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Growth of Interior spruce seedlings on forest floor materials Heineman, Jeanette Lynne 1991

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G R O W T H O F INTERIOR S P R U C E  SEEDLINGS  ON FOREST FLOOR MATERIALS by JEANETTE LYNNE HEINEMAN E . S c , The University of British Columbia, 1980  A THESIS S U B M I T T E D IN P A R T I A L F U L F I L L M E N T O F T H E REQUIREMENT FOR T H E DEGREE OF MASTER OF SCIENCE in T H E F A C U L T Y O F G R A D U A T E STUDIES (Faculty of Forestry, Dept. of Forest Science)  We accept this thesis as conforming to the required standard  T H E U N I V E R S I T Y O F BRITISH C O L U M B I A July 1991 ®Jeanette Lynne Heineman, 1991  In  presenting  degree  at the  this  thesis  in  University of  partial  fulfilment  of  of  department  this thesis for or  by  his  or  requirements  British Columbia, I agree that the  freely available for reference and study. I further copying  the  representatives.  an advanced  Library shall make it  agree that permission for extensive  scholarly purposes may be her  for  It  is  granted  by the  understood  that  head of copying  my 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  DE-6 (2/88)  ABSTRACT  On a site with a high water table and thick forest floor near Smithers, B . C . , two year-old Interior spruce (Picea glauca (Moench) Voss X Picea engelmanni Parry) container seedlings were outplanted onto rotten wood.  Large and small  mineral soil, H-layer material, F-layer material, and screef sizes were utilized.  Temperature and volumetric  water contents of the various substrates were monitored over the 1989 growing season, and fertilization with NH4NO3 was carried out at the beginning of the 1990 growing season.  Destructive sampling of the seedling population took place in August 1989 and  August 1990 in order to determine height, root collar diameter, root mass, shoot mass, total seedling mass, and shoot to root ratio. Foliar N concentrations were also determined in late August 1990. Differences in height and diameter for the seven screef size/substrate  treatments  were not significant, but the organic substrates produced seedlings of greater root, shoot, and total seedling mass than did mineral soil. Greater seedling mass was correlated most strongly with higher substrate temperature, and to a lesser extent with lower soil moisture content,  as well as with higher foliar N concentration.  differences  in survival' between the treatments.  There were no significant  Seedlings  growing in the organic  substrates had higher foliar N levels, and fertilization improved growth for all parameters. It is concluded that on sites such as this, better growth results can be achieved by planting Interior spruce seedlings high above the water table in F-layer material, where conditions are warmer and drier, than by making deep screefs down to more traditionally acceptable planting substrates such as mineral soil or even the well decomposed H-layer material.  ii  T A B L E OF CONTENTS  Abstract Table of contents List of tables List of figures Acknowledgements  ii iii v vii ix  1.0 I N T R O D U C T I O N  1  2.0 L I T E R A T U R E R E V I E W 2.1 Growth check in white spruce 2.2 Soil temperature effects 2.3 Water relations 2.4 Effects of nitrogen availability  3 3 4 6 9  :  3.0 E X P E R I M E N T A L M E T H O D S 3.01 Site description 3.02 Stock type 3.03 Experimental design. 3.04 Statistical analysis 3.05 Soil temperature monitoring 3.06 Watering. 3.07 Soil moisture content determination : 3.08 Determination of moisture retention curves for forest floor materials 3.09 Bulk density determination 3.10 Determination of forest floor depth 3.11 Seedling growth measurement 3.12 Fertilization 3.13 Foliar nitrogen analysis 3.14 Weather monitoring 4.0 R E S U L T S 4.1 Seedling growth Diameter Height Root mass Shoot mass Total mass Shoot mass to root mass ratio 4.3 Seedling survival 4.4 Foliar nitrogen concentration 4.5 Soil temperature 4.6 Soil moisture content  10 10 ..11 11 16 17 17 18 19 21 21 21 22 22 23 24 24 30 34 38 42 46 51 55 61 67 76  iii  4.7 Soil characteristics 4.7.1 Moisture retention 4.7.2 Bulk density 4.7.3 Forest floor depth 4.8 Weather  81 81 84 85 86  5.0 DISCUSSION 5.1 Soil temperature results 5.2 Soil moisture results 5.3 Fertilization and foliar nitrogen results 5.4 Seedling growth results 5.4.1 Root mass, shoot mass, & total mass 5.4.2 Shoot mass to root mass ratio 5.4.3 Diameter and height 5.5 Seedling survival results  88 88 92 96 99 102 108 109 110  6.0 C O N C L U S I O N S  113  REFERENCES  116  APPENDICES  120  iv  LIST O F T A B L E S  4.1.0.1 Initial seedling measurements  25  4.1.0.2 Significant differences between treatments  26  4.1.0.3 Significant differences between watering treatments  27  4.1.0.4 Significant differences between fertilization treatments  28  4.1.0.5 Significant differences between blocks  29  4.1.1.1 Seedling diameter by treatment  30  4.1.1.2 Seedling diameters by watering treatment  32  4.1.1.3 Seedling diameters by fertilization treatment  32  4.1.2.1 Seedling height by treatment  34  4.1.2.2 Seedling heights by watering treatment  36  4.1.2.3 Seedling heights by fertilization treatment  36  4.1.3.1 Seedling root mass by treatment  38  4.1.3.2 Seedling root mass by watering treatment  40  4.1.3.3 Seedling root mass by fertilization treatment  40  4.1.4.1 Seedling shoot mass by treatment  42  4.1.4.2 Seedling shoot mass by watering treatment  44  4.1.4.3 Seedling shoot mass by fertilization treatment  44  4.1.5.1 Total seedling mass by treatment  :  46  4.1.5.2 Total seedling mass by watering treatment  48  4.1.5.3 Total seedling mass by fertilization treatment  48  4.1.6.1 Shoot mass to root mass by treatment  51  4.1.6.2 Shoot mass to root mass ratio by watering treatment  53  v  4.1.6.3 Shoot mass to root mass ratio by fertilization treatment  53  4.3.0.1 Significant differences in seedling survival  55  4.3.0.2 Seedling survival by treatment  56  4.3.0.3 Seedling survival by watering/fertilization treatment  58  4.3.0.4 Seedling survival by block  59  4.4.0.1 Significant differences in foliar N for treatments and fertilization  61  4.4.0.2 Foliar nitrogen concentration by treatment  62  4.4.0.3 Percent of seedlings with adequate N levels by treatment  64  4.4.0.4 Percent seedlings with adequate N levels by substrate  64  4.5.0.1 Significant differences for soil temperatures by treatment  68  4.5.0.2 Daily soil temperatures  69  4.6.0.1 Significant differences in water contents between treatments  76  4.6.0.2 Significant differences in water contents between watering treatments  77  4.6.0.3 Significant differences in water contents between blocks  77  4.6.0.4 Mean volumetric water contents of material by treatment  78  4.7.1.1 Volumetric water contents of forest floor substrates by matric potential  82  4.7.2.1 Soil bulk density  84  4.7.3.1 Forest floor depth  85  4.8.0.1 Weather information from Smithers airport..  86  vi  LIST O F F I G U R E S  3.03.A  Layout of research area  12  3.03.B  Example of distribution of treatments within each sub-block  12  3.03.C  Illustration of screef size/substrate treatments  15  3.08.A  Hanging column apparatus  20  4.1.1. A Seedling diameter by treatment  31  4.1. L B Increase in seedling diameter by treatment  31  4.1.2. A Seedling height by treatment  35  4.1.2. B Increase in seedling height by treatment  35  4.1.3. A Seedling root mass by treatment  39  4.1.3. B Increase in root mass by treatment  39  4.1.4. A Seedling shoot mass by treatment  43  4.1.4. B Increase in shoot mass by treatment  43  4.1.5. A Total seedling mass by treatment  47  4.1.5.B Increase in total seedling mass by treatment  47  4.1.5. C Root mass, shoot mass, total mass by fertilization treatment  50  4.1.6. A Shoot to root ratio by treatment  52  4.1.6.B Increase in shoot to root ratio by treatment  52  4.3.0.A Seedling survival by treatment  57  4.3.0.B Seedling survival by fertilization treatment (Aug 1990)  58  4.3.0.C Seedling survival by block  59  4.4.0.A Foliar nitrogen concentration by treatment  63  4.4.0.B Percent seedlings with adequate N levels by treatment  65  vii  4.4.0.C Percent seedlings having adequate n levels by substrate  65  4.5.0.A Daily maximum & minimum soil temperatures by treatment...  70  4.5.0.B Daily average soil temperatures & daily range in soil temperature  70  4.5.0.C(a-g)  Daily maximum and minimum soil temperatures  ....71-73  4.6.0. A Mean volumetric water content by treatment  79  4.7.1. A Water retention curves for forest floor materials  83  4.8.0.A Temperature and precipitation 1989  87  4.8.0.B Temperature and precipitation 1990  87  viii  ACKNOWLEDGEMENTS  Thanks go to my supervisor Dr. Denis Lavender, and to my committee members Dr. Tim Ballard, Dr. Andy Black, and Dr. Chris Chanway for their help and advice regarding this project. I am also grateful to Gary Hanson and Doug Witella of Pacific Inland Resources for providing me with a research site and seedlings. Further thanks go to Allan Bahen of Summit Reforestation, Joe Wong of Woodmere Nursery, and Ann Macadam of the Ministry of Forests for use of facilities and equipment, as well as general support during my field work in Smithers.  ix  1.0 INTRODUCTION  White spruce (Picea glauca (Moench) Voss) is a major timber species of northcentral British Columbia, and  it commonly crosses with Engelmann spruce (Picea  engelmanni Parry) to form a hybrid known as Interior spruce.  Although some of the  literature refers to Interior spruce, the majority of work has been done on pure white spruce.  Since the two are closely related, and it is not usually  known to what degree  hybridization takes place, this study assumes that research concerning the pure species also applies to the hybrid. It is generally recommended that white spruce seedlings be planted in mineral soil, as organic materials of the forest floor have been thought to be an unsuitable substrate. For most sites where the water table is not close to the soil surface this policy is correct, because forest floor materials can dry out during hot summer weather, as reported by Potts (1985). Also, since low soil temperature is often a limiting factor to seedling growth in north-central B . C . ,  thermal properties such as conductivity, heat capacity, and  diffusivity make mineral soil more likely to warm up at depth than  organic materials.  This however, assumes that both materials are equally exposed to solar radiation. On some sites, particularly in the Interior Cedar-Hemlock zone near Hazelton, the forest floor can be thick and the water table high, so that the mineral soil is insulated from solar radiation, remaining cold and waterlogged for most of the growing season.  Broadcast  burning is a common form of site preparation in the Hazelton area, but it may be ineffectual at reducing the thickness of the forest floor in wetter, lower slope areas. Other site preparation methods such as mounding are aimed at alleviating this problem through creation of microsites  that  1  are warmer and drier. However,  this  INTRODUCTION  procedure is costly and the equipment is not always readily available, particularly if problem areas are limited to small portions of larger clearcut blocks. This study investigates the possibility that on sites with a thick forest floor and high water table that have not been mechanically site prepared, forest floor material may be an appropriate planting substrate for Interior spruce seedlings. The objectives of the study were as follows: l....To compare growth and survival of Interior spruce seedlings planted in F-layer material, H-layer material, mineral soil, and rotten wood. 2....To determine whether soil temperature had an effect on growth and survival of the seedlings. 3....To determine whether soil moisture content had an effect on growth and survival of the seedlings. 4....To determine whether nitrogen was a limiting factor to seedling growth on this site.  2  I  2.0 LITERATURE REVIEW  2.1 GROWTH CHECK IN WHITE SPRUCE  Interior spruce is a valuable crop tree in B . C . , and is the species most abundantly planted. In 1987,  Interior spruce, together with white spruce and Engelmann spruce,  comprised 48% of the seedlings grown in British Columbia (Silv. Br. M O F , 1987). In spite of the abundance with which we are planting these species and the hybrid, there are problems with growth and survival rates on particular site types.  It is not unusual for  white spruce seedlings to undergo a period of growth check after outplanting.  Growth  check is described by Mullin (1963) as a condition where shoots of seedlings do not extend more than 1 inch (2.5 cm) per year, whereas in the nursery, shoot extension of 6 inches (15 cm) per year is common.  Foliage is generally chlorotic, and needles are abnormally  short. Overall survival rates for white spruce and Interior spruce in B . C . in 1990 were 69% and 83% respectively  (Silv.Br. M O F , 1990, unpubl.), but there are some problem  areas where survival is low enough to have warranted problem analyses.  One of these  was done for the Sub-Boreal Spruce (SBS) and Boreal White and Black Spruce (BWBS) zones in the Prince George Forest Region of B . C . (Butt 1986). causes of plantation failure were perceived inappropriate moisture conditions.  In this study the main  to be brush competition,  cold soils, and  Another problem analysis was done for the Interior  Cedar-Hemlock (ICH) zone in the Prince Rupert Forest Region (Beaudry and McCullough 1989), where the main factors associated with regeneration failure were perceived to be poor treatment timing, brush competition, and poor site prescriptions as a result of lack of  3  LITERATURE  REVIEW  experience and data. Shallow soils, deep humus, excessive moisture, snow press, and low impact site preparation which stimulated competing vegetation were also regarded as important factors. Of the above list of factors, it is mainly soil temperature, soil moisture, and forest floor depth, as well as nitrogen availability that are relevant to this project, and which will be discussed below. A number of researchers have looked at the physiological response to low rooting temperature and excessive moisture.  These have mostly been controlled environment  studies, but as well there have been some ecophysiological studies that have attempted to assess the combination of factors found in the field.  2.2 SOIL  TEMPERATURE  EFFECTS  The optimum temperature for root growth of white spruce is 1 9 ° C , (Heninger and White  1974), but according to Binder et al.  (1987), the  average  midsummer soil  temperature on some sites in north-central B . C . was 1 0 ° C at 10cm depth. In addition to soil temperatures being well below the optimum for root growth of white spruce, Dobbs and McMinn (1977) found that shoot growth is hindered as well by low soil temperature. They found such noticeable differences in shoot growth at various soil temperatures that they suggest a threshold soil temperature exists around 1 0 ° C , below which shoot growth progresses more slowly. In part, cold soils are a direct result of climate, in that the winters are long and cold, and the growing season is short, so that the number of degree-days accumulated by a site over the growing season is relatively small. The climate, in combination with the type of coniferous vegetation in northern ecosystems typically leads to the development of a mor humus form (Kimmins 1987), which is thick and slow to decompose.  4  Klinka et al. (1981)  LITERATURE  REVIEW  define a mor humus as having distinct F and H horizons greater than 1 cm, and being predominantly mycogenous.  Fungi decompose organic material relatively slowly, and  there is a tendency, which becomes more marked with increasing altitude and latitude, for northern ecosystems to accumulate organic matter through the rotation (Salonius 1983). The thermal properties of organic material are such that a thick forest floor acts as an insulating layer, preventing the lower mineral horizons from warming up significantly, even when air temperatures rise in mid-summer.  This is especial^' true in cases where  there is a high water table. Thermal conductivity ( X), which is a measure of how well a material moves heat, is lower for organic material than for mineral soil, partly because of the physical properties of the material, and partly because of the larger amount of air spaces in the organic material.  Stathers and Spittlehouse (1990) state that the thermal  conductivity of dry mineral soil is five times that of dry organic material. Since water is a better conducter than air, and because water improves thermal contact between soil particles, moist soils have higher thermal conductivity than dry soils (Lutz and Chandler 1946). Volumetric heat capacity (C) is also important. It is a measure of the amount of heat required to raise the temperature of a given volume of soil by 1 ° C . Dry mineral soil has a volumetric heat capacity that is 3.3 times that of dry organic material (Stathers and Spittlehouse 1990), and the heat capacity of both materials is raised as water content increases.  Thermal diffusivity ( X/C) is a measure of how much and how rapidly a  material will be warmed at depth in response to surface temperature change.  Organic  material has a lower thermal diffusivity than mineral soil, with the result that underlying horizons remain cold the year round.  Low thermal admittance ( XC)^-^ accounts for the  large surface temperature fluctuations sometimes associated with forest floor materials, especially in the Southern interior of British Columbia. It was previously thought that root  5  LITERATURE REVIEW  collar damage occurred as a result of extremely high temperatures at the surface of the organic layer, but it has since been shown by Black et al. (1991) that the damage is a result of summer frost. Since a relatively small amount of heat is stored by the surface of the forest floor, that material cools rapidly at night and does not warm the air above it sufficiently to prevent frost damage to the seedlings.  2.3 WATER RELATIONS A number of explanations for the condition of growth check in white spruce are found in the literature.  