare II 2 6 IV 4 1 Clayton!a s i b i r i c a II 3 .3 I I I 2 .7 Cornus s e r i c e a I I I 1 . 3 II 1 . 8 Cornus una 1 aschkens i s. I I I 2 . 1 I 1 . 3 Delphinium m e n z i e s i i I + .3 Deschampsia caespi tosa I 1 . 1 I I I 4 .4 Deschampsia elongata II 3 .4 II 1 .8 Dicentra formosa I 2 . G IV 3 .3 Disporum hooker! I I I 1 .6 II 2 .7 Dryopteris expansa I + .3 II 1 . 1 Elymus glaucus I I I 3 .9 II 1 . 1 Epilobium angustifollum I I I 1 .8 IV 3 .5 Epilobium glandulosum I + .0 Epi1 obium minutum II 1 .3 IV 3 .4 Epilobium paniculatum I + .0 Equ1setum arvense I I I 3 . 1 V 5 . 1 Equi setum t e l m a t e ! a I 1 . 1 I 1 . 1 APPENDIX 4. (continued) V e g e t a t i o n u n l t 1 SF PE Number of p l o t s 9 13 S p e c i e s P r e s e n c e c l a s s and mean s p e c i e s s i g n i f i c a n c e Erigeron annuus I +. 3 Festuca subulif1ora I + 0 Festuca s u b u l a t a I I I 2 6 Fragaria vesca V 5. 1 II 3 1 Gallum aparlne I + 0 Gallum t r i f idum I + 7 Galium trlflorum I I I 3. 0 IV 3 3 Geranium p u s i l l u m I + 0 Geranium robert1anum I +. 3 I 1 7 Geum macrophyllum IV 3. 3 II 1 3 Glyceria e l a t a I + 1 Gnaphalium mlcrocephalum I + 7 Heracleum lanatum I 1 7 I + 8 Heuchera chlorantha I I I 1 . 6 I + 7 Holcus lanatus V 5. 6 II 1 4 Hoiodiscus d i s c o l o r I +. 0 I + 8 Hypericum anaga11oldes I + 0 Hypochoeris r a d i c a t a IV 3. 1 IV 3 3 Juncus effusus I + . 0 II 1 2 Juncus e n s i f o l i u s II 2 0 Juncus t e n u i s II 1 7 Kindbergia oregana I 1 1 Kindbergia praelonga I 1 1 Lactuca b i e n n i s II 2 0 Lathyrus nevadensis 11 2 3 I + 0 Lonicera c i 1 i o s a 11 1 5 Lonicera i n v o l u c r a t a IV 3 6 II 1 2 Lupinus polyphylIus IV 3 2 I I I 4 6 Luzula parv i f1ora I + 0 IV 3 5 Lysichitum americanum I + 0 Mahonia nervosa I I I 1 7 II 1 2 Maianthemum d i l a t a t u m II 1 3 IV 1 4 Malus fusca II + 7 I + 0 Mel lea s u b u l a t a II 2 7 Mentha a r v e n s i s I + 0 II 1 0 Mimulus moschatus I + 0 Moehringia macrophylla II 1 5 Myce1is m u r a l i s IV 3 1 V 4 6 Myosotis 1axa I + 0 Oenanthe sarmentosa II 1 6 Osmorhlza c h i l e n s i s II 2 7 II 1 0 P h a l a r i s arundlnacea I + .0 Phleum p r a t e n s e I I I 4 4 II 1 .2 PIagiomnium i n s i g n e I + .8 Plantago major I I I 1 6 I + .0 Poa compressa I 2 .6 I + . 1 Poa p a l u s t r i s I I I 5 .0 II 4 .8 Poa p r a t e n s i s I + .0 Poa t r i v i a l Is 11 3 .3 11 2 .7 Polytrichum juniperinum II 2 . 1 Polystichum muni turn I 1 .7 V 3 .3 Populus trichocarpa II 1 . 3 II 2 .4 Prunella v u l g a r i s II 2 .2 I + .0 Pseudotsuga menziesl 1 II 2 .2 Pteridium aquillnum V 4 .4 V 4 .2 Ranunculus repens I 2 . S Ranunculus u n c i n a t u s II 2 .2 II 1 .3 Rhytidiadelphus t r i q u e t r u s I + . 1 Rosa gymnocarpa II 1 .3 Rosa nutkana II 1 .5 I 1 .0 APPENDIX 4. (continued) V e g e t a t i o n u n i t Number of p l o t s Spec 1es SF PE 13 P r e s e n c e c l a s s and mean s p e c i e s s i g n i f i c a n c e Rubus parvlflorus V 5 . 5 V 4 4 Rubus s p e c t a b l l l s II 3. 3 V 5 0 Rubus urslnus V 5 . 0 IV 3 9 Rumex acetose11 a II + . 5 I + 7 Sal ix 1 as 1andra I + 0 S a l i x scouleriana I + 0 Sal ix s i t c h e n s i s II 1 8 I + 3 Sambucus racemosa I 1 7 IV 2 1 S c u t e l a r i a l a t e r i f l o r a I + 0 Senecio v u l g a r i s 11 2 6 II 2 1 Smilacina racemosa I + 0 Smilacina s t e l l a t a I + 0 I + 1 Soli dago canadensis II 1 7 I 1 5 Spiraea douglasii II 1 3 11 1 0 Stachys cooleyae IV 3 5 St el 1aria crlspa I 1 1 II 1 6 Symphoricarpos a/bus V 5 1 II 1 0 Taraxacum officinale IV 3 3 I + 0 Tellima grandiflora I + 0 I + 1 Thalictrum o c c i d e n t a l e I 2 6 T i a r e l l a t r i f o l I at a I + 0 II 1 2 Torreyochloa pauciflora I + 1 T r a u t v e t t e r i a carol iniens/s II 2 0 IV 2 0 T r i e n t a l i s l a t l f o l i a I I I 2 5 II 1 3 Trifolium hybridum I 1 1 I + 1 Trifolium pratense I + 0 Trifolium repens I + .0 Tri 11 ium ovatum II + 0 I + .0 Trisetum canescens I 1 .7 Trisetum cernuum I + .0 Tsuga heterophylla I + .0 Typha 1 at 1fol ia I + .0 Vaccinium parvifol ium I I I 1 .9 I I I 2 .3 Veronica americana II 3 . 