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Classification of trembling aspen ecosystems in British Columbia. Full report. Krestov, Pavel 2008

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CLASSIFICATION OF TREMBLING ASPEN ECOSYSTEMS IN BRITISH COLUMBIA P.V. Krestov, K. Klinka, C. Chourmouzis, and C. Hanel Forest Sciences Department THE UNIVERSITY OF BRITISH COLUMBIA March 2000 CLASSIFICATION OF TREMBLING ASPEN ECOSYSTEMS IN BRITISH COLUMBIA by P.V. Krestov1,2, K. Klinka2, C. Chourmouzis2, C. Hanel2 1Institute of Biology and Pedology Russian Academy of Sciences, Far Eastern Branch Vladivostok 690022 Russia 2Forest Sciences Department University of British Columbia 3036-2424 Main Mall, Vancouver, BC V6T 1Z4 Canada Scientia Silvica Extension Series Number 27 Forest Sciences Department THE UNIVERSITY OF BRITISH COLUMBIA March 2000 Scientia Silvica is published by the Forest Sciences Department, The University of British Columbia, ISSN 1209-952X Editor: Karel Klinka (klinka@interchange.ubc.ca) Production and design: Christine Chourmouzis (chourmou@interchange.ubc.ca) Financial support: Site Productivity Working Group of the BC Ministry of Forests iiiSUMMARY SUMMARY This report presents the first approximation of vegetation classification of trembling aspen ecosystems in interior British Columbia. The classification is based on a total of 186 plots sampled during the summers of 1995, 1997 and 1998. We used multivariate and tabular methods to synthesize and classify ecosystems according to the Braun- Blanquet approach and the methods of biogeoclimatic ecosystem classification. The aspen ecosystems were classified into 15 basic vegetation units (associations or subassociations) that were grouped into four alliances. Communities of the Populus tremuloides – Mertensia paniculata, and Populus tremuloides – Elymus innovatus alliances were aligned with the boreal Picea glauca & mariana order and were distributed predominantly in the Boreal White and Black Spruce zone; communities of the Populus tremuloides – Thalictrum occidentale alliance were also aligned with the same order, but were distributed predominantly in the Sub-Boreal Spruce zone; communities of the Populus tremuloides – Symphoricarpos albus alliance were aligned with the wetter cool temperate Tsuga heterophylla order and the drier cool temperate Pseudotsuga menziesii order and were distributed in the Sub-boreal Spruce, Interior Western Hemlock, Montane Spruce, and Interior Douglas-fir zones. We describe the vegetation and environmental features of these units and present vegetation and environmental tables for individual plots and units. ACKNOWLEDGEMENTS We thank the following individuals for helping in the preparation of this report: David New, David Brisco, Brad Collins, David Affleck, and Katherine Zidek for field assistance and sample preparation, Pal Varga for digitizing the photographs, Hong Qian for contributing the section on plant diversity, and Mike Ryan for the identification of byrophytes and lichens. We thank R. Kabzems (Fort St. John Forest District) for contributing vegetation and environmental data from aspen plots in northeastern BC sampled in 1995. We also thank the BC Forest Service Staff from the Dawson Creek, Fort St. James, Ft. Nelson, Mackenzie, and Morice Forest Districts for assistance in locating study stands and permits for cutting site trees. We gratefully acknowledge the financial support from the Site Productivity Working Group of the BC Ministry of Forests. iv Scientica Silvica Extension Series, Number 27, 2000 TABLE OF CONTENTS SUMMARY ........................................................................................................................... iii ACKNOWLEDGEMENTS..................................................................................................... iii INTRODUCTION.................................................................................................................. 1 METHODS Study Area .................................................................................................................. 3 Sampling ..................................................................................................................... 6 Vegetation Classification ............................................................................................. 7 Similarity and Cluster Analysis ........................................................................................... 9 Spectral Analysis ................................................................................................................ 9 Diversity Analysis ............................................................................................................. 10 RESULTS AND DISCUSSION Vegetation Classification ........................................................................................... 11 Vegetation-Environment Relationships ..................................................................... 26 Description of Plant Associations .............................................................................. 33 111 Populus tremuloides - Mertensia paniculata: Festuca altaica subassociation ........... 33 112 Populus tremuloides - Mertensia paniculata: Arnica cordifolia subassociation .......... 35 113 Populus tremuloides - Mertensia paniculata: Petasites frigidus subassociation ........ 37 210 Populus tremuloides - Ledum groelandicum association ........................................... 39 221 Populus tremuloides - Lathyrus ochroleucus: Hedysarum boreale subassociation ... 41 222 Populus tremuloides - Lathyrus ochroleucus: typic subassociation ........................... 43 223 Populus tremuloides - Lathyrus ochroleucus: Actaea rubra subassociation .............. 45 310 Populus tremuloides - Thalictrum occidentale association ........................................ 