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Relationships between coarse woody debris and understory vegetation in six forest ecosystems in British… Song, Xianghou 1997

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RELATIONSHIPS BETWEEN COARSE WOODY DEBRIS AND UNDERSTORY VEGETATION IN SIX FOREST ECOSYSTEMS IN BRITISH COLUMBIA  by Xianghou Song M.Sc, Nanjing Forestry University, P. R. China, 1985 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF , MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES DEPARTMENT OF FOREST SCIENCES We accept this thesis as conforming to the required standard  THE UNIVERSITY OF BRITISH COLUMBIA March 1997 .' © Xianghou Song, 1997  In  presenting this  degree  at the  thesis in  University of  partial  fulfilment  of  of  department  this thesis for or  by  his  or  scholarly purposes may be her  representatives.  permission.  Department of The University of British Columbia Vancouver, Canada  for  an advanced  Library shall make  it  agree that permission for extensive  It  publication of this thesis for financial gain shall not  DE-6 (2/88)  requirements  British Columbia, I agree that the  freely available for reference and study. I further copying  the  is  granted  by the  understood  that  head of copying  my or  be allowed without my written  Abstract  Understory vegetation in relation to coarse woody debris ( C W D ) was studied in six forest ecosystems which were located in six biogeoclimatic zones of British Columbia. Sample plots were located in each ecosystem and transect lines were used to set vegetation sample quadrats. Size of C W D was measured and classified into three classes based on the degree o f decay. Vegetation on each decay class o f C W D and forest floor was sampled and compared within each ecosystem and among different ecosystems using principal component analysis and cluster analysis. Effects of log size and canopy closure on the understory vegetation were also studied by regression analysis. The stands' structure in terms of species, D B H (diameter at breast height), and crown canopy was also measured. In total, 245 plant species were identified in this study, including 8 tree species seedlings, 30 shrubs, 58 herbs and grasses, 8 ferns, 54 mosses, 28 liverworts (hepatics), and 59 lichens. A l l together, 169 species inhabited C W D one third of which were confined to it. C W D is particularly important to non-vascular plants, especially lichens (in a dry forest) and liverworts (in a moist forest) for 95% of the lichens arid 96% o f the liverworts were found on C W D . C W D is also important to mosses, but the number o f species and the abundance were also high on the forest floor. A m o n g wood inhabiting (lignicolous) plants, lichens and liverworts are more sensitive to light, moisture, as well as rooting substratum than mosses. Lichens prefer dry and open forests and are more abundant on relatively fresh logs. Liverworts, in contrast, prefer moist and dense forests and are more abundant on medium or well decayed logs. A s a habitat, C W D is an important site for tree seedling regeneration, especially well decayed ones. Results also showed  that the abundances of different plant types (basically functional groups) were related to the degree of log decay. C W D has effects on the distribution and abundance of bryophyte growth-forms, e.g. mat type growth-forms and short turfs were more richly represented as wood-inhabiting species whereas weft type growth-forms were widely distributed on both C W D and forest floor, and their abundance increased as wood decay increased with the peak appearing on the forest floor. Analyses showed that vegetation/plant communities on C W D were significantly different from those on the forest floor in each of the six ecosystems. In general, forest floor vegetation was more different from each other than C W D vegetation among the study ecosystems. Evidence showed that log size and canopy closure had impact on species richness/diversity (number o f species per unit area in this context) and the number o f species was logarithmically correlated with log size and quadratically correlated with canopy closure. Usually, the larger the logs the more species were found, and there was a trend that this increase o f species number diminished and then nearly leveled off when logs reached a certain size. However, the canopy species relationship is different. The highest number of species was found under canopy closures of 65 - 75% and this number decreased with increase or decrease o f canopy closure. It is concluded that C W D is an important functional element in forest ecosystems. It is important to understory vegetation, especially to non-vascular plants. Therefore, in forest operations, maintaining certain amounts of C W D in different decay stages is essential to maintain biodiversity in forest ecosystems.  T A B L E  O F  C O N T E N T S  Abstract  ii  Table of Contents  iv  List of Tables  .vi  List o f Figures  viii  Acknowledgment  xi  Chapter 1  Introduction  1  Chapter 2  Literature Review  4  Chapter 3  2.1.  C W D in Forest Ecosystems  4  2.2.  Importance of C W D to Understory Vegetation in Forest Ecosystems  6  2.3.  C W D and wood dependent/preferring plants  9  2.4.  Plant succession on C W D  10  2.5.  C W D and species diversity  13  2.6.  C W D and forest management  14  Materials and Methods  16  3.1.  The Study Sites  16  3.2.  Field Methods  16  3.2.1. Stands Characterization Measurement  16  3.2.2. Decaying W o o d Measurement  19  ..  3.2.3. Quadrat Setting and Vegetation Sampling  20  3.2.4. Bryophyte Growth-form  21  3.3.  Data Analysis  22  3.3.1. Data Organization  22  3.3.2.  22  3.4.  Data Analysis  Nomenclature  24  iv  Chapter 4  Results and Discussion 4.1.  Characterization of the Ecosystems The Structure of the Stands  25  4.1.2.  The Coarse W o o d y Debris ( C W D )  37  Understory Vegetation Floristic Observations  39  4.2.2.  Plant Types in Relations to Different Rooting Substrata  42  4.2.3.  Bryophyte Growth-forms and Their Distribution Patterns  4.2.4.  55  4.2.4. b. Pearson Correlation  63  4.2.4. c. Cluster Analysis  63  4.2.5. Species Richness in Relation to L o g Size  66  4.2.6.  72  Species Richness in Relation to Canopy Closure Conditions  Literature cited  80 82  List o f plant species showing their plant type groups and their presence (+) and absence (0) on the C W D and forest floor substrata by ecosystems  87  List of plant species showing their plant type groups and their presence (+) and absence (0) on the C W D and forest floor substrata  A P P E N D L X IV  55  4.2.4. a. Principal Component Analysis  Conclusions  A P P E N D L X III  51  Understory Vegetation in Relation to C W D and Forest Floor among Six Study Ecosystems  APPENDLXII  39  4.2.1.  in Relation to Their Rooting Substrata  APPENDIX I  25  4.1.1.  4.2.  Chapter 5  25  98  List o f plant species confined to C W D showing their plant type groups and their presence (+) or absence (0) on three decay classes  105  A list o f bryophyte species and their growth-forms  107  L i s t of Tables  Table 1  The locations of the study plots and their climatic characteristic in the six ecosystems  Table 2  Decay classes of CWD used in the present study (modified from Triska and Cromack 1979).  Table 3  18 19  Plot and quadrat distribution showing the number of study plots established in each of the six ecosystems and the number of quadrats sampled on each of the four substratum categories  Table 4  20  The growth-form type for bryophyte species (slightly modified from Gimingham&Bires (1957) and During (1992)  21  Table 5  Density (stems/ha) of standing trees and snags in the six study ecosystems  33  Table 6  Basal area (m /ha) of standing trees and snags in the six study ecosystems  34  Table 7  Canopy closure (% cover) from the six study ecosystems  35  Table 8  The composition (percentage cover) of the forest ground surface in the six study ecosystems  Table 9  37  Diameters (cm) of the CWD (>15 cm) sampled for vegetation plots in the six study ecosystems  38  Table 10  Number of species in plant type groups found in the six study ecosystems  39  Table 11  Mean abundance (percentage cover) of the most abundant species on different substrata in the six study ecosystems  Table 12  Number of species in plant type groups found on different substrata in the six study ecosystems  Table 13  47  Mean abundance (% cover) of bryophyte growth-forms in relation to different substratum categories in the six study ecosystems  Table 15  45  Mean abundance (% cover) of plant type groups occurring on different substrata in the six study ecosystems  Table 14  .43  52  Percent variance explained by the first five factors generated by principal component analysis (PCA). Variables (plant species) in the PCA analyses were 56 in the CDF, 70 in the CWH, 67 in the MH, 124 in the IDF, 62 in the ICH, and 83 in the ESSF  55  Table 16  Percent variance explained by the first five factors generated by principal component analysis ( P C A ) . Variables (plant types) in the P C A analyses were 6 in C D F and 7 in all other ecosystems  Table 17  59  Pearson correlation coefficients o f species composition and the abundance among 24 category plots for all the six ecosystems. 245 species were used in the analysis  Table 18  Mean number o f species per quadrat on each log size class o f the three decay categories of C W D  Table 19  67  Regression equation parameters for predicting species number per quadrat in relation to log size for three C W D decay categories  Table 20  64  71  Regression equation parameters for predicting species number with the change of canopy closure conditions on both C W D and forest floor in each of the six study ecosystems  72  vii  L i s t of Figures  Figure 1  Locations o f the study plots in six forest ecosystems  Figure 2  Size class distribution of the standing trees from the sampled stands in the C D F ecosystem  Figure 3  50  Mean abundance (% cover) of bryophyte growth-forms in relation to different rooting substrata in each of the six study ecosystems  Figure 13  49  Mean abundance (% cover) o f different plant types in relation to different rooting substrata in all the study ecosystems  Figure 12  36  Mean abundance (% cover) o f different plant types in relation to different rooting substrata in each of the six ecosystems studied  Figure 11  35  Canopy closure (% cover) distributions for the study stands in the six ecosystems  Figure 10  31  Canopy closure (canopy crown % cover)for the study stands in the six ecosystems showing median and spread/range o f canopy cover  Figure 9  30  Size class distribution of the standing trees from the sampled stands in the E S S F ecosystem  Figure 8  29  Size class distribution of the standing trees from the sampled stands in the I C H ecosystem  Figure 7  28  Size class distribution of the standing trees from the sampled stands in the IDF ecosystem  Figure 6  27  Size class distribution o f the standing trees from the sampled stands in the M H ecosystem  Figure 5  26  Size class distribution of the standing trees from the sampled stands in the C W H ecosystem  Figure 4  17  53  Notched box plots of the first factor scores (factor 1) generated by Principal Component Analysis ( P C A ) on species data for each of the four substrata showing vegetation relationships among different substratum categories in the six ecosystems  Figure 14  .57  Ordinations of subplots along the first two axes of P C A on plant type group data for each of the six ecosystems  58  Figure 15  Ordinations of forest floor subplots along the first two axes of P C A on species data in the six ecosystems  Figure 16  60  Ordinations of C W D subplots along the first two axes of P C A on species data in the six ecosystems  Figure 17  61  Dendrogram produced by cluster analysis based on the 30 most abundant species showing vegetation relationships among different substrata and among different ecosystems  Figure 18  65  Mean species number per quadrat as a function o f C W D size classes found on decay class 1 logs for all the study ecosystems. The regression line was formed using a logarithm smoothing method  Figure 19  68  Mean species number per quadrat as a function o f C W D size classes found on decay class 2 logs for all the study ecosystems. The regression line was formed using a logarithm smoothing method  Figure 20  69  Mean species number per quadrat as a function of C W D size classes found on decay class 3 logs for all the study ecosystems. The regression line was formed using a logarithm smoothing method  Figure 21  70  The number of species found in each C W D sample quadrat (0.3 m ) vs. 2  canopy closure conditions for each of the six ecosystems studied showing the median (central point) and standard error (bar) Figure 22  74  The number of species found in each forest floor sample quadrat (0.3 m ) vs. 2  canopy closure conditions for each of the six ecosystems studied showing the median (central point) and standard error (bar) Figure 23  75  The number o f species found in each C W D sample quadrat (0.3 m ) vs. 2  canopy closure conditions for all the ecosystems combined showing the median (central point) and standard error (bar) Figure 24  76  The number of species found in each forest floor sample quadrat (0.3 m ) vs. canopy closure conditions for all the ecosystems combined showing the median (central point) and standard error (bar)  Figure 25  Number of plant species per sample quadrat found on C W D subplots in the six study ecosystems  Figure 26  77  Number of plant species per sample quadrat found on the forest floor  79  subplots in the six study ecosystems  ACKNOWLEDGEMENTS  Many people have made contributions to this project. First, I thank Dr. M . Feller, my supervisor, for the opportunity to do this study and for his directions throughout the project. Special thanks goes to Dr. G . Bradfield who helped with methodologies and data analysis. Dr. W . B . Schofield helped with some bryophyte identifications and checking all the bryophyte names. T. Goward assisted with lichen identification. Dr. K. Klinka helped with the initiation o f the study topic and the field methods. Dr. T . Sullivan has also made some suggestions for the study. H . K . Yearsley did the field data collection in the C D F ecosystem. Penny Olanski helped in some field work. T o all of these individuals I offer my thanks. The project has been supported through grants from the Natural Sciences and Engineering Research Council o f Canada.  xi  Chapter 1  Introduction  Coarse woody debris ( C W D ) is an important component in forest ecosystems. In coniferous forests, there is a large amount of C W D accumulation. A s a consequence of forest succession and disturbances, C W D plays certain ecological roles in the dynamics and structure of an ecosystem. A n understanding of these roles will contribute a better understanding of the structure and function of forest ecosystems (Franklin et al. 1987; Harmon et al. 1986;  Maser  andTrappe 1984; Maser etal. 1988; Means et al. 1992 ; Spies etal. 1988).  Coarse woody debris is commonly called decaying wood/logs (Andersson and Hytterborn 1991; Means et al. 1992; Soderstrom 1987), rotting/rotten wood/logs (Huffman et al. 1994), downed wood/boles (Marra and Edmond 1994), fallen logs/trees (Maser and Trappe 1984; McCarthy and Facelli 1990; M c C u l l o u g h 1948; Thompson 1980), or decomposing wood (Hytteborn et al. 1987 ). More precisely, C W D can be defined as "all kinds o f woody materials relatively large in size when initially added into a system." Therefore, it includes snags, downed logs, stumps, chunks of wood, large branches, and coarse roots. Fine woody debris and other forest litter are excluded from this definition, for their ecological functions are thought to be different (Facelli and Pickett, 1991).  C W D is a temporary substratum for it decays and disappears within a limited period o f time. The decay or decomposition process involves a series of changes in physical structure and chemical composition. For study purposes, decay classes were proposed to describe the degree of wood decay and relate to its ecological functions (McCullough 1948; Muhle and LeBlance 1975; Soderstrom 1988a, 1989; Triska and Cromack, Jr. 1979).  O f many ecological functions, the most significant is perhaps its influence on understory vegetation. It may influence the establishment, abundance, and distribution patterns of understory plants and tree seedling regeneration directly or indirectly, by changing forest floor micro-topography, creating various micro-environments, providing particular substrata, as well as serving as habitats.  Many attempts have been made to study understory vegetation in relation to C W D , and succession patterns on logs, including tree seedling regeneration (e.g. Franklin and Dyrness 1973; Harmon 1987; Harmon and Franklin 1989; Nakamura 1992), other vascular plants (e.g. Huffman et al. 1994; Thompson 1980), and more importantly bryophytes and lichens (e.g. Andersson and Hytterborn 1991; Bowe and Rayner 1993; Gustafsson and Hallingback 1988; Hallingback 1992; Harmon etal. 1986; Muhle and LeBlance, 1975; Soderstrom 1988b; 1989; Hedensa 1989; Soderstrom and Jonsson 1992). Most o f these studies were carried out in Europe, Japan, the United states, and Eastern Canada. Lists o f species on C W D were proposed and general log succession patterns were summarized through these studies.  Though previous studies revealed some important ecological characteristics and some functions of C W D in forest ecosystems, our current knowledge of the inter-relationships between C W D and forest understory vegetation is incomplete. C W D is known to provide habitat for various plants but there is little information on the plants which are associated with C W D versus other habitats (Harmon et al,  1986), especially the forest floor. Very few  quantitative studes have been done on the abundance of different plant types in relation to C W D at different decay stages. Few reports exist dealing with the ecological relationships  2  between plant growth-forms and C W D . N o attempts have been made to examine the relationship between log size and C W D vegetation. In addition, there is a need to examine i f there are differences in terms o f functions o f C W D in different ecosystems with different environmental conditions.  