One theory is that growth check is a result of internal moisture  stress leading to stomatal closure and reduced rates of photosynthesis, and hence reduced growth rates.  Binder et al. (1987) think it possible that slow growth in white spruce is a  result of just such a well developed drought resistance mechanism. This idea is supported by work by Buxton et al. (1985) who found that for lodgepole pine and white spruce, survival was inversely proportional to shoot growth when the seedlings were subjected to severe drought stress. White spruce had higher survival, but less growth than pine under these circumstances.  Under moderate water stress, however, it was found that white  spruce experienced stomatal closure gradually with increasing water stress, whereas lodgepole pine did not close its stomata until water stress was much greater.  This  suggests that pine is able to endure normal diurnal temperature and humidity fluctuations without stomatal closure, whereas  white spruce seedlings will respond to gradually  increasing internal moisture stress by gradual stomatal closure. There are several reasons why moisture stress may occur for white spruce seedlings, besides the most obvious which is lack of available soil moisture. The literature suggests that soil temperature and ability for water uptake are linked in white spruce  6  LITERATURE REVIEW  seedlings,  and  Goldstein et al. (1985)  even suggest that the position of treeline in  northern ecosystems is determined by soil temperatures that limit water uptake rather than by summer air temperatures.  Although viscosity of water increases as temperature  drops, it accounts for only part of the resistance to water uptake at low soil temperatures. This is particularly the case in seedlings removed from cold storage and grown at low soil temperatures,  and it is  suggested  that  cold storage  may  somehow  permeability of root cell membranes (Grossnickle and Blake 1985).  decrease  the  This effect on  resistance to water uptake was found to be reversible with time, but resulted in a period of\ water stress for newly planted seedlings. Delucia (1986) however, feels that cold soils affect photosynthetic rate in more ways than by creating water stress in the seedling.  He worked with Engelmann spruce  and found that leaf intracellular CO2 levels were not well correlated with either photosynthesis or stomatal behavior, and suggested that low soil temperatures somehow decrease  the  strength  of the  carbohydrate sink in the  roots.  This  would allow  accumulation of carbohydrates in the shoot and hence decrease photosynthesis through feedback inhibition. Another cause of poor water uptake in white spruce is flooding or waterlogged soil conditions.  Lees (1964) found that total immersion.of white spruce seedlings for 14 days  resulted in 100% mortality, whereas shorter periods of flooding caused less seedling death. Two-year-old seedlings were  more tolerant of flooding than one-year-old  seedlings.  Grossnickle (1986) found that flooding caused reduction in white spruce root growth, a condition that persisted even after flooding subsided. stress was exacerbated by cold storage. in oxygen, and Zinkan et al. (1974)  In this experiment, seedling water  Chronically waterlogged soils tend to be deficient  showed that lowering the oxygen content in the soil  7  LITERATURE REVIEW  solution to 27% of normal resulted in reduced vitality and growth in white spruce, as well as  foliar nitrogen deficiency.  Another problem, particularly in chronically waterlogged  soils, is that chemically reduced forms of elements such as iron and manganese can exist in concentrations high enough to be toxic to roots.  This was found to be the case for iron  on a Sitka spruce plantation in Britain (Sanderson and Armstrong 1980).  Krajina et al.  (1982) discuss the silvics of white spruce, and report that this species thrives on sites that are flooded frequently.  This seems to be in contradiction with the research discussed  above, but it may have to do with an inappropriate comparison between nursery seedlings and wild seedlings, since nursery seedlings, particularly if cold-stored, may have less ability to withstand flooding. Also, short periods of flooding would not result in anaerobic conditions, particularly at cold temperatures. Poor root-soil contact as a result of plug shape and planting technique can also cause water stress. system.  As well, bulk density of soil may restrict expansion of the root  Minore et al. (1969) found Sitka spruce roots to have less ability to penetrate soils  of high bulk density than did roots of other species, such as lodgepole pine. Another cause of water stress in white spruce seedlings which leads to stomatal closure is low air humidity. White spruce responds to decreasing air humidity by gradual stomatal closure, whereas lodgepole pine appears to have a threshold point that allows it to withstand lower humidity levels  before stomata close.  The implications are that  lodgepole pine may be better suited to enduring diurnal fluctuations in air humidity than white spruce (Grossnickle and Blake 1986; 1987).  8  LITERATURE REVIEW  2.4 EFFECTS OF NITROGEN AVAILABILITY The element that is most commonly limiting to tree growth in northern coniferous forests is nitrogen (Armson 1977).  It is essential to production of amino acids and  proteins, and one of the main symptoms of a deficiency is chlorosis, indicating an inhibition of chlorophyll production (Kimmins 1987). Although nitrogen is abundant in forest systems, it may be of limited availability as ammonium (NH4  +  ) or nitrate (NO3"), which are the forms usable by plants.  In  northern forest soils ammonium is more abundant than nitrate because of the low p H , and because nitrate is readily leached. The relative rates of immobilization and mineralization contribute  to  availability of nitrogen  (Knowles  1969).  In cold soils the  rate of  decomposition proceeds slowly, which is one reason why availability of nitrogen is limited. Van Cleve et al. (1990) showed that concentrations of ammonium-N were greatly increased when soil was heated to 8 - 1 0 ° C above ambient temperature.  Nitrogen concentrations in  the needles of black spruce (Picea mariana (Mill.) B.S.P.) were also increased significantly by this treatment.  9  3.0 E X P E R I M E N T A L M E T H O D S  3.01 SITE DESCRIPTION  A cutblock was chosen approximately 25 km W. of Smithers, B . C . , in the Trout Creek valley, near the headwaters of the Kitseguecla River, at an elevation of 700 meters. This  site is in the Interior Cedar-Hemlock moist cold subzone (ICHmcl), and before  logging supported a stand composed mainly of western hemlock and some large white spruce, with a few scattered subalpine fir. The research area was situated on a bench, on the lower portion of a 15-20% slope, of N W aspect. The humus-form was a hemihumimor according to criteria in Klinka et al. (1981), with an average H-layer thickness of 14.7 cm and an average F-layer thickness of 10.6 cm. The mineral soil was a Gleyed Humo-Ferric Podzol (Canadian Soil Survey Committee 1978) with a texture of loam to clay-loam. The site is classified as hygric according to Walmsley et al. (1980), with a water table ranging from 3-4 cm above the surface of the mineral horizon to 10-15 cm below the surface of the mineral horizon, depending on weather and position in the microtopography of the research area.  The site prescription produced by Pacific Inland Resources recommended planting  Interior spruce. The experimental area was approximately 0.3 hectares in size and was chosen because of its thick forest floor with well differentiated horizons, as well as because it appeared to be fairly homogenous in the characteristics of the forest floor and height of the water table.  10  EXPERIMENTAL  METHODS  3.02 STOCK TYPE Interior spruce container stock (Sx 313 Psb) was planted between June 12 and June 17, 1989.  It had been grown and cold-stored in a local Smithers nursery.  3.03 EXPERIMENTAL DESIGN This experiment uses a randomized complete allocation of the watering treatment.  block design with a split plot  There were three blocks, each split into two sub-  blocks (refer to Figure 3.03.A), for which seedlings in one sub-block were watered weekly and not watered in the other sub-block.  The watering treatment took place during the  summer of 1989, and was subsequently shown to have had no significant effect. Therefore the same split-plot layout was used in the summer of 1990 to administer a nitrogen fertilization treatment.  There were seven treatments, each with 27 replicates in each of  the 6 sub-blocks, for a total of 1134 seedlings. The replicates of all seven treatments were randomly allocated within each sub-block as far as stumps and microtopography allowed. This is illustrated by Figure 3.03.B, although it depicts only 6 replicates of each treatment rather than the actual 27.  11  EXPERIMENTAL  METHODS  Figure 3.03.A - Layout of research area  R O A D  Figure 3.03.B - Example of distribution of treatments within each sub-block ie:  mnwcxlered  5U-lo-block A  * this diagram shows only 6 replicates, replicates of each treatment  whereas the actual sub-block contained  12  27  EXPERIMENTAL METHODS  The seven treatments involved different combinations of the following 4 types of planting substrate and 2 screef sizes.  Planting substrate 1....mineral soil: humo-ferric podzol; loam to clay-loam; ph 5.3 2....H-layer: (humus material) - a terrestrial master horizon dominated by fine substances in which the original structures are macroscopically indiscernible (Klinka et al. 1981); p H 4.2 3....F-layer: (formultningsskiktet,  fermented* , decayed materials) - a master  organic horizon characterized by more-or-less disintegrated plant residues in which partial (rather than entire),  macroscopically discernible vegetative structures  are dominant  (Klinka et al. 1981); p H 4.5 4....rotten wood: generally bright orange; decomposed at least to the point of being fibrous; pH3.7  ^Klinka et al. (1981) note that the term 'fermented' originally referred to the presence of anaerobic processes, but has come to mean the decomposition of carbohydrates with the evolution of gas or the formation of acid or both and is used extensively in literature pertaining to this horizon.  13  EXPERIMENTAL  METHODS  Screef size A screef is a patch of ground where undesirable material is cleared away to expose appropriate planting substrate. Two screef sizes were utilized. Refer to Figure 3.03.C.  1....Small screef: regular planting size screef down to the substrate of concern but not exposing it.  2....Large screef: 50cm x 50cm of the substrate of concern is exposed  Treatments The seven treatments as shown in Figure 3.03.C were:  1....Mineral soil; large screef 2....Mineral soil; small screef 3....H-layer; large screef 4....H-layer; small screef 5....F-layer; large screef 6....F-layer; small screef 7....Rotten wood; small screef  |;  * no large screef treatment was employed for rotten wood because it did not occur in large enough patches to accomodate 50cm X 50cm.  14  EXPERIMENTAL  TREATMENT 1  METHODS  TREATMENT2  TREATMENT 7  FIGURE 3.03.C  15  EXPERIMENTAL  3.04 STATISTICAL  METHODS  ANALYSIS  Analysis of variance was carried out using U B C : G E N L I N (Greig and Bjerring 1980).  This package was also used to test for homogeneity of variance.  S A S - Proc  univariate (SAS Institute Inc. 1982) was used to check that the data points come from a normal distribution. Both G E N L I N and S A S were used on the U B C / M T S system. Results of the homogeneity  of variance tests and the transformations used to  satisfy this assumption for analysis of variance are reported in Appendix B. Results of the normality test are reported in Appendix C. Duncan's Multiple Range test was used on G E N L I N to separate means that were significantly different. A randomized complete block design was used for this project, and a single model was used for analysis of variance of all data except soil temperature data. A split-plot was used for allocating the watering treatment in 1989, and the fertilization treatment in 1990.  In the following model:  x  j i l q = H + j + TRi + Elji + Wi + W*TR + E2 B  U  u. is the overall mean, Bj is the effect of the j  t  n  (i)jl  + SE  (ijl)q  block, TRj is the effect of the i ^  treatment, E l j j is the interaction between the j^h block and the  treatment, Wj is the  effect of the l ^ watering or fertilization treatment, W*Trjj is the interaction of the l ^ n  watering or fertilization treatment with the i ^ treatment, E2(j)j[ is the interaction of the 1  jth block with the l ^ watering or fertilization treatment within the i ^ treatment, and n  n  SE(jji)q is the sampling error, the effect of the q  16  t n  n  replicate within each experimental unit.  n  EXPERIMENTAL  METHODS  Analysis of soil temperature data collected for each of the seven screef size/planting substrate treatments was carried out using the following model:  X  i  q  = L t  + TRi + E l  i q  where u. is the overall mean, TRj is the effect of the i ^ treatment, and E l is the n  residual error.  3.05 SOIL TEMPERATURE MONITORING A seven-channel CR-21 data logger with thermistors (101-probes) and a cassette recorder was  used to record soil temperatures.  A n area with average forest floor  characteristics was selected in one of the blocks, and one thermistor was installed beside a representative seedling in each of the seven treatments.  The thermistors were placed at a  depth of 7 cm, which is approximately where the midpoint of the root plug would be. Average temperature was recorded once an hour, and daily maximum and minimum were recorded once every 24 hours. Temperature monitoring was continuous in the same spot for the period of June 17 to August 26, 1989, with the exception of July 15 and August 11-12.  3.06 WATERING Seedlings in the 'watered' treatment were each given one liter of water once a week.  Water was either pumped or carried from a nearby creek, and was poured on so  that at least a 25 cm diameter area was wetted. Watering was carried out weekly during the summer of 1989, from June 21 to August 16.  17  EXPERIMENTAL  METHODS  3.07 SOIL MOISTURE CONTENT DETERMINATION Soil moisture content was monitored weekly, at two depths: 2-3 cm and 9-10 cm, which were later averaged. These depths were representative of the position occupied by the upper and lower third of the seedling root plug.  Soil samples were collected for each  treatment from three locations within each sub-block, and bulked.  These locations had  been prepared in the same manner as if seedlings were to be planted there. The samples were then weighed, dried in ovens for 30 hours at 1 0 0 ° C , and weighed again. Volumetric moisture content was calculated by the following formula:  MC  v o l  = (M /M )(Pb/p ) w  s  w  where: M  w  = mass of water (kg)  M = mass of solids (kg) g  p = bulk density of soil (kg dry soil/m^ soil) D  p  w  = density of water (1000 kg/m^)  Moisture content was sampled before the watering treatments began in order to establish a baseline, and then weekly for seven more weeks.  18  EXPERIMENTAL  3.08 DETERMINATION FLOOR  OF MOISTURE  RETENTION  CURVES  FOR  METHODS  FOREST  MATERIALS  A 'hanging column' apparatus (Hillel 1980) (Figure 3.08.A) was used to determine the water contents of H-layer, F-layer, and rotten wood, .over a range of matric potentials ranging from 0 to -20 kPa. Matric potential was calculated using:  ^m  =  -P g  h  W  where: \fr = matric potential (kPa) m  pw = density of water (1000 kg/m^) g = acceleration of gravity (9.81 m/s^) h = height of hanging column (m)  Undisturbed core samples were obtained using tuna Fish cans opened at both ends. Samples were refrigerated until use.  19  EXPERIMENTAL METHODS  F i g u r e 3.08.A - H a n g i n g c o l u m n apparatus  sample., porous plate-  7  h  outlet  Samples were placed on the porous plates in the funnels as shown above, below which the system was filled with water.  The samples were then flooded and allowed to  stand for 12 hours. The outlet was adjusted to a height of 0, which was at the interface of the sample and the porous plate, and the samples were allowed to drain to a point of equilibrium.  The top of the funnel was covered with plastic with only one small hole, to  minimize evaporation. The outlet was then moved down successively from 0 to 0.05, 0.10, 0.20, 0.35, 0.60, 0.85, 1.10, 1.60, and 1.98 m, over a period of several days.  A t each  point the system was allowed to reach equilibrium, and the mass of water drained off was measured.  After the last measurement was taken, the soil samples were removed,  20  EXPERIMENTAL  METHODS  weighed, dried at 1 0 5 ° C for 48 hours, and weighed again, and volumetric water contents at each matric potential were determined.  3.09 BULK DENSITY  DETERMINATION  Bulk density was determined by the undisturbed core method (Blake and Hartge 1986) for the organic materials and the excavation method (Blake and Hartge 1986) for mineral soil, where coarse fragments would have prevented insertion of the cylinder into the soil. Bulk density was determined by the formula:  Pb = M / V s  t  where:  pj^bulk density (kg/m^) M = mass of solids (kg) s  V =volume of soil (m^) t  3.10 DETERMINATION  OF FOREST FLOOR  DEPTH  The depth of the forest floor horizons were measured on the southern face of each of the large screef holes that had been created for Treatment 1, in each of the sub-blocks, for a total of 162 measurments.  3.11 SEEDLING  GROWTH  MEASUREMENT  At the end of the first growing season (third week of August 1989), 9 randomly selected seedlings were harvested from each of the seven treatments in each of the 6 sub-  21  EXPERIMENTAL  blocks.  METHODS  If any of the seedlings chosen were dead or had large amounts of dead foliage,  they were rejected and another was chosen that was of better vigour. This was to ensure that material measured and weighed was live. The roots were excavated carefully to get all pieces greater than 0.5 cm in length, and the root mass was contained in a plastic bag tied around the root collar.  Seedlings  were refrigerated until they were measured. Height was measured from the root collar to the tip of the terminal bud.  