48 411 Populus tremuloides - Viburnum edule: Spiraea betulifolia subassociation ............... 50 412 Populus tremuloides - Viburnum edule: Paxistima myrsinites subassociation .......... 52 421 Populus tremuloides - Rosa nutkana: Aralia nudicaulis subassociation .................... 54 422 Populus tremuloides - Rosa nutkana: Arnica cordifolia subassociation ..................... 55 423 Populus tremuloides - Rosa nutkana: Angelica genuflexa subassociation ................ 56 424 Populus tremuloides - Rosa nutkana: Senecio pseudoaureus subassociation ......... 57 425 Populus tremuloides - Rosa nutkana: Shepherdia  canadensis  subassociation ....... 58 REFERENCES................................................................................................................... 59 APPENDICES .................................................................................................................... 63 1INTRODUCTION Trembling Aspen Ecosystems INTRODUCTION Trembling aspen (Populus tremuloides Michx.) is one of the most common tree species in the second-growth forests of the boreal and temperate zones of North America (Little 1979). It occurs across all of non-arctic Alaska, Canada and the northern USA and reaches south to the west coast of Mexico. In British Columbia (BC), aspen grows in all forested biogeoclimatic zones, except the Mountain Hemlock (MH) zone.  It is common in the Boreal White and Black Spruce (BWBS), Sub-Boreal Spruce (SBS), Sub-Boreal Pine – Spruce (SBPS), Montane Spruce (MS), Interior Douglas-fir (IDF), and Interior Cedar - Hemlock (ICH) zones.  Its occurrence is marginal in the Costal Douglas-fir (CDF), Coastal Western Hemlock (CWH), Spruce – Willow – Birch (SWB), Engelmann Spruce – Subalpine Fir (ESSF), and Ponderosa Pine (PP) zones. Aspen has become an important timber crop species in the province, yet the full ecological value of aspen in the boreal forest is not yet fully understood.  The classic successional sequence of a boreal forest begins with the removal or disturbance of a coniferous stand by wildfire and the establishment of a broad-leaved stand. Over time the boreal conifers, such as white (Picea glauca (Moench) Voss) and black spruce (Picea mariana (Mill.) B.S.P) re-establish  and remain until the next stand-disturbing event. The increasing presence of seral aspen stands across the landscape and the increasing demand for timber has motivated forest managers to search for ways to utilize the aspen timber resource as well as to establish and grow coniferous trees in association with the aspen.  An improved knowledge of aspen ecology and ecosystems, and stand productivity and dynamics is needed in this pursuit, which presupposes classification of aspen ecosystems. There have been only a few ecological studies carried out in aspen ecosystems in BC. These studies included local classification of aspen ecosystems (e.g., DeLong 1988), aspen site index modelling and prediction from environmental factors (Chen et al. 1998a, 1998b), relationships between aspen site index and soil properties (Chen et al. 1998b), and humus form characterization (Fons et al. 1998). While this information has added to our knowledge base, many of these studies have been carried out on a local level. In order to integrate this information and provide a complimentary tool for further studies of aspen ecosystems in BC and their comparison with others across North America, we have developed a regional vegetation classification. The classification, which follows the biogeoclimatic ecosystem classification system, is based on samples of aspen- dominated stands across the BWBS, SBS, SBPS, IDF, MS and ICH zones of BC. Our aim was to organize aspen communities into groups that show the greatest number of vegetation and vegetation-environment relationships, are easily retained in memory and are easily conveyed through instruction. However, we do not claim that we have accounted for all of the many different aspen communities; thus the classification presented is but the first approximation. Other aspects of aspen growth and boreal ecology, such as height/age and site index models, the integration of these productivity relationships into the ecosystem classification, a characterization of understory plant diversity, humus forms, and soil nutrient conditions of aspen ecosystems, and a comparison of the above features between aspen and black spruce ecosystems are discussed in the following reports prepared for publication: Trembling aspen site index in relation to environmental measures of site quality at two spatial scales (Chen et al.),  Height growth models for trembling aspen in BC (Nigh et al.), Comparison of forest floor and mineral soil properties between black spruce and trembling aspen stands in the BWBS zone of BC (Kayahara 2 INTRODUCTION Scientica Silvica Extension Series, Number 27, 2000 et al.), and Plant diversity of mid-seral black spruce and trembling aspen stands in the BWBS and SBS zones (Qian et al.). In this report we present the vegetation classification, which includes, from the lowest to the highest hierarchical level: 13 subassociations, 6 associations, and 4 alliances. We present the summary and diagnostic tables and indicator plant analysis used to show floristic affinities among the units, and to interpret their relationships to climatic and edaphic gradients. The vegetation and environmental data for individual plots are also included in the appendices. This report is available in full colour or B&W printed versions or in electronic format on Scientia Silvica CD-ROM. For further information or to order a copy visit www.forestry.ubc.ca/klinka or contact Karel Klinka, Forest Sciences Department, University of British Columbia, 3036-2424 Main Mall, Vancouver BC  V6T 1Z4 (e-mail: klinka@interchange.ubc.ca). 