In most coniferous forests in B . C . , there is a large amount of C W D accumulation. However, most aspects concerning C W D in forest ecosystems have been poorly studied in this region, from the documentation of the quantity of C W D to the ecological functions of C W D (Harmon et al. 1986; Trofymow and Beese, 1990; ), except some related studies (e.g. Blackwell et al. 1992; Feller, 1989, 1991; Keenan et al. 1993) and some reports on tree seedling regeneration (e.g. Smith, 1955).  The objectives o f this study for six forest ecosystems in British Columbia were to: a) quantify C W D and its percentage cover o f the ground surface; b) investigate the abundance and distribution patterns o f understory plant species with respect to C W D and the forest floor; c) examine bryophyte growth-forms in relation to C W D in different decay classes and the forest floor substratum; d) examine the effects o f log size and canopy closure on understory vegetation; and e) study the relationships o f understory vegetation on both C W D and forest floor in different ecosystems with different environmental conditions.  3  Chapter 2  Literature Review  The ecology of C W D has been reviewed by Harmon et al. (1986). The following review focuses on more recent literature and on forest ecosystems.  2.1. C W D in Forest Ecosystems  The importance of C W D is associated with its amount in a system and the amount is determined by the rate of input and the rate o f decomposition. Input rate varies primarily with the productivity and size o f the trees in the ecosystem (Harmon et al. 1986), the mortality mechanism (i.e. disturbance such as windthrow, fire, insects, and diseases), and age o f the stands (succession). Decomposition rate is related to the species, temperature, moisture, and the availability of decomposers (McCarthy and Bailey 1994; Tyrrell and Crow 1994). Generally, there is little C W D accumulation in tropical forests; whereas large accumulations occur in temperate and boreal forests, especially in temperate coniferous forests. In old-growth Douglasfir (Pseudotsuga menziesii [Mirb.] Franco), for example, the biomass accumulation o f C W D reached 173 - 222 M g / h a (Spies et al. 1988; Means et al. 1992). In Pseudotsuga - Tsuga stands, this accumulation was as high as 511 Mg/ha (Harmon 1987). In western red cedar (Thuja plicana) and western hemlock (Tsuga heterophylla) forests on northern Vancouver Island, B . C . , Keenan et al. (1993) estimated a biomass o f 211 - 313 M g / h a o f woody debris. In general, biomasses o f 110 - 300 Mg/ha in coniferous forests and 2 0 - 5 0 Mg/ha in deciduous forests have been estimated (Harmon et al. 1986). Such an amount of woody material covers forest ground, from 14% in Picea sitchensis - Tsuga heterophylla forests in Olympic National Park, Washington, (Graham and Cromack 1982) to 15 - 25% in Pseudotsuga - Tsuga stands (Harmon  4  et al. 1986; Harmon 1987). Studies of C W D dynamics demonstrated that the accumulation of C W D is fairly high immediately following clear-cutting, then declines A ith the development of the stands (little C W D is added at this stage but decay is in process). The lowest amount of C W D occurred at the age of 40 to 60 years o f the stands, and then the amount increased again by the addition of new dead materials (Harmon et al. 1986). Spies and Franklin's (1988) data also showed a similar trend: the volume and biomass o f C W D were highest in old growth stands, intermediate in young stands, and lowest in mature forests.  The most significant characteristic of C W D is perhaps its state of decay or decomposition. The decay of C W D is a process o f substratum change, both physically and chemically. A s decay proceeds, length, diameter, surface area, volume, biomass, and density o f individual logs show a progressive decrease (Means et al., 1992). Three major processes are involved in the decomposition o f C W D : 1) leaching (chemical), 2) fragmentation (including physical fragmentation, e.g. seasoning, transportation, etc. and biological fragmentation, e.g. plants and animals) and 3) biological interaction (biochemical processes e.g. microbes, plants, and animals). Evidence showed that C W D is one of the important substrata in which nitrogen fixation takes place (Vitousek 1994). The decomposition of C W D releases its nutrients which are important to the continued health of the forests (Harmon et al. 1986; Keenan et al 1993; M a c M i l l a n 1988). In addition, C W D has a high water holding capacity, especially well decayed logs, and therefore it is an important source of water during periods o f drought. It is clear that C W D is one o f the essential functional components in a forest.  In order to describe the decay process, property changes, and its functions at different degrees of wood decay, different decay classes or stages have been proposed. In some cases,  5  eight decay classes were recognized (McCullough 1948; Soderstrom 1988a; 1989) and in the others, a five-stage classification was applied (Means et al. 1992; Muhle and LeBlance 1975; Spies and Franklin, 1988; Triska and Cromack, Jr. 1979). Since wood decay is a continuing process, any classification method cannot be absolute and is just for the convenience of study. Furthermore, a precise recognition o f decay classes is very difficult in the field, and therefore arbitrary decisions are unavoidable in this regard.  Addition of C W D will alter the forest floor microtopography and increase the heterogeneity of the landscape at small scales (Thompson, 1980). C W D also influences the transport and storage of soil (Harmon et al., 1986). C W D can occur in different forms and size classes and logs may lie in any direction, which creates a great structural diversity of microsites. Within a forest stand, microclimate varies to a greater degree vertically than horizontally. The diversity of vertical structure created by C W D is very important to forest floor species and some epiphytes. Furthermore, the addition of C W D can be considered to be a kind o f microdisturbance (Jonsson and Essen 1990; McCarthy and Facelli 1990). A patch o f vegetation may be dominated by a small number of, or even a single, species. The disturbance o f C W D may break the patch and create various habitats where more species can invade, hence enriching species composition. Investigations have shown that tree-fall disturbances are important for both the persistence o f colonists, and the maintenance of a high bryophyte diversity in borealforest ecosystems (Jonsson and Essen 1990).  2.2. Importance of CWD to Understory Vegetation in Forest Ecosystems  6  The presence o f C W D in a forest ecosystem may influence the understory vegetation directly or indirectly. It serves as habitat and provides substrata for understory species including lichens, bryophytes, and vascular plants as well as tree seedlings (Bowe and Rayner 1993; Harmon and Franklin 1989; Harmon etal. 1986; Hedenas 1989; Hytteborn et al. 1987; Lesica etal. 1991; Marstaller, 1989; M c C u l l o u g h 1948; Muhle and LeBlance, 1975; Soderstrom, 1987, 1988a, 1988b, 1989, 1992; Soderstrom and Jonsson 1989, 1992; Thompson 1980).  Vascular plants that can inhabit C W D include ferns, herbs, shrubs, and tree seedlings. There are few reports on ferns and their relationships with C W D . Some ferns are epiphytes (e.g. Polypodium glycyrrhiza D. C . Eat.) and usually inhabit living trees but little is known about the response of these plants after the tree falls. Limited studies have been done on shrub species and their communities in relation to C W D . Huffman et al. (1994) studied the regeneration o f salal (Gaultheria shallori) in the central Coast Range forests o f Oregon and their data demonstrated that the survival of two-year old seedlings of this shrub species was highest on rotten logs. It can be observed that the most common shrub species inhabiting C W D are the species of Vaccinium in most coniferous forests in southwestern B . C . Many herbaceous species can use C W D as habitat. For example, Thompson (1980) found 31 herbs growing on C W D . However, there remain uncertainties about the vigor and reproduction o f herbaceous species growing on C W D relative to those growing on soil and forest floor materials.  Compared to herbs and shrubs, more studies were conducted to examine at the relationships between tree seedling generation and C W D . Many examples illustrated that C W D is very important to tree recruitment and its value as nurse-logs and seedbeds has been widely recognized (Franklin and Dyrness 1973; Harmon 1987; Harmon and Franklin 1989; Harmon et  1  al. 1986). Nurse-logs are found in many forests throughout North America. In the moist temperate Picea sitchensis - Tsuga heterophylla forests o f the Pacific Northwest, rotten logs are major sites for tree seedling regeneration (Harmon et al., 1986). M c K e e et al. (1982) found that 88-97% of the tree seedlings were growing on C W D in these forests. This proportion is remarkable because only 6-11% of the ground surface in these forests is covered by logs (Graham and Cromack, 1982). In Japan, most seedlings of Abies veitchii and Tsuga diversifolia were found on decaying logs in subalpine forests (Nakamura 1992). However, the value o f C W D as a substratum for all tree regeneration in northwest North America has been questioned (e.g. Dobbs, 1972; Alexander et al. 1984). In addition, the dynamics o f tree seedlings on C W D has not been well studied.  Many attempts have been made to explain this high proportion o f tree seedlings growing on C W D . Position and substratum seem to be the major factors contributing to this result. Tree seedlings are very vulnerable when they are young, and are easily outcompeted by other understory species. Logs usually lie above the surface o f forest floor, and create less competitive sites for seedlings to establish. However, Harmon and Franklin's experiments (substratum vs. position) in Picea and Tsuga forests, Olympic National Park, Washington and Cascade Head, Lincoln, Oregon, suggested that position is not as important as substratum for the establishment of tree seedlings. When soil and logs were placed at the same level, significantly more seedlings survived on the log substratum with a mean survival of 3 % on logs and 0.1 % on soils and no significant effects could be attributed to position (Harmon and Franklin, 1989). They also found that more seedlings were found on freshly fallen logs than on very decayed ones with thick moss mats on them. The moss mats can exclude tree seedlings and greatly reduce  8  their survival rate. In consequence, logs are a good seedbed only during stages when moss mats growing on them are not sufficiently thick to exclude tree seedlings (Harmon, 1987).  A s a habitat, C W D may be more important to bryophytes and lichens in a forest ecosystem because more species o f these two groups inhabit or depend on it (e.g. Andersson and Hytterborn 1991; Bowe and Rayner 1993; Gustafsson and Hallingback 1988;  Hallingback  1992; Harmon etal. 1986; Muhle and LeBlance, 1975; Soderstrom 1988b; 1989; Hedenas 1989; Soderstrom and Jonsson 1992). Recently, the occurrence of bryophytes and lichens in relation to the presence of C W D has received considerable study in some regions, such as in Sweden. In Lycksele Lappmark, northern Sweden, Soderstrom (1988a) found 75 bryophyte and lichen species inhabiting rotten wood. Other bryoflora studies were made in the montane virgin forests and boreal forests and the results indicated that the presence of C W D is one o f the major factors which contributes to the rich bryoflora in these forests (Andersson et al.  1991;  Hallingback 1992; Hytteborn etal. 1987). In British Columbia, Canada, more than 100 species of bryophytes and lichens were found on C W D in coastal southern B . C . (Klinka et al. unpublished).  2.3. CWD Dependent Plants  A s a particular substratum, C W D is different from other substrata in forest ecosystems such as mineral soils, rocks, forest floor material, and even bark o f living tree trunks and is preferred by many plant species, especially bryophytes. They can be described as wood-inhabiting plants or epixylics. In  Betula-Picea forests near Kvikkjokk, northern Sweden, Hytteborn et al. (1987)  observed that Dicranumfragilifolium,Lophozia  longidens, L. guttlulata, Tetraphis pellucida,  and Blepharostoma trichophyllum were confined to decaying logs. Lesica et al. (1991) found that nearly all the species o f leafy liverworts present occurred on rotten logs in Swan Valley, Montana, U . S . A . Obviously, these liverworts are obligatory epixylics, and require well decayed wood to maintain viable populations (Soderstrom 1988b). O n the other hand, some species may inhabit different substrata but have an obvious preference to one or two substrata. Soderstrom et a/.(1989) investigated the spatial pattern and dispersal in a leafy hepatic, Ptilidium pulcherrimum, in Sweden and found that this species grew on rotting wood almost 75% o f the time. Such an example from vascular plants is Catasetum viridiflavum. This species can grow on both living trees and decaying wood, but the individuals on the latter substratum flowered more often than those on living trees (Zimmerman 1991).  Not only is C W D considered to be a particular substratum but this substratum is changing continuously in texture, property, and nutrient concentrations as decay proceeds. So the properties of sound wood are obviously different from those of very rotten wood. The changing substratum creates a niche gradient to which the inhabiting plants will respond. In Sweden, Soderstrom (1988a) investigated the occurrence of bryophytes and lichens on decaying wood at different stages of decay and found that some species prefer less decayed stages whereas others prefer well decayed stages. From these observations, epixylic species were classified into early epixylics and late epixylics. In another study, he observed that Barbilophozia attenuata, Blepharostoma trichophyllum, Calypogeia suecica, and Cephalozia leucantha never occurred on wood in early decay stages. Barks, softwood, and hardwood can also be considered to be different substrata. For example, Barbilophozia attenuata and another 5 species were never found on logs with a lot o f remaining bark, while, Riccardia latifrons was never found on softwood (Soderstrom, 1989).  2.4. Plant Succession on C W D  10  In forest ecosystems, succession on decaying wood is a common feature and it can be treated as a distinct case (Muhle and LeBlance 1975; Schuster 1949). A complex plant succession is initiated as soon as a bole falls to the forest floor (Harmon et al.  1986; Muhle and  LeBlance 1975). Succession on C W D includes two major processes, colonization and competition. The phases and the directions o f succession may be determined by the duration o f decay in a log, substratum variables, organic matter accumulation on the surface of the log, as well as by differences in climate. Muhle and LeBlanc (1975) reviewed some of the early literature about cryptogam succession on C W D (some of the literature was in languages other than English). In general, four stages o f succession were recognized: epiphytic/pioneer stage, epixylic stage, saprolignicolous stage, and humicolous terricolous stage (Muhle and LeBlanc 1975). M c C u l l o u g h (1948) reported that fallen logs were invaded first by lichens and liverworts, followed by mosses, then continued with herbs and shrubs. He also recognized another two succession patterns related to different environmental conditions. The patterns and sequences described by M c C u l l o u g h (1948) may occur in many situations, but causes of succession can be more complex and multi-directional. More recently, some further studies have been done on the succession patterns on C W D (Nakamura, 1987; Soderstrom, 1988a; 1988b; 1989). T o summarize all such studies, two general succession patterns - wood dependent succession and wood independent succession - can be recognized.  In wood dependent succession, species or communities depend on decaying wood properties for their rooting substratum. In other words, the succession process is intimately associated with the process of log decay. In this case, the state o f decay and the nature o f the wood substratum may determine the direction o f succession and community replacement. Soderstrom (1988a) studied the sequence of bryophytes and lichens in relation to substratum variables of decaying coniferous logs in northern Sweden and classified those species into four groups: facultative epiphytes, early epixylics, late epixylics, and ground flora species. Obviously, the former three groups and their succession pattern are wood dependent.  ll  Facultative epiphytes are those which occur mainly on living trees and can survive for some time after the tree falls. The early epixylics are new colonizers on fresh or sound logs and they usually establish and spread rapidly. Many Cladonia lichens and Lophozia liverworts are these species and can dominate early succession phases. However, these early epixylics are not good competitors. A s decay proceeds, the substratum becomes less favorable to these early colonizers, and as a consequence the population declines. Meanwhile some late epixylics invade the habitat, and finally replace the earlier ones. In Soderstrom's investigation, some  bryophytes such as Calypogeia integristipula, Lophozia incisa, Cephalozia affinis, Tetraphis pellucida, etc. were typical species appearing in the late phases o f log succession. In TsugaAbies forests in central Japan, succession patterns of bryophyte and lichen communities on rotten logs were distinguished by Nakamura (1987). A Parmelia-Dicranum community dominated the first phrase, followed by a Heterophyllium-Parmelia community, and then replaced by Heterophyllium-Blepharostoma and Scapania communities and finally, a Hylocomium-Pleurozium community appeared.  