Diameter was measured just above the root collar in two  places and an average was calculated. The root was separated from the shoot at the root collar, and each was dried at 7 0 ° C for 3 days. Samples were then weighed. A t the end of the second growing season (third week of August 1990) the procedure was repeated.  3.12  FERTILIZATION In mid-May of 1990, half the seedlings in the same split-plot layout that had been  irrigated the previous year were fertilized with ammonium nitrate (NH4NO3) fertilizer at a concentration of 200 kg/ha (70 kg/ha N). nitrate in 500 ml of water, which was  Each seedling was given 5 g of ammonium  sprinkled over a 50cm x 50cm area.  In some  cases, as with the small screef treatments down to mineral soil it was not possible to spread the solution out evenly, as it pooled in the bottom of the hole.  3.13 FOLIAR NITROGEN  ANALYSIS  Digestion for foliar nitrogen analysis was done using the Parkinson and Allen method (Parkinson and Allen 1975).  Analysis for ammonium-N was carried out using a  Technicon T R A A C S 800 Auto-analyser. Blanks were included with each batch, and the mg/1 N obtained for the blanks was subtracted from the mg/1 N obtained for each sample.  22  EXPERIMENTAL  METHODS  Reference samples were also included with each batch to determine that the analysis was within acceptable limits of accuracy.  Four batches were run, so that the blanks and  reference samples were repeated four times, but no replication of samples was possible due to the limited quantities of foliage available for sampling.  3.14 WEATHER MONITORING It was not within the range of this project to have a weather station on site, so weather information was obtained from the Smithers airport, which is approximately 15 km from the site, and slightly lower in elevation at 520 meters.  23  4.0 R E S U L T S  4.1 SEEDLING  GROWTH  Total seedling growth was measured in August 1989 and August 1990 for the parameters of diameter, height, root mass, and shoot mass.  Total seedling mass is the  sum of root mass and shoot mass, and shoot to root ratio is shoot mass divided by root mass. A representative sample of 25 seedlings was also measured for these parameters at the time of planting, and  from these initial measurements the increases in seedling  size/mass from June 1989 to August 1989, and from June 1989 to August 1990 were calculated.  These mean values for the initial seedling measurements are presented in  Table 4.1.0.1. In the following report of results, 'treatment' is used to refer to the seven combinations of screef size and planting material described in Section 3.03.  'Watering  treatment' refers to the unwatered and watered subplots, and 'fertilization treatment' refers to the unfertilized and fertilized subplots. When error bars are shown on bar graphs, they represent the standard error of the mean. When transformations were necessary to meet the assumptions of analysis of variance, the transformed data were used in the analysis, and those results are recorded in the tables of significance.  However, the real means and standard deviations are recorded  in the growth result tables, not the transformed values.  The 1990 diameter data was not  successfully transformed to meet the analysis of variance assumption of equal variances. Refer to Appendix B.  24  RESULTS  Table 4.1.0.1 - Initial seedling measurements Growth parameter  Size/mass  Diameter  0.29 cm  Height  23.0 cm  Root mass  0.684 g  Shoot mass  1.596 g  Total mass  2.280 g  Shootrroot  2.33  25  RESULTS  Significant growth results for treatments, watering, fertilization, and blocking are shown in Tables 4.1.0.2 to 4.1.0.5.  Table 4.1.0.2 • Significant differences between treatments ( o = 0.05) Growth parameter Diameter Probability  Total Aug 89 ns  Total Aug 90 ns  +  0.12939  0.14071  ns  ns  0.06709  0.10042*  Probability  3,6> 1,4,2 5,7>4,2 1>2 0.00071  6,3>4,1,2 7,5>1,2 4,1>2 0.00017*  Shoot weight Probability  3>7,1,6,5,4,2 7>2 0.00546  6,4,3>1,2 5>2 0.01640*  Total weight  3>7,6,1,5,4,2 7,6>4,2 1,5>2  6,4,3>1,2 5>2  0.00107  0.00906*  2>3,7,5,6 4>5,6 1>6 0.00810*  2>4,1,5,3,6,7 4> 1,5,3,6,7 1>7 0.00002*  Height Probability Root weight  Probability Shoot: root Probability  * transformed data used + not successfully transformed, so analysis of variance was carried out on data having unequal variances.  26  RESULTS  Table 4.1.0.3 - Significant differences between watering treatments (cn=0.05) Growth parameter  Total Aug 89  Diameter Probability  ns 0.19277  Height Probability  ns 0.50290  Root weight Probability  ns 0.21430  Shoot weight Probability  ns 0.60193  Total Weight Probability  ns 0.40667  Shoot:root Probability  ns 0.29665*  * transformed data used  27  RESULTS  Table 4.1.0.4 - Significant differences between fertilization treatments (Oi= 0.05)  |:  Growth parameter  Total Aug 90  Diameter Probability  ns 0.56534  Height Probability  F>NF 0.00375*  Root weight Probability  F>NF 0.00312*  Shoot weight Probability  F>NF 0.00027*  Total weight Probability  F>NF 0.00028*  Shoot:root Probability  ns 0.66276*  transformed data used  28  RESULTS  Table 4.1.0.5 - Significant differences between blocks (a=0.05) Growth parameter  Total Aug 89  Total Aug 90  Diameter Probability  A>B,C 0.00290  B,A>C 0.04320  Height Probability  ns 0.08513  A>B,C 0.00000*  Root wt. Probability  A>C 0.00602  A>C 0.03049*  Shoot wt. Probability  ns 0.93057  A>B>C 0.00000*  Total wt. Probability  ns 0.39108  A>B,C 0.00000f  Shoot:root Probability  O A 0.01252*  ns 0.12210*  * transformed data used  29  RESULTS  DIAMETER  Seedling diameters for the seven screef size/substrate treatments are presented in Table 4.1.1.1 and Figures 4.1.1.A and 4.I.I.B.  Seedling diameters for the watering and  fertilization treatments are presented in Tables 4.1.1.2 and 4.1.1.3 respectively.  Table 4.1.1.1 - Seedling diameter by treatment (cm) Treatment  Total Aug 89  Increase Jun 89-Aug 89  Total Aug 90  Increase Jun 89-Aug 90  1-lg.screef min. soil  0.44* 0.06 +  0.15  0.69 0.21  0.40  2-sm.screef min.soil  0.43 0.07  0.14  0.63 0.22  0.34  3-lg.screef H-layer  0.46 0.07  0.17  0.83 0.19  0.54  4-sm.screef H-layer  0.41 0.08  0.12  0.79 0.21  0.50  5-lg. screef F-layer  0.44 0.07  0.15  0.80 0.18  0.51  6-sm.screef F-layer  0.45 0.07  0.16  0.99 1.15  0.70  7-sm.screef rotten wood  0.45 0.06  0.16  0.76 0.22  0.47  * mean + standard deviation  30  RESULTS Figure 4.1.1.A - Seedling diameter by treatment  1.2 AUG 89  ft  AUG 90  0.8 o cr  w  §  . 0.6  UJ  1- lg.scr/MS 2- sm.scr/MS 3- lg.scr/H 4- sm.scr/H 5- lg.scr/F 6- sm.scr/F 7- sm.scr/RW  < Q  0.4  0.2  1  2  3  4  5  6  7  TREATMENT  Figure 4.1.1.B - Increase in seedling diameter by treatment  1.2 JUN-AUG 89  JN89-AUG90 0.8 CJ cr  UJ  <  0.6 1- lg.scr/MS 2- sm.scr/MS 3- lg.scr/H 4- sm.scr/H 5- lg.scr/F 6- sm.scr/F 7- sm.scr/RW  0.4  0.2  1  2  3  4  5  TREATMENT 31  6  7  RESULTS  Table 4.1.1.2 - Seedling diameters by watering treatment (cm) Watering treatment  Total Aug 89  Increase Jun 89-Aug 89  Unwatered  0.43* 0.78 +  0.14  Watered  0.45 0.63  0.16  * mean + standard deviation  Table 4.1.1.3 - Seedling diameters by fertilization treatment (cm) Fertilization treatment  Total Aug 90  Increase Jun 89-Aug90  Unfertilized  0.76* 0.67 +  0.47  Fertilized  0.81 0.23  0.52  * mean + standard deviation  32  RESULTS  SIGNIFICANT DIFFERENCES  Significant differences  IN DIAMETER  are presented  summarized for diameter below.  in Tables 4.1.0.2 to  4.1.0.5,  and are  Refer to Figure 3.03.C for a description of the screef  size/substrate treatments.  Total diameter August 1989 Diameters of seedlings in the seven treatments August 1989.  were not significantly different in  Neither did seedlings in the watered treatment have significantly different  diameters than seedlings in the unwatered treatment.  Diameters did vary significantly  between blocks, with Block A seedlings having larger mean diameter than seedlings in Blocks B and C. There was also a significant interaction between block and treatment, as well as between blocks and watering, within treatment (E2).  Total diameter August 1990 Again, there were no significant differences in diameter of seedlings from the seven treatments  in August 1990,  and neither were there significant differences  fertilized seedlings and unfertilized seedlings.  Seedlings  significantly greater in diameter than seedlings in block C.  33  between  in blocks B and A were  RESULTS  HEIGHT  Seedling heights for the seven screef size/substrate treatments are presented in Table 4.1.2.1 and Figures 4.1.2.A and 4.I.2.B.  Seedling heights for watering and  fertilization treatments are presented in Tables 4.1.2.2 and 4.1.2.3 respectively.  Table 4.1.2.1 Seedling height by treatment (cm) Treatment  Total Aug 89  1-lg.screef min.soil  28.6* 3.6 +  5.6  34.3 6.6  11.3  2-sm. screef min.soil  31.3 4.2  8.3  37.3 8.5  14.3  3-lg.screef H-layer  29.6 3.5  6.6  37.9 7.6  14.9  4-sm. screef H-layer  30.3 3.6  7.3  38.8 7.8  15.8  5-lg.screef F-layer  28.0 3.2  5.0  34.1 5.7  11.1  6-sm.screef F-layer  29.0 4.8  6.0  36.3 7.6  13.3  7-sm.screef rotten wood  28.7 3.7  5.7  33.4 6.7  10.4  Increase Jun89-Aug 89  * mean + standard deviation  34  Total Aug 90  Increase Jun 89-Aug 90  RESULTS F i g u r e 4.1.2.A - Seedling height by treatment  45 40  i -I 1  35  E o  30  AUG 89  i  AUG 90  25 20 15 10  1- lg.scr/MS 2- sm.scr/MS 3- lg.scr/H 4- sm.scr/H 5- lg.scr/F 6- sm.scr/F 7- sm.scr/RW  1  5 0 1  2  3  4  5  6  7  TREATMENT  F i g u r e 4.1.2.B - Increase in seedling height by treatment 45 40  J89-A89  35 J89-A90  o UJ  30 25 20 15 10 5  1 2  3  4  5  TREATMENT 35  1- lg.scr/MS 2- sm.scr/MS 3- lg.scr/H 4- sm.scr/H 5- lg.scr/F 6- sm.scr/F 7- sm.scr/RW  RESULTS  Table 4.1.2.2 - Seedling heights by watering treatments (cm)  :|:  +  Watering treatment  Total Aug 89  Unwatered  29.5* 4.2 +  6.5  Watered  29.2 3.7  6.2  Increase Jun 89-Aug 89  mean standard deviation  Table 4.1.2.3 - Seedling heights by fertilization treatment (cm) Fertilization treatment  Total Aug 90  Unfertilized  34.4* 6.2 +  11.4  Fertilized  37.4 8.1  14.4  * mean + standard deviation  36  Increase Jun 89-Aug 90  RESULTS  SIGNIFICANT DIFERENCES  Significant differences  IN HEIGHT  are presented in Tables 4.1.0.2 to  4.1.0.5,  and are  summarized below for height. Refer to Figure 3.03.C for a description of the screef size/substrate treatments.  Total height August 1989 Seedlings from the seven treatments were not significantly different from one another.  Watering did not have a significant effect on height of the seedlings, and there  were no significant differences between blocks.  Total height A ugust 1990 In August 1990, there were no significant differences in height between the seven treatments. Fertilized seedlings were taller than unfertilized seedlings, and seedlings from block A were significantly taller than seedlings in blocks B and C.  37  RESULTS ROOT MASS  Seedling root  mass for the seven treatments is presented in Table 4.1.3.1 and  Figures 4.1.3.A and 4.I.3.B.  Root mass by watering and fertilization treatment is  presented in Tables 4.1.3.2 and 4.1.3.3 respectively.  Table 4.1.3.1 - Seedling root mass by treatment (g) Treatment  Total Aug 89  Increase Jun 89-Aug 89  Total A u g 90  Increase Jun 89-Aug 90  1-lg.screef min.soil  0.930* 0.334 +  0.246  2.324 1.751  1.640  2-sm.screef min.soil  0.756 0.231  0.072  1.409 1.480  0.725  3-lg.screef H-layer  1.147 0.337  0.463  3.297 1.664 .  2.613  4-sm.screef H-layer  0.841 0.301  0.157  3.008 2.593  2.324  5-lg.screef F-layer  1.041 0.331  0.357  3.210 2.145  2.526  6-sm.screef F-layer  1.110 0.357  0.426  3.538 1.923  2.854  7-sm. screef rotten wood  1.037 0.281  0.353  3.313 2.296  2.629  * mean + standard deviation  38  RESULTS Figure 4.1.3.A - Seedling root mass by treatment  AUG 89  3.5  V7\ 3  <  2  AUG  .90  4 1- lg.scr/MS 2- sm.scr/MS 3- lg.scr/H 4- sm.scr/H 5- lg.scr/F 6- sm.scr/F 7- sm.scr/RW  1.5 1 0.5 m.  0 1  2  3  4  5  6  7  TREATMENT  F i g u r e 4.1.3.B - Increase in root mass by treatment  4 J89-A89  3.5 3  CP <  c/i <  m  2.5 2 1.5  0.5  1  2  3  4  5  TREATMENT  39  6  7  J89-A90  RESULTS  Table 4.1.3.2 - Seedling root mass by watering treatment (g) Watering Treatment  Total Aug 89  Increase Jun 89-Aug89  Unwatered  0.948* 0.328 +  0.264  Watered  1.013 0.345  0.329  * mean + standard deviation  Table 4.1.3.3 - Seedling root mass by fertilization treatment (g) Fertilization Treatment  Total Aug 90  Increase Jun 89-Aug 90  Unfertilized  2.362* 1.716 +  1.678  Fertilized  3.296 2.287  2.612  * mean + standard deviation  40  RESULTS  SIGNIFICANT DIFFERENCES  Significant  deferences  a  IN ROOT MASS  r  e  presented  in Tables  4.1.0.2 to 4.1.0.5, and  are  summarized below for root mass. Refer to Figure 3.03.C for a description of the screef size/substrate treatments.  Total root mass August 1989 In August 1989, seedlings from treatments 3, 6, 5 and 7 had significantly greater root mass than seedlings from treatment 4 and 2. Treatment 1 seedlings also had greater root mass than treatment 2 seedlings, and seedlings from treatments 3 and 6 had greater root mass than treatment 1 seedlings. Watering had no significant effect on root mass. Block A seedlings had significantly greater root mass than block C seedlings. There was significant interaction between blocks and watering, within treatment (E2).  Total root mass August 1990 Root mass of seedlings from treatments 6, 3, 7, 5, 4 and 1 were significantly greater than root mass of seedlings from treatment 2. Seedlings from treatment 6, 3, 7, and 5 had significantly greater root mass than seedlings from treatment 1. Treatment 6 and 3 seedlings had significantly greater root mass than seedlings from treatment 4. Fertilized seedlings had greater root mass than unfertilized seedlings, and seedlings from block A had significantly greater root mass than seedlings from block C.  41  RESULTS SHOOT MASS  Seedling shoot mass for the seven screef size/substrate treatments is presented in Table 4.1.4.1 and Figures 4.1.4.A and 4.I.4.B. Seedling shoot mass by watering and fertilization treatment is presented in Tables 4.1.4.2 and 4.1.4.3 respectively.  Table 4.1.4.1 - Seedling shoot mass by treatment (g) .Treatment  Total Aug 89  Increase Jun 89-Aug 89  1-lg.screef min.soil  3.391* 0.679 +  1.795  8.090 5.437  6.494  2-sm.screef min.soil  3.082 0.792  1.486  7.317 6.195  5.721  3-lg.screef H-layer  3.783 0.703  2.187  11.474 5.747  9.878  4-sm. screef H-layer  3.123 0.790  1.527  12.004 6.436  10.408  5-lg.screef F-layer  3.244 0.681  1.648  10.071 4.880  8.475  6-sm.screef F-layer  3.331 0.766  1.749  11.862 6.259  10.266  7-sm.screef rotten wood  3.445 0.712  1.849  9.608 6.878  8.012  * mean + standard deviation  42  Total Aug 90  Increase Jun 89-Aug 90  RESULTS Figure 4.1.4.A - Seedling shoot mass by treatment  w  AUG 89  '4 AUG 90  1- lg.scr/MS 2- sm.scr/MS 3- lg.scr/H 4- sm.scr/H 5- lg.scr/F 6- sm.scr/F 7- sm.scr/RW  < 4 2  'A 1  2  3  4  5  6  7  TREATMENT  F i g u r e 4.1.4.B - Increase i n shoot mass by treatment  14 J89-A89  12  m  10 oo <  J89-A90  1 2  3  4  5  TREATMENT 43  RESULTS  Table 4.1.4.2 - Seedling shoot mass by watering treatment (g) Watering Treatment  Total Aug 89  Increase Jun 89-Aug 89  Unwatered  3.316* 0.767 +  1.720  Watered  3.369 0.753  1.773  ' mean + standard deviation  H  T a b l e 4.1.4.3 - Seedling shoot mass by fertilization treatment (g) Fertilization Treatment  Total Aug 90  Unfertilized  8.313* 4.827 + 11.502 6.784  Fertilized  +  mean standard deviation  44  Increase Jun 89-Aug 90 6.717  9.906  RESULTS  SIGNIFICANT DIFFERENCES  Significant differences  IN SHOOT MASS  are presented  summarized for shoot mass below.  in Tables 4.1.0.2 to  4.1.0.5,  and are  Refer to Figure 3.03.C for a description of the screef  size/substrate treatments.  Total shoot mass August 1989 Shoot mass of seedlings from treatment 3 was significantly greater than shoot mass from any other treatment, and shoot mass of seedlings from treatment 7 was greater than that of seedlings in treatment 2.  There were no significant differences  between watered and unwatered seedlings, or between blocks.  There was significant  interaction between blocks and watering, within treatment (E2).  Total shoot mass August 1990 In August 1990, seedlings from treatments 6, 4, and 3 had significantly heavier shoots than seedlings in treatments 1 and 2, and treatment 5 seedlings had significantly greater shoot mass than seedlings in treatment 2. mass than unfertilized seedlings.  Fertilized seedlings had greater shoot  Block A seedlings had significantly heavier shoots than  block B seedlings, which in turn had significantly heavier shoots than block C seedlings.  45  RESULTS  T O T A L MASS  Total seedling mass for the seven treatments is presented in Table 4.1.5.1 and Figures 4.1.5.A and 4.I.5.B. Total seedling mass by watering and fertilization treatment is presented in Tables 4.1.5.2 and 4.1.5.3 respectively.  Table 4.1.5.1 - Total seedling mass by treatment (g) Treatment  Total Aug 89  Increase Jun 89-Aug89  Total Aug 90  Increase Jun 89-Aug 90  1-lg.screef min.soil  4.321* 0.886 +  2.041  10.414 7.066  8.134  2-sm.screef min.soil  3.838 0.956  1.558  8.726 7.594  6.446  3-lg. screef H-layer  4.931 0.924  2.651  14.771 7.170  12.491  4-sm. screef H-layer  3.964 0.942  1.684  15.012 8.522  12.732  5-lg.screef F-layer  4.285 0.859  2.005  13.281 6.815  11.001  6-sm.screef F-layer  4.440 0.958  2.160  15.399 7.970  13.119  7-sm.screef rotten wood  4.482 0.770  2.202  12.921 8.949  10.641  * mean + standard deviation  46  RESULTS Figure 4.1.5.A - Total seedling mass by treatment  16  1  P  14  AUG 89  AUG 90  12 to tn <  10 1- lg.scr/MS 2- sm.scr/MS 3- lg.scr/H 4- sm.scr/H 5- lg.scr/F 6- sm.scr/F 7- sm.scr/RW  A 1  2  3  4  5  6  7  TREATMENT  F i g u r e 4.1.5.B - Increase in total seedling mass by treatment  J89-A89  16 14  ^  in  GO  <  J89-A90  10 8  A\ 1 ,  2  3  4  5  TREATMENT 47  6  RESULTS  Table 4.1.5.2 - Total seedling mass by watering treatment (g) Watering treatment  Total Aug 89  Increase Jun 89-Aug 89  Unwatered  4.264* 0.941 +  1.984  Watered  4.382 0.966  2.102  * mean + standard deviation  Table 4.1.5.3 - Total seedling mass by fertilization treatment (g) Fertilization treatment  Total Aug 90  Increase Jun 89-Aug 90  Unfertilized  10.675* 6.369 +  8.395  Fertilized  14.798 8.735  * mean + standard deviation  48  12.518  RESULTS  SIGNIFICANT DIFFERENCES  Significant differences  IN TOTAL SEEDLING  MASS  are presented in Tables 4.1.0.2 to  summarized below for total seedling mass.  4.1.0.5, and are  Refer to Figure 3.03.C for a description of  screef size/substrate treatments.  