3METHODS Study Area Trembling Aspen Ecosystems METHODS Study Area The study area encompassed nearly the entire interior area of the province where aspen stands form a significant landscape component (Table 1, Figure 1). The area included (in order from north to south) the BWBS, SBS, SBPS, ICH, IDF, and MS biogeoclimatic zones (Meidinger and Pojar 1991). The BWBS, SBPS, and SBS zones are part of the Canadian Boreal Forest Region (Krajina 1969). The BWBS zone is influenced by a continental, montane boreal climate and subject to frequent outbreaks of arctic masses, while the climate influencing the SBS and SBPS zones is milder. Forest fires are frequent in all these zones, maintaining a large portion of the landscape in early and mid-seral stages. White spruce, hybrid spruce (Picea engelmannii x glauca), black spruce, subalpine fir (Abies lasiocarpa (Hook.) Nutt.), lodgepole pine (Pinus contorta var. latifolia Dougl. ex Loud), trembling aspen, balsam poplar (Populus balsamifera L.) and black cottonwood  (P. trichocarpa Torr. & Gray), paper birch (Betula papyrifera Marsh.) and Alaska paper birch (Betula neoalaskana Sarg.) are the major tree species. In upland ecosystems, aspen typically forms pure stands of various sizes ranging form small cohorts to large-area stands. The IDF, ICH, and MS zones are part of the Cordilleran Montane Forests Region (Krajina 1969) and are influenced by a cool continental temperate climate (with the MS zone grading into a continental subalpine boreal climate). These temperate zones are much warmer than the BWBS, SBS and SBPS zones but have about the same annual precipitation (Table 1). Aspen stands are not as extensive as in the boreal zones. Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), western redcedar (Thuja plicata (Donn ex D.Don) Spach), western hemlock (Tsuga heterophylla (Raf.) Sarg.), western larch (Larix occidentalis Nutt.), lodgepole pine, subalpine fir, and hybrid white spruce are the major tree species in these temperate zones. The soils typically associated with aspen communities in the province are Brunisols, Luvisols, and Podzols (rarely Gleysols, Regosols, or Organic soils), developed from a variety of parent materials. Regardless of site characteristics, the associated humus forms are Mormoders, Moders (frequently laminated), Hemimors, Mullmoders and Mulls (Fons et al. 1998). More detailed information about the vegetation and environment of the zones studied is given in Krajina (1969) and Meidinger and Pojar (1991). 4 M ETH O D S Study Area Scientica Silvica Extension Series, N um ber 27, 2000 Table 1. General spatial, climatic, and growth characteristics of the trembling aspen study plots stratified by biogeoclimatic zones. Biogeoclimatic zone Number of plots Elevation (m) Latitude (°N) Longitude (°W) Mean annual precipitation (mm) Mean annual temperature (°C) Site index (m) (standard  deviation)All plots Site index plots Boreal White and Black Spruce (BWBS) 88 59 525-980 55°42'-59°35' 120°26'-133°10' 446 [46]1 1. Number of climatic stations with precipitation records 0.6 [84]2 2. Number of climatic stations with temperature records 13.7 (4.64) Sub-boreal Spruce (SBS) 25 20 790-1025 52°08'-54°35' 121°21'-124°32' 645 [78] 2.1 [129] 16.7 (3.13) Sub-boreal Pine - Spruce (SBPS) 7 6 870-1040 52°34'-52°35' 123°01'-123°20' 479 [14] 2.4 [11] 18.7 (3.45) Interior Douglas Fir (IDF) 23 20 960-1285 49°22'-52°11' 119°05'-123°31' 442 [90] 5.1 [73] 16.3 (5.25) Montane Spruce (MS) 19 17 980-1285 49°01'-49°31' 115°30'-119°35' 598 [13] 3.1 [12] 22.8 (4.96) Interior Cedar-Hemlock (ICH) 24 19 380-1025 49°02'-55°28' 116°11'-128°31' 795 [60] 5.5 [60] 21.7 (4.81) Total or total range 186 141 380-1285 49°01'-59°35' '115°30'-133°10' 276 (IDF) to 1916 (SBS) -3.2 (SBS) to 9.7 (IDF) 5.5 - 30.7 5METHODS Study Area Trembling Aspen Ecosystems  Figure 1. Map showing the native range of trembling aspen in British Columbia and the location of plots sampled in 1997 and 1998; the plots sampled by Kabzems in northeastern BC in 1995 are not shown on this map. Distribution frequency Sample plots infrequent frequent very frequent isolated stand plot location number of plots at a location (4) (8) (5) (3) (3) (3) (3) (4) (7) (3) (3) (3) (3) (3) (8) (2) (4) (4) (4) (5) (6) (2) (2) (9)(5) (2) (2) 6 METHODS Sampling Scientica Silvica Extension Series, Number 27, 2000 Sampling Sampling in the northeastern portion of the BWBS zone was carried out in 1995 by R. Kabzems, Fort St. John Forest District. We continued the sampling in other areas in 1997 and 1998. The candidate stands were located close to access roads branching off from the Cassiar and Alaska Highways, around Tumbler Ridge, and north of Fort St. James, and from highways in southern BC (Figure 1). During the summer of 1997 we (i) carried out a reconnaissance, (ii) located candidate stands for sampling, and (iii) described 50 plots; during the summer of 1998 we completed description and sampling of selected stands. The complete data set includes vegetation and environment information obtained from 186 plots. These study plots were deliberately located over the widest possible range in climate (latitude, longitude, elevation), topography (aspect, slope gradient), soil moisture and soil nutrient conditions throughout six biogeoclimatic zones: BWBS, SBS, SBPS, IDF, ICH, and MS (Table 1). The study plots, 20 by 20 m squares (0.04 ha), were selected in naturally established, unmanaged, fully stocked, even-aged (immature, early mature, and mature >50 but <150 years at breast height) stands without a history of suppression. The developmental stage of the selected stands ranged from stem exclusion to understory reinitiation (Oliver and Larson 1996). Each stand had a uniform canopy layer formed by trembling aspen and uniform understory vegetation, with the floristic composition varying from site to site. Biogeoclimatic subzone was identified using maps obtained from the regional offices of the BC Ministry of Forests. Latitude