1 I I I 1 .7 Veronica s c u t e l l a t a I I I 2 .6 Vicia americana I + .0 II 1 . 2 Viola sp. I + .7 Viola glabe11a II 1 .3 I + .0 V iola palust ri s I + .0 1 S?...Symphoricarpos-Fragaria p.a., PB...Polystichum-Equisetum p.a. APPENDIX 5 98 A COMPARISON OF GRAND FIR AND DOUGLAS-FIR GROWTH PERFORMANCE IN THE ELK RIVER TREE FARM R E . Carter, P. Bernardy, andK. Klinka Faculty of Forestry. University of British Columbia 270-2357 Main Mall, Vancouver, B.C. V6T 1W5 • INTRODUCTION This paper presents the results of a portion of the study entitled, "Classification and Rehabilita-tion Interpretations of Hardwood Ecosystems in the Elk River Tree Farm" (Bernardy 1988). The objectives of this larger project are to: 1. classify hardwood ecosystems in the Elk River Tree Farm; 2. provide site-specific interpretations for tree species selection, microsite selection, and site preparation; 3. compare growth performance of Douglas-fir and grand fir in a 40 year-old plantation in the study area; and, 4. produce a 1:5,000 site map for a selected complex of hardwood ecosystems with an area of approximately 50 ha. This study was undertaken to examine possible differences in the growth performance of grand fir [Abies grandis (Dougl. ex D. Don) Lindl.] and Douglas-fir [Pseudostuga menziesii (Mirb.) Franco] growing in a mixed 40 year-old plantation of un-known origin on the Quinsam River Flats, ap-proximately 3 km west of the Campbell River Air-port. Considering the range of soil moisture regimes found across the study sites, this planta-tion occupied the relatively driest soil moisture regime (SMR) (winter-wet to summer fresh). Such special SMRs have not yet been considered in characterizing the quality of coastal forest sites (Klinka etal. 1984). • The'primary objective of the study was to ex-amine trends in height, diameter and annual volume increment between the two species over time. The number and diameter of all branches at each whorl were also described. Expected gTowth performance (i.e. volume and form) of each species was then inferred from trends identified at time of sampling. • STUDY AREA The study area is located in Very Dry Maritime biogeoclimatic subzone (CWHxm) (Klinka et al. 1988). Total annual precipitation is approximate-ly 1406 mm while growing-season (April-Septem-ber) precipitation averages 328 mm. Mean temperature is 8.2 °C. The plantation has an area of approximately 0.5 ha and fell within the Alnus-Polystichum-Mycelis site unit (CWHxm: winter wet to 6ummer fresh soil moisture regime and medium to rich soil nutrient regime; Bernardy 1988). The soils are derived from marine silts and are moderately to strongly mounded with dominant and codominant trees generally found on top of these mounds. The soils are loamy in texture with a mean rooting depth of 32 cm and the presence of gleying visible at an average depth of 44 cm. A compacted silt layer is located at a depth of 70 cm. • METHODS Stem analysis was carried out on ten trees of each species with sample trees chosen to represent