W o o d independent succession usually takes place after litter/humus or moss mats accumulate on C W D . During the succession process, the species may use wood as a substratum but do not depend on it. In this case, decaying wood just serves as a "platform". A s epixylic communities develop on logs, mats o f these organisms form, which increases the ability o f retaining litter fall, and a layer o f humus begins to accumulate. The accumulation o f litter/humus changes the log surface in texture and properties which allows more forest floor species to invade. So wood independent succession can be characterized by: 1) thick litter/humus accumulation, 2) C W D in its late stages o f decay and 3) more forest floor species and less epixylics involved. W o o d independent succession is a more complex process in which more taxa are involved. These taxa include bryophytes, lichens, herbs and grasses, shrubs, and tree seedlings.  12  During the process of wood independent succession, competition is more intensive. A s colonization proceeds, both intra- and inter-specific competition increases. There is a tendency for more complex and larger plants to compete with simpler, smaller li c forms (Harmon et al. 1986) if these larger life forms could colonize the log substratum. However, because larger life forms need more nutrient and water supplies and more space to develop their root system, the limitation of space and these supplies in logs (especially when logs rise above the ground) lead most o f these species to become dwarfed or even die out before completing their life cycles. Finally they are outcompeted by smaller life forms. In other cases, small plants can screen out the larger plants because the thick mats of small plants can prevent the seeds of larger life forms from reaching the real moist woody substratum. For example, deep carpets o f Hylocomium and Rhytidiadelphus mosses can prevent log colonization by tree seedlings ( M c K e e et al. 1982). Some experiments showed that deep moss layers (> 5 cm) would exclude tree seedlings (Harmon and Franklin 1989). If larger plants can send their roots into decaying wood or even successfully send roots into the underlying mineral soil, their ability to compete will be greatly increased, and therefore they may dominate the late succession phases. W o o d independent succession is also influenced by other environmental factors such as climate, light intensity (e.g. canopy opening), moisture, etc. Mesic and xeric environments would favor different plants and plant communities which may lead to successions in different directions.  2.5.  C W D a n d Species Diversity  Evidence shows that the addition o f C W D can enrich species diversity by creating various micro-sites, providing substrata, as well as serving as habitat. O n a global scale, the diversity of mosses, for example, is much higher in temperate regions than in tropical regions. One of the major factors contributing to the rich bryoflora in temperate regions is the large amount o f C W D available in the temperate forests (Hallingback 1992). This situation is also true on a local scale. Lesica et al. (1991) studied bryophyte and lichen communities in old-growth and managed second growth forests in Montana, U . S . A . , and compared the species composition and 13  diversity in both forests. Their report showed that richness and species diversity were much higher in the old-growth forest than in the managed second growth forest. Some species, e.g. Anastrophyllum  hellerianum, Jamesoniella  autumnalis,  Nephroma  spp, and several other  species, were found only in the former forest. Almost all these species are wood-inhabiting and the large amount o f C W D in the old-growth stand was the major reason for the presence o f these species. Andersson and Hytterborn's (1991) study showed a similar result. A l l these studies have illustrated that the absence o f large C W D and shortages o f logs in some decay classes in managed stands make it difficult for some species to maintain their populations or even impossible for some species to establish. There were no proper substrata and habitats available for these wood-inhabiting species in the managed forests.  2.6. CWD and Forest Management  Traditional forest management is now being challenged by many new concepts such as nature conservation, biodiversity, as well as maintaining long term site productivity. In modern forestry operations, C W D has to be considered as an important element in a forest ecosystem, and there-fore a proper management o f this element is necessary. Improper management activities can greatly reduce the amount o f C W D by removing existing C W D such as snags or relatively large, less decayed logs. In some cases, clearcutting can remove approximately 90% of the live stem volume (Spies and Franklin 1988). This intensity o f removal o f potential C W D could lead to serious shortage o f woody materials in the system. The shortage o f C W D means a scarcity o f habitats for some particular plants. This, plus rapid change in micro-climate, especially drought and increase in intensity o f light caused by the removal o f the tree canopy, can cause a decrease in biodiversity. Gustafsson and Hallingback (1988) studied the bryophyte flora and vegetation o f managed and virgin coniferous forests in south-west Sweden and found that species richness and total cover were higher in the virgin stand than in the managed forests. This was a response to the absence o f large logs and the change in microclimate in managed stands. Similarly, Soderstrom's (1988b) investigations showed that  14  bryophyte and lichen flora were much richer in natural stands than in managed stands, especially epixylic species e.g. Blepharostoma tichophyllum, Calypogeia integristipula, Cephalozia affinis  and Lepidozia reptans.  Decaying wood is a temporary substratum which changes during decomposition until it finally disappears. This means that species can grow on each log only for a finite period o f time and then have to disperse to new logs in order to survive as a population. T o maintain a high diversity of epiphyte species, the presence of C W D in various decay stages is essential. In some managed stands, the amount of C W D is diminished and some decay stages may be missing, so species depending on a relatively narrow range o f decay classes may die out due to a temporary shortage of the particular stages of wood (Soderstrom, 1988b). The destruction of habitat would cause the extinction of some species. In Sweden, for example, Calicium subquercinum,  Cephalozia lacinulata, Cyphelium trachylioides, Scapania masslongi, and Sphinctrina anglica have become extinct (Laaka 1992; Soderstrom 1988b). Scapania masslongi has disappeared from Finland (Laaka 1992). Extinctions of bryophyte species occurred elsewhere in Europe and Asian countries (Koponen 1992). Most endangered are the taxa which inhabit special environments or substrata, such as rotten wood in virgin forests (Koponen 1992). The extinction of these taxa is, at least partially, due to deforestation and improper forestry operations. Therefore, providing a certain amount of C W D in various decay stages in managed stands is absolutely necessary to maintain a high diversity o f plant species in forests.  15  Chapter 3  Materials and Methods  3.1. The Study Sites  The study was carried out in two localities, one in southwestern B . C . near Vancouver, and one in southern central B. C , near Kamloops. Three ecosystems (biogeoclimatic zones (Krajina, 1959,1965; Meidinger and Pojar, 1991)) were selected for each locality. In the southwestern locality, Coastal Douglas-fir ( C D F ) , Coastal Western Hemlock ( C W H ) , and Mountain Hemlock ( M H ) ecosystems were selected and in the southern central locality Interior Douglas-fir (IDF), Interior Cedar Hemlock (ICH), and Engelmann Spruce-Subalpine fir (ESSF) (Figure 1). The plot locations, elevations, and major climatic data are shown in Table 1.  In general, the ecosystems in the southwest locality are warmer and wetter than those in the southern central locality. However, the C D F is fairly dry with annual precipitation less than 1000 m m , which is almost as same as that in the I C H . In both localities, gradients in elevation, precipitation, and temperature can be generally recognized (Table 1).  3.2. Field Methods  3.2.1. Stand Characterization Measurements  Three study plots (each approximately 1 hectare) were established in each zonal ecosystem in old-growth or mature forests. The plots selected were relatively uniform in terms of age,  16  F i g u r e 1.  Locations o f the study plots in six forest ecosystems.  dominant tree species composition, canopy structure, as well as topography, micro-climate, etc. Within each plot three 20 m X 20 m subplots were randomly located to determine stand composition. D B H (diameter at breast height) for all the stems (including snags) was assessed and the species were recorded.  17  o  c o  CN CN  o  SO CN  o  Tt CN  o  ©  so  o  Tt  >n  o  O >/"> CN  cn  O  o  CN  o  SO CN  o  o  c ©n  «o  rm  ©  >/->  so  so  — r-  3 3 •a  0  1  I 2 'I- '§• & u  2. o o  o  oo —  o  o  CN  B  ft  .it:  u  x: a. •5 O O O  X!  •a  •a  •o a. 3 O 2  s  o  CN  03 CN  CN  o  o  o  o 0-  a!  o  o  OS  ©  cn  o  o  s  CM  CN  p od  Os  sq od  cn  o  d P  ^  cd cj  c B  ~  2  feu  o  E  OS  CN.  so  cn  os  ©  so  Os oo so  OS CN  CN  Tt  0  1  > o  U •a  ft ft  3 O  •8 u to  a.  o  u  =5  I —  |  I §  »I  CO  > >  B ~B o  U  ft O O  ft s  •c  00  . 3 ffl  ti  ft ft —1  3 O  00  J  o  CN  c  00  o  U CO  3 O  c3  u c  cs  5 <  * O  o  CJ  o  S BC g  o  a  1 a o ri  cd  1  o U  c  3 o  u  60 3  •a u  O  a  DC  s ft  00  CJ  o  'C " C  rs S  E  ej  DC  00  c  w  _ft £1 3 OO  00 00  w  3.2.2. Decaying W o o d Measurement  Decay class/stage of the decaying C W D is classified into three categories (Table 2) which is modified from Triska and Cromack (1979), and Sollins (1982,1987) and is based on physical characteristics such as texture, color, shape, and the presence or absence of bark or twigs.  Table 2.  Decay classes o f C W D used in the present study (modified from T r i s k a and Cromack 1979). Decay Class*  Characteristic  DI*  D2  D3  Bark  Intact  Sloughing  Detached or absent  Structure o f wood  Sound  Sapwood decayed heartwood sound  Heartwood decayed or fragmented  Color of wood  Almost original color  Reddish brown to light brown  Red-brown or dark brown  Branch <4 cm  Present  Absent  Absent  Texture o f rotten part  Intact or mostly intact, sapwood partly sort  Hard, large pieces  soft, powdery when dry  * CWD decay class: DI (fresh), D2 (medium decayed), and D3 (well decayed).  The quantity o f C W D present was estimated from the line intersect method (Van Wagner 1968) using 3 equilateral triangles (30 m side) randomly located within each plot to measure the amount of C W D and ground surface cover. W o o d volumes obtained from the transects were converted into masses using measurements of wood relative density.  19  3.2.3. Quadrat Setting and Vegetation Sampling  In each sample plot transect lines were set randomly and small quadrats were laid out along the lines on different rooting substrata (i.e. on C W D and forest floor) with usually 50 (although with 40 in one instance and 60 in another) quadrats per plot, among which 30 were established on C W D (10 on each of the three decay classes) and the rest were established on the forest floor. Quadrat was dependent on log size: 30 cm X 100 cm (logs with diameter >30 cm) and 15 cm X 200 cm (on logs with diameter < 30 cm). Only downed logs with diameters greater than 15 cm were chosen for sampling. A total o f 930 quadrats was sampled (Table 3).  Table 3. Plot and quadrat distribution showing the number of study plots established in each of the six ecosystems and the number of quadrats sampled on each of the four substratum categories Substratum category* Ecosystem  Number of plots  DI  D2  D3  FF  CDF CWH MH IDF ICH ESSF  3 3 3 3 3 3  30 30 30 30 30 30  30 30 30 30 30 30  30 30 30 30 30 30  30 90 60 90 60 60  Total  18  180  180  180  390  * DI - D3 : same as those in Table 2; FF: forest floor. A l l species occurring in the quadrat were recorded and samples for species unidentified in the field were collected and taken to the laboratory for detailed examination. The percentage coverage of each species in the quadrat was recorded by visually estimating the vertical crown shoot-area projection. Meanwhile, diameters and decay class o f the sampled logs were also recorded. Canopy closure conditions, i.e. canopy crown cover (in percentages), above the  20  quadrats were estimated visually. Photographs were taken for some sample quadrats for more careful laboratory analysis o f canopy conditions.  3.2.4. Bryophyte Growth-form  According to their morphological characters, bryophyte species were grouped into growthforms which mainly follow Gimingham & Birse (1957), Barkman (1988), and During (1992) (Table 4).  Table 4. The growth-form type for bryophyte species (slightly modified from Gimingham & Birse (1957) and During (1992)  Direction of main shoots Vertical extension of shoots (cm)  Radiating from central point  Erect (Acrocarps)  Turfs <1 0.5-3 >3  open turfs (to)* short turfs (t) tall turfs (T)  Cushions  small cushions (cu) large cushions (Cu)  Various, often horizontal or ascending (Pleurocarps)  Mats thalloid mats (Mth) rough mats (Mr) wefts (W)  smooth mats (Ms) dendroids (D)  * Reference letters  21  3.3. Data Analysis  3.3.1. Data Organization  The vegetation data from the same substratum (i.e. D I , D 2 , D 3 , and F F ) within each plot were combined and averaged forming a substratum subplot or category subplot, e.g. C D F 1 D 1 indicates the subplot on decay class 1 (DI) logs in plot 1 in the Coastal Douglas-fir ecosystem. In this way 4 category subplots were obtained for each plot (12 such subplots for each ecosystem). A vegetation table (species by subplots) was therefore generated for each ecosystem. In addition, a general vegetation table o f the six ecosystems was formed by combining all the vegetation data. T o compare C W D vegetation and forest floor vegetation, all subplots in the same category within an ecosystem were combined forming four category plots for each ecosystem.  T o examine the functions o f C W D in different decay classes on different plant types, species were grouped into seven plant type groups (basically taxonomic groups, i.e. tree seedlings, shrubs, herbs & grasses, ferns, mosses, liverworts, and lichens). Bryophyte species were grouped by growth-forms (life-forms). The mean abundance o f each plant type or each growth-form on each substratum category was calculated.  3.3.2. Data Analysis  Principal component analysis ( P C A ) (Goodall, 1954; Manly, 1994) was used to determine the environmental factors that influence the vegetation composition and vegetation differences  22  among C W D subplots and forest floor subplots by calculating and plotting factor scores for all the subplots. Correlation analysis was used to determine the relationships among C W D vegetation and forest floor vegetation.  Cluster analysis was employed to group subplots on both C W D and forest floor. The thirty most dominant species (total abundance on all plots in all ecosystems > 10) were selected for the analysis. Data standardization followed the rule that the mean value o f a variable is zero and the standard deviation is one (Manly, 1994). The formula is expressed below:  Value - Mean or  Value =  [ 1]  st  SD  Where V a l u e is standardized value, V a l u e st  or  is original value (% cover), S D is standard  deviation. Euclidean distance and the Ward minimum variance method were used in the analysis and clustering.  Species richness (number of species per unit area in this context) in relation to canopy closure and log size was analyzed using regression analysis. The species richness appeared to vary with canopy closure and log size. T o test for these effects, regression models were developed. In testing the effect o f log size on species number, diameters o f logs were grouped into 13 size classes with 5 cm intervals. Then a mean species number within a size class was calculated by a weighted means model.  S Y S T A T (Wilkinson, 1990) statistical software was employed to carry out the analyses. Microsoft excel software was used to plot some of the graphs. A l l the analyses were performed  23  on P C computers. Unless noted elsewhere, all statistical tests were deemed significant or highly significant when 0.01<p <0.05 or p < 0.01, respectively.  3.4.  Nomenclature  Nomenclatures follow Hale and Culberson (1970) for lichens, Stotler and Crandall-Stotler (1977) for liverworts, Anderson et al. (1990) for mosses, and Taylor and MacBryde (1977) for vascular plants.  24  Chapter 4 Results and Discussion  4.1. Characterization of the Ecosystems  4.1.1. The Structure of the Stands  The stands in which the study plots were set are old-growth or mature forests characterized by uneven age and uneven size of the trees. Only a few tree species dominated these stands (Figures 2-7). In coastal B . C . , these species were Douglas-fir (Pseudotsuga menziesii), western redcedar, and western hemlock in the C D F , western redcedar, western hemlock and amabilis fir {Abies amabilis) in the C W H , and western red cedar, western hemlock, mountain hemlock (Tsuga mertensiana), and amabilis fir in the M H . Scattered individuals of big-leaf maple (Acer macrophyllum) (in the C D F ) and yellow cedar (Chamaecyparis nootkatensis) (in the M H ) were also found. In the interior ecosystems, the dominant tree species were interior Douglas-fir (Pseudotsuga menziesii var. glauca), lodgepole pine (Pinus contorta), and trembling aspen (Populus tremuloides) in the IDF, western hemlock, western red cedar, and lodgepole pine in the I C H , and Engelmann spruce (Picea engelmannii) and subalpine fir (Abies lasiocarpd) in the E S S F . There were some snags in the stands, with the greatest number in the C W H , M H , and ESSF.  Tree density in terms o f number o f standing stems per unit area is shown in Table 5. Density o f trees is determined by the age o f the stands, tree size, and environmental conditions. A m o n g the six study areas, tree density is highest in the I C H and IDF and lowest in the C D F .  