and longitude were determined from topographic maps, elevation was measured with a Thommen pocket altimeter, and aspect was measured with a pocket compass. Site, vegetation, and soil of each plot were described according to Luttmerding et al. (1990). All plant species present within the plot were identified and their cover percentage was estimated. These cover values were converted to classes (+ to 9) of the Domin-Krajina scale of species significance. The plant nomenclature followed Qian and Klinka (1998). Unknown plants were collected and identified in the laboratory. A soil pit was dug at each plot and soils were described and identified according to the Canadian Soil Classification System (Agriculture Canada Expert Committeee on Soil Survey 1987). Humus samples were taken from each plot for a visual analysis and identification in the laboratory using the humus form classification of Green et al. (1993). The type of ground cover (forest floor, decaying wood, mineral soil, coarse fragments, and open water) was recorded. A more complete description of the field methods is given in Brooke et al. (1970) and Luttmerding et al. (1990). Soil moisture and nutrient regimes were estimated in the field by a systematically guided evaluation of a selected number of topographic (slope, aspect, gradient, and position) and soil morphological properties (humus form, rooting depth, soil texture, coarse fragment content, soil aeration, soil mineralogy, and the presence and depth of the growing-season water table). This procedure is based on interpreting relationships between these properties, soil water-holding capacity, and available nutrient levels in the soil (Green and Klinka 1994). Field-estimates of SNRs were substantiated by soil nutrient analysis (Kayahara et al. 2000), while SMRs were only field-estimated and not directly measured. Using the criteria proposed by Klinka et al. (1989), we converted relative SMRs to actual SMRs by consulting Wang et al. (1994) for the SBS zone, Banner et al. (1993) for the BWBS zone and New (1999) for the IDF, ICH, and MS zones (Table 2). For field estimates of SNR we used the following mean relative frequencies of nitrophytic species: 1% for very poor SNR, 4% for poor SNR, 9% for medium SNR, 25% 7METHODS Vegetation Classification Trembling Aspen Ecosystems for rich SNR, and 38% for very rich SNR Wang (1992). A complete description of indicator plant analysis is given in Klinka et al. (1989). Table 2. Estimated generalized relationships between relative and actual soil moisture regimes (SMRs) for the study zones. Actual SMRs are abbreviated as follows: ED - excessively dry, VD - very dry, MD - moderately dry, SD slightly dry, F - fresh, M - moist, VM - very moist, W - wet. Definitions of actual SMRs are given in Klinka et al. (1989). Vegetation Classification Our objective was to produce ecologically meaningful classes of ecosystems that could be identified and used as a framework for examining vegetation-environment relationships. Consistent with the methods of the biogeoclimatic ecosystem classification, the plots within each group had to represent communities that had affinities in floristic composition and physiognomy.  The groups of plots were required to (1) be floristically distinct, and (2) occupy a floristically defined segment of the edaphic and local climatic gradients. We classified the ecosystems into vegetation units at three categorical levels (subassociation, association, and alliance) using the Braun-Blanquet approach (Mueller- Dombois and Ellenberg 1974: 177-210; Westhoff and van der Maarel 1980: 287-399). This method consists of grouping the plots in a way that each group is separated from all other groups by an exclusive diagnostic combination of species. These diagnostic species must be either differential species, which have a much higher presence (proportion of plots of a group that it occurs in) than in other groups, or a dominant differential species, which have higher species significance (percent cover) than in other groups. The exact criteria are as follows (Becking 1957): differential species: species that may be associated with more than one vegetation unit in a hierarchy; presence class ≥ III (occurring in ≥ 40% of the plots of this unit) and at least two presence classes greater than in other units of the same hierarchical level within the same higher level unit. dominant-differential species: species that may be associated with more than one vegetation unit in a hierarchy; presence class ≥ III, mean species significance ≥ 5 (≥ 10% cover) and two or more species significance classes greater than in other units of the same hierarchical level within the same higher level unit. Biogeoclimatic zone Relative Soil Moisture Regime 1 2 3 4 5 6 7 Boreal White and Black Spruce VD MD SD SD F-M VM W Sub-boreal Spruce VD MD SD F M VM W Sub-boreal Pine – Spruce VD VD MD MD SD F-M VM-W Montane Spruce VD MD SD SD F M-VM W Interior Cedar – Hemlock VD MD SD F M VM W Interior Douglas-fir ED VD VD MD SD F-M VM-W 8 METHODS Vegetation Classification Scientica Silvica Extension Series, Number 27, 2000 There is no universally accepted methodology for, nor agreement upon, the required composition of the diagnostic combination of species for a particular category (Becking 1957; Mueller-Dombois and Ellenberg 1974; Westhoff and van Maarel 1980). We used the principle of relative differentiation that allows delineation of a subassociation or association by an exclusive diagnostic combination of species. The diagnostic combination must include at least one differential species or dominant-differential species. However, a subassociation or association that represents the central concept, i.e. typic, of a higher circumscribing unit can be recognized without a diagnostic combination of species. A typic unit can be differentiated by the absence or low occurrence of species that