an unbiased sample of dominant and codominant trees. Height and diameter at breast height was measured for 20 trees of each species and the average determined. All trees falling within two standard deviations of the mean height and diameter for each species were then considered to be suitable candidate trees with a sub-sample of 10 trees randomly selected from this sub-sample for felling and analysis. Stem form irregularities were identified prior to felling each tree. Following felling, the number and diameter of all branches at each of the first ten whorls above breast height was determined. Annual height increment for each of the last 15 99 APPENDIX 5. (continued) years (1973-1987) and length of the live crown were nlso recorded. The trees were then sectioned and disks collected at 30, 60, and 130 cm above germination point with another eight disks sampled at equal spacing between 130 cm and the top of the tree. Sample disks were then labelled and taken to the laboratory for analysis. Bark thickness and annual ring width was determined to the nearest 0.1 mm for all rings on each disk with measurements repeated along the longest and shortest radius to overcome errors due to stem eccentricity. These measurements were then used to calculate annual diameter and volume increment using the TRAP program of Emanual (1987). All numerical analyses were car-ried out using Lotus Symphony (Lotus 1988) and SYSTAT (Wilkinson 1986) software on a microcomputer. • RESULTS • Height, Diameter, and Length of Live Crown Mean growth performance data for each species are given in Table 1. No significant differences were identified in total height, diameter at breast height, or length of live crown. Significant dif-ferences were also not apparent when these vari-ables were examined over the 1973-1987 period using repeated-measures ANOVA (Milliken and Johnson 1984).The slightly greater height and diameter of grand fir appears to represent a con-tinuing trend (Figures 1 - 4). The similar live crown lengths in both species may imply that shade tolerance in this environment is comparable between the two species. Table 1. Mean and standard deviation for growth performance measures for each species. Species Height Dbh LLC' Branch Branch Total (m) (cm) (m) No. Diameter Volume (mm) m 3 Dougias-lir 27.35 3B.3 14.5 7.3 19.6 1.184 2.35 4.2 3.1 18 3.9 0.297 Grand fir 28.68 40.2 15.0 5.5 15.6 1.329 2.21 3.0 2.5 .0.5 1.4 0.308 LLC - length of live crown • Branching Characteristics Douglas-fir sample trees had significantly poorer branching characteristics than the grand fir. Douglas-fir had a significantly greater number of branches per whorl (p<0.006) and branches of larger diameter (p<0.003). These larger diameter branches are likely to be more persistent, creating larger and more frequent loose knots than will be found in grand fir. • Volume Relationships Mean total volume for grand fir was ap-proximately 12% greater than the mean total volume of Douglas-fir at time of sampling. However, total volume in 1974 was an average of 96% greater for Douglas-fir than grand fir (Figure 6). C2 — — K3~->-Figure 1. Trends in annual height increment between Douglas-fir and grand fir (1973-1987) Diameter (cm) Figure 2. Trends in annual diameter increment between Douglas-fir and grand fir between 1975 and 1986. Figure 3. Trends in cumulative annual height Increment between Douglas-fir and grand fir. 100 APPENDIX 5. (continued) Diameter (cm) ** Volume (m3) Figure 4. Trends in cumulative annual diameter increment