25  nfi^  tfi^  jO^  ©0«  10-  ftO.^  QO«  fO-^ ftO-  ^oA  A  A  A  DBH (cm)  AO-^  ^O.^ O . ^ 4 0 ^ 3  5 0 . ^ eo-  1  A  DBH (cm)  DBH (cm)  Figure 2, ecosystem  Size class distribution of the standing trees from the sampled stands in the  V>«*  »o  ^o-*  *o  »o  B  40^  0  ^0  ftO^  10  eo»^  »o  »o  ^o^ ftO«^ o»^  A  o°  -vOO  9  DBH (cm)  ^o^  •\0-*  so-*  40^  g©.\  eo-^  ^o-*  fO^  DBH (cm)  a  •  \  i  • O  4=  500 r 400 300 200 -  1  T  1  1  1  1  1  r Tsuga heterophylla 1  1  1  100 •"^V*  0  «\-»°  jO^  J ' 0  «  0 ,  «V*° »°*  gO«  A  DBH (cm)  200  DBH (cm)  Figure 3 . Size class distribution of the standing trees and snags from the sampled stands the C W H ecosystem  m  150  ~i  i  1  ~i  1  Abies  g 100 • o +  1  1  r  amabilis  50 1  -i  0 mfl.i  6  o«  A  e©A  1  1  10A  e<>'  1  1  A  •  90A'  i *  DBH (em)  •  • E ••  \  DBH (em)  150  ~i  i  i  i  i  i  1  1  r  Tsuga heterophylla  100 50  0  *  0  tVWI  nta  PSCT  pogq  1  1  KKKS  DBH (cm)  • 60 \ 50 I 40 • 30 • 20 o 10 + 0  "i  1  1  1  1  1  1  Tsuga  m m  1  1—  mertensiana  r&a  _J wrx^  DBH (cm) "i  r-  1  1  1  1  —1  r  DBH (cm)  Figure 4 . Size class distribution of the standing trees and snags from the sampled stands the M H ecosystem  o \  1  0  0  0  800  |  600  m  400  °  200 [•  Pseudotsuga menziesii var. glauca  0 ^°. ^0 A  \o«*  3  0  *0  ^o.^  6  0  6  o.^  -fO  0  _0 7  goA e°*  3  DBH (cm) 150  S  100  AO.^  3.0.^ oA  AO^  3  eO*  A  DBH (cm) 100  AO-*  ao«  A  5.0.^  AO«  go.  A  a  ©OA  DBH (cm)  400  L\*  A  A  A0-*  ^ O  .,30 „ ,A,O  6  A  3  oA  A  oA  o 6  ©o  oA  w 6  oA  *o  -to T  DBH (cm)  Figure 5. Size class distribution of the standing trees and snags from the sampled stands the IDF ecosystem  AO^  gO^  3 0 ^ 40«  $ 0 - eO*  A  A  DBH  (cm)  1000 Tsuga heterophylla  800 E  600 400  o  200 0  J88S3  K33K7g  *0.  «0^  *0-  iO-  AO^  ^0-  $0^  ffi^  I  I  A  A  A  A  annum  *0-  *0.^  50-  ftO^  A  A  T  DBH (cm)  250  ,  1  ,  ,  Snags  200 E  r  150 100  o +  50 0 \*  L  ^iQ 30 Ao AO^ ^0-^ 30^ AO« DBH  6 a  o  6  60-  a  o  _io  t  1  O  e°*  (cm)  Figure 6, Size class distribution of the standing trees and snags from the sampled stands the ICH ecosystem  DBH (cm)  DBH (cm)  Figure 7. Size class distribution of the standing trees and snags from the sampled stands the ESSF ecosystem  Table 5.  Density (stems/ha) of standing trees and snags in the six ecosystems. Plot  Ecosystem CDF  CWH  MH  2  3  Pseudotsuga menziesii Thuja plicata Tsuga heterophylla Acer macrophyllum  208 208 50 0  142 50 475 0  417 217 58 8  256 158 194 3  (177) (77) (199) ( 4)  Total living trees  466  667  700  611  (103)  Abies amabilis Taxus brevifolia Thuja plicata Tsuga heterophylla  138 42 108 625  367 0 0 691  8 0 192 883  186 14 100 733  (147) (20) (79) (109)  Total living trees  913  1058  1083  1033  (75)  Snags  108  267  383  253  (113)  Abies amabilis Chamaecyparis nootkatensis/ Thuja plicata* Tsuga heterophylla T. mertensiana  217  92  475  261  (160)  92 167 400  8 142 17  92 466 108  64 258 175  (40) (147) (163)  Total living trees  876  259  1141  758  (370)  25  33  541  200  (241)  Pseudotsuga menziesii var. glauca Populus tremuloides Pinus contorta  1800 388 338  2000 0 238  888 0 100  1563 129 242  (899) (183) (160)  Total living trees  Snags IDF  ICH  2526  2238  988  1934  (668)  Snags  413  175  688  425  (169)  Thuja plicata Tsuga heterophylla Pinus contorta  725 800 25  879 2600 0  463 1300 0  689 1567 8  (172) (759) (12)  1550  3479  1763  2264  (864)  Snags  138  613  100  284  (233)  Abies lasiocarpa Picea engelmannii  617 362  842 117  1133 84  882 188  (363) (151)  Total living trees  979  959  1217  1052  (117)  Snags  524  225  509  419  (215)  Total living trees  ESSF  Mean (s. d.)  1  Species  Standard deviations (s.d.) are in parenthesis. * Yellow cedar and western red cedar were recorded as one species - cedar.  32  This is because in the IDF, tree size was relatively small (Figure 5) and in the I C H , there was much western hemlock regeneration with D B H less than 10 c m (Figure 6). However, in the C D F , large-sized coastal Douglas-fir were present (Figure 2).  Basal area was determined by both the number and size of standing stems. The size class distributions of the standing trees (Figure 2 -7) showed that the basal areas were different from the density in each ecosystem with the greatest in the C W H and C D F and least in the IDF (Table 6). This was because large western redcedars were present in the C W H (Figure 3) and large coastal Douglas-firs in the C D F (Figure 2). In the IDF, however, more than 90% of the stems were quite small with D B H less than 30 cm (Figure 5). In the E S S F , the stems were relatively even in size and the D B H for most stems ranged from 20 cm to 40 c m which led to a medium stem density and basal area (Figure 7, Tables 5 and 6).  Canopy structure (% crown cover in this study) is another way to illustrate the structure of a stand, reflecting the age, the size of the trees, and environmental conditions. The canopy closure conditions are given in Table 7 and Figure 8 and Figure 9.  In the study stands, canopy crown closure was highest in the I C H with 87%, 89%, and 83% for the three plots, and lowest in the IDF with 46%, 49%, and 43% for the three plots respectively (Table 7). The canopy covers were generally normally distributed in most ecosystems (Figure 9).  33  c Basal area (m /ha) of standing trees and snags in the six ecosystems. 2  Table 6.  Plot  Ecosystem CDF  CWH  Species  1  2  Pseudotsuga menziesii Thuja plicata Tsuga heterophylla Acer macrophyllum  63.26 17.71 3.75 0.00  85.76 8.68 6.06 0.00  46.93 9.05 4.77 0.06  65.32 11.81 48.63 0.02  (15.92) (4.18) (0.95) (0.03)  Total living trees  84.72  100.5  60.81  125.78  (16.32)  Abies amabilis Thuja plicata Tsuga heterophylla  3.79 156.47 25.91  13.42 0.00 45.42  0.31 51.28 38.12  5.84 69.25 36.48  (5.54) (65.13) (8.05)  Total living trees  186.17  58.84  89.71  111.57  (54.32)  55.50  25.75  34.87  38.71  (12.45)  Abies amabilis 3.54 Chamaecyparis nootkatensis/ Thuja plicata* 32.47 Tsuga heterophylla 13.19 T. mertensiana 34.39  5.55  9.49  6.19  (2.47)  0.22 71.10 16.87  13.06 46.23 2.67  15.25 43.50 17.98  (13.26) (23.72) (12.97)  Total living trees  83.59  93.74  71.45  82.92  (9.11)  4.23  12.58  62.66  26.49  (25.80)  Pseudotsuga menziesii var. glauca Populus tremuloides Pinus contorta  15.29 0.27 17.24  18.60 0.00 6.90  30.25 0.11 0.00  21.38 0.13 8.05  (6.42) (0.11) (7.09)  Total living trees  32.80  25.50  30.36  29.56  (3.03)  8.18  3.58  4.28  5.35  (2.02)  Thuja plicata Tsuga heterophylla Pinus contorta  3.90 38.39 7.67  5.91 50.70 0.00  2.59 56.70 0.00  4.13 48.60 2.56  (1.36) (7.62) (3.62)  Total living trees  49.96  56.61  59.29  55.29  (3.92)  2.03  3.19  1.68  2.30  (0.65)  26.26 16.82  36.89 6.48  35.95 5.28  33.03 9.53  (4.80) (5.18)  Total living trees  43.08  43.37  41.23  42.56  (0,95)  Snags  20.75  9.00  12.07  13.94  (4.98)  Snags MH  Snags IDF  Snags ICH  Snags ESSF  Abies lasiocarpa Picea engelmannii  3  Mean  (s. d.)  Standard deviations (s.d.) are in parentheses. * Yellow cedar and western red cedar were recorded as one species - cedar.  34  Table 7.  Canopy closure (% cover) from the six study areas. Plot  1  Ecosystem Mean  71 73 75 46 87 60  CDF CWH MH  IDF ICH ESSF  Mean  S. D.  61 69 70 49 89 52  (9) (12) (9) (16) (6) (13)  S. D.  Mean  S. D.  (10) (11) (8) (21) (6) (12)  74 *  (9)  80 43 83 51  (7) (23) (8) (7)  Not available. Standard deviations (S. D.) are in parentheses.  100  CD  i— Z3 CO  p o  >> Q. O  c  CO  O  CDF  CWH  ESF  ICH  IDF  MH  Ecosystem  outside value  m edian inner fences outer fences  Figure 8. Canopy closure (canopy crown % cover) for the study stands in the six ecosystems showing median and spread/range of canopy cover. Symbols in the graph are illustrated underneath.  35  10  20  Figure 9.  30  40  50  Canopy closure (%)  60  70  80  90  Canopy closure (% cover) distributions for the study stands in the six  study ecosystems.  36  4.1.2. Coarse W o o d y Debris ( C W D )  The amount of C W D in terms of percentage cover (or percentage o f projected area) on the ground surface is shown in Table 8. In most cases, a percentage cover o f 10 -16% was estimated  Table 8 ^ £ T h e composition (Percentage cover) of the forest ground surface in the six study ecosystems. CWD Area/ Plot  Forest Floor  Root  78  0  0  0  2 3 Ave  82 78 79  0 0 0  1 1 1  2 10 4  -  CWH - 1 2 3 Ave  66 74 76 72  0 0 0 0  3 6 1 4  0 0 2 1  _  MH- 1 2 3 Ave  87 90 91 89  0 0 1 0  1 0 0 0  IDF - 1 2 3 Ave  90 94 88  0 0 0  91  CDF - 1  Rock  Mineral Soil  DI *  -  D2  D3  _  _  -  -  Total 22 15 12 16  -  -  -  -  -  31 20 21 24  0 0 0 0  1 3 1 1  7 5 5 6  5 2 2 3  13 9 8 10  0 2 1  0 0 1  10 4 11  1  0  3 2 5 3  2 0 3  0  5 2 3 3  2  8 11  -  _  88  0  3 Ave  91 88 89  0 0 0  0 1 0 0  0 0 0 0  3 1 2 2  4 2 3 3  6 5 6 5  8 12 10  ESSF - 1 2 3 Ave  83 86 82 84  0 0 0 0  0 0 1 0  0 0 0 0  2 3 1 2  6 6 4 5  8 5 11 8  16 14 16 15  I C H -1 2  Not available.  37  with the highest (24%) in the C W H and lowest (8%) in the IDF. Compared to similar forests elsewhere, the percentage cover o f the C W D from the C W H ecosystem is almost the same as those from Pseudotsuga-Tsuga stands in Oregon and Washington, U S A (Harmon et al. 1986). However, in the C D F ecosystem o f this study (also dominated by Pseudotsuga and Tsuga), an average o f 16% was obtained. This number was much lower than numbers from Oregon and Washington. In the E S S F ecosystem, C W D covered 15% o f the ground surface. This is fairly high compared to other studies on Picea-Abies stands in Oregon and Washington where  9. Diameters (cm) of the CWD (>15 cm in diameter) sampled for vegetation plots in the six study ecosystems.  Table  D2  D3  Mean (s.d.)  Mean (s.d.)  DI Ecosystem/ Plot  Mean (s.d.) (n=10)  (n=10)  (n= 10)  CDF  -1 2 3  34 33 28  (21) (8) (ID  31 35 32  (10) (6) (9)  25 32 35  (5) (14) (7)  CWH  -1 2 3  55 43 43  (26) (16) (16)  59 32 41  (36) (5) (13)  38 49 44  (12) (8) (13)  M H  -1 2 3  36 40 37  (14) (13) (16)  39 41 36  (10) (14) (8)  45 49 41  (13) (15) (6)  IDF  -1 2 3  25 34 28  (12) (14) (11)  30 42 25  (10) (19) (11)  38 36 33  (10) (10) (15)  ICH  -1 2 3  30 30 34  (7) (8) (9)  30 34 31  (8) (7) (15)  36 38 34  (8) (ID (7)  ESSF  -1 2 3  27 36 30  (5) (13) (7)  24 28 33  (6) (5) (8)  29 43 35  (6) (11) (6)  38  only about 6% of C W D projected area was estimated (Harmon et al. 1986).  The sizes (in diameter) of the sampled logs were calculated and a mean value and standard deviation for each decay category/class in each plot is given in Table 9. Relatively large logs were encountered in the C W H and M H ecosystems with mean diameters of 45 cm and 40 cm, respectively. In the other four ecosystems, the mean diameters o f sampled logs were quite similar, ranging from 32 to 33 cm.  4.2. Understory Vegetation  4.2.1. Floristic Observations  In total, 245 understory plant species (including tree seedlings) were found in this study including 8 species o f tree seedlings, 30 shrubs, 58 herbs & grasses, 8 ferns, 54 mosses, 28 liverworts, and 59 lichens. Highest species richness was found in the IDF where 124 species were recorded, which accounts for 50% of the total number of species found in all six study areas. Next came the E S S F where 82 species were recorded. The numbers o f plant species found in the other four ecosystems were similar ranging from 56 to 70 (Table 10). Table 10.  Number of taxa/species in plant type groups found in the six study ecosystems.  Plant type Tree seedlings Shrubs Herbs & grasses Ferns Mosses Liverworts Lichens Total  CDF  CWH  MH  IDF  ICH  ESSF  3 7 8  4 12 14 5 19 12 6 70  4 5 18 3 20 15 11 66  1 15 35 1 28 8 36 124  2 7 8 3 14 16 12 62  2 6 14 2 29 12 17 82  16 5 17 56  Total 8 30 58 8 54 28 59 245  39  The richness of plant species in the IDF ecosystem is probably a response to two major factors - open canopies and a relatively dry environment. In the three IDF plots, the canopy closure was only 46%, 43%, and 49% (Table 7). These open canopies provided enough light for understory species, especially for herbs and grasses (35 species of this kind were found, accounting for more than half of the total species in this group). The IDF ecosystem is located in an area with a relatively dry climate (with only 747 mm annual precipitation) (Table 1). The dry forested environment plus enough light availability is ideal for lichen populations (36 species, accounting for 63% of the total lichen species). A similar result was obtained by Johnson (1981) in the Northwest Territories, Canada, where lichens were most abundant in patches with more light, higher temperatures and lower air humidity.  Many lichen species were also found in the CDF and ESSF (each with 17 species). It is known that the CDF is also a relatively dry ecosystem (Pojar and Meidinger 1991) with a mean annual precipitation of 955 mm where some lichen populations have surely been favored. The high number of lichen species found in the ESSF is consistent with other studies of this ecosystem (Goward 1994).  A prominent component of the understory vegetation in all the study areas was the bryophytes. Both the number of taxa (82 species) and the abundance (which will be discussed later) showed their prominence. Since this was not a comprehensive floristic study and the study plots were located in quite small, relatively uniform stands, the bryoflora encountered was undoubtedly incomplete for each ecosystem. However, there were still considerable numbers of species which were not listed in previous bryoflora studies (Krajina 1959; Schofield 1988), especially in the M H (more than 20), IDF (18), ICH (more than 10, most of which were  40  liverworts) and ESSF (more than 20). Thus, further bryoflora assessments are necessary to complete the floristic and vegetation classifications for B C , especially in the interior regions.  Although widely distributed, it was seldom that a bryophyte species was found in 5 or all of the 6 study ecosystems. This wide distribution pattern applied only to a few taxa, e.g. Blepharostoma trichophyllum, Cephalozia bicuspidata, Dicranum fuscescens, Mnium spinulosum, and Plagiothecium laetum. Most species were found in 4 or fewer ecosystems. Some species occurred in both the coast and the interior ecosystems, e.g. Barbilophozia lycopodioides, Lepidozia reptans, Lophocolea heterophylla, Lophozia ventricosa, Ptilidium californicum, Hylocomium spendens, Brachythecium starkei, Hypnum circinale, Rhytidiadelphus triquetrus. According to the available data, however, some species showed more limited ranges and were restricted either to the coast or to the interior. Examples of the former are Frullania californica, Plagiochila porelloides, Scapania bolanderi, Plagiothecium undulatum, Rhizomnium glabrescens, Sphagnum girgensohnii; whereas examples of the latter are Dicranum tauricum, Ptilium crista-castrensis, Lescuraea saxicola, Pohlia nutans, and Timmia austriaca.  It is interesting to note that the floristic similarities between the ICH and the coastal ecosystems are highly significant. Many bryophyte species present in the coast were also present in the ICH (e.g. Lepidozia reptans, Lophocolea heterophylla, and Hypnum circinale). It is also interesting that many "interior species" extended their range to the M H ecosystem, e.g. Lophozia ventricosa, Brachythecium leibergii, Pleurozium schreberi, Rhizomnium nudum, and Rhytidiopsis robusta. With regard to vertical distribution, some species appeared only at high  elevations, examples being Rhytidiopsis robusta, Rhizomnium nudum, Buxbaumia piperi, and Dicranum pallidisetum.  In each ecosystem, only a few taxa dominated the understory vegetation, e.g. Eurhynchium oreganum and Hylocomium splendens in the CDF, Plagiothecium undulatum, Hypnum  circinale, and Rhytidiadelphus loreus in the CWH, etc. A list of the most abundant species in different ecosystems is given in Table 11. In addition, a species list for each of the six study areas is given in Appendix I and another species list for all the study areas is in Appendix II.  4.2.2. Plant Types in Relation to Different Rooting Substrata  Of the 245 species, 169 species were found on decaying logs (89 on DI, 110 on D2,120 on D3, respectively) and 190 species were found on the forest floor (Appendices I and II). Based on the data available, there were slightly more species (131) confined either to CWD (56 species) or to forestfloor(75 species) than those (114) which grew on both substrata. In general, vascular plants were forest floor (terricolous) species but non-vascular plants were more richly represented by wood-inhabiting (lignicolous) species. The data showed that all species confined to CWD were non-vascular plants. In contrast, the species confined to forest floor were mainly vascular plants accounting for 77% of the total species restricted to it. When species were grouped into plant type groups (basically taxonomic groups in most cases), relationships between a particular plant type and their rooting substrata could be examined. These relationships can be shown by both the number of species and the abundance  42  Table 11. Mean abundance (percentage cover) of the most abundant species on different substrata in the six srudv ecosystems.  Ecos.  