characterize other subassociations or associations of the same hierarchical level within the same higher level unit (Pojar et al. 1987: 131-132). The major tool used to achieve this objective was a computer-aided program, VTAB- Ecosystem Reporter, Revision 19907a (Emanuel 1999), which produces the various tables required in the analysis and synthesis of vegetation data. It arranges columns (plots or groups of plots) and rows (species) according to the criteria specified by the user for each step of the tabular analysis and synthesis. The following four analytical steps were used to synthesize the data: Step 1 Plots were stratified into floristically similar groups using a two-way indicator species analysis (TWINSPAN, Hill 1979). This program divides the plots into two groups, then further subdivides each of these groups in subsequent steps. When all the plots in a group are relatively uniform according to predetermined criteria, subdivision of this group stops. Step 2 For each of the groups obtained in step 1, a tentative vegetation plot table, which shows the species significance of each species in all plots of the group (e.g., Appendices 2 through 16), was produced and examined for within-group similarities and differences. A tentative differentiated summary vegetation table (e.g., Table 5), showing species presence and average species significance for each group, was used to examine floristic affinities and differences between groups. Step 3 Tentative environmental plot tables, which show selected environmental characteristics for all plots within each group (e.g., Appendices 17 through 31), were used to determine whether the floristically similar plots were also similar in environmental characteristics. Floristically and environmentally aberrant plots were reassigned to the group to which they were most closely related. After reassignment, the summary vegetation tables were inspected to determine to which extent the groups of plots could be differentiated from each other in a hierarchical manner. The groups that could not be differentiated were merged. Steps 2 and 3 were repeated iteratively in a process of successive approximation (Poore 1962), in which the production of revised vegetation and environmental tables continued until there were no more plot re-assignments and group mergers. Step 4 A tentative hierarchy of groups was then proposed, where each group was considered to be either an association or a subassociation depending on its relationship to the hierarchy. A preliminary diagnostic table showing the diagnostic combination of species for every group was produced. Step 4 was repeated in a process of successive approximation in which the production of tentative diagnostic tables continued until exclusive diagnostic combinations of species were obtained for each group of the hierarchy. This process typically required 9METHODS Vegetation Classification Trembling Aspen Ecosystems changes in the structure of the hierarchy and occasionally merging of some of the groups lacking a diagnostic combination of species. Instead of using phytosociological nomenclature (Barkman et al. 1976) we used the scientific names without suffixes for naming vegetation units. Plant alliances and associations were named using the generic and specific names of two dominant species from the diagnostic combination of species for that association, e.g., the Populus tremuloides – Lathyrus ochroleucus plant association. Plant subassociations were named by adding a colon (:) to the association name, followed either by the term ‘typic’ (to represent what we believed to be the central concept of that association) or the name of one diagnostic species, e.g., the Populus tremuloides – Lathyrus ochroleucus: Actaea rubra plant subassociation. All units based on the synthesis of <10 sample plots were considered tentative. Similarity and Cluster Analysis Using VTAB, we compared floristic similarities between pairs of vegetation units using Sørenson’s index based on presence/absence of species (Equation 1, Magurran 1988), as well as on species cover (Equation 2, Qian et al. 1997). The presence/absence index is a simple but effective measure of the number of species shared between two vegetation units. Both indices enable the comparison of floristic similarity between vegetation units.  Equation 1. , where Equation 2. , where We carried out a cluster analysis using the average linkage method with values of the Sørenson presence/absence index as the distance measure. A dendrogram based on this cluster analysis was constructed to illustrate the relationships between the units. Spectral Analysis To provide a simple means for characterizing the vegetation of a group of plots complementary to tabular analysis, VTAB-assisted ‘spectral analysis’ was carried out (Mueller-Dombois & Ellenberg 1974:315-319). Spectral analysis was performed on indicator species groups for climate (CL), soil moisture regime (SMR), and soil nutrient regime (SNR), and on life forms (LF) (coniferous trees, broad-leaved trees, evergreen shrubs, deciduous shrubs, ferns, graminoids, herbs, mosses, liverworts, lichens, parasites and saprophytes, and dwarf woody plants) (Klinka et al. 1989). Spectra presenting the relative frequency of each life form (or indicator species group) were constructed for each vegetation unit. Relative frequencies were calculated using Equation 3 (Klinka et al. 1996). The plots were not standardized, i.e., plots with a greater total vegetation cover or indicator species cover contribute relatively more to the spectrum of the vegetation unit. SI 2c a b+( )----------------= SI 2CA B+( )-----------------= a = the number of species in the first unit, b = the number of species in the second unit, and c = the number of species common to both units. A = the cover sum of all species in the first unit, B = the cover sum of all species in the second unit, and C = the sum of the lower of the two cover values for the species common to both units. 