Total mass August 1989 In August 1989 mass of entire seedlings from treatment 3 was greater than that of seedlings from any other treatment.  Seedlings from treatments 7 and 6 were heavier  than seedlings from treatments 4 and 2, and seedlings from treatments 1 and 5 were significantly heavier than seedlings from treatment 2.  Watering produced no significant  differences in seedlings mass, and there were no differences between blocks. There was significant interaction between blocks and watering, within treatment (E2).  Total mass August 1990 Total mass of seedlings was significantly greater in treatments 6, 4, and 3 than in treatments 1 and 2. Treatment 5 seedlings were also heavier than treatment 2 seedlings. Fertilized seedlings  were significantly heavier than unfertilized seedlings.  seedlings were heavier than block B and C seedlings.  49  Block A  RESULTS  F i g u r e 4.1.5.C - Root mass, shoot mass, total mass by fertilization treatment  16 14 12 10  \r> 8 in < 6 4 2 0 ROOT  SHOOT  50  TOTAL  RESULTS  SHOOT MASS T OROOT MASS RATIO  Shoot mass to root mass ratios for the seven treatments are presented in Table 4.1.6.1 and Figures 4.1.6.A and 4.I.6.B. Ratios for watering and fertilization treatments are presented in Tables 4.1.6.2 and 4.1.6.3 respectively.  Table 4.1.6.1 - Shoot mass to root mass ratio by treatment Treatment  Total Aug 89  Increase Jun 89-Aug 89  Total Aug 90  Increase Jun 89-Aug 90  1-lg.screef min. soil  4.02* 1.36 +  1.69  4.04 1.66  1.71  2-sm.screef min.soil  4.36 1.60  2.03  7.01 3.50  4.68  3-lg.screef H-layer  3.61 1.36  1.28  3.66 1.25  1.33  4-sm. screef H-layer  4.14 1.74  1.81  5.13 2.57  2.80  5-lg.screef F-layer  3.41 1.29  1.08  3.75 1.72  1.42  6-sm.screef F-layer  3.28 1.25  0.95  3.71 1.62  1.38  3.59 . 1.38  1.26  3.51 2.39  1.18  7-sm.screef rotten wood  * mean + standard deviation  51  RESULTS Figure 4.1.6.A - Shoot to root ratio by treatment  AUG 89  AUG 90 5 o cr >O O  5 4 ^  fe  X  w  3  .1  2  3  4  5  6  1- lg.scr/MS 2- sm.scr/MS 3- lg.scr/H 4- sm.scr/H 5- lg.scr/F 6- sm.scr/F 7- sm.scr/RW  7  TREATMENT  Figure 4.1.6.B - Increase in shoot to root ratio by treatment  J89-A89  J89-A90 o o cr vo o x  1- lg.scr/MS 2- sm.scr/MS 3- lg.scr/H 4- sm.scr/H 5- lg.scr/F 6- sm.scr/F 7- sm.scr/RW  00  TREATMENT 52  RESULTS  Table 4.1.6.2 - Shoot mass to root mass ratio by watering treatment Total Aug 89  Increase Jun 89-Aug 89  Unwatered  3.91* 1.65 +  1.58  Watered  3.64 1.23  1.31  Watering treatment  * mean + standard deviation  Table 4.1.6.3 - Shoot mass to root mass ratio by fertilization treatment Fertilization treatment  Total Aug 90  Increase Jun 89-Aug 90  Unfertilized  4.48* 2.50 +  2.15  Fertilized  4.30 2.43  1.97  * mean + standard deviation  53  RESULTS  SIGNIFICANT DIFFERENCES  Significant differences  IN SHOOT MASS TO ROOT MASS RATIO  are presented  in Tables  summarized below for shoot mass to root mass ratio.  4.1.0.2 to  4.1.0.5,  and are  Refer to Figure 3.03.C for a  description of the screef size/substrate treatments.  Shoot mass to root mass ratio August 1989 Seedlings from treatments  2, 4, and 1 had higher  shoot to root ratios than  seedlings from treatment 6, and seedlings from treatment 4 also had a significantly higher ratio than seedlings from treatment 5. Treatment 2 seedlings had the highest shoot to root ratio, and it was significantly higher than the ratio for treatments 3, 7, 5 and 6. Watering had no significant effect on shoot to root ratio.  Seedlings from block C had significantly  higher shoot to root ratios than seedlings from block A . There was significant interaction between blocks and watering, within treatment (E2).  Shoot mass to root mass ratio August 1990 Treatment 2 seedlings had a significantly greater shoot to root ratio than seedlings from any other treatment. seedlings from treatments  Treatment 4 seedlings had a higher shoot to root ratio than 1, 5, 3, 6, and 7.  Seedlings from treatment 1 also had a  significantly higher shoot to root ratio than seedlings from treatment 7.  Fertilization  resulted in no significant differences in shoot to root ratio, and there were no differences between blocks in August 1990.  54  RESULTS  4.3 SEEDLING SURVIVAL  Seedling survival was assessed on three dates, August 1989, May  1990, and  August 1990. Significant differences in seedling survival are presented in Table 4.3.0.1. Seedling survival by screef size/substrate treatment are found in Table 4.3.0.2 and Figure 4.3.O.A. Seedling survival by watering and fertilization treatments is presented in Table 4.3.0.3. Seedling survival by block is found in Table 4.3.0.4 and Figure 4.3.O.C.  Table 4.3.0.1. - Significant differences i n seedling survival (oc=0.05) Date  Treatments 1-7  Watering/ fertilization  Block  Aug 89 Probability  ns 0.30011  ns 0.58785  ns 0.08235  May 90 Probability  ns 0.05499  ns 0.41099  A>C,B 0.00099  Aug 90 Probability  ns 0.12633  F>NF 0.00157  A>C>B 0.00008  55  RESULTS  Table 4.3.0.2 - Seedling survival by treatment (%) Treatment  Aug 89  May 90  Aug 90  1-lg.screef min. soil  100.00* 0.00 +  96.08 4.80  77.45 8.67  2-sm. screef min.soil  100.00 0.00  98.04 3.04  66.67 13.24  3-lg.screef H-layer  99.38 1.51  96.08 4.80  72.55 14.25  4-sm.screef H-layer  97.53 3.02  92.16 8.04  55.88 25.43  5-lg. screef F-layer  95.68 4.32  85.29 13.79  69.61 14.61  6-sm.screef F-layer  98.15 3.10  81.37 14.61  69.61 22.76  7-sm.screef rotten wood  98.15 2.03  82.35 17.05  61.77 23.75  * mean + standard deviation  /  56  RESULTS  F i g u r e 4.3.0.A - Seedling survival by treatment  AUG 89  MAY 90  < > >  AUG 90  Qi Z>  1- lg.scr/MS 2- sm.scr/MS 3- lg.scr/H 4- sm.scr/H 5- lg.scr/F 6- sm.scr/F 7- sm.scr/RW  Ul  TREATMENT  57  RESULTS Table 4.3.0.3 - Seedling s u r v i v a l by watering/fertilization treatment (%) Watering/ fertilization  Aug 89  Unwatered  98.59* 2.18 +  Watered  98.24 3.23  May 90  Aug 90  Unfertilized  -  91.32 11.56  60.51 16.86  Fertilized  -  89.08 12.52  74.79 17.26  * mean + standard deviation  F i g u r e 4.3.0.B - Seedling survival by fertilization treatment (Aug 1990)  58  RESULTS  T a b l e 4.3.0.4 - Seedling survival by block (%) Block  Aug 89  May 90  A  99.47* 1.34 +  99.16 2.13  81.09 11.11  B  97.62 3.73  84.45 14.15  52.94 17.26  C  98.15 2.41  86.98 10.62  68.91 14.49  * mean + standard deviation  F i g u r e 4.3.0.C - Seedling survival by block  BLOCK 59  Aug 90  RESULTS  SIGNIFICANT DIFFERENCES  Significant differences summarized below.  IN SURVIVAL  RESULTS  for survival are presented  in Table 4.3.0.1, and are  Refer to Figure 3.03.C for a description of the  seven screef  size/substrate treatments.  Seedling survival There were no significant differences in seedling survival between the 7 treatments on any of the dates of assessment. survival in August 1989.  Watering resulted in no significant differences in  Fertilized seedlings did not have significantly different survival  than unfertilized seedlings in May 1990, but in August 1990 fertilized seedlings had significantly higher survival than unfertilized seedlings. significant differences  In August 1989 there were no  in seedling survival between blocks.  In May 1990 there was  significantly higher survival in block A than in blocks C or B, and in August 1990 block A seedlings had higher survival than block C seedlings, which in turn had significantly higher survival than block B seedlings.  60  RESULTS  4.4 FOLIAR NITROGEN CONCENTRATION  Foliage was collected in the third week of August 1990, and foliar nitrogen analysis was  done as described in Section 3.13.  Significant differences in foliar nitrogen  concentrations are presented in Table 4.4.0.1, and foliar N contents by treatment are in Table 4.4.0.2. The percentage of seedlings sampled having adequate nitrogen levels of 1.55 cg/g or greater (Ballard and Carter. 1985), is presented by screef size/substrate treatment in Table 4.4.0.3, and by substrate in Table 4.4.0.4.  Table 4.4.0.1 - Significant differences i n foliar N for treatments and fertilization treatments (cx= 0.05) Treatment/ Fert. trmt  Significant differences  Treatment 1-7 Probability  6,5>2,1 7>1 0.01816  Fertilization treatment Probability  F>NF 0.01321  RESULTS  Table 4.4.0.2 - Foliar nitrogen concentration by treatment (cg/g) Treatment  Foliar N  1-lg. screef min.soil  1.314* 0.457 +  2-sm.screef min.soil  1.675 1.314  3-lg.screef H-layer  1.906 0.575  4-sm.screef H-layer  2.170 0.926  5-lg.screef F-layer  2.543 1.128  6-sm.screef F-layer  2.643 0.872  7-sm.screef rotten wood  2.258 0.939  * mean + standard deviation  62  0  RESULTS  Figure 4.4.0.A - F o l i a r nitrogen concentration by treatment  4 FERT.  3.5 3  AVERAGE  2.5 UNFERT. cr <  2  o ^  1.5 1  •-T  1  T  ft  l l il l 2  0.5 0  2  1 T 4 TREATMENT  63  1- lg.scr/MS 2- sm.scr/MS 3- lg.scr/H 4- sm.scr/H 5- lg.scr/F 6- sm.scr/F 7- sm.scr/RW  RESULTS  Table 4.4.0.3 - Percent of seedlings with adequate N levels by treatment* Treatment  1-lg.screef min.soil 2-sm.screef min.soil 3-lg.screef H-layer 4-sm. screef H-layer 5-lg. screef F-layer 6-sm. screef F-layer 7-sm.screef rotten wood  Total % Adequate  Unfertilized % Adequate  Fertilized % Adequate  22.2  11.0  33.0  50.0  33.0  62.0  64.7  62.0  67.0  75.0  60.0  86.0  70.5  55.0  87.0  94.1  87.0  100.0  85.7  83.0  87.0  * based on seedlings sampled for foliar N  Table 4.4.0.4 - Percent seedlings with adequate N levels by substrate* Treatment  % Adequate  Min. soil  34.3  H-layer  70.0  F-layer  82.3  Rotten wood  85.7  * based on seedlings sampled for foliar N i  64  RESULTS Figure 4.4.0.B - Percent seedlings with adequate N levels by treatment  120  LJ I— < o UJ Q <  FERT.  100  AVERAGE 80  I  60  00 o Q UJ Ul  00  40  IHI  20  I 3  4  :  II  UNFERT.  1- lg.scr/MS 2- sm.scr/MS 3- lg.scr/H 4- sm.scr/H 5- lg.scr/F 6- sm.scr/F 7- sm.scr/RW  TREATMENT F i g u r e 4.4.0.C - P e r c e n t seedlings h a v i n g adequate N levels by substrate  100  i  65  RESULTS  SIGNIFICANT DIFFERENCES  IN FOLIAR N  CONCENTRATION  Significant differences are presented in Table 4.4.0.1, and are summarized below. Refer to Figure 3.03.C for a description of the screef size/substrate treatments.  Foliar nitrogen content Foliar nitrogen content of seedlings in treatments 6 and 5 was significantly higher than that of seedlings in treatments 2 and 1. Foliar N content of seedlings in treatment 7 was significantly  higher than of seedlings in treatment  1.  Fertilized seedlings had  significantly higher foliar nitrogen than unfertilized seedlings.  There were no significant  differences between blocks.  66  RESULTS  4.5 SOIL  TEMPERATURE  Soil temperatures  were  recorded continuously for each  treatment during the period from June 18 to August 25, 1989.  screef  size/substrate  Because of the limitation  of the number of channels on the data logger, soil temperatures were monitored in one location only, so there is no data for block to block differences, or for differences between watered versus unwatered subunits, or fertilized versus unfertilized subunits. average  temperatures  temperatures.  were  recorded, as  Significant differences  well  as  daily  maximum and  in soil temperatures between  Hourly minimum  treatments  are  presented in Table 4.5.0.1, and mean daily soil temperatures are found in Table 4.5.0.2 and Figures 4.5.0.A and 4.5.O.B. Daily maxima and minima over the growing season for each of the seven screef size/substrate treatments are presented in Figures 4.5.0.C (a-g).  67  RESULTS  Table 4.5.0.1 - Significant differences for soil temperatures by treatment (cx=0.05) Significance  Temperature measurement  7>6,3,4,1,2 5,6,3>4,1,2 4,1>2 0.00000*  Daily maximum Probability  Probability  7,6,4,5>3,2,1 3>2,1 2>1 0.00000*  Daily average Probability  7,5,6>3,4,1,2 3,4>1,2 0.00000*  Daily range  7>5,1,6,4,2 3,5> 1,6,4,2 1,6>4,2 4>2 0.00000*  Daily minimum  Probability * transformed data used  68  RESULTS  Table 4.5.0.2 - Daily Soil Temperatures (P-C) Treatment  Maximum  1- lg.screef min.soil  13.278* 1.469+  2- sm.screef min.soil  Minimum  Average  Range  9.974 1.384  11.292 1.295  3.304 1.120  11.179 1.127  10.546 1.265  10.811 1.213  0.633 0.272  3- lg.screef H-layer  15.671 1.955  11.339 1.636  13.239 1.627  4.332 1.269  4- sm.screef H-layer  13.794 1.733  12.336 1.560  13.002 1.587  1.458 0.514  5- lg.screef F-layer  16.106 1.946  12.273 1.794  14.034 1.758  3.832 0.973  6- sm.screef F-layer  15.702 2.044  12.441 1.749  13.898 1.821  7- sm.screef rotten wood  16.821 2.321  12.493 1.812  14.479 1.934  * mean + standard deviation  69  .  3.261 0.976 4.328 1.115  RESULTS Figure 4.5.0.A - Daily maximum & minimum soil temperatures by treatment  16  14 12 UJ LY Z> t— < LY UJ Q_ UJ  i  la  10  I  8  1- ]g.scr/MS 2- sm.scr/MS 3- lg.scr/H 4- sm.scr/H 5- lg.scr/F 6- sm.scr/F 7- sm.scr/RW  6 4 2 0 1  2  3  4  5'  6  7  TREATMENT  Figure 4.5.0.B - Daily average soil temperatures & daily range in soil temperature  16 14  o o  12  UJ LY  10  LY UJ  8  i— <c  o_  i  6  la  4 2 0  I: 3  4  5  TREATMENT 70  1- lg.scr/MS 2- sm.scr/MS 3- lg.scr/H 4- sm.scr/H 5- lg.scr/F 6- sm.scr/F 7- sm.scr/RW  RESULTS Figure 4.5.0.C(a-g) - Daily maximum and minimum soil temperatures (June 18Aug 22/89)  a - Treatment 1 (large screef, mineral soil) 22 20 18  July .-16  Aug 15 DATE  71  RESULTS Treatment 3 (large screef, H-layer) 22  MAX.  WM  11111111111111 111  June 18  Aug 15  DATE  Treatment 4 (small screef, H-layer)  WAX. CC ZD I—  <  WIN  June 18  11111 111111111111 11  11111 1111111  July 16 DATE  Aug 15  Treatment 5 (large screef, F-layer)  WAX.  WIN  June 18  Aug 15  DATE 72  RESULTS  - Treatment 7 (small screef, rotten wood)  June 18  1  July 16 DATE  Aug 15  73  RESULTS SIGNIFICANT DIFFERENCES  IN MEAN DAILY SOIL  TEMPERATURE  Significant differences are presented in Table 4.5.0.1 and are summarized below.  Daily maximum Substrate in treatments 7 and 5  had  significantly higher daily  temperatures than soil materials in the other 5 treatments. temperatures for substrates in treatments 6 and 3  The daily  maximum maximum  were significantly higher than the  temperatures of substrates in treatments 4, 1, and 2. Soil material in treatments 4 and 1 was warmer than material in treatment 2.  Daily minimum The daily minimum temperature for treatments 1, 2, and 3 was significantly lower than for treatments 5, 4, 6, and 7. Mineral soil treatments 1 and 2 had lower minimum temperatures than treatment 3 , and treatment 1 had a lower daily minimum temperature than treatment 2.  Daily average Substrates in treatments 7, 5, and 6 was significantly warmer than substrates in treatments 3, 4, 1, and 2. Treatments 3 and 4 had higher average temperatures than in treatments 1 and 2.  74  RESULTS Daily  range Rotten wood in treatment 7 had a significantly wider range in daily temperature  than substrates in treatments 5, 1, 6, 4, and 2.  Substrate of treatments 3 and 5 had a  wider range in temperature than material in treatments 1, 6, 4, and 2. treatments  1 and 6 had a wider range than substrate in treatments  treatment 4 had a wider range than treatment 2.  75  Substrate in 4 and 2, and  RESULTS  4.6 SOIL MOISTURE  CONTENT  Gravimetric moisture contents of the soil materials in the seven treatments were determined in the week prior to commencing the watering treatment in June 1989, in order to get a baseline measurement.  Moisture contents were then determined weekly  from June 21 to August 16, while the watering treatment was underway.  Significant  differences in water content are presented in Tables 4.6.0.1 to 4.6.0.3. Mean volumetric water contents for each of the seven screef size/substrate treatments are found in Table 4.6.0.4 and Figure 4.6.0.A. These data were not successfully transformed to meet the analysis of variance requirement for equal variances. Refer to Appendix B.  Table 4.6.0.1 - Significant differences i n water'contents between treatments (<x=0.05) Time Period  Significant differences  Before watering Probability  1,2>4,3,7,6,5 4,3,7>6,5 0.00000  During watering Probability  1,2>4,3,7,5,6 4,3,7>5,6 0.00000  76  RESULTS  Table 4.6.0.2 - Significant differences i n water contents between watering treatment subplots (a=0.05) Time period  Significant differences  Before watering Probability  ns 0.15094  During Probability  ns 0.08812  Table 4.6.0.3 - Significant differences i n water contents between blocks (ot=0.05) Time period  Significant differences  Before watering Probability  ns 0.14481  During watering Probability  C>A>B 0.00001  77  RESULTS  Table 4.6.0.4 - M e a n volumetric water contents of material by treatment (mft-Zmft-) Treatment  Before watering  During watering  1-lg.screef min.soil  0.678* 0.256 +  0.676 0.149  2-sm. screef min.soil  0.600 0.092  0.630 0.135  3-lg. screef H-layer  0.494 0.080  0.517 0.090  4-sm.screef H-layer  0.520 0.076  0.536 0.088  5-lg. screef F-layer  0.289 0.022  0.272 0.027  6-sm.screef F-layer  0.295 0.072  0.251 0.026  7-sm.screef rotten wood  0.468 0.057  0.463 0.049  * mean + standard deviation  78  RESULTS  F i g u r e 4.6.0.A - V o l u m e t r i c water content by treatment  1  2  3  4  5  6  7  TREATMENT  SIGNIFICANT  DIFFERENCES  Significant  differences  IN VOLUMETRIC  are presented  WATER  in Tables  CONTENT  4.6.0.1 to 4.6.0.3, and are  summarized below.  Volumetric water contents before watering Water contents of mineral soil in treatments 1 and 2 were significantly higher than water contents of the soil materials in any of the other treatments. The water contents of substrates from treatments 4, 3 and 7 were significantly higher than water contents of substrates from treatments 5 and 6 .  There were no significant differences in water  79  RESULTS content in the subunits that were to be watered or unwatered before the watering treatment began.  There were no differences in water contents of the soil materials  between blocks.  