Species  Plant Type  DI  Substratum D2 D3  FF  Total* cover  CDF  Gaultheria shallon Linnaea borealis Hylocomium splendens Rhytidiadelphus triquetrus Eurhynchium oreganum Isothecium myosuroides  SH SH M M M M  1.2 0.0 0.0 0.0 0.2 2.1  11.5 0.0 1.6 0.1 16.8 4.8  18.0 0.4 21.4 0.0 36.3 3.6  24.4 2.82 28.7 2.4 26.6 0.0  20.9 2.3 23.9 1.9 29.5 1.7  CWH  Tsuga heterophylla Blechnum spicant Rhytidiadelphus loreus Hypnum circinale Rhizomnium glabrescens Plagiothecium undulatum Scapania bolanderi  S F M M M M LW  1.7 0.0 0.8 17.7 2.6 2.1 13.2  8.7 0.0 15.6 18.7 2.8 6.6 12.1  12.7 2.1 12.4 3.8 6.6 12.7 11.6  4.1 10.3 7.0 0.2 2.9 12.9 1.1  4.8 7.6 7.3 3.4 3.1 11.0 3.7  MH  Abies amabilis Vaccinium membranaceum Vaccinium ovalifolium Hypnum circinale Rhytidiopsis robusta  S SH SH M M  0.0 0.0 0.0 5.4 0.0  0.1 0.0 0.1 23.4 9.7  1.8 0.4 2.8 25.6 13.6  4.4 6.8 17.8 2.3 19.8  4.0 6.1 15.9 4.3 18.6  IDF  Linnaea borealis Arnica cordifolia Calamagrostis sp. Brachythecium reflexum Pleurozium schreberi Parmeliopsis hyperopta  SH H H M M L  0.1 0.0 0.0 0.0 0.5 4.0  0.8 0.0 0.0 0.0 1.1 9.1  3.2 0.0 0.1 0.0 6.1 12.1  5.7 7.7 6.8 3.2 14.5 0.7  5.3 7.0 6.2 2.9 13.4 1.3  ICH  Rubus pedatus Valeriana sitchensis Rhytidiopsis robusta Hylocomium splendens Rhytidiopsis robusta Pleurozium schreberi Barbilophozia lycopodioides  SH H M M M M LW  0.0 0.0 0.1 0.1 0.1 0.2 0.0  0.6 0.0 1.3 6.3 0.4 6.7 0.2  5.5 0.0 1.6 16.3 2.7 15.3 1.9  6.7 7.5 4.8 28.4 12.2 27.2 6.5  6.1 6.3 4.2 25.9 11.0 25.2 5.6  ESSF  Rhododendron albiflorum Vaccinium membranaceum Gymnocarpium dryopteris Dicranum fuscescens Rhizomnium nudum Lophozia guttulata  SH SH F M M LW  0.0 0.0 0.0 3.0 0.0 2.7  0.0 0.0 0.1 24.9 0.0 18.2  0.3 2.3 0.1 52.6 0.1 6.6  24.7 11.5 14.5 2.5 14.3 1.5  20.8 9.8 12.2 7.6 11.8 7.5  * Total cover - estimated by weighting substratum % cover by the proportion of ground surface occupied by the substrata.  43  of a particular plant type on different rooting substrata.  It is evident that C W D is particularly important to lichens. A m o n g the 59 species found in this study, 56 species (accounting for 95% of the total species of this type) were found on C W D of various decay stages, among which 40 were confined to it (accounting for 71% o f the total species restricted to C W D (Appendix III)). Moreover, more lichen species were found on D I than on any other substratum in the C D F (13 out o f 17*), I C H (4 out of 6*), M H (10 out of 11*), and I C H (10 out o f 12*). In the IDF and E S S F , lichens were abundant on both D I and D2 C W D . This result further indicates the importance of fresh or relatively less decayed logs to lichens, suggesting their dominant role in early stages of log succession (McCullough 1948; Muhle and LeBlance 1975; Soderstrom 1988a).  Liverworts also were strongly associated with C W D . O f the 28 species of this type that were encountered in this study, 27 could be found on C W D . Though 21 species were present on the forest floor, the abundance on it was much lower than on the C W D (Table 13). In this investigation, most liverwort species were found on D2 (20) or D3 (25). The most common ones were spp.,  Scapania bolanderi, Lepidozia reptans, Blepharostoma trichophyllum, Lophocolea  Lophozia spp., Cephalozia spp., and Ptilidium spp. This result is very similar to those of  other studies, e.g. Hytteborn et al. (1987) and Soderstrom (1988a, 1989;) in Europe and, Lesica et al. (1991) in the U . S . A . It was found that liverworts were most abundant in the C W H , M H , and E S S F ecosystems and least abundant in the IDF (Table 13). One of the differences between the former three ecosystems and the latter one is the moisture conditions. A s discussed before, it  * Total species of this type  44  Table 12. ecosystems.  Number of taxa in plant type groups found on different substrata in the six study  CWD Ecos.  Plant type  DI  CDF  Seedlings Shrubs Herbs & Grasses Ferns Mosses Liverworts Lichens Total  1 1 1 0 8 3 13 27  CWH  Seedlings Shrubs Herbs & Grasses Ferns Mosses Liverworts Lichens Total  MH  IDF  ICH  D2  D3  1 4 0 0 9 3 8  2 5 T 0 14 5 16 43  2 5 7 0 7 0 1  3 7 8 0 16 5 17  25  2 4 0 0 10 5 3 24  22  56  2 2 2 1 11 9 4 31  4 2 4 1 9 5 1 26  2 7 6 3 12 9 3 42  4 8 9 4 16 12 5 58  4 12 14 5 14 8 2 59  4 12 14 5 17 12 6 70  Seedlings Shrubs Herbs & Grasses Ferns Mosses Liverworts Lichens  3 0 0 0 5 5 10  4 2 1 1 15 10 2  4 4 5 2 20 14 11  4 5 8 3 11 8 0  Total  23  35  4 4 5 1 13 14 3 44  60  39  4 5 8 3 20 15 11 66  Seedlings Shrubs Herbs & Grasses Ferns Mosses Liverworts Lichens Total  0 1 0 0 5 1 11 18  1 2 0 0 7 0 23 33  0 5 3 0 12 3 16 39  1 5 3 0 13 4 34 60  1 15 35 1 25 5 17 99  1 15 35 1 28 8 36 124  Seedlings Shrubs Herbs & Grasses Ferns Mosses Liverworts Lichens Total  1 0 0 0 9 2 10 22  1 0 0 0 10 10 10 31  2 1 3 0 12 15 6 39  2 1 3 0 14 16 11 47  2 7 8 3 8 7 1 36  2 7 8 3 14 16 12 62  Total C W D  FF  Total  45  Table 12.  (Continued) CWD Total C W D  FF  Total  Ecos.  Plant type  DI  D2  D3  ESSF  Seedlings Shrubs Herbs & Grasses Ferns Mosses Liverworts Lichens Total  1 0 0 0 16 6 9 32  •2 1 3 1 13 7 13 40  2 4 6 2 18 11 12 55  2 4 6 2 22 11 17 64  2 6 14 2 24 9 2 59  2 6 14 2 29 12 17 82  Total  Seedlings Shrubs Herbs & Grasses Ferns Mosses Liverworts Lichens Total  4 4 2 0 30 16 33 89  8 8 6 2 27 20 40 110  6 14 12 6 31 25 26 120  8 18 14 6 40 27 56 169  8 30 58 8 46 21 19 190  8 30 58 8 54 28 59 245  was wetter in the C W H , M H , and E S S F ecosystems but drier in the IDF. It seems that moist forests with an abundance of well decayed C W D would be favorable to liverwort populations.  A m o n g all the plant types, mosses were most abundant in all the study ecosystems and seemed to exist on a wider range o f substrata. Mosses were found on all the three categories o f C W D (40 species) as well as on the forest floor (46 species). Though more moss species were found on forest floor in the C W H , IDF and E S S F (Table 12), the abundances were highest on D2 or D3 in all the six ecosystems (Table 13; Figures 10 and 11). It seems that C W D is also an important rooting substratum for mosses in B C ' s forests just as in other areas in Europe, Japan, and other north American temperate forests (Anderson et. al,  1991; Gustafsson and  Hallingback, 1988; Hallingback, 1992; Longton, 1992; Muhle and LeBlance, 1975; Nakamura, 1987; Rose, 1992).  46  Vascular plants, in contrast, occur most often on the forest floor and most species were found only on this substratum (48 out o f 58 species in total). Ferns, except Dryopteris expansa, were also more abundant on the forest floor. Herbs, grasses, and shrubs were almost confined to the forest floor substratum with only a few exceptions (e.g. some species o f Vaccinium, Clintonia).  Linnaea,  It may be concluded that vascular plants are predominantly forest floor species and  more compatible with this substratum than were non-vascular plants.  Table 13.  Mean abundance (% cover) of plant type groups occurring on different substrata in the six study ecosystems. Substratum  Ecos.  Plant type  CDF  Seedlings Shrubs Herbs & Grasses Fems Mosses Liverworts Lichens  0.0 1.2 0.0 0.0 10.3 0.3 4.5  Total  16.2 (2.3)  66.5  Seedlings Shrubs Herbs & Grasses Ferns Mosses Liverworts Lichens  Total  CWH  MH  Seedlings Shrubs Herbs and Grasses Fems Mosses Liverworts Lichens  Total  DI  D2  D3  FF  6.1 0.1  (0.8) (13.4) (0.0) (0.0) (19.8) (3.8) (0.1)  0.0 (0.0) 28.2 (25.2) 1.2 (1.7) 0.0 (0.0) 58.1 (16.8) 0.0 (0.0) 0.0 (0.0)  (3.2)  94.8  (27.8)  87.5 (10.1)  1.7 (1.9) 0.1 (0.2) 0.3 (0.5) 0.1 (0.1) 25.2 (10.4) 15.2 (10.7) 1-3 (2.0)  10.1 (6.1) 1.4 (1.2) 0.3 (0.3) 2.1 (3.6) 45.6 (19.7) 16.6 (8.6) 0.1 (0.1)  12.9 6.4 1.6 4.8 39.1 14.5 0.0  (3-1) (7.6) (1.8) (2.1) (19.2) (10.9) (0.0)  9.6 5.5 13.0 29.4 2.3 0.3  43.9  (1.7)  76.2 (197)  79.4 (26.1)  67.5 (18.2)  2.2 0.0 0.0 0.0 8.1 3.4 3.6  (3.3) (0.0) (0.0)  4.6 0.2 0.0 0.0 44.8 9.9 0.2  (5.0) (0.1) (0.0) (0.0) (2.0) (9.8) (0.2)  10.9 5.3 4.2 0.1 46.0 15.5 0.8  (10.5) (3-3) (5.2) (0.2) (26.0) (5.0) (1.5)  6.2 (4.9) 28.2 (7.0) 12.6 (11.4) 0.3 (0.4) 25.1 (12.0) 2.2 (0-8) 0.0 (0.0)  59.8  (8.1)  82.8  (12.3)  74.6  (0.0) (2.0) (0.0) (0.0) (5.2) (0-3) (1.8)  (0.0) (2.1) (2.2) (2.9)  17.3 (3.8)  0.0 11.8 0.0 0.0  (0.0) (8.1) (0.0) (0.0) 48.7 (11.8) 5.6 (1.7) 0.5 (0.3)  0.5 18.5 0.0 0.0  69.7  7.3  (6.3) (4.9) (0.6) (3.4) (8.5) (1.7) (0.1)  (7.3)  47  Table 13.  (Continued) Substratum  Ecos.  Plant type Seedlings Shrubs Herbs & Grasses Ferns Mosses Liverworts Lichens Total  IDF  Seedlings Shrubs Herbs & Grasses Ferns Mosses Liverworts Lichens Total  ICH  ESSF  Seedlings Shrubs Herbs & Grasses Ferns Mosses Liverworts Lichens Total  DI  0.0 0.1 0.0 0.0 5.0 0.2 13.6  (0.0) (0.1) (0.0) (0.0) (6.6) (0.3) (5.0)  18.9 (5.9)  D2  D3  FF  0.0 (0.0) 1.2 (1.3) 0.0 (0.0) 0.0 (0.0) 12.8 (12.6) 0.0 (0.0) 20.7 (6.0)  0.0 (0.0) 3.9 (4.0) 0.3 (0.6) 0.0 (0.0) 33.8 (5.5) 0.3 (0.4) 25.2 (11.3)  1.0 17.4 25.1 0.3 22.8 0.7 3.5  34.7  63.5 (4.1)  70.8 (10.8)  (8.2)  (1.4) (4-3) (1.7) (0.4) (8.5) (1.1) (2.5)  (0.4) (0.0) (0.0) (0.0) (6.5) (0.8) (1.1)  0.5 (0.4) 0.0 (0.0) 0.0 (0.0) 0.0 (0.0) 72.0 (11.8) 6.0 (3.7) 3.7 (0.9)  4.3 0.5 0.6 0.0 87.4 3.1 2.2  (2.3) (0.8) (0.5) (0.0) (2.7) (1.0) (1.1)  5.8 7.0 3.8 0.3 70.3 2.8 0.7  (4.2) (0.9) (5.1) (0.2) (5.1) (2.6) (1.0)  18.4 (7.0)  82.2 (9.0)  98.0 (4.2)  90.8  (0.3)  (0.1) (0.0) (0.0) (0.0) (2.2) (1.8) (0.5)  0.8 0.6 0.4 0.1 33.5 22.1 6.4  (0.4) (1.0) (0.1) (0.2) (7.1) (3.0) (0.7)  2.9 (0.7) 9.4 (2.9) 1.8 (1.6) 0.4 (0.3) 80.2 (2.9) 13.4 (1.8) 3.3 (1.6)  0.1 (0.1) 48.1 (0-6) 19.2 (10.7) 14.9 (10.2) (1.2) 39.5 10.5 (9.8) 0.1 (0.8)  13.0 (2.9)  63.8  (5.3)  111.2 (1.9)  132.4 (10.8)  0.3 0.0 0.0 0.0 13.0 3.1 2.0  0.1 0.0 0.0 0.0 5.2 4.6 3.1  Standard deviation are in parentheses.  Tree seedlings, however, were more abundant on C W D (especially on well decayed C W D ) than on the forest floor in most ecosystems. In the C D F , all seedlings were found on C W D . In the C W H , M H , and E S S F , 77%, 74%, and 97% o f seedlings respectively were found on C W D . This result supports other studies which concluded that decaying logs were major sites for tree seedling regeneration (Harmon 1987; Harmon and Franklin, 1989; M c K e e et al. 1982). In the IDF, however, just a few seedlings were encountered and almost all o f them were found on the  48  Figure 10. Mean abundance (% cover) of different plant types in relation to different rooting substrata in each of the six ecosystems studied. DI - D 3 - wood decay classes; F F - forest floor; L - lichens; L W - liverworts; M - mosses; F - fems; H - herbs & grasses; S H - shrubs; S - tree seedlings.  49  Figure 11. Mean abundance (% cover) of different plant types in relation to different rooting substrata in all the study areas. DI - D3 - wood decay classes; FF - forest floor; M - mosses; LW - liverworts; L - lichens; F - ferns; H - herbs & grasses; S - tree seedlings; SH - shrubs.  50  forest floor instead o f on the C W D . It is known that moisture is an important factor for seedling germination. In the IDF the reason for the absence o f tree seedlings growing on C W D is most probably because it is too dry for seed germination or seedling survival. It appears that logs are good sites for tree seedling regeneration only in the moister ecosystems. In a relatively dry ecosystem, C W D is still important to plants such as lichens or some mosses, as in the IDF ecosystem in this study.  4.2.3.  Bryophyte Growth-forms and Their Distribution Patterns in Relation to Their  Rooting Substrata  Seven bryophyte growth-forms were found in this study and their mean abundances on different substratum categories are shown in Table 14 and Figure 12  (Buxbaumia piperi as a D -  Dendroid - was encountered once and is not included). A species list for all the bryophytes and their growth-forms is given in Appendix IV.  The most common growth-form was wefts  (W). Next came smooth mats (Ms) and short turfs (t). In general, mat-forms (Mr, M s , and Mth) and small turfs were much more abundant on C W D (especially D2 and D3) whereas wefts were more abundant on the forest floor. These results illustrated general trends o f bryophyte growthforms and their relation to their rooting substrata.  The abundance data showed that there were obvious relationships between growth-forms and their rooting substrata. For example, smooth mats (Ms) and thalloid mats were almost confined to C W D substrata with peak abundances usually on D2 (Figure 12, a, c, e, and f (Mth  51  Table 14. Mean abundance (% cover) of bryophyte growth-forms in relation to different substratum categories in the six study ecosystems. Growth-form Substratum Ecos. category  Mr Mean (s.d.)  Ms Mean (s.d.)  Mth Mean (s.d.)  CDF  DI D2 D3 FF  0.0 0.0 0.0 0.0  (0.0) (0.0) (0.0) (0.0)  9.0 (5.2) 25.1 (10.0) 7.8 (7.9) 0.0 (0.0)  0.1 0.9 0.3 0.0  (0.1) (1.1) (0.5) (0.0)  CWH  DI D2 D3 FF  0.2 0.0 0.1 0.0  (0.2) (0.0) (0.2) (0.0)  21.1 28.4 19.3 13.9  (1.3) (5.2) (5.2) (8.8)  1.5 1.8 0.3 0.0  MH  DI D2 D3 FF  3.0 3.5 4.5 1.7  (2.3) (3.4) (5.0) (0.7)  5.7 (2.3) 25.5 (12.1) 30.9 (14.9) 3.0 (3.1)  IDF  DI D2 D3 FF  2.7 6.1 5.5 0.0  (0.3) (5.0) (4.6) (0.0)  ICH  DI D2 D3 FF  3.2 3.7 1.2 0.1  (1.1) (5.1) (0.8) (0.8)  ESSF  DI D2 D3 FF  1.5 2.3 1.1 0.0  (1.0) (3.4) (1.8) (1.3)  MEAN DI D2 D3 FF  1.8 2.6 2.1 0.3  (1.3) (2.1) (1.9) (0.6)  t Mean (s.d.)  W Mean (s.d.)  (0.4) (0.6) (9.1) (0.0)  0.0 0.2 8.6 0.0  (0.6) (0.2) (9.1) (0.0)  0.7 (1.1) 18.7 (6.5) 59.1 (21.1) 58.1 (16.7)  (2.2) (2.8) (0.5) (0.0)  16.2 (10.3) 15.0 (10.0) 19.6 (8.7) 4.5 (3.8)  0.0 0.7 0.7 0.7  (0.1) (1.1) (1.6) (0.7)  0.9 (0.7) 16.1 (11.3) 13.3 (13.0) 12.9 (5.4)  0.2 3.9 1.4 0.1  (0.4) (5.3) (1.2) (0.0)  1.1 7.9 10.0 1.7  (0.6) (8.4) (1.6) (2.4)  1.5 2.0 0.0 0.0  (0.6) (3.5) (0.0) (0.0)  0.0 (0.0) 11.9 (10.8) 14.7 (12.7) 21.8 (16.3)  (0.0) (0.0) (0.1) (1.0)  0.0 0.0 0.2 0.0  (0.0) (0.0) (0.4) (0.0)  1.7 5.2 20.5 2.0  (2.9) (6.6) (5.3) (1.2)  0.0 0.0 0.3 1.5  (0.0) (0.0) (0.3) (0.8)  0.8 1.2 6.1 19.2  9.3 (6.0) 32.4 (5.3) 20.6 (12.2) 3.2 (2.8)  0.0 1.7 1.5 0.1  (0.0) (1.2) (0.8) (0.0)  3.3 26.7 32.2 1.1  (2.5) (7.9) (4.7) (1.4)  0.0 0.0 0.0 0.0  (0.0) (0.0) (0.0) (0.0)  0.3 (0.4) 13.4 (13.7) 35.1 (15.9) 68.7 (1.4)  (0.0) (0.3) (1.6) (6.5)  3.1 19.6 9.8 0.1  (1.4) (3.0) (1.6) (1.8)  3.7 (1.4) 25.8 (2.9) 55.0 (10.4) 0.3 (12.7)  0.0 0.0 0.0 0.0  (0.0) (0.0) (0.0) (0.0)  0.8 (0.7) 4.9 (3.5) 14.0 (10.6) 0.7 (1.6)  7.5 (7.1) 18.6 (13.3) 13.6 (9.5) 5.0 (4.9)  0.8 4.6 2.2 0.1  (1.1) (6.8) (3.0) (0.0)  4.4 (5.4) 15.0 (8.5) 24.3 (14.1) 1.6 (1.5)  0.0 0.1 0.2 0.4  (0.0) (0.2) (0.2) (0.6)  0.6 (0.3) 11.0 (6.1) 23.7 (15.9) 30.2 (24.6)  0.0 0.0 0.1 0.6  0.1 0.2 2.8 9.0  0.3 9.5 8.6 0.0  T Mean (s.d.)  (3.9) (5.0) (6.6) (7.2)  Mr - rough mats; Ms - smooth mats; Mth - thalloid mats; t - short turfs; T - tall turfs; and W - wefts Standard deviation (s.d.) are in parenthesis.  52  Figure 12. Mean abundance (% cover) of bryophyte growth-forms in relation to different rooting substrata in each of the six study ecosystems. DI - D3 - wood decay classes; F F forest floor. Mr - rough mats; Ms - smooth mats; Mth - thalloid mats; t - short turfs; T - tall turfs; W - wefts..  53  alone)) and short turfs were also almost confined to C W D substrata but were most abundant on D3 (Figure 12: b, c, d, and f). In contrast, wefts were predominantly forest floor species and their abundances on C W D generally increased as wood decay increased with the peak usually appearing on the forest floor (Figure 12, a, b, d, e).  The presence and abundance o f a particular growth-form on a particular substratum also reflected other abiotic and biotic factors in the ecosystem. For example, smooth mats were abundant on C W D in all the ecosystems but not in the IDF, possibly as a result o f its dry environment. Wefts were abundant on the forest floor in all the ecosystems (highest in the C D F and ICH) except E S S F where other forest floor plants, i.e.  Rhododendron and Vaccinium, were  dominant. It appeared that wefts were important components in the forest floor vegetation when vascular plants were less abundant. The bryophyte life-form-substrata relations further illustrated that the use of bryophyte life-forms is of potential value in understanding forest ecology as well as their habitats (Gimingham and Birse 1957; Barkman 1988; During 1992).  54  4.2.4.  Understory Vegetation Relationships among Different Substrata and among  Ecosystems  a. Principal Component Analysis  The results from principal component analysis ( P C A ) show that the first five axes explained 68% - 83%) o f the total variance (Table 15). The scores from each factor reflect the differences among the subplots in their vegetation composition and abundances in one  Table 15. Percent variance explained by the first five factors generated by Principal Component Analysis (PCA). Variables (plant species) in the P C A analyses were 56 in the C D F , 70 in the C W H , 67 in the M H , 124 in the IDF, 62 in the ICH, and 83 in the ESSF. Axes Ecosystem  CDF CWH MH IDF ICH ESSF  1  18.3 22.5 20.8 28.6 25.1 28.8  2  15.2 17.4 18.0 22.0 15.3 14.2  3  12.9 15.4 14.0 17.1 11.5 12.6  4  11.5 10.7 10.2 7.3 11.2 10.0  5  10.2 8.2 9.5 5.8 8.2 8.0  dimension. Consequently, vegetation on one subplot differs from that on other subplots in many dimensions. The first factor ( P C A 1) explains most o f the variance, and therefore it reveals the most important environmental factor (component) that determines the vegetation/species composition. In this study, the subplots were based on three decay classes of wood (DI, D 2 , and D3) and one forest floor substratum, which form a substratum gradient. Other environmental factors, such as moisture, temperature, and light intensity, were relatively uniform within the study plots in each ecosystem and did not form any clear gradient. 55  Box plots of the first factor scores against substratum category show that forest floor (FF) and C W D (DI, D 2 , and D3) were significantly different in their species composition in the IDF, C W H , I C H and E S S F ecosystems (Figure 13: b, c, d, and f). Some overlap occurred between C W D (particularly D3) and forest floor in the C D F and M H (Figure 13: a and e) because in the C D F (especially in plots 1 and 2), the most dominant species, e.g.  Eurhynchium oreganum,  Hylocomium splendens, and Gaultheria shallon on D3 had similar abundances as on the forest floor. In the M H , species on D3 seemed to be very diverse. Some were also found on D 2 , and some were present on F F . A s a result, overlap occurred among these three subplots. A m o n g the three C W D categories, differences also existed (especially in the three coastal ecosystems). However, the overlaps indicated that these differences were generally insignificant.  Similar analyses ( P C A ) were made based on plant type group data (i.e. tree seedlings, shrubs, herbs and grasses, etc.) for each ecosystem. The variances explained by the first five components are shown in Table 16.  Because species were grouped into plant type groups, the  number of variables was greatly reduced, and, as a consequence, the first two factors explained a higher proportion (from 65.3% to 74.2%) of the total variance.  