10 METHODS Vegetation Classification Scientica Silvica Extension Series, Number 27, 2000 Equation 3. , where Diversity Analysis To compare diversity in the understory vegetation of study stands, we used the number of plant species in each sample plot as index of species diversity. Mean species diversity per plot and standard deviations of the means were calculated for each delineated vegetation unit. Analysis of variance (ANOVA) and Tukey's honestly significantly different (HSD) tests were used to detect significant differences between the means. Fj Ci i 1= n ∑ Cij i 1= n ∑ j 1= m ∑ --------------------------=  = relative frequency (%) of species group j (j = 1,2,3...m) for attribute LF (m= 12), CL (m= 6), SMR (m= 6), SNR (m= 3); and  = midpoint percent cover value of species i (i= 1,2,3...n). Fj Ci 11RESULTS AND DISCUSSION Vegetation Classification Trembling Aspen Ecosystems RESULTS AND DISCUSSION Vegetation Classification All 186 study plots were classified into a 3-level hierarchy of vegetation units that included 13 subassociations, 6 associations, and 4 alliances (Table 3). These units were delineated according to floristic differences (diagnostic combinations of species) that are summarized in Table 4 and Table 5; non-diagnostic species are shown in Appendix 1. The significance values of all species in each plot of each of the fifteen basic vegetation units (vegetation plot tables) are given in Appendices 2 through 16; environmental characteristics of each plot in each of the fifteen units (environmental plot tables) are given in Appendices 17 through 31. For brevity, when referring to vegetation units in the text, we avoided using 'Populus tremuloides' and the specific names without creating ambiguities; e.g., Mertensia alliance instead of Populus tremuloides - Mertensia paniculata alliance. The diagnostic table indicates that differentiation of 15 basic units was reasonably strong as each unit in the proposed hierarchy has several differential species (usually more than five), except for the Rosa - Senecio subassociation with only one differential species. The summary table provides a useful overview of distribution of the species that occur at least in one unit with the presence ≥III (41 to 60%) across a given unit. Table 3. Synopsis of delineated vegetation units in trembling aspen ecosystems indicating levels of generalization and relationships. The row containing the names of associations are printed in bold fonts. Numerical codes indicate position of a unit in the hierarchy; the same codes are used in diagnostic and summary vegetation tables. Asterisk indicates an insufficient sampled unit (<10 plots). Code Plant alliance Plant association Plant subassociation 100 Populus tremuloides - Mertensia paniculata 110 Populus tremuloides - Mertensia paniculata 111 Populus tremuloides - Mertensia paniculata: Festuca altaica* (4 plots) 112 Populus tremuloides - Mertensia paniculata: Arnica cordifolia (14 plots) 113 Populus tremuloides - Mertensia paniculata: Petasites frigidus (13 plots) 200 Populus tremuloides - Elymus innovatus 210 Populus tremuloides - Ledum groelandicum (10 plots) 220 Populus tremuloides - Lathyrus ochroleucus 221 Populus tremuloides- Lathyrus ochroleucus: Hedysarum boreale (11 plots) 222 Populus tremuloides- Lathyrus ochroleucus: typic (31 plots) 223 Populus tremuloides- Lathyrus ochroleucus: Actaea rubra (10 plots) 300 Populus tremuloides - Thalictrum occidentale 310 Populus tremuloides - Thalictrum occidentale (10 plots) 400 Populus tremuloides - Symphoricarpos albus 410 Populus tremuloides - Viburnum edule 411 Populus tremuloides - Viburnum edule: Spiraea betulifolia (17 plots) 412 Populus tremuloides - Viburnum edule: Paxistima myrsinites (10 plots) 420 Populus tremuloides - Rosa nutkana 421 Populus tremuloides - Rosa nutkana: Aralia nudicaulis (14 plots) 422 Populus tremuloides - Rosa nutkana: Arnica cordifolia* (9 plots) 423 Populus tremuloides - Rosa nutkana: Angelica genuflexa* (9 plots) 424 Populus tremuloides - Rosa nutkana: Senecio pseudoaureus * (9 plots) 425 Populus tremuloides - Rosa nutkana: Shepherdia canadensis (15 plots) 12 RESU LTS AN D  D ISCU SSIO N Vegetation Classification Scientica Silvica Extension Series, N um ber 27, 2000 Table 4. Diagnostic combinations of species for the vegetation units in aspen ecosystems. The diagnostic combination of species for each vegetation unit is shaded in grey. Presence values ≥III are printed in bold. An asterisk (*) indicates an insufficiently sampled unit (<10 plots). Vegetation unit 111 112 113 210 221 222 223 300 411 412 421 422 423 424 425 Number of plots 4 14 13 10 11 31 10 10 17 10 14 9 9 9 15 Species Diagnostic value1 Species presence 2  and species significance3 100 & 110 Populus tremuloides - Mertensia paniculata alliance and association Cladina stellaris (ic) II h I h I h Cladonia ecmocyna (ic) II h I h I h Empetrum nigrum (ic) II h I h II 2 Festuca altaica (d) IV 6 II + III 1 Geocaulon lividum (d) IV 3 V 2 IV 1 IV 3 I h I h I h Mertensia paniculata (d) III 1 IV 3 IV 2 III 2 IV 3 I h I h I h I h Pedicularis labradorica (ic) III + I + II h Peltigera membranacea (ic) II h II h II 2 I h Pleurozium schreberi (dd) IV 3 IV 7 IV 6 IV 4 I h I + I h III 4 III 4 III + I h I h I h Salix scouleriana (d) IV 6 II 4 III 4 II 4 I 3 II 2 I + I h Shepherdia canadensis (d) V 5 V 7 IV 3 I 1 IV 4 IV 4 I 1 I 4 II 4 II 1 I h III 4 I 3 III 5 IV 6 111 Populus tremuloides - Mertensia paniculata: Festuca altaica subassociation* (4 plots) Arctostaphylos uva-ursi (d) IV 5 II 4 I 2 I 2 III 5 I h I h II 4 III 6 Festuca altaica (dd) IV 6 II + III 1 Galium boreale (d) V 3 I h III 1 IV 4 IV 3 II 2 III + IV 1 II + II + II h I + III + Juniperus communis (d) IV 5 II 3 I h I h II 3 III 5 Pulsatilla patens  (d) III + I h I h II h Trisetum spicatum (d) III + I h I h I h I h Viburnum edule (dd) IV 6 IV 3 III 4 I 2 V 4 V 5 III 4 IV 6 IV 4 I + II 1 112 Populus tremuloides - Mertensia paniculata: Arnica cordifolia subassociation (14 plots) Arnica cordifolia (d) V 4 II 2 I 1 I + I h II h II h II 4 IV 4 II + II 1 I h Orthilia secunda (d) III + V 1 III h I h III 1 I 2 II h II h III + I h II h I h II h II + Shepherdia canadensis (dd) V 5 V 7 IV 3 I 1 IV 4 IV 4 I 1 I 4 II 4 II 1 I h III 4 I 3 III 5 IV  6 113 Populus tremuloides - Mertensia paniculata: Petasites frigidus subassociation (13 plots) Lupinus arcticus (d) II 2 II 1 IV 3 II 3 I 2 Mitella nuda (d) III + I h III 2 I h II h I h Petasites frigidus (d) I h IV 3 V 4 III 3 III 3 IV 3 III 2 II + I h I h 200 Populus tremuloides - Elymus innovatus alliance Calamagrostis canadensis (d) II h I h III 2 IV 3 III 3 IV 3 II h II h I h III 6 II h IV + I 2 Elymus innovatus (d) III 1 V 5 IV 4 II 1 Salix sp. (d) IV 3 III 4 V 4 II 3 13 RESU LTS AN D  D ISCU SSIO N Vegetation Classification Trem bling Aspen Ecosystem s 210 Populus tremuloides - Ledum groenlandicum association (10 plots) Abies lasiocarpa (d) II 2 II 4 I h IV 2 I 1 I h I 2 II 4 I + I + II 4 I 3 Cladina rangiferina (d) IV 4 I t Geocaulon lividum (d) IV 3 V 2 IV 1 IV 3 I h I h I h Ledum groenlandicum (d) I 1 II 3 V 7 II 4 II 4 Lycopodium clavatum (d) III 3 I 1 Lycopodium complanatum (d) I h IV 5 I + I h Melampyrum lineare (d) IV 2 I h I h I h Peltigera aphthosa (d) II h II 2 II 1 IV 4 I t I h I h I h I h I h I h Picea mariana (d) III 4 IV 5 III 4 I 2 I 2 I 2 Pinus contorta (d) II h I 4 II 5 III 3 I h I 2 I 2 I 2 I 2 I 4 III 5 II 4 II 5 IV 5 IV 6 Pleurozium schreberi (d) IV 3 IV 7 IV 6 IV 4 I h I + I h III 4 III 4 III + I h I h I h Polytrichum juniperinum (d) V 3 I h I h Spiraea betulifolia (d) I + V 3 II 2 II 2 II + I 3 IV 4 I + II 1 IV 1 III 3 III 1 I h Stereocaulon tomentosum (d) II + III 2 Vaccinium vitis-idaea (d) II 3 I h III 3 V 5 III 3 II 3 220 Populus tremuloides - Lathyrus ochroleucus association Amelanchier alnifolia (d) II 1 I h I h III 4 II + III 2 I h IV 4 III + III 2 II + V 6 IV 2 II h Aster conspicuus (d) I + I 3 IV 5 IV 4 III 4 III 3 III 4 I h I h I 1 V 3 III 3 II 3 Fragaria virginiana (d) IV + III 2 III 2 IV 2 IV 2 III 1 III 1 III + I h II + II h II 1 IV + III + Galium boreale (d) V 3 I h III 1 IV 4 IV 3 II 2 III + IV 1 II + II + II h I + III + Lathyrus ochroleucus (d) I + II 2 V 4 V 3 III 3 III 2 III 2 I + II h Pyrola asarifolia (d) I h II 1 V 4 IV 4 I 2 II h III + II + II h Rosa acicularis (d) V 4 V 4 V 3 I 2 V 4 V 5 V 4 IV 5 V 5 IV 4 II 3 II h I h II + 221 Populus tremuloides - Lathyrus ochroleucus: Hedysarum boreale subassociation (11 plots) Achillea millefolium (d) III + III + III + IV 1 I h I h III + III h I h II h I h III + III 2 Arctostaphylos uva-ursi (d) IV 5 II 4 I 2 I 2 III 5 I h I h II 4 III 6 Hedysarum boreale (d) IV 4 Oryzopsis asperifolia (d) I + I h III 4 I + I h II h I 3 Vaccinium myrtilloides (d) V 7 IV 4 I 4 222 Populus tremuloides - Lathyrus ochroleucus: typic subassociation (31 plots) Cornus canadensis (dd) IV 5 IV 6 V 5 II 5 V 6 IV 4 III 2 III 3 IV 3 IV 5 II 5 III 4 Hylocomium splendens (d) II h V 7 IV 7 I h I 3 IV 3 I h III 4 I + II + I + I h Orthilia secunda (d) III + V 1 III h I h III 1 I 2 II h II h III + I h II h I h II h II + Rubus pubescens (d) I + II 2 V 4 III 3 III 2 IV 3 III 1 I + Salix sp. (d) IV 3 III 4 V 4 II 3 Vegetation unit 111 112 113 210 221 222 223 300 411 412 421 422 423 424 425 Number of plots 4 14 13 10 11 31 10 10 17 10 14 9 9 9 15 Species Diagnostic value1 Species presence 2  and species significance3 14 RESU LTS AN D  D ISCU SSIO N Vegetation Classification Scientica Silvica Extension Series, N um ber 27, 2000 223 Populus tremuloides - Lathyrus ochroleucus: Actaea rubra subassociation (10 plots) Actaea rubra (d) I h I + I h V 4 II + III 2 I h I h I h III 4 I 2 Aralia nudicaulis (d) I h I + I 1 II 4 IV 5 II 3 IV 5 V 4 IV 5 II 4 I + I 3 Cornus sericea (d) I + V 4 Delphinium glaucum (d) IV + III + I h IV 4 Equisetum pratense (d) I h I h I 4 II h IV 5 III + I h II h I h II h Galium triflorum (d) I h I h I h V 4 II h II h II h III + IV + IV + IV + Heracleum maximum (d) I h III 4 I 2 I 1 I + I + Lonicera involucrata (d) I 2 I + I h II 1 IV 4 III 4 III 4 III 2 I + I h II 5 I h Mitella nuda (d) III + I h III 2 I h II h I h Osmorhiza berteroi (d) II h II + I + I h I h III 2 I h V 2 III + IV 2 IV 1 V 3 IV + I h Populus balsamifera (d) II 2 I 2 I 1 III 5 I 4 I 3 III 5 I 1 I 2 I 4 Ribes oxyacanthoides (d) I h III 3 Viola canadensis (d) I h III 4 II 1 I + I h III 2 II + I h 300 & 310 Populus tremuloides - Thalictrum occidentale alliance and association (10 plots) 400 Populus tremuloides - Symphoricarpos albus alliance Amelanchier alnifolia (d) II 1 I h I h III 4 II + III 2 I h IV 4 III + III 2 II + V 6 IV 2 II h Elymus glaucus (d) I h I h I + I h IV + III + IV 1 IV + III h V 1 II h Maianthemum racemosum  (ic) I h I + I + I h III 3 III 2 II 3 II + IV 4 III 3 I h Maianthemum stellatum  (ic) I 1 I h III 1 II h III 3 IV 2 III + I h Osmorhiza berteroi (ic) II h II + I + I h I h III 2 I h V 2 III + IV 2 IV 1 V 3 IV + I h Paxistima myrsinites  (d) I h II 5 V 7 II 2 III 2 II 5 III 4 II 3 Symphoricarpos albus (d) II 2 I + II + IV 4 III + IV 3 III + IV 6 IV 5 II + 410 Populus tremuloides - Viburnum edule association Aralia nudicaulis (d) I h I + I 1 II 4 IV 5 II 3 IV 5 V 4 IV 5 II 4 I + I 3 Cornus stolonifera (ic) I h I 2 I h II 3 IV 5 IV 5 III 4 III 2 III 3 II 5 Epilobium angustifolium (ic) V 6 V 6 IV 3 IV 3 III 2 V 4 IV 3 V 6 III 2 III + I h I h I h II + II + Lathyrus ochroleucus (d) I + II 2 V 4 V 3 III 3 III 2 III 2 I + II h Lonicera involucrata (d) I 2 I + I h II 1 IV 4 III 4 III 4 III 2 I + I h II 5 I h Pleurozium schreberi (d) IV 3 IV 7 IV 6 IV 4 I h I + I h III 4 III 4 III + I h I h I h Pyrola asarifolia (ic) I h II 1 V 4 IV 4 I 2 II h III + II + II h Rosa acicularis (d) V 4 V 4 V 3 I 2 V 4 V 5 V 4 