Volumetric water contents during watering treatments The  volumetric water contents of mineral soil from treatments  1 and 2 were  significantly higher than the water contents of soil materials from any other treatment. The water contents of substrates in treatments 4, 3, and 7 were significantly higher than the water contents of substrates from treatments 5 and 6. There were no significant differences in volumetric water contents of soil materials in the unwatered and watered subunits during the period of watering. Blocks had significantly different water contents, with block C water content higher than block A, which was higher than block B water content.  80  RESULTS  4.7 SOIL  CHARACTERISTICS  4.7.1 M O I S T U R E R E T E N T I O N  Water retention curves for the three substrates of the forest floor were obtained as described in Section 3.08.  Volumetric water contents over the range of matric potentials  obtained through use of the hanging column apparatus are presented in Table 4.7.1.1, and are plotted as water retention curves in Figure 4.7.1.A. Also plotted in Figure 4.7.1.A are the mean volumetric water contents of each of the substrates for the period of June 21Aug 16, 1989.  81  RESULTS  Table 4.7.1.1 - Volumetric water contents of forest floor substrates (mQjmQ.) Matric potential (kPa)  H layer  F layer  -0.0  0.909* 0.101 +  0.835 0.062  0.815 0.089  -0.5  0.861 0.072  0.705 0.039  0.795 0.101  -1.0  0.744 0.039  0.527 , 0.047  0.650 0.053  -2.0  0.669 0.068  0.417 0.041  0.595 0.055  -3.5  0.597 0.066  0.360 0.034  0.529 0.052  -6.0  0.549 0.061  0.330 0.032  0.492 0.061  -8.5  0.524 0.055  0.319 0.031  0.468 0.066  -11.0  0.508 0.049  0.312 0.030  0.448 0.071  -16.0  0.480 0.039  0.303 0.029  0.412 0.075  -19.8  0.465 0.032  0.297 0.029  0.394 0.074  * mean + standard deviation  82  j  Rotten wood  RESULTS  mean volumetric water content for H-layer mean volumetric water content for rotten wood mean volumetric water content for F-layer  83  RESULTS  4.7.2 B U L K D E N S I T Y  Bulk density was determined using the method described in Section 3.09, and mean bulk densities for the four substrates are presented in Table 4.7.2.1.  Table 4.7.2.1 - Soil bulk density (kg/ml) Material  +  Bulk density  Mineral soil  1521.73* 89.84 +  H-layer  169.62 10.83  F-layer  123.44 15.66  Rotten wood  166.00 14.70  mean standard deviation  84  RESULTS  4.7.3  FOREST FLOOR DEPTH  Mean forest floor depths, and the mean depth for the F-layer and H-layer are given in Table 4.7.3  Table 4.7.3.1 - Forest floor depth (cm) Horizon  Depth  H-layer  14.72* 4.52 +  F-layer  10.65 6.16  Total  27.79 7.74  * mean + standard deviation  85  RESULTS  4.8  WEATHER  Weather information was obtained from the Smithers airport, approximately  15  km from the research site, and is summarized below for the growing seasons of 1989 and 1990.  Table 4.8.0.1 - Weather information from Smithers airport Date  Mean daily maximum (°C)  Mean daily minimum (°C)  Mean daily average (°C)  May 89 Jun 89 Jul 89 Aug 89  16.8 21.8 22.6 22.6  3.1 6.3 8.7 10.3  9.6 12.7 15.7 16.5  10.0 14.1 15.7 42.0  May 90 Jun 90 Jul 90 Aug 90  16.5 18.5 23.6 24.6  3.9 7.0 8.7 9.8  10.2 12.7 16.2 17.5  39.3 75.0 29.0 17.2  86  Total monthly ppt. (mm)  RESULTS  Figure 4.8.0.A - Temperature and precipitation 1989 (mid-May to mid-Aug)  25  Aug 1 June 1  July 1 DATE  Figure 4.8.0.B - Temperature and precipitation 1990 (mid-May to mid-Aug)  301  1  25  June 1.  Aug 1  July 1 DATE 87  5.0 DISCUSSION  The main objective of this study was to look at the ability of Interior spruce seedlings to grow and survive in four substrates: mineral soil, H-layer, F-layer, and rotten wood, on a hygric site with a thick forest floor in the I C H m c l .  A further objective was to  gather data concerning soil temperature and moisture conditions on this site, and determine whether these factors were related to growth and survival. As well, there was an attempt to determine whether nitrogen was a limiting factor to growth and survival on this site, and whether this varied for the four substrates. This chapter will first discuss the results of the soil temperature study, then go on to the results of the soil moisture study, and the effects of the watering treatment. Then it will discuss the effects of fertilization with ammonium nitrate, and the outcome of the foliar nitrogen study. This information will be used to interpret and discuss the results of the seedling growth study, with regard to several growth parameters, as well as seedling survival.  5.1 SOIL TEMPERATURE  RESULTS  Due to the constraint of having only one data logger with seven channels, soil temperatures were taken in one location only, selected because it appeared to -be average in its forest floor characteristics for the research site as a whole.  Statistically, it is not  possible to say that this data is representative of the entire research site, but it is assumed that while the temperatures themselves may have varied slightly from place to place, the relative relationship between the temperatures of the materials in the seven treatments would be similar over time.  88  DISCUSSION Soil temperature fluctuation reflected fluctuation in air temperature, as can be seen by comparing Figures 4.5.0.C(a-g) with Figure 4.8.0.A. Trends in temperature for the materials in the seven treatments were very similar for daily maximum and daily average, but occurred over a larger temperature range for daily maximum, and so were more pronounced. Mean daily maximum temperature was also most clearly correlated with the various parameters of seedling growth, particularly root mass, which will be discussed in detail further on. The highest mean daily maximum temperature occurred in rotten wood (treatment 7) at 1 6 . 8 ° C .  This was followed by F-layer material (treatments 5 and 6), at 1 6 . 1 ° C and  1 5 . 7 ° C respectively,  then by H-layer material (treatments 3 and 4), at 1 5 . 7 ° C and  1 3 . 8 ° C , and finally by mineral soil (treatments 1 and 2) at 1 3 . 3 ° C and 1 1 . 2 ° C .  Rotten  wood in treatment 7 reached a significantly higher mean daily maximum temperature than any of the materials in the other treatments, except treatment 5.  It should also be  noted that the large screef treatments for mineral soil, H-layer, and F-layer had mean daily maximum temperatures materials.  than the small screef treatments  higher  in the same  Trends in mean daily average temperature were similar, ranging from 1 4 . 5 ° C  for rotten wood in treatment 7, to 1 0 . 8 ° C for mineral soil/small screef in treatment 2. These results are as expected, and can be explained in terms of several factors. The four materials have different thermal properties, and these vary further with water content.  Difference in volumetric heat capacity of the four materials is probably the most  important factor.  Mineral soil has a higher volumetric heat capacity than organic  material, largely as a result of differences in bulk density, and the volumetric heat capacity of both materials increases as water content increases (Lutz and Chandler 1946). On this site, mineral soil had a higher volumetric water content than the organic  89  '/  DISCUSSION materials, and this factor in combination with its much greater bulk density, accounts in large part for why mineral soil remained cooler than the forest floor materials throughout the growing season.  Bulk densities of the materials varied from 1522 kg/rn^ for mineral  soil to 169 kg/m^ for H-layer, to 166 kg/m^ for rotten wood, to 123 kg/m^ for F-layer. Again, because of differences in bulk density, H-layer material had a higher heat capacity than F-layer material.  It also had higher water content than F-layer material,  further increasing the heat capacity.  However, while daily maximum temperature was  greater for F-layer material than H-layer material, the difference between the two was not as great as between mineral soil and the H-layer. There is a greater difference in water content between the two organic materials than between the H-layer and mineral soil, but the difference in bulk density is very much less, which probably accounts for the lesser difference in maximum temperature.  In addition, H-layer material was darker in colour,  and moister, than F-layer material, and so could be expected to have a lower albedo than the F-layer surface, and therefore would have absorbed a higher proportion of  solar  radiation. This is possibly why treatment 3 achieved maximum daily temperatures close to those of F-layer materials, in spite of the differences in water content and bulk density. Rotten wood had the highest daily maximum temperature, but it had a bulk density and water content similar to that of H-layer material.  A possible reason for its  higher temperature is its dominant position in the microtopography, which will be discussed further on. A second factor to consider is thermal conductivity which governs the ability of a material to move heat.  The greater amount of air spaces and pores in organic material,  particularly the F-layer, make it a poorer conductor than mineral soil.  Since water is a  better heat conductor than air, increased water content improves thermal conductivity.  90  DISCUSSION  The  large screef treatments however, show that thermal conductivity had much less  Mmpact on soil temperatures than did volumetric heat capacity.  Enough surface area was  exposed in these treatments that mineral soil, having a higher thermal conductivity and a higher water content than the other substrates, should have warmed more than the organic substrates, which was not the case at the 7-8 cm depth of the probes. It appears that volumetric heat capacity (C) was large enough in this situation to lower the thermal diffusivity ( X /C), so that sufficient heat did not move downwards to produce temperatures as high as those occuring in the organic substrates. Microtopography was mentioned earlier as a possible reason why rotten wood achieved the highest maximum daily temperature, while probably having a higher volumetric heat capacity than F-layer material. In the spot where soil temperature was monitored, and again this is typical of the entire research site, rotten wood and F-layer material formed the uppermost horizon, with rotten wood often forming mounds on the F layer surface.  This was followed by H-layer material, and finally by mineral soil, which  occupied the lowermost horizon. Materials in the highest position would have been exposed to solar radiation for more of the day than material in lower positions, as well as being less shaded by vegetation.  In particular, mineral soil in small screef treatments was shaded  nearty all the time. Mean daily minimum soil temperature results are interesting with regard to screef size.  The lowest mean daily minimum temperature was reached in treatment 1 (large  screef/mineral soil) at 9 . 9 ° C , followed by treatment 2 (small screef/mineral soil) at 1 0 . 5 ° C , and  then by material in treatment 3 (large screef/H-layer) at 1 1 . 3 ° C .  treatments were all significantly different from one another at a=0.05. treatments  These three The other four  (5, 4, 6, 7) were not significantly different from each other, ranging in  91  DISCUSSION minimum daily temperature from 1 2 . 3 ° C for treatment 5 to 1 2 . 5 ° C for treatment 7. The large screef treatments for mineral soil, H-layer, and F-layer all reached lower daily minimum temperatures than the small screef treatments of the same material. This is because  removal of the organic material allowed greater surface area for the emission of  long wave radiation during the night. In the discussion of daily maximum temperature, it was noted that the small screef treatments, particularly 2 and 4 (mineral soil and H layer), did not warm up as much as large screef treatments because of insulation provided by the overlying forest floor material, and because so little surface area was exposed to incoming solar radiation.  For the same reason, heat did not escape as readily during the  night, and these treatments did not cool down as much as the same materials in large screef situations.  In addition, the steep-sided screef holes of treatments 2 and 4 (refer to  Figure 3.03.A) would have emitted long wave radiation back and forth during the night, limiting cooling. Along with daily minimum soil temperatures, it is helpful to look at the daily range in temperature for each of the seven treatments, which was calculated as the difference between daily maximum and daily minimum.  Since they neither warmed up nor cooled  down as much, soil materials in small screef treatments had significantly smaller daity temperature ranges than did soil materials in large screef treatments.  This is most  noticeable for treatment 2 (small screef/mineral soil) and treatment 4 (small screef/Hlayer), which had average daily temperature ranges of 0 . 6 ° C and 1 . 5 ° C respectively, as opposed to 4 . 3 ° C for treatment 7 (small screef/rotten wood).  92  DISCUSSION  5.2 S O I L M O I S T U R E R E S U L T S Volumetric water content of the soil materials in the seven treatments, in each of the three blocks, was monitored weekly during the period of June 19 to August 15, 1989, as described in Chapter 3.  The first measurement was taken before commencing the  watering treatment, and it established that there were no initial significant differences (a = 0.05) in soil water content between the watered and unwatered subplots.  However,  the water content determination for the subsequent seven weeks of the watering treatment also revealed no significant difference in water content between the two subplots. In other words, the watering treatment did not create significant differences in water content between the watered and unwatered subplots. The purpose of the watering treatment was to determine whether lack of moisture was a limiting factor to survival and growth of seedlings on this site, particularly for seedlings growing in the F-layer, which because of its structure and elevated position above the water table was most likely to dry out.  The watering treatment was not  effective in creating a significant change in soil water content which could be correlated with growth and survival data.  No differences in any of the growth parameters, or in  seedling survival, were found as a result of the watering treatment, so the question remains unsettled. There were substrates.  significant differences  in volumetric water content  for the four  Mineral soil had the highest water content at 0.64 m^/m^, followed by the H -  layer at 0.51 m^/m^, rotten wood at 0.47 m^/m^, and finally by the F-layer at 0.29 m^/noA  Except for rotten wood and the H-layer, the water contents of all soil materials  were significantly different from one another. water content as a result of screef size.  There were no significant differences in  It should be noted that the volumetric water  93  DISCUSSION  content of mineral soil is higher than expected considering the bulk density of that material, and it is possible that excess water from seepage got into the soil tins during sampling. The differences in water content of the four substrates can be explained in terms of their structure, and position above the water table.  Mineral soil occupied the lowest  position, and the water table was very close to the upper limits of this horizon, so naturally the water content was very high. H-layer material and rotten wood were similar in bulk density and somewhat similar in texture, since both were quite decomposed, and lost their structure easily when rubbed between the fingers.  Neither material had large  pore spaces such as were observed in the F-layer, which may account for the similarity of the volumetric water contents, as well as similarity in their water retention curves (Figure 4.7.1.A).  The F-layer material is only partially decomposed, retaining much of the  structure of the litter materials.  The result of this is a substantial volume of large pore  spaces in the F-layer, which drain quickly as precipitation occurs. This structure, together with its higher position above the water table result in F-layer material having a lower overall moisture content.  These water contents are particularly important with regard to  their effect on soil thermal characteristics. The initial determination of water content, before watering began, revealed no significant differences at a=0.05 between blocks. Subsequent monitoring during the seven weeks of the watering treatment, however, showed that block C material had significantly higher water content than material in block A , which was in turn significantly higher than material in block B. It is possible that fluctuations in the height of the water table during this period varied between the blocks, so that differences were revealed at some times and not at others, depending on recent trends in precipitation. Differences in water content of  94  DISCUSSION  the three blocks is possibly related to differences in seedling growth, which will be discussed further on. Water retention curves were determined for the H-layer, F-layer, and rotten wood, but no water retention curve was attempted for mineral soil for two reasons. First, coarse fragment content of the mineral soil meant it was not possible to get undisturbed core samples, so that the hanging column method was not suitable, and a more complicated laboratory method would have been required.  