Ordinations o f subplots (three subplots per substratum) along the first two axes o f P C A showed that the forest floor subplots were well separated from all the C W D subplots in this twodimensional ordination for almost all the ecosystems (Figure 14), four (the C W H , IDF, I C H , and E S S F ) by axis one ( P C A I) and two (the C D F and M H ) by axis two ( P C A II).  In the C D F , a tiny  overlap occurred between F F and D 3 . This suggests that some of the components in D3 and F F vegetation were similar in this ecosystem. With regard to the C W D subplots, D l s were  56  Figure 13. Notched box plots showing the distribution of substratum types along the first P C A axis of the species data in the six ecosystems. Boxes with non-overlapping notched segments indicate statistically significant differences (McGilletal, 1987).  3.0  r  ~i  CDF  A  1.9  0.8  < o  o  u  B  o  -0.3  -2.5  D  #  -1.5  L_  0.5  -0.5  o  A  _J  -2.5  <  A  1.5  2.5  2.5  PCA I 2.5  1.5  CWH  A  •  h  0.5  -0.5  1.5  *  A  •o <  ICH  A  •  -0.5  -  -1.5  h-  -1.5  O -1.5  -1.0  i  i  -0.5  0.0  0.5  i  i  1.0  1.5  -2.5  2.0  PCA I  Figure 14.  -  •  < O  •  -2.5  A  A  0.5  m  o  -  A  -1.5  ® O  ° °  -0.5  -  0.5  1.5  2.5  PCA I  Ordinations of subplots along the first two axes of P C A on the plant  type dita for each of the six ecosystems.  Symbols in the graph: o - DI; • - D2; A -  D3; * - F F .  58  Table 16. Percent variance explained by the first five factors generated by principal component analysis/PCA). Variables (plant types) in the P C A analyses were 6 in C D F and 7 in all other ecosystems. Axes Ecosystem  CDF CWH MH IDF ICH ESSF  1  38.9 39.9 34.9 49.2 44.9 47.1  2  29.9 25.4 31.4 20.0 18.4 27.1  3  4  5  14.4 17.0 15.3 15.2 16.4 15.2  10.1 • 8.7 10.9 10.7 10.6 7.7  4.4 6.7 4.5 4.1 6.1 2.3  generally more uniform in their vegetation composition (closer grouping of plots) than were the D2s and D3s. This is particularly true in the M H , IDF, I C H , and E S S F . These patterns reflect the vegetation relationships among logs at different decay stages and suggest that logs in more advanced stages o f decay support more diverse vegetation composition.  In order to examine understory vegetation relationships among the different ecosystems (inter-ecosystem) another analysis ( P C A ) was made based on the combined species data from all the six ecosystems. Ordinations of forest floor subplots and C W D subplots along the first two axes o f P C A for the six study ecosystems are shown in Figures 15 and 16. It seemed that the P C A axis I represents the moisture gradient whereas P C A axis II represents elevation gradient to some extent. It was illustrated that the forest floor vegetation (Figure 15) differed more from each other than did C W D vegetation (Figure 16) among ecosystems. T w o possible reasons may explain this: species composition and habitat differences. It is known that non-vascular plants have a wider distribution range than vascular plants. C W D vegetation was dominated by nonvascular plants whereas forest floor vegetation was dominated by vascular plants or by both  59  2  0  1 h < O Q_  -2  -3  -4  -5 -6  Figure 15.  - 5  Ordinations of forest floor subplots along the first two axes of P C A  on species data in the six study ecosystems.  O - C D F , • - C W H , A - M H , 6 - IDF,  V . ICH,o- ESSF.  60  •  •  •  o o o o  'A  o  0  o  <  •  A  V  o <0  O Q_  o  o  -2 0 . 2 5  - 0 . 2 5  - 0 . 7 5  0 . 7 5  P C A  Figure 16.  Ordinations of C W D subplots along the first two axes of P C A on  species data in the six study ecosystems. O - C D F , • - C W H , A - M H , o - IDF, V - I C H , o - ESSF.  61  plants or by both vasculare and non-vasculars. Secondly, forest floor vegetation is more likely to be affected by the regional climate, forest humus form, and soil type, and these factors are usually different in different ecosystems. However, C W D substrata are likely to be less influenced by soil and climate, and therefore likely to be similar in different ecosystems. The figures also illustrated that the three coastal ecosystems (the C D F , C W H , and M H ) and one interior ecosystem, the I C H , were more or less related to each other but the other two interior ones, the IDF and E S S F , were somewhat distinct. T o some extent, this result corresponds to the differences in climatic factors and forest vegetation among these ecosystems (Klinka et al. 1991; Pojarera/. 1987).  62  b. Pearson correlations  Pearson correlations of species abundance among different substrata for all the six ecosystems showed that, within an ecosystem, C W D substrata (DI, D 2 , and D3) were highly correlated (usually P < 0.01), especially the neighbor pairs (i.e. D I and D 2 , D2 and D 3 , Table 17). In general, low correlations existed between C W D and F F , but that of D3 and F F were usually high except in the E S S F .  A m o n g the ecosystems, the C W D subplots in the three coastal ecosystems and in the I C H were generally highly correlated with each other, but the IDF and E S S F subplots were not.  In  general, forest floor subplots were not as highly correlated as were C W D subplots. The forest floor vegetation was somewhat related to the elevations of the ecosystems since correlations were high only between M H and E S S F , C D F and I C H , C D F and C W H , I C H and IDF, I C H and CWH.  This result conforms with the P C A ordinations shown in Figures 15 and 16. The  relatively low correlation in forest floor vegetation composition among different ecosystems further suggests that forest floor vegetation is more diverse than C W D vegetation at an interecosystem level.  c. Cluster Analysis  The dendrogram (Figure 17) produced by cluster analysis (based on the 30 most abundant species) shows that subplots are roughly grouped by ecosystems. However, all the D I subplots (except those for the IDF) exhibited close relationships and shortest distances were found among  63  Table 17.  Pearson correlation coefficients of species composition and the abundance among 24  category plots for all the six ecosystems. 245 species were used in the analysis. 1  CDFDl  CDFD2 CDFD3  CDFFF  CWHD1 CWHD2 CWHD3 CWHFF  MHD1  MHD2 MHD3  MHFF  CDFDl  1.00  CDFD2  0.72** . 1.00  CDFD3  0.14*  0.68**  CDFFF  0.08  0.55** 0.94**  1.00  CWHD1  0.72**  0.63** 0.09  -0.01  1.00  CWHD2  0.49** 0.08  -0.01  CWHD3 CWHFF  0.56** 0.12 -0.02  0.16* 0.01  0.00 0.13  0.81** 0.49** 0.12  1.00 0.80* 0.43*  1.00 0.70**  1.00  MHD1  0.73**  0.53** 0.02  -0.02  0.63**  0.50*  0.11  -0.02  1.00  MHD2  0.78**  0.63*  0.21*  0.04  0.73**  -0.02 -0.02  0.72**  MHD3 MHFF  0.60** 0.04 0.58** 0.04  0.76**  0.66*  0.30**  0.06  0.80** 1.00 0.72** 0.95** 1.00  0.05  0.03  -0.02  -0.02  0.05  0.07  0.07  0.08  0.05  0.32** 0.45**  1.00  IDFD1 IDFD2  -0.02 -0.02  -0.02 -0.02  -0.02 -0.02  -0.02 -0.02  -0.02 -0.02  -0.02  0.01  0.00  -0.02  -0.03  -0.03  -0.01 -0.01  -0.03 -0.03 -0.03  -0.03  -0.03  -0.01 -0.02 -0.03 -0.04  -0.02 -0.02  IDFFF  -0.03 -0.03 -0.03 -0.04  -0.03 -0.04  IDFD3  -0.03 -0.03 -0.03 -0.04  ICHD1 ICHD2  0.80** 0.68**  0.65** 0.06 0.62** 0.15*  0.71** 0.61**  0.57** 0.48**  0.14* 0.12  -0.01 0.02  ICHD3 ICHFF  0.40** 0.01  0.43** 0.25** 0.04 0.31**  -0.01 0.08 0.22 0.42**  0.37** 0.02  0.31** 0.03  0.13* 0.04  0.08 0.15  0.83** 0.82** 0.76** 0.06 0.64** 0.69** 0.64** 0.05 0.36** 0.43** 0.41** 0.06 0.01 0.13* 0.15* 0.19*  ESSFD1  0.00  0.08  0.04  -0.02  -0.01  -0.03  -0.01  -0.04  0.10  0.03  0.02  -0.01  ESSFD2  0.00  0.11  0.06  -0.02  0.00  -0.02  0.01  -0.03  0.02  0.01  0.00  0.01  ESSFD3  0.00  0.13*  0.07  -0.02  0.00  -0.02  0.02  -0.02  0.00  0.04  -0.03  -0.02  -0.02  -0.03  -0.03  -0.04  -0.02  -0.01  -0.01 -0.04  0.01  ESSFF  0.02  0.05  0.25**  ESSFD3  ESSFFF  Table 17.  1.00  0.06 0.10  IDFD2  IDFD3  IDFFF  ICHD1  ICHD2 ICHD3 ICHFF  1DFD1  1.00  IDFD2  0.84** 1.00  IDFD3  0.66** 0.85** 1.00  IDFFF  0.04  0.08  0.27** 1.00  ICHD1  0.13*  0.09  0.14*  0.00  1.00  ICHD2  0.00  0.19*  0.11  0.89** 1.00 0.62** 0.89** 1.00 0.04 0.24** 0.54** 1.00  1CHD3  0.01  0.01 0.02  ICHFF  0.02  0.04  0.18*  ESSFD1  0.18*  0.21*  0.38** 0.04  -0.01  0.00  0.21*  0.27** 0.26** 0.48** 0.02  ESSFD3  -0.01  0.01  0.30** 0.16*  ESSFFF  -0.03  -0.03  0.01  1  -0.03 -0.03  -0.03 -0.03 -0.04  0.00  (continued) IDFD1  ESSFD2  -0.04 -0.04  -0.03  0.08  0.24** 0.41** 0.49** 0.04 0.23** 0.48** 0.57** 0.03 0.26** 0.59** 0.74** 0.14* 0.09 0.03 0.06 -0.01  ESSFD1  ESSFD2  1.00 0.92**  1.00  0.74**  0.85**  1.00  0.05  0.07  0.12  1.00  Combined and averaged data from three subplots on the same substratum in each ecosystem  * 0.01 <P<0.05; **P<0.01  64  TREE DIAGRAM  EUCLIDEAN DISTANCES  0.000 IDFD3  5.000  +I  IDFD2 IDFD1 CDFF CDFD3 +—  CDFD2  +I  MHF MH03 MHD2 CWHD1  + I  CDFD1 ESSFD1 MHD1  +  I +I  ICHD1 ICHD2  +I  ICHD3  ICHF IDFF  +-  ESSFD2 ESSFD3 CWHD2 CWHD3 CWHF ESSFF  Figure 17.  I +I  +-  Dendrogram produced by cluster analysis based on the 30 most  abundant species showing vegetation relationships among different substrata and among different ecosystems. IDFD3 represents decay class 3 in the IDF.  65  these subplots. Forest floor subplots of the E S S F showed little relationship to any other subplots. Within a given ecosystem, C W D subplots were generally more closely related to each other than to the forest floor subplots.  4.2.5. Species Richness in Relation to L o g Size  The mean number of species per quadrat in each decay category was calculated for different log sizes and the result is shown in Table 18. A logarithmic model was developed to examine the relationships between the number o f species and log size. The model is expressed as:  [2]  Y = B + B,log(X) 0  where 7 is the number o f species, Xis  the diameter of logs, Bo and B] are estimated constants.  It was interesting to find that the number o f species (per unit area) was significantly related to log size for all the three decay categories, i.e. the number o f species increased with an increase in log diameter (Figures 18,19, and 20). It is possible that large logs are more efficient than smaller logs in retaining seeds of vascular plants and spores or other reproductive fragments of non-vascular plants. A n d it is probably true that large logs are more efficient in retaining forest litterfall, which may protect the seeds on logs from being eaten by birds or other animals and may be used by these plants for nutrients when they have decayed. Therefore, more species were found on large logs than on small logs.  The species - log size relationship was most significant for D3 and then for D 2 , and finally D I (Table 19). In log succession, the colonization period takes place on relatively fresh logs. This is an unstable period and clumps of species may occupy part of the log and leave other  66  in CN  CN CN  CN  CN  00  00  vo  ^  co  ~ H  S2  1-2  JO  z ° T3  CO  Q  C  CN CN  S3  o  oo o  CN  ©  co co ©  m ©  O  co «t  o  © in ©  in  ©  vo 00 ©  CN CN CN  CN  00 "ca  5  3  VO en  cr <*>  co  VO CO CO  CO vq •<*  in  in  o o  ON  CO  o CN 00  vo 00  o © ON  VO vd  o © oo  CS <D  •3 .S -o 0> T3  3  "o X u  (D Ui CJ  .2 &  12 3  ? CN CN  «M  z ° 03  1 ^ _CS  4)  m  o  in in  CN  ON  o  CO  -3-  in  ON  ON  ON  o  m  ©  in  CN o vd  vo  vo  co  O  O  ^-1 oo  O 00  o CN 00  ©  00  CO  OO ON  o  Eo  CN  >n r-^ r-  § -a  .—i  m  0O  ^  CM  Q  CO  oo  CN  ON  in  ON  in  vd  CO  VO vd  vo  o m  *  o © 00  T3  cn  00 O  cS  u  — I  O  CN CO  3  «4H  CN  o  CN  z °  CN CO  VO CN  r-  CN  CO CN  CO  vo  ON  CN  CO  CN  CN  r(N  o  co cS  fe  18  CN  o  vo in  o  ©  ON  r-  ©  ©  CN in ©  ON  VO ©  CN  p  CO 00 ©  VO  VO  CN  <-< f—1  CN (N  VO '-I  _CS <U  >n <N cS  CN  3  cr  m CO  ON  00  -Cj-  CO  CO vd  00  CO CN vd  o m  vd  o p vd  o in  CN  CO CO ON  O in •*)•'  o ©  CN <N  in  N  CS  o CN  -3 CO  N  *  60 cd  m —<  o  CN  in CN  o CO  m co  o  m  ©  in m  ©  VO  in vo  ©  60  o  67  Q  I  •10  I  I  I  I  I  I  I  20  30  40  50  60  70  80  Log diameter (cm)  Figure 18. Mean species number per quadrat as a function of C W D size class found on DI for all the study ecosystems. The best fit logarithmic regression line is also shown. Refer to Table 19 for equations.  68  Figure 19. Mean species number per quadrat as a function of CWD size classes found on D2 for all the study ecosystems. The bestfitlogarithmic regression line is also shown. Refer to Table 19 for equations.  10  20  30  40  50  60  70  80  Log- diameter (cm)  Figure 20. Mean species number per quadrat as a function of CWD size classes found on D3 for all the study ecosystems. The bestfitlogarithmic regression line is also shown. Refer to Table 19 for equations.  parts uncolonized. It is hypothesized that, as succession proceeds, further colonization takes place, meanwhile competition becomes severe. B y the time a log becomes well decayed, a relatively stable community has formed. 1 his community is relatively stable in species composition, and the number of species is more or less determined by log size, which results in a stronger relationship between species number and log size, than for less well decayed logs.  The number of species initially increases more rapidly with log size, then slows down and finally levels off (Figures 18, 19, and 20). T o explain this phenomenon it is necessary to consider the quadrat size, especially the width (maximum of 30 cm). The sample area contains just a portion o f the log vegetation and a finite quadrat size can include only a certain number o f species, it may be hypothesized that there is a point at which the maximum number o f species  T a b l e 19.  Regression equation parameters for predicting species number per quadrat in  relation to log size for three C W D decay categories.  Log decay class  B\  B2  r  DI  -4.346  2.899  0.362  2.020  13  D2  -3.872  2.930  0.556  1.364  12  D3  -6.987  3.573  0.797  0.947  13  2  s.e.  N  Note: r = corrected r-squared; s.e. = standard error; N = number of case 2  (per unit area) has been gained. After reaching this point, this number cannot increase anymore regardless of how large the log gets and how many species there are on the whole log. That is why the number o f species (in the sample area) levels off when the logs reached a certain size.  71  4.2.6. Species Richness in Relation to C a n o p y C l o s u r e Conditions  Correlation between species richness (species number per unit area in this context) and canopy closure conditions (% cover o f canopy crown) varies from ecosystem to ecosystem. Since the canopy closure - species richness correlation was nonlinear, a quadratic regression model which gave the best fit regression equations was used to develop equations relating species number to canopy closure. The model used was  Y = A+BX+CX  [3]  2  Where Y is the number o f species, Xis  canopy closure (crown % cover), and A, B, and C are  estimated coefficients. The equation was used to test both C W D quadrats and forest floor (FF) quadrats for each ecosystem. The results are listed in Table 20. Significant regression equations T a b l e 20  Regression equation parameters for predicting species number with the  change o f canopy closure conditions on both C W D and forest floor in each o f the six study ecosystems.  Substratum  Ecos.  A  B  C  r  2  N  CDF  CWD FF  7.220 -4.365  -0.000 0.333  -0.001 -0.003  0.148* 0.163*  87 29  CWH  CWD FF  -0.861 9.190  0.229 -0.012  -0.002 -0.000  0.032 0.023  46 49  MH  CWD FF  -17.908 -49.089  0.661 1.531  -0.005 -0.010  0.070* 0.111*  90 60  IDF  CWD FF  3.298 10.685  0.090 -0.018  -0.001 -0.000  0.037 0.133*  90 89  ICH  CWD FF  -38.926  -0.006  0.072*  90  13.208  1.068 -0.084  0.000  0.059  60  CWD FF  29.954 16.507  -0.833 -0.218  0.007 0.002  0.091* 0.042  ESSF  Note: r = corrected r-squared, * significant at PL 0.05; 2  N S  NS  NS  N S  N S  N S  90 60  = not significant; N = number of cases.  72  for both C W D and forest floor were found only in the C D F and M H and no significant equations for both''CWD and forest floor were found only in the C W H . In other ecosystems, significant equations were found either for C W D or for forest floor.  In most, but not all, situations, there seemed to be a trend that the number of species was lower when canopy closure was relatively high or low, and the maximum number of species appeared at intermediate canopy closures o f 65% to 80% (Figures 21 and 22). This result is similar to that found by Harmon (1987) in a study on Picea  sitchensis and Tsuga heterophylla  seedling survival at different canopy closure conditions in Oregon.  Although some significant equations were found between number of species and canopy closure, they varied from ecosystem to ecosystem. It appears that the species number is influenced by many environmental factors and canopy closure is just one of them. So canopy closure is only a partial predictor of the species richness in an ecosystem.  However, when data from the six ecosystems were combined, a clearer trend of number of species vs. canopy closure was observed on both C W D and forest floor substrata (Figures 23 and 24). In the case o f forest floor substrata, the number o f species was negatively correlated with canopy closure. In other words, species number increased with a decrease in canopy closure or with an increase in canopy opening. A slightly different trend was found for C W D substrata, where fewer species were found in very open canopies, e.g. greater than 65% (less than 35% canopy closure). One explanation for this could be related to the difference in species  73  40  50  55  60  65  70  75  80  85  90  10  20  30  30  50  55  60  65  70  75  80  85  90  60  65  50  55  60  65  70  75  80  Canopy closure (% cover)  50  60  70  80  90  70  75  80  85  90  95  98  Canopy closure (% cover)  Canopy closure (% cover)  40  40  Canopy closure (% cover)  Canopy closure (% cover)  85  90  30  35  40  45  50  55  60  65  70  75  80  Canopy closure (% cover)  Figure 21. The number of species found in each C W D sample quadrat (0.3 m ) vs. canopy closure conditions for each of the six ecosystems studied showing the median (central point) and standard error (bar). 2  60  65  70  75  80  Canopy closure  85  90  30  35  40  45  50  55  60  65  70  75  Canopy closure  Figure 22. Number of species found in each forest floor sample quadrat (0.3 m ) vs. canopy closure conditions for each of the six ecosystems studied showing the median (central point) and standard error (bar). 