be-tween Douglas-fir and grand fir (1975-1986). Grand fir has had a consistently greater cumulative annual increment (CAI) since 1974. If this trend continues grand fir will soon have a much greater volume than Douglas-fir on an in-dividual tree basis. This trend is shown in Figure 6. The greater CAI of grand fir relative to Douglas-fir was significantly diiferent over time based on repeated measures A N O V A (p<0.001). The contribution of each year was relatively con-sistent over the 12 year period. • Form Changes in diameter with height were evaluated in each species. Taper was found to be approximately the same. Regression of diameter against height found Douglas-fir decreased in diameter by 1.333 cm for each meter of height and grand fir decreased an average of 1.30 cm for each meter of height. When the average diameter of each species was plotted against sampling height the two species were indistinguishable. CZ)""*"» E S « — Figure 5. Trends in annual volume increment between Douglas-fir and grand fir (1975-1986). • Discussion This study has investigated growth perfor-mance differences on only one site, using a rela-tively small sample size; therefore, caution should be exercised when considering other sites and stand conditions. Recognizing these limitations, Figure 6. Trends in cumulative volume Increment between Douglas-fir and grand fir (1975-1986). the results of this study represent a valuable con-tribution to tree species decision-making in view of the absence of growth data for the coastal popula-tion of grand fir. The superior growth of grand fir on suitable coastal sites has previously been recog-nized on the basis of qualitative observations with little empirical evidence. For example, D.E. Mc-Mullan (1977, pers. comm.) reported 18% higher volume for a grand fir tree of the same height and age as a 108 year-old Douglas-fir plus tree (No. 622). The different growth pattern of these two species over time suggests that making any com-parisons prior to age 30 would produce different results (Omule 1987). The study site occurs in the relatively driest ecosystem suitable for conifer establishment on the Quinsam River Flats. Conifer growth perfor-mance will be poorer in other, wetter ecosystems in this area; however, Grand fir will likely show an even greater improvement in growth perfor-mance relative to Douglas-fir in these wetter ecosystems. • Conclusions Estimates of growth performance prior to this stand reaching an age of 30 to 40 years would have led to faulty conclusions. The early success of Douglas-fir on this site appears to be in decline whereas grand fir appears to be performing quite well.Grand fir now has a greater total height and diameter (not significant) and total volume (p<0.01). Grand fir growth rate continues to in-crease at a greater rate than Douglas-fir growth rate. Therefore, early growth of grand fir (i.e., <30 years) does not appear to give a reliable prediction of the species' productivity throughout the rota-tion. Grand fir also had better general form, with smaller and fewer branches than Douglas-fir. • References Bernardy, P. 1988. Classification and rehabilitation interpretations of hardwood ecosys-101 APPENDIX 5. (continued) terns in the Elk River Tree Farm. M.Sc. thesis (in progress) Faculty of Forestry, Univ. British Columbia, Vancouver, B.C. Emanual, J. 1987. TRAP - a tree ring analysis program for volume calculations and graphical output from radial increment data. Nutricon Forest Consulting, Vancouver, B.C. Emanual, J. 1987. VTAB - Ecosystem classifica-tion and analysis. Faculty of Forestry, Univ. of British Columbia. 