Second, the water content of the mineral  soil on this site was so high all year around, that its ability to retain moisture seemed irrelevant. The three water retention curves and the average water contents for the three organic materials are shown in Figure 4.7.1.A. Although these curves only deal with high (not very negative) matric potentials to -20 kPa, it can be seen that average water contents of H-layer material and rotten wood fall onto their respective curves at close to 10 kPa. The average water content of F-layer material does not quite fall on the retention curve at -20 kPa, but it is close, and if the slope of the curve remained constant the point would fall onto the curve at around -25 kPa. To put this in perspective, coniferseedlings survive soil water potentials of -2 to -3 M P a (-2000 to -3000 kPa) (Ballard and Dosskey 1985), although growth may be inhibited at much less negative water potentials. Day and MacGillivray (1975) found that root growth was severely limited at soil moisture potentials of -1.5 bars (-150 kPa), and Spittlehouse and Stathers (1990) state that most plants stop growing at about -1 M P a (-1000 kPa). In this study, soil matric potentials were no lower than -30 kPa, so it can safely be said that on this particular site, lack of moisture was not a limiting factor to growth or survival, even in the F-horizon. The hydraulic conductivity of soil is also an important factor in terms of seedling water relations. It was beyond the scope of this study to determine hydraulic conductivity  95  DISCUSSION of the four soil materials, but it is recognized that the ability of a soil to move water along gradients to roots is as important as the amount of water present at various matric potentials. The steep drop-off of the water retention curve for the F-layer material at very low matric potential is also an indication that much of the water in the F-layer is drained off rapidly from large pore spaces, accounting for its lower water content than the other soil materials.  5.3 FERTILIZATION & FOLIAR NITROGEN ANALYSIS In May 1990, ammonium nitrate fertilizer was applied in the same split-plot layout as was used for the watering treatment in 1989.  The main reason for the fertilization  treatment was to determine whether or not nitrogen was limiting to growth on this site, and whether there were any differences in nitrogen status and response to fertilization between the seven treatments.  Although this site had a thick forest floor, no doubt  containing high levels of nitrogen, it is possible that very little nitrogen was in an available form, due to the slow mineralization rates resulting from low soil temperature. In August 1989, a number of slightly chlorotic seedlings had been observed, particularly in the F-layer treatments and rotten wood.  In most cases the seedlings  appeared otherwise healthy, but were paler green than seedlings in the H-layer and mineral soil.  If nitrogen deficiency was causing the chlorosis, then fertilization could be  expected to improve growth and survival. Results are reported as cg/g foliar nitrogen on a dry-mass basis (Table 4.4.0.2), and also as percentage of seedlings having adequate nitrogen (Table 4.4.0.3), using the  96  DISCUSSION values given by Ballard and Carter (1985).  According to this publication, foliar nitrogen  levels of 1.55 cg/g are adequate for white spruce. Fertilization with ammonium nitrate did significantly improve seedling growth for all of the pamameters except shoot to root ratio. There was also increased survival in the fertilized subplot as compared to the unfertilized subplot, although this difference may be due more to the presence of the fungus Rhizina undulata in the unfertilized subplot, than to the  benefits  of increased  levels of available  nitrogen  in the  fertilized  subplot.  Unfortunately, there was no way to quantify mortality that could be attributed to Rhizina rather than to other causes. Differences in growth that resulted from fertilization will be discussed fully in Section 5.4. As expected, foliar nitrogen levels were found to be significantly higher in the fertilized subplot at 2.32 cg/g N than in the unfertilized subplot at 1.78 cg/g N .  In the  fertilized subplot 75.4% of seedlings sampled had adequate nitrogen levels, as opposed to 57.9% of the unfertilized seedlings. Seedlings in the seven substrate/screef treatments had significantly different foliar nitrogen levels, and this was apparent for both the fertilized and unfertilized subplots, as can be seen in Figure 4.4.0.A.  Highest foliar nitrogen levels were found in seedlings from  treatments 6 and 5 (F-layer) at 2.64 cg/g and 2.54 cg/g respectively.  Seedlings growing in  rotten wood (treatment 7) had foliar nitrogen levels of 2.26 cg/g, followed by seedlings growing in treatments 4 and 3 (H-layer), with 2.17 cg/g and 1.91 cg/g respectively.  The  lowest foliar nitrogen levels were found in seedlings growing in mineral soil, with treatment 2 seedlings (small screef) at 1.67 cg/g, and treatment 1 (large screef) at 1.31 cg/g.  The only significant differences were that seedlings in treatments 6, 5, and 7 had  97  DISCUSSION higher N levels than treatment 1 seedlings, and treatments 6 and 5 also had significantly higher N levels than treatment 2 seedlings. Foliar nitrogen levels have been shown to be correlated with levels of mineralizable N in soil (Zo'ttl 1960, as cited by Ballard and Carter 1985) indicating that available nitrogen levels were higher in organic materials, particularly the F-layer, than in mineral soil.  This is to be expected, since most fungal activity takes place in the F-layer.  In  addition, since soil temperature is highest in the F-layer, the rate of decomposition by fungi is higher than in lower horizons. Low levels of foliar nitrogen in seedlings planted in mineral soil could also be related to the presence of water-logged conditions, since standing water was sometimes observed in the mineral soil screefs, particularly early in the season.  Zinkan et al. (1974)  found that reduced oxygen content in the soil solution resulted in foliar nitrogen deficiency in white spruce seedlings. The foliar nitrogen results indicate clearly that the cause of chlorosis in seedlings ?  growing in F-layer material and rotten wood was not nitrogen deficiency.  not ewft Fertilization did  not noticeably improve the slight chlorosis observed in seedlings in the F-layer and rotten wood.  These seedlings were, however, the ones that showed the highest levels of foliar  nitrogen before fertilization, when adequate levels were found in 71% of seedlings sampled from the F-layer  and 83% of the seedlings in rotten wood, as opposed to only 20% in  mineral soil. Sixty-one percent of seedlings sampled in the H-layer had adequate nitrogen levels.  Figure 4.4.0.B shows the improvement in the percentage of seedlings having  adequate nitrogen levels after fertilization. Seedlings in small screef treatments appeared to show a better response to fertilization, possibly because they may have received higher concentrations of fertilizer at the time of fertilization. It was difficult to achieve  98  even  DISCUSSION  application of the solution for seedlings in deep screefs, where  the solution tended to pool  in the bottom of the hole when applied. A problem with the analysis of foliar nitrogen levels in this study was the small number of seedlings sampled. It was only decided to do foliar nitrogen analysis after the first growing season,  and there was not an adequate  number of seedlings in the  experiment, after destructive sampling for growth measurements, to allow for more than three seedlings from each experimental unit to be sampled for foliage.  In some cases,  particularly in block B where mortality had been highest, only one or two seedlings were sampled, whereas Ballard and Carter (1985) recommend a mimimum sample size of 20. However, the total sample size was adequate to measure the overall effect of fertilization. Further research could be done to study the relationship between planting material and foliar nitrogen levels. Since low nitrogen levels were not shown to be responsible for chlorosis on this site, the paler foliage colour may have been due to pigment degradation resulting from intense sunlight. Seedlings in F-layer material and rotten wood were the most chlorotic, and they were also the seedlings that received the most direct sunlight, due to their elevated position in the microtopography, and the lesser amount of competing vegetation on mounds. Binder et al. (1987) report that optimum light intensity for growth of white spruce seedlings is provided by about 30% shading by competing vegetation.  5.4 SEEDLING GROWTH RESULTS Destructive sampling of seedlings was carried out twice, once after the first growing season in August 1989, and once after the second growing season in August 1990. Height, diameter, root mass, shoot mass, total seedling mass, and shoot mass to root mass  99  DISCUSSION ratio were determined, and analysed for significant differences at a=0.05. The increase in size/mass from time of planting to time of sampling was also calculated. The main trend in the data shows a better growth response for seedlings planted in any of the forest floor materials than in mineral soil, especially for the mineral soil/small screef treatment.  This is more pronounced for the mass measurements than for height  and diameter. The most obvious correlation between seedling environment and seedling growth is for maximum soil temperature and root, shoot, and total mass.  A l l of the organic  materials were warmer than mineral soil, and seedlings growing in these substrates were heavier by August 1990 than seedlings growing in mineral soil. A second relationship is between seedling mass and soil moisture content, where lower moisture content appears to be correlated with greater seedling weight.  This is  probably due to the effect of soil moisture content on soil temperature, as well as to the inhibition of root growth and water uptake resulting from water-logged  or flooded  conditions. A third factor that may be involved, especially with regard to poorer growth response in mineral soil, is lack of available nitrogen. when considering the small percentage  This relationship is more striking  of seedlings with adequate nitrogen levels in  mineral soil, than it is when considering average foliar nitrogen content. The watering treatment carried out in 1989 had no significant effect on any of the growth parameters, whereas fertilization with ammonium nitrate in May 1990 produced significant differences for all growth parameters except shoot to root ratio. Particularly in August 1990, block A produced seedlings of greater size/mass than seedlings in block C , and sometimes block B. This may be partly due to the significantly  100  DISCUSSION  higher water content of soils in block C. Because of its effect on volumetric heat capacity and thermal conductance, higher moisture content of soils in block C probably resulted in slightly colder temperatures than in blocks A and B. In addition, the higher water content is an indicator of a higher water table relative to the height of the various horizons, and it is possible that flooded or waterlogged conditions were in effect for more of the year than in other blocks, which according to Grossnickle (1986) has an adverse effect on root growth in white spruce. Block A , however, had a significantly higher water content than block B, but in general also produced larger, heavier seedlings, indicating that some other factors must be involved, but are not apparent in the data. The total depth of the forest floor was also greater for block C than for block B, which means that it would have more effectively insulated lower horizons, resulting in lower soil temperature, particularly for small screef treatments.  Again, this helps to explain differences in seedling growth between blocks C  and B, but does not help in explaining why block A seedlings did better than either of the other blocks.  Having the resources to monitor soil temperature in all three blocks would  have helped in identifying differences in temperature that resulted from variations in moisture content and forest floor depth. Analysis of the growth data for August 1989 showed that the error term E2 (interaction between blocks and watering, within treatment), was significant for all growth parameters except height.  This is hard to explain except in terms of the residual error  term, which E 2 is tested against.  The residual is very small due to the large number of  seedlings sampled and the small variation between them at this sampling date, and this allowed small differences in E2 to be significant. significant for the August 1989 data.  101  This source of variation was only  DISCUSSION Transformations were carried out on data sets having unequal variances, as shown in Appendix B.  In August 1990,  data sets for all growth parameters required  transformations. This indicates that within some treatments there was a greater variation in seedling growth response than within other treatments. This can be expected in a field experiment by the end of the second growing season, because  small differences in  environment exist within a block, and do not affect seedlings in different treatments the same way.  5.4.1 ROOT MASS, SHOOT MASS, & TOTAL MASS Root mass, shoot mass  and total seedling mass  all show similar trends in  significant differences between treatments, and these trends are more pronounced in August 1990 than in August 1989. Mass differences between seedlings in the seven screef size/substrate treatments show clearly that more growth occurred in seedlings planted in the three organic substrates than in mineral soil. The most highly significant results were found in the analysis of root mass, and these differences can be explained very well in terms of variations in soil temperature and soil moisture for the seven treatments.  Mass of oven dried roots in August 1990 varied  from 3.54 g for seedlings in treatment 6 (small screef/F-layer) to 1.41 g for seedlings in treatment 2 (small screef/mineral soil). Seedlings from treatment 2 had significantly less root growth than seedlings in any of the other six treatments, a trend that is found for both dates of sampling, and is also noticeable for shoot mass and total seedling mass. Treatment 1 seedlings (large screef/mineral soil) had significantly greater root mass in August 1990 than seedlings in treatment 2 (small screef/mineral soil), but less than  102  DISCUSSION  seedlings in any of the organic material treatments except treatment 4 (small screef/Hlayer). Examination of Figure 4.1.3.A along with Figure 4.5.0.A relationship between soil temperature and root growth.  reveals the strong  Treatments with higher soil  temperatures produced seedlings with greater root mass, and in relative terms the variation in root growth between the seven treatments is very similar to the variation in maximum daily temperature.  This correlation is further emphasized by the fact that in  both mineral soil and H-layer material, large screef treatments, being warmer than small screef treatments, produced seedlings with greater root mass than those in small screef treatments.  This difference did not show up between treatments 5 and 6 (F-layer), but  there was very little temperature difference between these two treatments.  According to  Heninger and White (1974), the optimum temperature for root growthJn white spruce is 19?C.  Dobbs and McMinn (1977) also found that all aspects of white spruce seedling  growth were best at a soil temperature of 2 0 ° C and were very poor at 1 0 ° C . Further examination of Figures 4.1.3.A and 4.5.0.A show that the relative difference in root mass between seedlings planted in mineral soil (treatments 1 and 2) and seedlings in forest floor materials (treatments 3, 4, 5, 6, 7) is somewhat greater than the relative differences in soil temperature for those treatments.  This may be partly due to  soil moisture levels, which show an inverse relationship to root growth, particularly in the case of the mineral soil treatments.  This can be seen by comparing Figure 4.1.3.A with  Figure 4.6.O.A. In addition to contributing tojow soil temperature, high soil water content can adversely affect root growth. Grossnickle (1986) flooded the roots of cold-stored white spruce seedlings for 14 days, and found that no root growth occurred in these seedlings even after flooding subsided, for the entire 42 days of the study. The height of the water  103  DISCUSSION table on this site was very near the surface of the mineral horizon, and in some cases, such as at the beginning of the growing season and after heavy rainfall, standing water could be observed in the bottom of the screefs in treatments 1 and 2. In addition, a rotting smell indicative of anaerobic conditions was observed in some of the wetter screefs when the mineral soil was disturbed. If anaerobic conditions did exist for some of the seedlings, there could have been an adverse effect on seedling root growth as a result of low oxygen content (Zinkan et al. 1974) or toxic conditions (Sanderson and Armstrong 1980). In addition to inhibiting root growth, conditions of excessive moisture may also interfere with water uptake in cold soils.  Grossnickle (1986) found indications of greater  internal water stress in flooded sedlings than non-flooded seedlings.  White spruce is  known to be very sensitive to internal water stress, and responds by stomatal closure, thus reducing photosynthesis (Grossnickle and Blake 1987). Van den Driessche (1987) was also able to show that for Sitka spruce, current photosynthate is the primary carbon source for new root development, so that reduced photosynthesis could in turn inhibit root growth. These findings help account for the overall poorer growth of seedlings in mineral soil. In addition to growing in conditions of low soil temperature and high soil water content, seedlings in mineral soil were  found to have lower levels of foliar nitrogen than  seedlings growing in forest floor materials.  Lower N levels would contribute to their  overall poorer growth response, which is supported by the fact that fertilization resulted in a significant increase in  all seedling growth parameters except shoot to root ratio.  Seedlings in the fertilized subplot had an average root mass of 3.30 g versus 2.36 g in the unfertilized subplot. The much lower bulk density of the organic substrates than mineral soil would also seem to partially account for the greater root growth in forest floor materials.  104  DISCUSSION In both August 1989 and August 1990, seedlings in block A had significantly greater root mass than seedlings in block C. This is assumed to be due mainly to the higher water content of material in block C. During excavation of roots, differences growing in the four soil materials.  were noted in root form for seedlings  Although they were not quantified, these differences  are worth mention as a possibility for future study, and because they help in interpreting the growth results.  