2  75  Figure 23.  Number of species found in each C W D sample quadrat (0.3 m ) vs. 2  canopy closure conditions for all the ecosystems combined showing the median (central point) and standard error (bar).  1 6  14  00 CD  1 2  "o  CD Q_ 00  1 0  -  "o  CD _Q F  6  4  2  10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 C a n o p y closure (% cover)  Figure 24.  Number of species found in each forest floor sample quadrat (0.3 m )  vs. canopy closure conditions for all the ecosystems combined showing the median (central point) and standard error (bar).  77  composition of C W D and forest floor vegetation. A s discussed before, C W D vegetation was dominated by non-vascular plants whereas forest floor vegetation comprised a more balanced mixture of both non-vascular and vascular plants. It is known that non-vascular plants (especially mosses and liverworts) are generally shade-tolerant while some vascular plants are relatively shade-intolerant. When canopies get quite open (closure < 30% or so) the number o f species on forest floor still increases but the number of species on C W D begins to decrease. Another factor which affects the number of species is probably the humidity in the stands which may decline when canopies become open. Some bryophytes, especially liverworts, which are sensitive to humidity, may disappear when moisture conditions cannot meet the minimum requirement.  With respect to the number of species (per sample quadrat) in different ecosystems, it appeared that this number was more uniform on C W D (Figure 25) than on forest floor (Figure 26) as was the case for vegetation composition which was discussed previously.  78  20  .0?  o  15  CD d CO  10  5  h  0  T  T CDF  CWH  ESSF  ICH  IDF  MH  Ecosystem  Figure 25.  Number o f plant species per sample quadrat found on C W D subplots in  the six study ecosystems. Symbols are explained in Figure 8.  CDF  C W H ESSF  ICH  IDF  MH  Ecosystem  Figure 26.  Number of species per sample quadrat found on the forest floor subplots  in the six study ecosystems. 79  C h a p t e r 5 Conclusions  The literature suggests that coarse woody debris is an important functional component in forest ecosystems. It provides a substratum and serves as habitat for various plants. C W D is very important to understory plants including tree seedlings in forest ecosystems. It affects the abundance, distribution patterns, and species diversity o f understory vegetation. From the present study it can be concluded that:  A ) C W D provides a substratum and serves as habitat for various plant species, especially lichens, liverworts (hepatics), mosses, and tree seedlings in almost each of the six forest ecosystems studied except tree seedlings in the IDF.  B) For some understory species (e.g. some lichens, liverworts, and mosses) C W D is the only rooting substratum. The absence o f C W D would probably result in the absence o f these wood-inhabiting species.  C) In different ecosystems, C W D has different effects on understory vegetation. Thus, in dry (e.g. the IDF) or open (e.g. E S S F ) forests it is more favorable to lichens whereas in moist or dense forests (e.g. the C W H , M H , and ICH) it is more favorable to liverworts. However, in both situations, it is always important to mosses.  D) Some plant species are associated with certain decay classes o f C W D . Thus, as wood decays, the plant species growing on it change. A shortage of some decay classes could cause the absence of some particular species that depend on them.  80  E) Nioie plant species are found on larger C W D materials than on smaller ones. T o ensure the full diversity o f plant species on C W D , larger logs should be left in the stands in harvesting operations.  For all these functions performed by C W D to understory plant species in different forest ecosystems there is a need to preserve all these ecosystems. 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Temperate forest management: its effects on bryophyte and lichen floras and habitats, in J . W . Bates and A . M . Farmer (Eds.)  Bryophytes & lichens in a changing  environment, pp.211-233. Schuster, R . M . , 1949. The ecology and distribution o f Hepaticae in central and western N e w  York. Amer. Midi. Nat. 42(3): 513 - 712. Sbderstrom, L. 1987. The regulation of abundance and distribution patterns of bryophyte species on decaying logs in spruce forests. PhD thesis, Umea  University.  . 1988a. Sequence of bryophytes and lichens in relation to substratum variables of decaying coniferous wood in northern Sweden. —  Nordic J. Bot. 8: 89-97.  . 1988b. The occurrence of epixylic bryophyte and lichen species in an old natural and a  managed forest  stand in northeast Sweden. Biol. Conserv. 45: 169-178.  . 1989. Regional distribution patterns o f bryophyte species on spruce logs in northern Sweden.  The Bryologist 92: 349-355.  Soderstrom, L. and B. G . Jonsson. 1989. Spatial patterns and dispersal in the leafy hepatic  Ptilidium pulcherrimum. J. of Bryology. 15: 793-802. and substratum.  . 1992. Fragmentation of old-growth forest and bryophytes on temporary  Svensk Botanisk Tidskrift 86: 185-198.  Sollins, P. 1982. Input and decay of coarse woody debris in coniferous stands in Western Oregon and Washington. Can. J. For. Res.  12: 18-28.  Sollins, P., S. P. Cline, T. Verhoeven, D. Sachs, and G . Spycher. 1987. Patterns o f log decay in old-growth  Douglas-fir forests. Can. J. For. Res.  17: 1585-1595.  Spies, T. A . , J . F. Franklin, and T. B. Thomas. 1988. Coarse woody debris in Douglas-fir forests of western Oregon and Washington.  Ecology 69: 1689-1702.  Stotler, R. and B. Crandall-Stotler. 1977. A checklist o f the liverworts and hornworts of North America.  The Bryologist 80: 405-428.  Taylor, R. L. and B. MacBryde. 1977.  Vascular plants of British Columbia: a descriptive  resource inventory. University of British Columbia Press. 85  Ter Baak, C . J . F. 1986. Canonical correspondence analysis: a new eigenvector technique for multivariate direct gradient analysis. Ecology 67: 1167-1179. Thompson, J . N . 1980. Treefalls and colonization patterns of temperate forest herbs. Am. Nat.  Midi.  104: 176-184.  Triska, F. J . and K. Cromack, Jr. 1979. The role of wood debris in forests and streams, in Waring, R. H . (Ed.)  Forests:freshperspectives from ecosystem analysis. Proc. 40th Annu. B i o l .  Colloquium. (Oreg. State Univ.) pp. 171-190. Tyrrell, L . E . and T.R. Crow, 1994. Dynamics o f dead wood in old-growth hemlock-hardwood forests of northern Wisconsin and northern Michigan. Can. J. For. Res: 24(8): 1672-1683. V a n Wagner, C . E . 1968. The line intersect method in forest fuel sampling. For. Sci. 14: 20-26. Wikinson, L. 1986.  SYSTAT: The system for statistics. S Y S T A T Inc., Evanston, IL. 822 pp.  86  Appendix I List of plant species showing their plant type groups and their presence (+) and absence (0) to the C W D and forest floor substrata by ecosystems (S - tree seedlings; SH - shrubs; H - herbs & grass; F - ferns; M - mosses; L W - liverworts; L - lichens;)  Ecos. CDF  Species  Plant type  Pseudotsuga menziesii var. menziesii Thuja plicata Tsuga heterophylla Chimaphila umbellata Gaultheria shallon Linnaea borealis Mahonia nervosa Rubus parviflorus* Rubus ursinus* Vaccinium parvifolium Corallorhiza maculata Fragaria virginiana Galium trifidum Listera cordata Pyrola asarifolia Tiarella trifoliata Trientalis latifolia Viola sp Brachythecium frigidum Dicranum fuscescens Dicranum scoparium Eurhynchium oreganum Hylocomium splendens Hypnum circinale Isothecium myosuroides Mnium spinulosum Neckera douglasii Plagiothecium laetum Polytrichum juniperinum Rhizomnium glabrescens Rhytidiadelphus loreus Rhytidiadelphus triquetrus SJJLignum girgensohnii Trachybryum megaptilum Blepharostoma trichophyllum Lepidozia reptans Lophocolea cuspidata Lophocolea heterophylla Scapania bolanderi Cladonia bacillaris Cladonia contocraea  S S S SH SH SH SH SH SH SH H H H H H H H H M M M M M M M M M M M M M M M M LW LW LW LW LW L L  DI  Substratum D2 D3 0  + 0  +  + +  0  0  + + + +  + + +  0 0 0 0 0 0 0 0 0 0 0  +  + + + + + +  +  0 0  0 0  + 0  + 0 0 0 0 0 0  + 0 0 0 0 0 0  + + 0  + + + + 0  + 0 0 0 0 0  FF  0 0 0 0 0  +  + + +  0 0 0  0 0 0  + + + + +  + + + + +  0 0 0 0 0 0 0 0 0 0 0  + + + + + 0 0  + + 0  + + + + + + 0  +  0  0  + + + + +  + + 0 0  +  0 0 0  0 0  +  + + +  + +  0 0  +  + + + + +  0 0 0 0 0  0  0 0  +  0  0  87  Appendix I (continued)  Ecos.  CWH  Species  Substratum D2 D3  Plant type  DI  Cladonia cornuta Cladonia Jimbriata Cladonia gracilis Cladonia hypogimia Cladonia macilenta Cladonia spl Cladonia sp2 Cladonia squamosa Cladonia transcendens Haematomma lapponicum Hypogymnia austerodes Ochrolechia sp Parmelia sulcata Parmeliopsis hyperopta Platismatia glauca  L L L L L L L L L L L L L L L  + +  0 0  0 0 0  +  + + .+  +  Abies amabilis Thuja plicata Tsuga heterophylla Chimaphila umbellata Linnaea borealis Menziesia ferruginea Oplopanax horridus Rosa gymnocarpa Rubus pedatus Rubus spectabilis Sambucus racemosa ssp. pubens Taxus brevifolia Vaccinium alaskaense Vaccinium ovalifolium Vaccinium parvifolium Boykinia occidentalis Calypso bulbosa Clintonia uniflora Coptis asplenifolia Cornus canadensis Goodyera oblongifoha Listera caurina Orthilia secunda Pyrola sp Smilacina stellata Streptopus amplexifolius Tiarella trifoliata Tiarella unifoliata  S S S SH SH SH SH SH SH SH SH SH SH SH SH H H H H H H H H H H H H H  0  + + + + + + 0  + + 0 0 0 0  +  0 0 0  + + +  0 0 0 0  + 0 0  +  0 0 0  0 0 0 0 0 0 0  + + +  + +  0  +  0 0 0 0 0  0  0  + 0  + 0  0 0 0 0 0 0  +  +  +  + + +  0 0 0 0  0 0 0  + +  + +  +  + 0  + 0 0 0 0 0 0  0 0 0 0 0  0 0 0 0 0 0  + +  + + 0 0  0  0 0 0 0 0  + + + 0  FF 0 0 0  + 0 0 0 0 0 0 0 0 0 0 0  + + + + + + + + + + + + + + + + + + + + + + + + + + + +  88  Appendix I (continued)  Ecos.  Species  Tolmiea menziesii Athyrium Jilix-femina Blechnum spicant Dryopteris expansa Gymnocarpium dryopteris Lycopodium selago Antitrichia curtipendula Brachythecium starkei Dicranum fuscescens Dicranum scoparium Eurhynchium oreganum Hylocomium splendens Hypnum circinale Isothecium myosuroides Plagiothecium laetum Plagiothecium undulatum Polytrichastrum alpinum Polytrichum juniperinum Rhizomnium glabrescens Rhytidiadelphus loreus Rhytidiadelphus triquetrus Rhytidiopsis robusta Sphagnum girgensohnii Bazzania denudata Blepharostoma trichophyllum Cephalozia bicuspidata Frullania californica Jamesoniella autumnalis Lepidozia reptans Lophocolea heterophylla Lophozia incisa Plagiochila porelloides Porella naviculars Ptilidium californicum Scapania bolanderi Cladonia cornuta Cladonia squamosa Cladonia symphycarpa Coniocybe furfuracea Parmeliopsis hyperopta Sphaerophorus globosus MH  Plant type  DI  H F F F F F M M M M M M M M M M M M M M M M M LW LW LW LW LW LW LW LW LW LW LW LW L L L L L L  0 0 0 0 0  S Abies amabilis Thuja plicata/Chamaecyparis nootkatensis S Tsuga heterophylla  + + + + + +  0 0 0  0  +  + + +  0 0 0 0  0 0 0 0  + +  + +  0  0  0  +  + +  -f  +  + + +  0  0  0  +  + +  + + + + + + +  0 0  0  + +  + +  0 0  0 0 0 0 0  + 0 0  + +  +  0  + + +  + + + + + + + + + 0  + + 0 0  S  Substratum D2 D3  + +  0  0 0 0 0  + + 0 0 0 0 0  + + +  FF  + + + + + + 0  .+ 0  + + + + + + + + + + + + +  0  0  + + + +  + + +  0  + + +  + +  0  0  0  +  +  0  0 0  + + + + +  + 0  + 0 0 0  0 0 0  +  + + +  + + +  89  Appendix  Ecos.  Species  I (continued)  Substratum D2 D3  Plant type  DI  Tsuga mertensiana Chimaphila menziesii Menziesia ferruginea Rubus pedatus Vaccinium membranaceum Vaccinium ovalifolium Calypso bulbosa Clintonia uniflora Cornus canadensis Goodyera oblongifolia Listera cordata Streptopus roseus Tiarella trifoliata Tiarella unifoliata Blechnum spicant Gymnocarpium dryopteris Lycopodium annotinum Brachythecium leibergii Brachythecium starkei Buxbaumia piperi Dicranum fuscescens Dicranum pallidisetum Heterocladium procurrens Hypnum circinale Isothecium myosuroides Mnium spinulosum Plagiomnium insigne Plagiothecium denticulatum  S SH SH SH SH SH H H H H H H H H F F F M M M M M M M M M M  +  +  +  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0  0 0  0  var. obtusifolium Plagiothecium laetum Plagiothecium undulatum Pleurozium schreberi Pterigynandrum fdiforme Rhizomnium glabrescens Rhizomnium nudum Rhytidiadelphus loreus Rhytidiopsis robusta Sphagnum girgensohnii Barbilophozia lycopodioides Bazzania denudata Blepharostoma trichophyllum Cephalozia bicuspidata Cephalozia connivens Cephalozia lunulifolia  M M M M M M M M M M LW LW LW LW LW LW  + +  0  +  0 0 0  +  0  + +  0 0 0 0 0 0 0 0 0 + + + + + + + + + +  0  0 0 0 0  + +  0 0 0 0  +  +  +  0 0  + +  0 0  0 0 0 0  + + + +  0  + + +  0  + + + + + + +  0 0 0 + + +  0 0 0  FF + + + + + + + + + + + + + + + + +  0  0 0 0  + +  + +  +  0  +  0  + +  0  + + +  0  0  0  + + +  + +  0  0 0  + + + +  + + + +  0  0 0 0  + + + + + +  + + +  0  90  Appendix I (continued)  Ecos.  Species Jungermannia sp Lepidozia reptans Lophocolea cuspidata Lophocolea heterophylla Lophozia ventricosa Ptilidium californicum Riccardia latifrons Scapania bolanderi Scapania umbrosa Cladonia contocraea Cladonia cornuta Cladonia squamosa Cladonia symphycarpa Coniocybe furfuracea Lecanora sp Lichen sp4 Parmeliopsis ambigua Physcia sp Platismatia glauca Thelotrema lepadinum  IDF  Pseudotsuga menziesii var. glauca Alnus viridis Amelanchier alnifolia Arctostaphylos uva-ursi Chimaphila umbellata Juniperus communis Linnaea borealis Mahonia aquifolium Paxistima myrsinites Rosa acicularis Shepherdia canadensis Spiraea betulifolia Symphoricarpos albus Vaccinium membranaceum Vaccinium ovatum Vaccinium parvifolium Allium cernuum Antennaria pulcherrimum Antennaria racemosa Arnica angustifolia Arnica cordifolia Astragalus alpinus Calamagrostis sp Carex sp  Plant type LW LW LW LW LW LW LW LW LW L L L L L L L L L L L S SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH H H H H H H H H  DI 0  + 0  + 0  + 0 0 0  + + +  Substratum D2 D3 0 0  + + + + 0  + + + 0  0  + + + + + + + + + +  +  0  0 0 0 0 0 0 0 0  +  0 0 0 0 0 0  + 0 0  0 0 0  +  +  0 0  0 0  +  +  +  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0  0 0  0  + + + + + + +  0 0 0 0 0 0 0  + 0 0  + + 0 0 0 0 0 0 0 0  + 0  FF + 0  + + 0  + 0  + 0 0 0 0 0 0 0 0 0 0 0 0  + + + + + + + + + + + + + + + + + + + + + + + +  91  Appendix I (continued)  Ecos.  Species Cerastium sp Corallorhiza striata Disporum trachycarpum Epilobium angustifolium Fragaria virginiana Fritillaria lanceolata Galium boreale Galium trifidum Goodyera oblongifolia Hieracium aurantiacum Lathyrus ochroleucus Listera cordata Orthilia secunda Pedicularis bracteosa Pedicularis sp Poa sp Pyrola chlorantha Schizachne purpurascens Smilacina racemosa Smilacina stellata Streptopus amplexifolius Taraxacum officinale Thalictrum occidentale Trifolium repens Vicia americana Viola adunca Zygadenus venenosus Polystichum munitum Aulacomnium palustre Brachythecium erythrorrhizon Brachythecium frigidum Brachythecium leibergii Brachythecium reflexum Brachythecium starkei Bryum ambylodon Ceratodon purpureus Dicranum fuscescens Dicranum polysetum Dicranum scoparium Dicranum tauricum Eurhynchium oreganum Hypnum subimponens Mnium spinulosum Plagiomnium insigne  Substratum D2 D3  Plant type  DI  H H H H H H H H H H H H H H H H H H H H H H H H H H H F M M M M M M M M  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0  +  +  0 0 0 0 0  0 0  M M M M M M M M  + 0  +  + +  0 0 0 0  0 0 0 0  0 0 0 0  + 0 0 0 0 0 0 0 0 0 0 0  + 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0  + + + + + 0  + +  FF  + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + 0  + + +  92  Appendix I (continued)  Species Plagiothecium denticulatum var. obtusifolium Plagiothecium laetum Pleurozium schreberi Pohlia nutans Ptilium crista-castrensis Rhytidiadelphus loreus Rhytidiadelphus triquetrus Tayloria serrata Tetraphis pellucida Timmia austriaca Tortula norvegica Tortula ruralis Barbilophozia lycopodioides Calypogeia muelleriana Cephalozia bicuspidata Lophozia excisa Lophozia Jloerkei Lophozia guttulata Lophozia ventricosa Ptilidium pulcherrimun Bryoria sp Cetraria chorophylla Cetraria ericetorum Cetraria islandica Cetraria sp Cladina mitis Cladonia bacillaris Cladonia cariosa Cladonia cenotea Cladonia subcervicornis Cladonia cornuta Cladonia crispata Cladonia depormis Cladonia fimbriata Cladonia gracilis Cladonia pleurota Cladonia spl2 Cladonia sp4 Cladonia sp5 Cladonia sp6 Cladonia sp7 Cladonia sp8 Cladonia squamosa Cladonia sulphurina  Substratum D2 D3  Plant type  DI  M M M M M M M M M M M M LW LW LW LW LW LW LW LW L L L L L L L L L L L L L L L L L L L L L L L L  0 0  0 0  0 0  + + +  + + +  + + +  0 0 0 0 0 0 0 0 0 0 0 0 0 0  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0  0 0  + + + + + + +  + +  0 0  0 0 0  + + + + + + + +  + + + 0 0 0 0 0 0 0 0 0  + + 0 0 0 0 0 0 0 0 0 0  +  + 0  + + + + + 0 0 0  + + + + + + +  + 0 0  + 0  + 0 0 0 0  + +  FF  0 0 0  + 0  +  0 0  0 0 0  +  +  0  0  + + +  + 0  +  0 0 0 0 0  + + +  +  +  0 0  0 0 0 0 0  0  +  + + + +  0 0 0  +  0  0  + +  93  Appendix I (continued)  Ecos.  ICH  Species  Plant type  Cladonia symphycarpa Hypogymnia enteromorpha Hypogymnia physodes Letharia vulpina Lichen sp3 Parmeliopsis ambigua Parmeliopsis hyperopta Peltigera aphthosa Peltigera canina Peltigera spl Peltigera sp2 Xanthoria candelaria  L L L L L L L L L L L L  Thuja plicata Tsuga heterophylla Chimaphila umbellata Linnaea borealis Paxistima myrsinites Rosa acicularis Rubus pedatus Taxus brevifolia Vaccinium membranaceum Clintonia uniflora Corallorhiza striata Cornus canadensis Goodyera oblongifolia Pyrola asarifolia Smilacina racemosa Tiarella unifoliata Viola sempervirens Athyrium fdix-femina Gymnocarpium dryopteris Pteridium aquilinum Brachythecium hylotapetum Brachythecium leibergii Dicranum fuscescens Dicranum scoparium Dicranum tauricum Hylocomium splendens Hypnum circinale Mnium spinulosum Plagiothecium laetum Pleurozium schreberi  S S SH SH SH SH SH SH SH H H H H H H H H F F F  Pohlia nutans Ptilium crista-castrensis  M M M M M M M M M M M M  DI  Substratum D2 D3  0  0  +  + + + + + +  +  0 0 0  0 0 0 0 0  0 0 0 0  0  + + + +  +  0  + +  + + + + + + + + + + + + + + + + + + + + +  0  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0  +  + + + + + + + +  + + +  0  + +  0  +  0 0  0  + + + +  0 0 0 0  + + + + +  +  0  + + + + +  FF  0  + 0 0 0 0 0  + 0  + 0 0 0  + 0 0 0 0  + + + + 0  + + + + +  0  + 0 0  + + 0  0  0  + + +  +  +  0  94  Appendix I (continued)  Ecos.  