61 pp. Klinka, K.; R.N. Green, P.J. Courtin, and F.C. Nuszdorfer. 1984. Site diagnosis, tree species selection, and slashburning guidelines for the Vancouver Forest Region. Land Management Rpt. No. 25, Prov. of British Columbia, Min. For. , Vic-toria, B.C. 180 pp. Klinka, K ; P.J. Courtin, J. Pojar, and D.V. Meidinger. 1988. Revision of biogeoclimatic units in coastal British Columbia, (submitted for publi-cation in Phytocoenologia). Lotus Development Corp. 1988. Lotus Sym-phony. 453 pp. Milliken, G.A and D.E. Johnson. 1984. Analysis of messy data: Volume 1 Designed experiments. Van Nostrand and Rheinhold, New York. 473 pp. Omule, S. 1987. Comparative height growth to age 28 for 6even species in the CWHd 6ubzone. FRDA Rpt. No. 5. B.C. Ministry of Forests and Lands and Canadian Forestry Service, Victoria, B.C. 9 pp. Wilkinson, L. SYSTAT, The system for statis-tics. Systat Inc., Evanston, 111. UNIVERSITY OF BRITISH C O L U M B I A F A C U L T Y OF FORESTRY Forest Sciences Department 270-2357 Main Mall Vancouver, B.C. Canada V6T 1W5 Mr. Paul Bernardy M.Sc. Candidate Faculty of Forestry, University of British Columbia Paul: Please accept this note as permission to use the research note entitled, "A comparison of grand fir and Douglas-fir growth performance in the Elk River Tree Farm", as an Appendix in your M.Sc. thesis. Reid Carter Research Associate N a t i o n a l L i b r a r y o f C a n a d a B i b l i o t h S q u e n a t i o n a l e d u C a n a d a C a n a d i a n T h e s e s S e r v i c e S e r v i c e d e s t h e s e s c a n a d i e n n e s N O T I C E A V I S T H E Q U A L I T Y O F T H I S M I C R O F I C H E I S H E A V I L Y D E P E N D E N T U P O N T H E Q U A L I T Y O F T H E T H E S I S S U B M I T T E D F O R M I C R O F I L M I N G . L A Q U A L I T E D E C E T T E M I C R O F I C H E D E P E N D G R A N D E M E N T D E L A Q U A L I T E D E L A T H E S E S O U M I S E A U M I C R O F I L M A G E . U N F O R T U N A T E L Y T H E C O L O U R E D I L L U S T R A T I O N S O F T H I S T H E S I S C A N O N L Y Y I E L D D I F F E R E N T T O N E S O F G R E Y . M A L H E U R E U S E M E N T , L E S D I F F E R E N T E S I L L U S T R A T I O N S E N C O U L E U R S D E C E T T E T H E S E N E P E U V E N T D O N N E R Q U E D E S T E I N T E S D E G R I S . National Library of Canada Bibliotheque nationale du Canada Canadian Theses Service Service des theses-canadiennes Ottawa, Canada K1 A 0N4 The author has granted an irrevocable non-exclusive licence allowing the National Library of Canada to reproduce, loan, distribute or sell copies of his/her thesis by any means and in any form or format, making this thesis available to interested persons. The author retains ownership of the copyright in his/her thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without his/her per-mission. L'auteur a accorde une licence irrevocable et non exclusive permettant a la Bibliotheque nationale du Canada de reproduire, prefer, distribuer ou vendre des copies de sa these de quelque maniere et sous quelque forme que ce soit pour mettre des exemplaires de cette these a la disposition des personnes interessees. L'auteur conserve la propriete du droit d'auteur qui protege sa these. Ni la these ni des extraits substantiels de celle-ci ne doivent etre imprimes ou autrement reproduits sans son autorisation. ISBN 0-315-55058-9 Canada 

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