Seedlings growing in treatment 2 (mineral soil/small screef) produced  the least root weight, and in most cases, new roots formed on these seedlings were adventitious roots on the lower portions of the shoot.  The deep screefs collected loose  organic material, and although some attempt was made to keep them cleaned out, there was usually a few centimeters of debris at the bottom of these holes, and this is where root growth took place.  If the spot happened to be fairly well drained, there was some root  development in the mineral soil. The same was true of seedlings grown in large screefs in mineral soil (treatment 1). When a high water table was apparent, the little root growth that occurred was at the very surface of the soil.  If the large screef spot was in a more  well drained area, the root mass tended to be bushy, and many branched, with most of the tips appearing to be mycorrhizal. Generally, roots did not extend jmore_than. 10 cm from the plug, except along the surface of the soil.  H-layer material also produced a bushy,  multibranched root, but with many more fine root tips than in the mineral soil. were also some long roots extending away from the plug, up to 0.5 particularly in the large screef treatment. mycorrhizal.  There  m in length,  Root tips in this material also appeared to be  F-layer material produced seedlings with root forms that were much less  bushy, but with a great man}' more long coarse roots extending up to 0.75 or 1.0 m from the plug. They were not branched as many times close to the root plug, and it is estimated  105  DISCUSSION  that the unsuberized root surface area, that is associated with water and nutrient absorption, was less for this type of root than for the finer root system in the H-layer, even if the total root weight may have been greater. mycorrhizal.  Again, root tips appeared to be  These seedlings also produced a great many roots at the base of the root  plug, which grew down into the H-layer material, and were finer than those growing in the F-layer.  Seedlings growing in rotten wood produced variable root forms. In some cases  very few roots developed, and those few did not appear to be mycorrhizal. These seedlings were generally chlorotic and unhealthy looking. Seedlings of better vigour produced roots that appeared to be mycorrhizal, and were similar to those described for F-layer seedlings; long, coarse roots that grew through the rotten wood into F-layer material, or finer roots that grew downward into H-layer material. Further study of the relationship between root form and planting material in relation to ability for water and nutrient uptake could help interpret growth responses in different substrates. Trends in seedling shoot mass are similar to those discussed for root mass, except for some differences between August 1989 and August 1990.  In August 1989, seedlings  in treatment 3 (large screef/H-layer) were significantly larger at 3.78 g than seedlings in any other treatment.  There were no other significant differences in August 1989, except  that seedlings in rotten wood (treatment 7) had greater shoot mass at 3.44 g than seedlings in treatment 2 (small screef/mineral soil) at 3.08 g. By August 1990, seedlings in treatments 6 and 4 (small screef/F-layer and small screef/H-layer) had attained greater shoot mass than treatment 3 seedlings. these  treatments  had  significantly  heavier  shoots  than  seedlings  All three of  in mineral  soil  (treatments 1 and 2), and seedlings growing in treatment 5 (large screef/F-layer) also had greater shoot mass than seedlings in treatment 2. In August of 1990 shoot mass ranged  106  DISCUSSION from 12.00 g in treatment 4 to 7.32 g in treatment 2. The trend in shoot mass for August 1990 reflects that of root mass closely, except in the case of treatment 4 (small screef/Hlayer), and it follows that seedlings with the most well developed root systems would be capable of supporting the greatest shoot development, as well as vice-versa because of the relationship between current photosynthate and new root growth (van den Driessche 1987). The correlation between soil temperature and root growth has been discussed, and seems to hold for shoot growth as well.  The only slight difference in response is for  seedlings in treatment 4, which started out slowly in 1989 in terms of both root and shoot growth, but by August  1990 had the greatest shoot weight, but had not increased  proportionally in root weight, resulting in an increased shoot to root ratio.  There is no  ready explanation for the increase in shoot weight in this particular treatment. Seedlings in the fertilized subplot had an average shoot mass of 11.50 g, which was significantly higher than the shoot mass of 8.31 g for unfertilized seedlings. This is proportional to the increase in root mass, since the shoot mass to root mass ratio was not changed significantly by fertilization. Shoot mass in block A was significantly higher than shoot mass in block B, which was significantly higher than shoot mass in block C. As with root mass, it is difficult to explain this, except in terms of the higher water content of block C, which still does not shed light on the overall superior growth of seedlings in block A. Seedling total mass was calculated as the sum of root mass and shoot mass for each seedling, and because of the generally higher mass of shoots than roots, trends in total mass reflect closely those of shoot mass. Total seedling mass in August 1990 ranged from 8.73 g in treatment 2 (small screef/mineral soil) to 15.40 g in treatment 6 (small  107  DISCUSSION screef/F-layer). Significant differences between treatments are nearly identical to those for shoot mass, as are significant differences for the fertilization treatments, and between blocks.  5.4.2 S H O O T M A S S T O R O O T M A S S R A T I O The trend in shoot mass to root mass ratio was similar in August 1989 and August 1990, and shows that seedlings from treatment 2 (small screef/mineral soil) had a much higher shoot to root ratio than any of the other treatments. In August 1990, the shoot to root ratio was 7.01 for seedlings in treatment 2. The next highest was treatment 4 (small screef/H-layer), with a shoot to root ratio of 5.13. similar shoot to root ratios, ranging from 4.04  The other treatments all had fairly for seedlings in treatment 1 (large  screef/mineral soil), to 3.51 for seedlings in treatment 7 (rotten wood). The obvious trend here is that seedlings planted in small screef treatments had higher shoot to root ratios than seedlings in large screef treatments. more pronounced by August 1990. response to low light levels.  This is apparent in August 1989, but is much  Seedlings in small screefs got taller, possibly in  The higher shoot to root ratios for treatments 2 and 4 could  be due to colder, wetter soils inhibiting root growth, while height growth increased shoot weight disproportionally to root weight.  As previously discussed, it is also possible that  small screef treatments received somewhat higher nitrogen levels, due to uneven fertilizer application, which could have caused a greater increase in shoot growth than root growth. However, there were no significant differences between fertilized and unfertilized subplots to support this idea. It is generally considered that nursery stock, particularly container stock, is out of proportion as far as shoot to root ratio is concerned. However, it is not just the mass of  108  DISCUSSION  roots that is important, but the morphology as well, since plugs expose a relatively small root surface area to the soil.  In this study, shoot to root ratio increased somewhat from  the time of planting to the times of sampling, but for seedlings planted in the organic materials this increase was relatively small, and was not associated with a decline in seedling health. In fact, it was obvious that although the shoot to root ratio was somewhat higher, seedlings that had experienced significant root growth were exploiting a much greater volume of soil than was the case for the original plugs.  5.4.3 D I A M E T E R A N D H E I G H T There were no significant differences in diameter and height of seedlings in the seven treatments, but figures 4.1.1.A and 4.1.1.B show that by August 1990, there was a trend toward larger diameters for seedlings growing in organic materials, as compared to mineral soil. Diameters in August 1990 ranged from 0.63 cm for seedlings in treatment 2 (small screef/mineral soil) to 0.99 cm for seedlings in treatment 6 (small screef/F-layer). Although the differences were not significant, they reflect the tendency shown in seedling mass for better growth in forest floor materials than in mineral soil.  Fertilization  increased diameter significantly. During the period of June 1989 to August 1990, seedlings in treatment 2 (small screef/mineral soil) showed the greatest height increase, followed by seedlings in treatment 4 (small screef/H-layer).  Seedlings in small screef treatments  were in very shaded  conditions, and the height increase was probably a response to this. By August 1990, the tallest seedlings were found in treatment 4 and 3 (H-layer), and in treatment 2 (small screef/mineral soil).  Treatment 2 seedlings were tall, but they had the lowest shoot mass  109  DISCUSSION  of all the treatments.  Treatment 4 seedlings on the other hand, were tall, but had the  greatest shoot mass. It is clear from the data that although an increase in height will result in a slight increase in shoot mass, it is not the main factor involved in shoot mass increase.  Seedlings  growing in mineral soil weighed less than those in organic materials, but were at least as tall.  Height seems to have been influenced more by light levels than by soil temperature  or moisture levels, or even by foliar nitrogen levels. As with the other growth parameters, fertilization did result in a significant increase in height, as would be expected where overall seedling growth was improved. In August 1990, seedling height in block A was significantly greater than in blocks B or C, as was the case for all other growth parameters except shoot to root ratio, and again is not readily explained.  5.5 S E E D L I N G S U R V I V A L R E S U L T S Seedling survival was assessed at three dates: August 1989, May 1990, and August 1990, the results of which are presented in Figure 4.3.0.A.  Survival was close to  100% for all treatments in August 1989, but by May 1990 it had declined somewhat. Although there  were  still no significant  differences  (a=0.05) in survival between  treatments, it can be seen that mortality was slightly higher in F-layer material and rotten wood (treatments 5, 6, 7).  By August 1990, survival had declined again, ranging  from 77.4% in treatment 1 (large screef/mineral soil) to 55.9% in treatment 4 (small screef/H-layer), but again, differences were not significant. Unfortunately, these results do not reflect seedling survival as a result of the inherent differences in the four substrates, since much of the mortality can be attributed to  110  DISCUSSION the root pathogen Rhizina undulata. This fungus occurs in patches on burned sites, and results in death of infected seedlings.  Apothecia of the fungus were first noted in forest  floor materials in August 1989, one year following burning. Both Ginns (1974) and Thies et al. (1977) used the presence of apothecia as evidence of pathogenicity, since the fungus is difficult to isolate from more by August 1990.  seedlings.  By M a y 1990 there were some dead seedlings, and  According to Ginns (1974), most mortality caused by Rhizina  occurs in the first year after planting, and although these results were for Douglas-fir, the effect on white spruce would be similar.  It can therefore be expected that no further  mortality as a result of Rhizina would occur on the research site after the 1990 growing season.  Occurence of the fungus in forest floor materials, particularly the F-layer, can be  explained in terms of the life cycle of the fungus.  Rhizina requires fire to trigger  germination of spores, and since the heat of slash fires penetrates only a few centimeters into the F-layer, that is where one would expect the fungus to grow.  This suggests that  Rhizina caused a higher proportion of mortality in the surface F-layer and rotten wood materials, than in the H-layer and mineral soil.  This is supported by the trends in  survival over the three sampling dates, where there was a greater decrease in survival from August 1989 to May 1990 in the F-layer and rotten wood than in mineral soil and the H-layer, but between May 1990 and August 1990, the decrease in mortality was greater in mineral soil and H-layer material than in the' F-layer and rotten wood.  It is  speculated than most of the mortality that occured during the period of August 1989 to May 1990 was due to the fungus, whereas mortality occurring from May 1990 to August 1990 could have been mainly due to other causes. Rhizina occurred on this site in two main patches,  the largest one in the  unfertilized subplot of block B, and a smaller one in block C that was in both the fertilized  111  DISCUSSION and unfertilized subplots.  This is thought to be the main cause of the  significant  differences in survival between blocks, and in May 1990 block A had higher survival than either block B or block C . In August 1990, block A had higher survival than block C, which had higher survival than block B.  No signs of Rhizina were observed in block A ,  and survival was 81%, as opposed to 69% in block C, and 53% in block B (refer to Table 4.3.0.4), giving an indication of the amount of mortality that could be attributed to the fungus. There were also significant differences in survival between the fertilized subplot at 75%, and the unfertilized subplot at 61%, however it is impossible to say how much of this is really due to higher nitrogen levels.  The largest patch of Rhizina was found in the  unfertilized subplot of block B, and accounts for much of the higher survival that is attributed to fertilization in the analysis. It is unfortunate that Rhizina occured in the study area, because there is no way of saying accurately how much seedling death was due to factors other than the fungus.  A  guess is that if the fungus had not been present, there would have been less mortality in F-layer material, and possibly rotten wood. Also, given the poor state of root development for seedlings in treatments 1 and 2, particularly those in small screefs, it is expected that by the third growing season mortality in mineral soil would have increased relative to other substrates, where a greater percentage of the surviving seedlings appeared to be well established.  112  6.0 C O N C L U S I O N S  The results of this study show clearly that, after two growing seasons, Interior spruce seedlings planted in F-layer and H-layer material  were heavier than seedlings  growing in mineral soil. This is true of root, shoot, and total mass, and is most pronounced in the comparison of seedlings growing in organic materials with those growing in the small screef/mineral soil treatment. Results were less clear for seedlings growing in rotten wood, but the trend was for better growth in rotten wood than in mineral soil. Height and diameter did not show significant differences. Better growth in organic materials on this site can be attributed mainly to higher soil temperature in combination with lower water content.  Higher soil temperature was  clearly associated with greater seedling mass, and particularly with greater root mass. Because of the high water table on this site, and the fact that the most negative soil water potential was only about -30 kPa, it is safe to say that lack of moisture was not limiting to growth or survival, even in the F-layer.  Excess water, on the other hand, could have  been a limiting factor to growth and survival for seedlings planted in mineral soil, since standing water was observed at times in the bottom of screef holes, and there something of an inverse relationship between soil moisture and  seedling mass.  was High  water content increases the heat capacity of soils, which on this site would negatively impact soil temperature. Low foliar nitrogen levels also appear to be related to poor growth in mineral soil. Although average  nitrogen contents for seedlings in the various treatments  showed  deficiency only for seedlings in the large screef/mineral soil treatment (according to levels reported by Ballard and Carter (1985)), the percentage of seedlings sampled with adequate  113  CONCLUSIONS  nitrogen levels was much lower in mineral soil than in other materials. Fertilization with ammonium nitrate also increased seedling growth for all parameters except shoot mass to root mass ratio, indicating that even if foliar nitrogen content was adequate, it was less than optimum for growth of white spruce. It is concluded that nitrogen deficiency was not the cause of the slight chlorosis observed in seedlings in the F-layer and rotten wood, since these substrates produced seedlings with the highest foliar nitrogen levels, and the highest percentage of seedlings with adequate N levels.  A possible explantation for the paler green foliage of seedlings  growing in these substrates is chlorophyll degradation resulting from over intense light levels.  Binder et al. (1987) suggest that 30% shading by competing vegetation provides  optimal light conditions for white spruce seedlings. Shoot mass to root mass ratio was lower for seedlings growing in organic materials than in mineral soil, with the exception of the H-layer/small screef treatment.  