ESSF  Species  Plant type  Rhytidiopsis robusta Tetraphis pellucida Barbilophozia lycopodioides Bazzania denudata Blepharostoma trichophyllum Cephalozia bicuspidata Cephalozia lunulifolia Cephalozia sp Jamesoniella autumnalis Jungermannia sp Lepidozia reptans Lophocolea cuspidata Lophocolea heterophylla Lophozia floerkei Lophozia incisa Lophozia ventricosa Ptilidium californicum Ptilidium pulcherrimun Bryoria sp Cetraria chorophylla Cladonia bacillaris Cladonia cornuta Cladonia depormis Cladonia sulphurina Hypogymnia austerodes Nephroma sp Parmelia sulcata Parmeliopsis ambigua Parmeliopsis hyperopia Peltigera canina  M M LW LW LW LW LW LW LW LW LW LW LW LW LW LW LW LW L L L L L L L L L L L L  Abies lasiocarpa Picea engelmannii Lonicera utahensis Menziesia ferruginea Rhododendron albiflorum Ri;l „s pedatus Vaccinium membranaceum Vaccinium ovalifolium Arnica cordifolia Carex sp Clintonia uniflora Cornus canadensis Listera cordata Mitella breweri  S S SH SH SH SH SH SH H H H H H H  DI  + 0 0 0 0 0 0 0  + 0 0 0 0 0 0 0  + 0  + + 0  + + + + 0  + + + + + 0 0 0 0 0 0 0 0 0 0 0 0 0  Substratu n D2 D3  + 0  + 0  + 0  + + + 0 0 0  + + + + + 0 0  + + + + + + + + +  + + + + + + + + + + + + +  +  0  0 0  + + + + 0 0 0  + 0  + + + 0  +  0  0  +  +  + +  + +  0 0 0  0 0  + 0 0 0 0 0 0 0 0  FF  + + + + 0 0  + + + 0  0  + 0  + 0  + 0 0 0 0 0  + + + + 0 0 0 0 0 0 0  + 0 0 0 0  + + + + + + + + + + + + + +  95  Appendix I (continued)  Substratum Ecos.  Species Osmorhiza purpurea Streptopus roseus Streptopus streptopoides Tiarella trifoliata Tiarella unifoliata Valeriana sitchensis Veratrum viride Viola glabella Gymnocarpium dryopteris Lycopodium annotinum Brachythecium erythrorrhizon Brachythecium frigidum Brachythecium hylotapetum Brachythecium leibergii Brachythecium oedipodium Brachythecium reflexum Brachythecium spl Brachythecium starkei Dicranella subulata Dicranum fuscescens Dicranum pallidisetum Dicranum scoparium Dicranum tauricum Eurhynchium praelongum Hylocomium splendens Isothecium myosuroides Lescuraea saxicola Mnium spinulosum Plagiothecium laetum Pleurozium schreberi Polytrichastrum alpinum Pohlia nutans Pseudoleskea stenophylla Rhizomnium nudum Rhytidiadelphus squarrosus Rhytidiadelphus triquetrus Rhytidiopsis robusta Sanionia uncinatus Timmia austriaca Barbilophozia lycopodioides Blepharostoma trichophyllum Cephalozia bicuspidata Cephalozia connivens Cephalozia lunulifolia Lophoz'a guttulata  Plant type  DI  D2  D3  FF  H H H H H H H H F F M M M M M M M M M M M M M M M M M M M M M M M M M M M M M LW LW LW LW LW LW  0 0 0 0 0 0 0 0 0 0  0  0  + +  + +  + + + + + + + + + + + + + + +  + 0 0  + + + 0 0 0  + + + +  0  0  +  +  0 0 0  0 0 0  +  + + + + +  0 0 0 0  + + 0 0  +  0  + 0  0  + +  + + + +  0  0  +  + + +  0  +  0 0 0 0  0 0 0 0 0  +  0  0 0  + + +  + + +  + + +  0  0  0  +  +  +  0  0  0  + + + +  +  +  0  0  + + +  + + +  + + + + + + + + + + + +  0  0  + +  + + + + + +  0 0 0  +  0  0 0 0  +  +  0  +  0 0  0  + 0  +  0  + + + 0  + + +  96  Appendix I (continued)  Ecos.  Species Lophozia incisa Lophozia longidens Lophozia sp Lophozia ventricosa Ptilidium californicum Ptilidium pulcherrimun Cladonia bacillaris Cladonia cenotea Cladonia chlorophaea Cladonia contocraea Cladonia cornuta Cladonia depormis Cladonia fimbriata Cladonia gracilis Cladonia phyllophora Cladonia splO Cladonia sp9 Cladonia squamosa Cladonia sulphurina Lichen spl2 Parmeliopsis ambigua Parmeliopsis hyperopta Peltigera canina  Plant type LW LW LW LW LW LW L L L L L L L L L L L L L L L L L  DI  Substratum D2 D3  +  +  0 0  0 0  + +  + + +  0  + 0 0  + + + + 0 0 0  + 0 0 0  + + +  + +  0 0  0  + + + +  + + +  0  0  + + + + + + +  +  0  + 0 0  + + + + +  FF  0  + + + + + + + + + +  0 0 0 0 0 0 0 0 0 0 0 0 0  0 0 0  +  +  +  0 0  * Species may be present on FF but was encountered on CWD in this investigation  97  Appendix II  List of plant species showing their plant type groups and their presence (+) and absence (0) on CWD and forest floor substrata (S - tree seedlings; SH - shrubs; H - herbs & grass; F - ferns; M - mosses; LW - liverworts; L - lichens) Species Abies amabilis Abies lasiocarpa Picea engelmannii Pseudotsuga menziesii var. menziesii Pseudotsuga menziesii var. glauca Thuja plicata Tsuga heterophylla Tsuga mertensiana Alnus viridis Amelanchier alnifolia Arctostaphylos uva-ursi Chimaphila umbellata Gaultheria shallon Juniperus communis Linnaea borealis Lonicera utahensis Mahonia aquifolium Mahonia nervosa Menziesia ferruginea Oplopanax horridus Paxistima myrsinites Rhododendron albiflorum Rosa acicularis Rosa gymnocarpa Rubus parviflorus* Rubus pedatus Rubus spectabilis Rubus ursinus * Sambucus racemosa ssp. pubens Shepherdia canadensis Spiraea betulifolia Symphoricarpos alb us Taxus brevifolia Vaccinium alaskaense Vaccinium membranaceum  Plant type S S S S S S S S SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH SH  DI 0 +  0 0 0 + + +  0 0 0 0  Substratum D2 D3 + + +  + + +  0  0 0  + + + +  + + +  0 0  0 0  +  +  0  0  +  +  +  0  0  0  +  +  +  0 0 0 0 0 0 0 0 0 0  0 0  0 0  +  + + +  0 0 0 0 0 0  +  + +  0 0 0 0 0 0 0 0 0  0 0 0 0 0 0 0 0 0  0 + +  0 0  FF + + + + + + + + + + + + + + + + + + + + + + + +  0  + + +  + +  0 0 0  + + + + + + +  +  0 + +  0  98  Appendix II (continued)  Species  Plant type  DI  Substratum D2 D3  +  + +  + +  H  0  0  0  Antennaria pulcherrimum  H  0  0  0  Antennaria racemosa  H  0  0  0  Arnica angustifolia  H  0  0  0  Arnica cordifolia  H  0  0  0  Astragalus alpinus  H  0  0  0  Boykinia occidentalis  H  0  0  0  Calamagrostis sp  H  0  0  +  Calypso bulbosa  H  0  0  0  Carex sp  H  0  0  0  Cerastium sp  H  0  0  0  Chimaphila menziesii  H  0  0  0  Clintonia uniflora  H  0  0  +  Coptis asplenifolia  H  0  +  0  Corallorhiza maculata  H  0  0  0  Corallorhiza striata  H  0  0  0  Cornus canadensis  H  +  +  +  Disporum trachycarpum  H  0  0  0  Epilobium angustifolium  H  0  0  0  Fragaria virginiana  H  0  0  +  Fritillaria lanceolata  H  0  0  0  Galium boreale  H  0  0  0  Galium trifidum  H  0  0  0  Goodyera oblongifolia  H  0  0  0  Hieracium sp  H  0  0  0  Hieracium aurantiacum  H  0  0  0  Lathyrus ochroleucus  H  0  0  0  Listera caurina  H  +  0  0  Listera cordata  H  0  0  +  Mitella breweri  H  0  0  0  Orthilia secunda  H  0  0  0  Osmorhiza purpurea  H  0  0  0  Pedicularis bracteosa  H  0  0  0  Pedicularis sp  H  0  0  0 0 0  Vaccinium ovalifolium  SH  0  Vaccinium parvifolium  SH  Allium cernuum  Poa sp  H  0  0  Pyrola asarifolia  H  0  0  FF  + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +  99  Appendix II (continued)  Species  Pyrola chlorantha Schizachne purpurascens Smilacina racemosa Smilacina stellata Streptopus amplexifolius Streptopus roseus Streptopus streptopoides Taraxacum officinale Thqlictrum occidentale Tiarella trifoliata Tiarella unifoliata Tolmiea menziesii Trientalis latifolia Trifolium repens Valeriana sitchensis Veratrum viride Vicia americana Viola adunca Viola glabella Viola sempervirens Viola sp Zygadenus venenosus Athyrium filix-femina Blechnum spicant Dryopteris expansa Gymnocarpium dryopteris Lycopodium annotinum Lycopodium selago Polystichum muniturn Pteridium aquilinum Antitrichia curtipendula Aulacomnium palustre Brachythecium frigidum Brachythecium oedipodium Brachythecium erythrorrhizon Brachythecium leibergii Brachythecium reflexum Brachythecium sp 1  Plant type  DI  Substratum D2 D3  H  0  0  +  H  0  0  0  H  0  0  0  H  0  0  H  0  0  H  0  H  0  + +  + + + +  H  0  0  0  H  0  0  0  H  0  H  0  + +  + +  FF  + + + + + +  F  0  0  +  F  0  0  0  + + + + + + + + + + + + + + + + + + + + + + +  M  +  0  0  0  M  0  0  0  M  0  +  + + + +  M  + + + + +  0  0  M  0  0  +  + + + + + + +  H  0  0  0  H  0  0  0  H  0  0  0  H  0  0  0  H  0  0  0  H  0  0  0  H  0  0  0  H  0  0  0  H  0  0  0  H  0  0  0  H  0  0  0  F  0  0  F  0  0  F  0  F  0  + +  F  0  0  + + + + +  F  0  0  0  M M M  + 0  100  Appendix II (continued)  Species  Plant type  M Brachythecium sp2 M Brachythecium starkei Bryum ambylodon M M Buxbaumia piperi M Ceratodon purpureus M Dicranella subulata Dicranum fuscescens M Dicranum pallidisetum M Dicranum polysetum M M Dicranum scoparium M Dicranum tauricum M Drepanocladus uncinatus M Eurhynchium praelongum M Eurhynchium oreganum M Heterocladium procurrens M Hylocomium splendens M Hypnum circinale M Hypnum subimponens Isothecium myosuroides M M Lecuraea saxicola M Pseudoleskea stenophylla M Mnium spinulosum M Neckera douglasii M Plagiomnium insigne M Plagiothecium denticulatum var.obtusifolium M Plagiothecium laetum M Plagiothecium undulatum M Pleurozium schreberi M Polytrichastrum alpinum M Pohlia nutans M Polytrichum juniperinum M Pterigynandrum JiIif orme M Ptilium crista-castrensis M Rhizomnium glabrescens M Rhizomnium nudum M Rhytidiadelphus loreus M Rhytidiadelphus squarrosus  DI  + +  Substratum D2 D3  Fl  0  0  +  +  0  0  0  + + +  0  +  0  0  0  0  0  + + + + + + +  0  0  0  + +  + +  + + + + + +  0  0  + +  + + +  0  0  0  0  0  +  + + + +  +  + +  0  0  + +  0  + +  0  0  0  + +  +  +  + + + + + + +  0  0  0  0  0  +  0  +  + + + + + +  + + + + +  0  0  0  + + + + + + + +  + + + + + +  0  0  0  + + + +  + + + +  0  0  + + + + +  0  0  0  +  +  +  0  0  0  + + + 0  0  101  Appendix II (continued) Species  Plant type  Rhytidiadelphus triquetrus  M  Rhytidiopsis robusta  M  Sphagnum girgensohnii  M M M M M M M LW LW LW LW LW LW LW LW LW LW LW LW LW LW LW LW LW LW LW LW LW LW LW LW LW LW LW LW L  Tayloria serrata Tetraphis pellucida Timmia austriaca Tortula norvegica Tortula ruralis Trachybryum megaptilum Barbilophozia lycopodioides Bazzania denudata Blepharostoma trichophyllum Calypogeia muelleriana Cephalozia bicuspidata Cephalozia connivens Cephalozia lunulifolia Cephalozia sp Frullania californica Jamesoniella autumnalis Jungermannia sp Lepidozia reptans Lophocolea cuspidata Lophocolea heterophylla Lophozia excisa Lophozia floerkei Lophozia incisa Lophozia longidens Lophozia guttulata Lophozia sp Lophozia ventricosa Plagiochila porelloides Porella navicularis Ptilidium californicum Ptilidium pulcherrimun Riccardia latifrons Scapania bolanderi Scapania umbrosa Bryoria sp  DI  Substratum D2 D3  FF  + +  + +  + +  + + +  0  0  0  0  0  0  0  0  + +  0  0  0  0  0  0  0  0  0  0  0  0  0  +  + + + + + + + + + + + + + + +  + + + + + + + + + + +  0  0  0  +  0  + + + + +  0  +  + +  +  0  0  + + +  +  + + + + + +  0  0  +  +  + + +  0  0  0  + + + + +  +  + +  0  0  0  + +  + +  0  0  +  + +  + + + + +  0  0  +  0  + +  0 0  0  +  0  0  0  0 0  + + + + + + + 0 0  + + + +  0  + 0  102  Appendix II (continued) Species  Plant type  DI  Substratum D2 D3  Cetraria chorophylla Cetraria ericetorum Cetraria islandica Cetraria sp Cladina mitis Cladonia cervicornis subsp Cladonia bacillaris Cladonia cariosa Cladonia ecnotea Cladonia chlorophaea Cladonia contocraea Cladonia cornuta Cladonia crispata Cladonia depormis Cladonia fimbriata Cladonia gracilis Cladonia hypogimia Cladonia macilenta Cladonia phyllophora Cladonia pleurota Cladonia spl  L  +  +  L  0  +  +  L L  0  L  0  + +  L  0  0  L  +  L  0  L  0  L  0  L  L  + + + + +  + + + + + +  L  FF  0  0  + +  + +  0  0  0  0  + +  0  +  0  0  +  +  0  0  + +  0  +  0  0  0  0  + + +  + + +  L  0  0  0  L  0  0  L  0  0  L  0  L  +  Cladonia splO  L  0  Cladonia spl1 Cladonia sp2 Cladonia sp4 Cladonia sp5 Cladonia sp6 Cladonia sp7 Cladonia sp8 Cladonia sp9 Cladonia squamosa Cladonia sulpuurina Cladonia symphycarpa Cladonia transcendens Coniocybe furfuracea Haematomma lapponicum Hypogymnia austerodes Hypogymnia enteromorpha  L  0  L  +  + + + +  + +  + + + +  L  0  L  L L L  0  0 0  0  0  0  0  + +  0  +  0  0  0 0  0  + +  0 0  0  L  0  0  0  L  0  0  0  L  0  L L  + + +  + + + + •+  +  L  0  0  L  0  L  + + + +  +  L  L L L  0  0  + + + +  0  + 0 0  0  0  0  0  0  + + +  0  0  0  0  +  0  103  Appendix II (continued) Species  Plant type  Hypogymnia physodes Lecanora sp Letharia vulpina Lichen sp Nephroma sp Ochr sp Parmelia sulcata Parmeliopsis ambigua Parmeliopsis hyperopia Peltigera aphthosa Peltigera canina Peltigera spl Peltigera sp2 Physcia sp Platismatia glauca Sphaerophorus globosus ver. gracilis Thelotrema lepadi Xanthoria candelaria  L L L L L L L L L L L L L L L L L L  DI + + + +  Substratum D2 D3 0  0  FF 0  0  0  0  0  0  + +  + +  + + + +  + + + + + + +  0  0  0  0  +  0  0  0  +  0  0  0  +  + +  0  0  0  0  0  0  + + + +  + + + +  0  0  0  0  0  0  0  +  0  0  0  0  0  +  +  0  * Species may be present on FF but was encountered on CWD in this investigation  104  Appendix I I I List of pi-"t species confined to C W D showing their plant type groups and their presence (+) or absence (0) on three decay classes (SH - shrubs; M - mosses; L W - liverworts; L - lichens;)  Species  Plant type  Rubus parviflorus *  SH  DI  C W D Substratum D2  D3  0  +  0  Rubus ursinus*  SH  0  0  +  Antitrichia curtipendula  M  +  0  0  Buxbaumia piperi  M  0  0  Drepanocladus uncinatus  M  0  +  Heterocladium procurrens  M  0  + + +  Neckera douglasii  M  0  0  Pterigynandrum filiforme  M  + +  0  0  Tayloria serrata  M  0  0  0  Lophozia longidens  LW  0  0  + + + + + +  Porella  naviculars  LW  +  0  0  Riccardia latifrons  LW  0  0  + + + +  + +  Tetraphis pellucida  M  0  0  Cephalozia sp  LW  0  +  Frullania californica  LW  0  Lophozia incisa  LW  + +  +  Scapania umbrosa  LW  0  Cetraria chorophylla  L  +  Cetraria sp  L  0  Cladina mitis  L  0  0 0 0  Cladonia cervicornis subsp  L  0  0  +  Cladonia cariosa  L  0  0  Cladonia chlorophaea  L  0  Cladonia contocraea  L  Cladonia crispata  L  + +  + + +  0  +  0  0  0  + +  Cladonia macilenta  L  Cladonia phyllophora  L  0  0  Cladonia pleurota  L  0  Cladonia spl  L  +  Cladonia splO  L  0  + + +  +  Cladonia sp2  L  +  0  0 0  0  0 0  Cladonia sp4  L  0  Cladonia sp5  L  0  + +  Cladonia sp6  L  0  0  +  Cladonia sp7  L  0  0  Cladonia sp8  L  0  + +  0  0  105  Appendix III (continued) Species Cladonia sp9 Cladonia sulphurina Cladonia symphycarpa Cladonia transcendens Coniocybe furfuracea Haematomma lapponicum Hypogymnia austerodes Hypogymnia enteromorpha Hypogymnia physodes Lecanora sp Letharia vulpina Ochr sp Parmelia sulcata Parmeliopsis ambigua Parmeliopsis hyperopta Physcia sp Platismatia glauca Sphaerophorus globosus ver. gracilis Thelotrema lepadi Xanthoria candelaria  Plant type  DI  L L L L L L L L L L L L L L L L L L L L  + + 0 0 + + + + + + + + + + + + + + + 0  CWD Substratum D2 D3 + + 0 + 0 + + + 0 0 + + + + + 0 0 + 0 +  + + + 0 0 0 0 + 0 0 0 0 0 + 0 0 0 0 0 +  * Species may present on FF but was encountered on CWD in this investigation  106  Appendix IV A list of bryophyte species and their growth-forms (Mr - rough mats; Ms - smooth mats; Mth - thalloid mats; t - short turfs; T - tall turfs; W - wefts) Species Barbilophozia floerkei (Web. et Mohr) Loeske Barbilophozia lycopodioides (Wallr.) Loeske Bazzania denudata (Torrey ex Gott. et al. )Trev. Blepharostoma trichophyllum (L.) Dum. Calypogeja muelleriana (Schiffn.) K.Mull. Cephalozia bicuspidata (L.) Dum. Cephalozia connivens (Dicks.) Lindb. Cephalozia lunulifolia (Dum.) Dum. Cepholozia sp Frullania californica (Aust.) Evans Jamesoniella autumnalis (DC.) Steph. Jungermannia sp Lepidozia reptans (L.) Dum. Lophocolea cuspidata (Nees) Limpr. Lophocolea heterophylla (Schrad.) Dum. Lophozia excisa (Dicks.) Dum. Lophozia guttulata (Lindb. et H.Arnell) Evans Lophozia incisa (Schrad.) Dum. Lophozia longidens (Lindb.) Macoun Lophozia sp Lophozia ventricosa (Dicks.) Dum. Plagiochila porelloides (Torrey ex Nees) Lindenb. Porella naviculars (Lehm. et Lindenb.) Lindb. Ptilidium californicum (Aust.) Underw. Ptilidium pulcherrimum (G. Web.) Hampe Riccardia latifrons Lindb. Scapania bolanderi Aust. Scapania umbrosa (Schrad.) Dum. Antitrichia curtipendula (Hedw.) Brid. Aulacommiumpalustre (Hedw.) Schwaegr. Brachythecium erythrorrhizon Schimp. Brachythecium frigidum (C. Mull.) Besch. Brachythecium hylotapetum B. Hig. & N . Hig. Brachythecium leibergii Grout Brachythecium oedipodium (Mitt.) Jaeg. Brachythecium reflexum (Starke) Schimp. Brachythecium sp  Growth-form t Ms Ms Mr Ms Ms Ms Ms . Ms Ms Ms Ms Ms Mth Mth Mth Mth Mth Mth Mth Mth t Ms Mr Mr Mth t Ms Mr T W W W W W W W  107  Appendix I V (Continued) Species  Growth-form  (Brid.) Schimp. Bryum ambylodon C. Mull. Buxbaumia piperi Best Ceratodon purpureus (Hedw.) Brid. Brachythecium starkei  Dicranella subulata (Hedw.) Schimp.  Turn. Dicranumpallidisetum (Bail.) Irel. Dicranum fuscescens  Dicranum polysetum Sw. Dicranum tauricum Sapeh.  (Sull.) Jaeg. Eurhynchium praelongum (Hedw.) Schimp. Heterocladium procurrens (Mitt.) Haeg. Hylocomium splendens (Hedw.) Schimp. Hypnum circinale Hook. Hypnum subimponens Lesq. Isothecium myosuroides Brid. Lescuraea saxicola (Schimp.) P Milde Mnium spinosum (Voit) Schwaegr. Neckera douglasii Hook. Plagiomnium insigne (Mitt.) T. Kop. Plagiothecium denticulatum (Hedw.) Schimp. Plagiothecium laetum Schimp. Plagiothecium undulatum (Hedw.) Schimp. Pleurozium schreberi (Brid.) Mitt. Eurhynchium oreganum  Pohlia nutans (Hedw.) Lindb. Polytrichastrum alpinum (Hedw.)  G. L. Sm.  Hedw. Pseudoleskea stenophylla Ren. & Card. Pterigynandrum filiforme Hedw. Ptilium crista-castrensis (Hedw.) De Not. Polytrichum juniperinum  Rhizomnium glabrescens (Kindb.) T. Kop. Rhizomnium nudum  (Britt. & Williams) T. Kop.  Rhytidiadelphus loreus (Hedw.) Warnst. Rhytidiadelphus squarrosus  (Hedw.) Wamst.  Rhytidiadelphus triquetrus (Hedw.) Warnst. Rhytidiopsis robusta  (Hook.) Broth.  Sanionia uncinata (Hedw.) Loeske Sphagnum girgensohnii Russ. Tayloria serrata (Hedw.)  Bruch & Schimp.  W t D t t t t T t W W  w w Ms  w Ms Ms t Ms T Ms Ms Ms W t T T Ms Ms W t t  w w w w w T T  108  Appendix IV  Species  (Continued)  Growth-form  Tetraphis pellucida Hedw. Timmia austriaca Hedw. Tortula norvegica (Web.) Wahlenb. ex Lindb,  Tortula ruralis (Hedw.) Gaertn. et al.  Trachybryum megaptilum (Sull.) Schof.  109  

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