Seedlings  growing in forest floor materials were better able to achieve an appropriate balance between shoot and root after planting than were seedlings growing in mineral soil, where low soil temperature and high soil water content in the deep screef holes inhibited root growth, and low light levels induced height growth away from the shaded conditions. While this study expresses the differences in growth for seedlings planted in different materials and in different screef sizes, it is restricted in its ability to state conclusively what the limiting factors were, and to what degree they were interrelated. Further study needs to be done with regard to growth limiting characteristics of forest floor materials, and the results need to be tested on different sites. Seedling survival was not significantly different for  any of the treatments, but  results were complicated by the presence of the fungus Rhizina undulata, since it is  114  CONCLUSIONS thought that it increased mortality in forest floor materials, particularly the F-layer and rotten wood, more than in mineral soil. The  implication of this study, in practical terms, is that for sites in the I C H m c l  that have a thick forest floor and a high water table, planting on elevated materials, with a minimal screef, will produce better growth results than screefing down through the F layer material in an effort to get to mineral soil, or even H-layer material.  Planting  substrate itself appears to be less important than the temperature and moisture conditions of the material. It is interesting that even rotten wood, which has long been considered an unsuitable planting material for white spruce seedlings, produced better growth results than mineral soil. This study is particularly applicable in the treatment of small areas of larger cutblocks, where it is not logistically feasible to employ mechanical site preparation techniques to improve the availability of suitable microsites.  115  REFERENCES  Armson, K . A . 1977. Toronto.  Forest Soils: Properties and Processes. University of Toronto Press,  Ballard, T . M . and R i E . Carter. 1985. Evaluating Forest Stand Nutrient Status. Management Rep. No.20, B . C . Min. of Forests.  Land  Ballard, T . M . and M . G . Dosskey. 1985. Needle water potential and soil-to-foliage flow resistance during soil drying: a comparison of Douglas-fir, western hemlock, and mountain hemlock. Can. J . For. Res. 15: 185-188. Beaudry, L . J . and L . D . McCulloch. 1989. Forest regeneration in the ICHg, Prince Rupert Forest Region: A Problem Analysis. F R D A Project 1.44, Research Section, Prince Rupert Forest Region, B . C . Min. of Forests. Binder, W . D . , D . L . Spittlehouse, D . A . Draper. 1987. 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Plantation failure and backlog rehabilitation in the Sub-Boreal Spruce and Boreal Black and White Spruce zones in the northern interior of British Columbia: a problem analysis. F R D A Project 1.15, Silviculture Branch, B.C. Min. of Forests and Lands, Victoria, B . C . Buxton, G . F . , D.R. Cyr, E . B . Dumbroff. 1985. Physiological responses of 3 northern conifers to rapid and slow induction of moisture stress. Can. J . Bot. 63: 11711176. Canadian Soil Survey Committee (CSSC). 1978. The Canadian system of soil classification. Canada Dept. of Agriculture, Publ. 1646. Supply and Services Canada, Ottawa. 164 p.  116  REFERENCES Day, R.J. and G.R. MacGillvray. 1975. Root Regeneration of Fall-Lifted White Spruce Nursery Stock in Relation to Soil moisture Content. For. Chron. 51: 196-199. y  Delucia, E . H . 1986. Effect of low root temperature on net photosynthesis, stomatal conductance, and carbohydrate concentration in Engelmann spruce (Picea engelmannii Parry ex Engelm.) seedlings. 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Taxonomic Classification of Humus Forms in Ecosystems of British Columbia. Land Management Report No. 8 (first approximation), B . C . Min. of Forests.  117  REFERENCES Knowles, R. 1969. Microorganisms and nitrogen in the raw humus of black spruce forests. Trend 15: 13-17. Krajina, V . J . , Klinka, K . , J . Worrall. 1982. Distribution and Ecological Characteristics of Trees and Shrubs of British Columbia. University of B.C., Faculty of Forestry. 131p. Lees, J . C . 1964. 226.  Tolerance of white spruce seedlings to flooding. For. Chron. 40: 221-  Lutz, H . J . and F . F . Chandler, Jr. 1946.  Forest Soils. John Wiley and Sons, Inc., N . Y .  Minore, D., C E . Smith, R . F . Woollard. 1969. Effects of high soil density oh seedling root growth of seven northwestern tree species. U S D A Forest Service Reseach Note. PNW-112. Mullin, R . E .  1963.  Planting check in spruce. For. Chron. 39: 252-259.  Parkinson, J . A . and S.E. Allen. 1975. A wet oxidation procedure for the determination of nitrogen and mineral nutrients in biological material. Comm. Soil Sci. Plant Anal. 6: 1-11. Potts, D . F . 1985. Water potential of forest duff and its possible relationship to regeneration success in the northern Rocky Mountains. Can. J . For. Res. 15: 464468. Salonius, P.O. 1983. Effects of organic-mineral soil mixtures and increasing temperature on the respiration of coniferous raw humus material. Can. J . For. Res. 13: 102107. Sanderson, P . L . and W. Armstrong. 1980. Phytotoxins in periodically waterlogged forest soils. Journal of Soil Science 31: 643-653. SAS Institute Inc. 1982. SAS User's Guide: Basics, 1982 Edition. Cary, N.C.:SAS Institute,Inc, 923pp. Silviculture Branch, M O F .  1989.  Unpublished information letter.  Silviculture Branch, M O F L . 1987. Forest Nursery Stock Production: Review, Forecast, and Producers in British Columbia. File: 257. Spittlehouse, D . L and R.J. Stathers. Rep. No.65, B.C. M O F .  1990.  Stathers, R . J . and D . L Spittlehouse. 1990. Project 130, B.C. Min. of Forests.  Seedling microclimate. Land Management  Forest soil temperature manual. F R D A  118  REFERENCES Thies, W . G . , K . W . Russell, L . C . Weir. 1977. Distribution and damage appraisal of Rhizina undulata in western Oregon and Washington. Plant Disease Reporter 61(10): 859-862. Van Cleve, K . , W.C. Oechel, J . L . Horn. 1990. Response of black spruce (Picea mariana) ecosystems to soil temperature modification in interior Alaska. Can. J . For. Res. 20: 1530-1535. van den Driessche, R. 1987. Importance of current photosynthate to new root growth in planted conifer seedlings. Can. J . For. Res. 17: 776-782. Walmsley, M . , G. Utzig, T. Void, D. Moon, and J . van Barneveld (editors). 1980. Describing ecosystems in the field. B . C . Min. Environ./Min. Forests R A B Tech. Paper 2/Land Management Rep. No. 7. Zinkan, C . G . , J . K . Jeglum, D . E . Harvey. 1974. Oxygen in water culture influences growth and nutrient uptake of jack pine, black spruce and white spruce seedlings. Can. J . Plant Science 54: 553-558. Zottl, H . 1960. Die Mineralstickstoffanliefering in Fichten-und Kiefernbestanden Bayerns. Forstwiss. Cbl. 79: 221-236.  119  APPENDIX A ANALYSIS OF VARIANCE TABLES Diameter 1989 Source Block Trmt Bl*Tr Water W*Tr Bl*W(Tr) Resid. Total  DF  MS  F  2 6 12 1 6 14 336 377  0.0248 0.0183 0.0087 0.0187 0.0111 0.0100 0.0042  5.9475 2.0981 2.0866 1.8723 1.1061 2.3981  DF  MS  F  2 6 12 1 6 14 336 377  35.523 68.127 25.171 7.743 8.373 16.374 14.314  2.4817 2.7065 1.7585 0.-4729 0.5113 1.1439  SS  DF  MS  F  0.889 6.694 1.483 0.402 1.465 3.327 28.766 43.026  2 6 12 1 6 14 336 377  0.4444 1.1157 0.1236 0.4022 0.2441 0.2377 0.0856  5.1914 9.0265 1.4437 1.6923 1.0273 2.7760  SS 0.0496 0.1096 0.1045 0.0187 0.0664 0.1401 1.4018 1.8907  P 0.0029 0.1294 0.0173 0.1928 0.4065 0.0033  Test term Resid. Bl*Tr Resid. Bl*W(Tr) Bl*W(Tr) Resid  Height 1989 Source Block Trmt Bl*Tr Water W*Tr Bl*W(Tr) Resid. Total  SS 71.05 408.76 302.05 7.74 50.23 229.24 4809.50 5878.60  P 0.0851 0.0671 0.0539 0.5029 0.7901 0.3181  Test term Resid. Bl*Tr Resid. Bl*W(Tr) Bl*W(Tr) Resid  Root weight 1989 Source Block Trmt Bl*Tr Water W*Tr Bl*W(Tr) Resid. Total  120  P 0.0060 0.0007 0.1443 0.2143 0.4477 0.0006  Test term Resid. Bl*Tr Resid. B1*W(TT)  Bl*W(Tr) Resid  APPENDIX A  Shoot weight 1989 Source Block Trmt Bl*Tr Water W*Tr Bl*W(Tr) Resid. Total  SS  DF  MS  F  2 6 12 1 6 14 336 377  0.0376 2.9931 0.5315 0.2661 0.6842 0.9344 0.5228  0.0720 5.6315 1.0166 0.2848 0.7322 1.7872  DF  MS  F  2 6 12 1 6 14 336 377  0.7160 6.9626 0.8443 1.3227 1.2948 1.8072 0.7606  0.9415 8.2468 1.1101 0.7319 0.7165 0.7165 2.3761  SS  DF  MS  F  0.921 3.876 1.522 0.246 1.739 2.935 34.865 46.105  2 6 12 1 6 14 336 377  0.4605 0.6461 0.1268 0.2464 0.2899 0.2096 0.1038  4.4377 5.0942 1.2222 1.1752 1.3828 2.0202  0.075 17.959 6.378 0.266 4.105 13.082 175.670 217.540  P 0.9306 0.0055 0.4329 0.6019 0.6319 0.0392  Test term Resid. Bl*Tr Resid. Bl*W(Tr) Bl*W(Tr) Resid  Total weight 1989 Source Block Trmt Bl*Tr Water W*Tr Bl*W(Tr) Resid. Total  SS 1.432 41.776 10.131 1.323 7.769 25.300 255.550 343.280  P 0.3911 0.0011 0.3507 0.4067 0.6429 0.0037  Test term Resid. Bl*Tr Resid. Bl*W(Tr) Bl*W(Tr) Resid  Shoot to root ratio 1989 Source Block Trmt Bl*Tr Water W*Tr Bl*W(Tr) Resid. Total |;  data transformed by log(SR)  121  P 0.0125 0.0081 0.2659 0.2966 0.2879 0.0159  Test term Resid. Bl*Tr Resid. Bl*W(Tr) Bl*W(Tr) Resid  APPENDIX A  Diameter 1990-1 Source Block Trmt Bl*Tr Fert F*Tr Bl*F(Tr) Resid. Total  SS  DF  MS  F  1.380 3.688 3.645 0.115 1.297 4.634 59.908 74.539  2 6 12 1 6 14 276 317  0.6898 0.6147 0.3037 0.1148 0.2162 0.3310 0.2171  3.1780 2.0237 1.3994 0.3468 0.6531 1.5249  P 0.0432 0.1407 0.1655 0.5653 0.6878 0.1015  Test term Resid. Bl*Tr Resid. Bl*F(Tr) Bl*F(Tr) Resid  * Unequal variances, but unable to transform.  Height 1990 Source Block Trmt Bl*Tr Fert F*Tr Bl*F(Tr) Resid. Total  =  SS  DF  MS  1.046 0.813 0.699 0.508 0.342 0.591 9.626 13.647  2 6 12 1 6 14 276 317  0.5232 0.1355 0.0582 0.5085 0.0570 0.0422 0.0349  DF  MS  2 6 12 1 6 14 276 317  0.9445 2.7789 0.2269 3.5069 0.5992 0.2761 0.2672  F 15.0020 2.3272 1.6699 12.0430 1.3495 1.2106  P 0.0000 0.1004 0.0731 0.0037 0.3002 0.2669  Test term Resid. Bl*Tr Resid. Bl*F(Tr) Bl*F(Tr) Resid  * transformed by log(ht)  Root weight 1990* Source Block Trmt Bl*Tr Fert F*Tr Bl*F(Tr) Resid. Total  SS 1.889 16.674 2.723 3.507 3.595 3.866 73.742 107.000  F  transformed by (root wt.)  122  3.5350 12.2470 0.8493 12.7000 2.1700 1.0335  P 0.0305 0.0002 0.5995 0.0031 0.1090 0.4199  Test term Resid. Bl*Tr Resid. Bl*F(Tr) Bl*F(Tr) Resid  APPENDIX  A  Shoot weight 1990* Source Block Trmt Bl*Tr Fert F*Tr Bl*F(Tr) Resid. Total  SS 23.081 23.976 11.386 16.615 6.556 9.963 184.170 278.370  DF 2 6 12 1 6 14 276 317  MS  F  11.541 3.996 0.949 16.615 1.093 0.712 0.667  17.295 4.211 1.422 23.347 1.535 1.066  P 0.0000 0.0164 0.1552 0.0003 0.2377 0.3882  Test term Resid. Bl*Tr Resid. BPF(Tr) Bl*F(Tr) Resid  ' transformed by (shoot wt.)  Total weight 1990 Source Block Trmt Bl*Tr Fert F*Tr Bl*F(Tr) Resid. Total  SS 26.315 36.052 14.575 21.732 9.225 13.134 244.860 369.88  DF 2 6 12 1 6 14 276 317  * transformed by (total wt.)  F  MS 13.1570 6.0087 1.2146 21.7320 1.5375 0.9381 0.8872  14.8310 4.9473 1.3690 23.1660 1.6389 1.0574  P 0.0000 0.0091 0.1803 0.0003 0.2088 0.3968  Test term Resid. Bl*Tr Resid. Bl*F(Tr) Bl*F(Tr) Resid  u,!:)  Shoot to root ratio 1990 Source Block Trmt Bl*Tr Fert F*Tr Bl*F(Tr) Resid. Total  SS  DF  MS  0.648 15.411 1.594 0.042 0.959 2.989 42.204 63.850  2 6 12 1 6 14 276 317  0.3240 2.5685 0.1328 0.0424 0.1599 0.2135 0.1529  F  * transformed by log(SR)  123  2.1190 19.3360 0.8687 0.1985 0.7491 1.3960  P 0.1221 0.0000 0.5795 0.6628 0.6202 0.1542  Test term Resid. Bl*Tr Resid. Bl*F(Tr) Bl*F(Tr) Resid  APPENDIX A  Seedling survival August 1989 Source Block Trmt Bl*Tr Water W*Tr Bl*W(Tr) Resid. Total  SS 25.424 86.051 125.170 1.304 7.823 59.323 0.000 305.090  DF  MS  2 6 12 1 6 14 0 41  12.712 14.342 10.430 1.304 1.304 4.237 0.000  F 3.0000 1.3750 2.4615 0.3077 0.3077 0.0000  P 0.0823 0.3001 0.0554 0.5878 0.9225 1.0000  Test term Bl*W(Tr) Bl*Tr Bl*W(Tr) Bl*W(Tr) Bl*W(Tr) Resid  Seedling survival May 1990 Source Block Trmt Bl*Tr Fert F*Tr Bl*F(Tr) Resid. Total  SS 1731.60 1787.90 1232.50 52.66 27.99 1026.50 0.00 5859.20  DF  MS  2 6 .12 1 6 14 0 41  865.800 297.980 102.710 52.662 4.665 73.325 0.000  F 11.8080 2.9012 1.4008 0.7182 0.0636 0.0000  P 0.0010 0.0550 0.2710 0.4110 0.9986 1.0000  Test term Bl*F(Tr) Bl*Tr Bl*F(Tr) Bl*F(Tr) Bl*F(Tr) Resid  Seedling survival August 1990 Source Block Trmt Bl*Tr Fert F*Tr Bl*F(Tr) Resid. Total  SS 5581.20 1810.70 1708.70 2142.90 584.68 1960.70 0.00 13789.00  DF 2 6 12 1 6 14 0 41  F  MS 2790.60 301.79 142.39 2142.90 97.45 140.05 0.00  19.926 2.119 1.017 15.301 0.696 0.000  124  P 0.0001 0.1263 • 0.4826 0.0016 0.6574 1.0000  Test term BPF(Tr) Bl*Tr Bl*F(Tr) Bl*F(Tr) Bl*F(Tr) Resid  APPENDIX A  Foliar nitrogen levels August 1990 Source Block Trmt Bl*Tr Fert F*Tr Bl*F(Tr) Resid. Total  SS  DF  MS  F  2.212 23.087 11.283 6.610 5.679 11.505 27.958 89.619  2 6 12 1 6 14 67 108  1.1060 3.8479 0.9403 6.6100 0.9466 0.8218 0.4173  2.6505 4.0923 2.2533 8.0436 1.1519 1.9693  P 0.0780 0.0182 0.0183 0.0132 0.3841 0.0340  Test term Resid. Bl*Tr Resid. Bl*F(Tr) Bl*F(Tr) Resid  Maximum soil temperature 1989* Source Trmt Resid. Total  SS  DF  MS  F  7.960 7.856 15.817  6 455 461  1.327 0.017  76.842  MS  F  P 0.0000  Test term Resid.  * data transformed by log(max)  Minimum soil temperature 1989* Source Trmt Resid. Total  SS  DF  3.216 10.320 13.535  6 455 461  0.536 0.0238  23.632  P 0.0000  Test term Resid.  * data transformed by log(min)  Average soil temperature 1989* Source Trmt Resid. Total  SS 4.906 8.120 13.027  DF 6 455 461  MS  F  0.818 0.018  45.820  data transformed by log(avg)  125  P 0.0000  Test term Resid  APPENDIX A  Soil temperature range 1989  :|  Source Trmt Resid. Total  SS 212.110 47.952 260.060  DF  MS  6 455 461  35.352 0.105  F 335.44  P 0.0000  Test term Resid.  * data transformed by log(range)  Soil moisture content before watering treatment 1989 Source Block Trmt Bl*Tr Water W*Tr Bl*W(Tr) Resid. Total  SS 0.073 0.763 0.062 0.038 0.079 0.213 0.000 1.209  DF 2 6 12 1 6 13 0 40  MS  F  0.0368 0.1272 0.0052 0.0381 0.0132 0.0164 0.0000  2.250 24.472 0.317 2.329 0.804 0.000  P 0.1448 0.0000 0.9723 0.1509 0.5843 1.0000  Test term Resid. Bl*Tr Resid. Bl*W(Tr) Bl*W(Tr) Resid  Soil moisture content during watering 1989 Source Block Trmt Bl*Tr Water W*Tr BPW(Tr) Resid. Total  SS 0.234 6.747 0.311 0.030 0.089 0.272 1.505 9.178  DF 2 6 12 1 6 14 250 291  MS  F  0.1172 1.1246 0.0259 0.0302 0.0150 0.0194 0.0060  126  19.467 43.370 4.307 1.553 0.770 3.228  P 0.0000 0.0000 0.0000 0.2332 0.6061 0.0001  Test term Resid. Bl*Tr Resid. Bl*W(Tr) Bl*W(Tr) Resid  APPENDIX B RESULTS OF HOMOGENEITY OF VARIANCE TESTS  G r o w t h data 1989* Parameter Diameter Height Root wt. Shoot wt. Total wt. Shoot:root  Transformed by 0.17195 0.02008 0.07513 0.54199 0.30481 0.00000  * based on the Chi-square statistic, probability is less than 0.05.  log(SR)  0.02327  Reject hypothesis that variances  are equal if  G r o w t h data 1990* Parameter  P  Transformed by  P  Diameter  0.00000  log(diam)  0.00000  Diameter  0.00000  (diam) ° . 5  0.00000  Height  0.00423  log(ht)  0.08344  Root wt.  0.00036  (rtwt)°-  Shoot wt.  0.00009  (shwt)°-  Total wt.  0.00117  (totwt) -  Shoot:root  0.00000  log(SR)  * based on the Chi-square statistic, probability is less than 0.05.  0.59223  5  0  0.12070  5  5  0.30242 0.09303  Reject hypothesis that variances are equal when  127  APPENDIX B  Soil temperature data Parameter  P  Transformed by  P  Maximum  0.00000  log(max)  0.12761  Minimum  0.03198  log(min)  0.46075  Average  0.00119  log(avg)  0.70652  Range  0.00000  log(range)  0.00070  * based on the Chi-square statistic, probability is less than 0.05.  Soil moisture d a t a Parameter VW(wk 1)  VW(wk 2-8)  Reject hypothesis that variances are equal when  4  P  Transformed by  P  0.00178  (VW)°-  5  0.01420  0.00178  log(VW)  0.05758  0.00000  (VW)°-  5  0.00000  0.00000  log(VW)  0.00000  * based on the Chi-square statistic. Reject hypothesis that variances are equal when probabilities are less than 0.05. This set of transformations was unsuccessful, and none of it was used in the analysis.  128  APPENDIX C RESULTS OF NORMALITY TESTS  G r o w t h data 1989 p r o b a b i l i t i e s * Trmt* Water 1-NW 1-W 2-NW 2-W 3-NW 3-W 4-NW 4-W 5-NW 5-W 6-NW 6-W 7-NW 7-W  Ht. 0.377 0.806 0.563 0.014 0.605 0.295 0.373 0.662' 0.277 0.456 0.343 0.296 0.102 0.808  Diam. 0.051 0.305 0.169 0.500 0.504 0.645 0.353 0.152 0.123 0.491 0.752 0.663 0.774 0.605  * B a s e d on the S h a p i r o - W i l k statistic. if probability is below 0.05.  Root wt. 0.298 0.084 0.687 0.990 0.942 0.417 0.049 0.240 0.575 0.595 0.227 0.610 0.335 0.581  Shoot wt. 0.543 0.728 0.358 0.814 0.308 0.472 0.341 0.022 0.876 0.444 0.326 0.459 0.346 0.046  Total wt. 0.452 0.737 0.118 0.485 0.406 0.679 0.541 0.100 0.381 0.066 0.789 0.363 0.271 0.252  Shoot:  * root 0.541 0.807 <0.010 0.485 <0.010 0.560 0.706 0.502 0.927 0.073 0.753 0.324 0.297 0.324  Reject hypothesis t h a t d a t a is n o r m a l l y distributed  129  APPENDIX C  Growth data 1990 probabilities*  Trmt* Water 1-NW 1-W 2-NW 2-W 3-NW 3-W 4-NW 4-W 5-NW 5-W 6-NW 6-W 7-NW 7-W  Ht. 0.027 0.020 0.025 0.243 0.031 0.096 0.096 0.245 0.414 0.349 0.098 <0.010 0.292 0.513  Diam. 0.365 0.538 0.274 0.400 0.630 0.346 0.441 0.559 0.154 0.287 <0.010 0.498 0.039 0.962  Root wt. 0.365 0.951 0.083 0.034 0.765 0.832 0.845 0.557 0.541 0.492 0.344 0.450 0.261 0.475  Shoot wt. 0.443 0.546 0.097 0.042 0.205 0.069 0.623 0.470 0.402 0.022 0.858 0.493 0.286 0.261  Total wt. 0.412 0.653 0.085 0.045 0.349 0.107 0.739 0.452 0.373 0.084 0.612 0.724 0.140 0.262  Shoot: root 0.904 0.188 0.676 0.323 0.724 0.235 <0.010 1.000 0.093 0.156 0.095 0.117 <0.010 0.471  * Based on the Shapiro-Wilk statistic. Reject hypothesis that data is normally distributed if probability is below 0.05.  130  APPENDIX C  Soil temperature data probabilities Trmt  Daily maximum  1 2 3 4 5 6 7  Daily minimum  Daily average  <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01  <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01  <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01  Daily range <0.150 0.087 <0.150 <0.150 0.028 <0.150 <0.150  * based on the Kolomogrov D statistic. Reject hypothesis that data is normally distributed if probability is less than 0.05. Except for 'daily range', this data was not normally distributed.  Soil moisture data probabilities* Trmt*water  1-1 1-2 2-1 2-2 3-1 3-2 4-1 4-2 5-1 5-2 6-1 6-2 7-1 7-2  Water content week 1  Water content weeks 2-8  0.172 0.397 1.000 0.758 0.210 0.464 0.785 0.194 0.966 0.650 0.465 0.124 0.430 0.291  0.747 0.801 0.039 0.311 <0.010 0.519 0.129 <0.010 0.392 0.393 0.366 0.351 0.653 0.742  * based on the Shapiro-Wilk statistic. Reject hypothesis that data is normally distributed if probability is less than 0.05  131  

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