IV 5 V 5 IV 4 II 3 II h I h II + Rubus pubescens (d) I + II 2 V 4 III 3 III 2 IV 3 III 1 I + Viburnum edule (d) IV 6 IV 3 III 4 I 2 V 4 V 5 III 4 IV 6 IV 4 I + II 1 Vegetation unit 111 112 113 210 221 222 223 300 411 412 421 422 423 424 425 Number of plots 4 14 13 10 11 31 10 10 17 10 14 9 9 9 15 Species Diagnostic value1 Species presence 2  and species significance3 15 RESU LTS AN D  D ISCU SSIO N Vegetation Classification Trem bling Aspen Ecosystem s 411 Populus tremuloides - Viburnum edule: Spiraea betulifolia subassociation (17 plots) Achillea millefolium (d) III + III + III + IV 1 I h I h III + III h I h II h I h III + III 2 Actaea rubra (d) I h I + I h V 4 II + III 2 I h I h I h III 4 I 2 Aster ciliolatus (d) I h I h II + I + I h I h III 1 I h II + II h III + II h Aster conspicuus (d) I + I 3 IV 5 IV 4 III 4 III 3 III 4 I h I h I 1 V 3 III 3 II 3 Fragaria virginiana (d) IV + III 2 III 2 IV 2 IV 2 III 1 III 1 III + I h II + II h II 1 IV + III + Galium boreale (d) V 3 I h III 1 IV 4 IV 3 II 2 III + IV 1 II + II + II h I + III + Osmorhiza berteroi (ic) II h II + I + I h I h III 2 I h V 2 III + IV 2 IV 1 V 3 IV + I h Picea glauca (d) II 1 IV 6 IV 5 III 5 V 5 IV 4 III 5 IV 7 V 6 II 3 III 4 II 4 III 4 III 4 I + Ribes lacustre (d) I h I h I h II 2 II 3 III 2 I h II 1 II h I h I h Spiraea betulifolia (d) I + V 3 II 2 II 2 II + I 3 IV 4 I + II 1 IV 1 III 3 III 1 I h Thalictrum occidentale (d) I 3 I + III 3 V 2 II 2 I h II 1 V 5 III 3 I + Viburnum edule (dd) IV 6 IV 3 III 4 I 2 V 4 V 5 III 4 IV 6 IV 4 I + II 1 412 Populus tremuloides - Viburnum edule: Paxistima myrsinites subassociation (10 plots) Betula papyrifera (d) I h I h II 1 I 2 I + I 2 III 6 III 5 IV 6 I h Corylus cornuta (d) I 4 III 6 Paxistima myrsinites  (d) I h II 5 V 7 II 2 III 2 II 5 III 4 II 3 Rhytidiadelphus triquetrus (d) I 4 I + I h II 2 IV 3 I 3 Thuja plicata (d) III 5 II 6 II 2 II 2 Tsuga heterophylla (d) III 3 I + II 5 420 Populus tremuloides - Rosa nutkana association Acer glabrum (ic) II 4 III 5 III 5 II 3 II 4 I h Alnus incana  (ic) I h I 1 I 3 II 4 III 5 II 3 II 5 III 5 I 3 Festuca subuliflora (ic) I h I h I h I h IV 2 III h II h III + II h Galium triflorum (ic) I h I h I h V 4 II h II h II h III + IV + IV + IV + Hieracium scouleri (ic) I h II h I h II h II h Lonicera utahensis (ic) I h II 4 I h II 4 II 4 I h Mahonia aquifolium (d) I 3 I h II h III 2 IV 3 IV 4 II 2 Pinus contorta (ic) II h I 4 II 5 III 3 I h I 2 I 2 I 2 I 2 I 4 III 5 II 4 II 5 IV 5 IV 6 Pseudotsuga menziesii (ic) I 3 I 2 II 4 I 3 I + IV 6 III 5 IV 5 II 5 Rosa nutkana (d) I h III + III + IV 4 IV 4 III 2 421 Populus tremuloides - Rosa nutkana: Aralia nudicaulis subassociation (14 plots) Aralia nudicaulis (d) I h I + I 1 II 4 IV 5 II 3 IV 5 V 4 IV 5 II 4 I + I 3 Calamagrostis canadensis (dd) II h I h III 2 IV 3 III 3 IV 3 II h II h I h III 6 II h IV + I 2 Populus balsamifera (d) II 2 I 2 I 1 III 5 I 4 I 3 III 5 I 1 I 2 I 4 Tiarella trifoliata (d) III + 422 Populus tremuloides - Rosa nutkana: Arnica cordifolia subassociation* (9 plots) Arnica cordifolia (d) V 4 II 2 I 1 I + I h II h II h II 4 IV 4 II + II 1 I h Chimaphila umbellata (ic) I + I + III 2 II h I h I 1 Pinus monticola (dd) I 2 II 3 III 5 I h Vaccinium caespitosum (dd) I + I 3 I 1 I h II h III 6 I 1 Vegetation unit 111 112 113 210 221 222 223 300 411 412 421 422 423 424 425 Number of plots 4 14 13 10 11 31 10 10 17 10 14 9 9 9 15 Species Diagnostic value1 Species presence 2  and species significance3 16 RESU LTS AN D  D ISCU SSIO N Vegetation Classification Scientica Silvica Extension Series, N um ber 27, 2000 423 Populus tremuloides - Rosa nutkana: Angelica genuflexa subassociation* (9 plots) Actaea rubra (d) I h I + I h V 4 II + III 2 I h I h I h III 4 I 2 Amelanchier alnifolia (dd) II 1 I h I h III 4 II + III 2 I h IV 4 III + III 2 II + V 6 IV 2 II h Angelica genuflexa (d) I h I h IV 4 I h Aster conspicuus (d) I + I 3 IV 5 IV 4 III 4 III 3 III 4 I h I h I 1 V 3 III 3 II 3 Disporum hookeri (d) I h III 4 II 2 I 2 II 1 IV 5 II h I h Lilium columbianum (d) I h II h V + II h I h Thalictrum occidentale (d) I 3 I + III 3 V 2 II 2 I h II 1 V 5 III 3 I + 424 Populus tremuloides - Rosa nutkana: Senecio pseudoaureus subassociation* (9 plots) Senecio pseudaureus (d) I h II + I h II h IV 1 I h 425 Populus tremuloides - Rosa nutkana: Shepherdia canadensis subassociation (15 plots) Arctostaphylos uva-ursi (dd) IV 5 II 4 I 2 I 2 III 5 I h I h II 4 III 6 Galium boreale (ic) V 3 I h III 1 IV 4 IV 3 II 2 III + IV 1 II + II + II h I + III + Juniperus communis (ic) IV 5 II 3 I h I h II 3 III 5 1 Species diagnostic values: d = differential, dd = dominant differential, ic = important companion (Pojar et al. 1987). 2 Species presence classes (the percentage of plots in which the species occurs): I = 1-20%, II = 21-40%, III = 41-60%, IV = 61-80%, V = 81-100%. 3 Species significance classes and the corresponding mid-point and range (in parentheses) of cover: t = 0.005 (0.001-0.009), h = 0.05 (0.01 - 0.099), + = 0.2 (0.1- 0.299), 1 = 0.4 (0.3-0.499), 2 = 0.75 (0.5-0.999), 3 = 1.5 (1-1.999), 4 = 3.5 (2-4.999), 5 = 7.5 (5-9.999), 6 = 15 (10-19.999), 7 = 35 (20-49.999), 8 = 60 (50- 69.999), 9 = 85 (70-100). Vegetation unit 111 112 113 210 221 222 223 300 411 412 421 422 423 424 425 Number of plots 4 14 13 10 11 31 10 10 17 10 14 9 9 9 15 Species Diagnostic value1 Species presence 2  and species significance3 17 RESU LTS AN D  D ISCU SSIO N Vegetation Classification Trem bling Aspen Ecosystem s Table 5. Differentiated (in descending order of presence from left to right) summary table of the vegetation units in aspen ecosystems. This table contains only plant species present in ≥ 41% of the plots in at least one vegetation unit (presence class ≥III ). As most of these species were diagnostic (differential, dominant- differential, and important companion species, Table 6) for a vegetation unit, only non-diagnostic species are shaded in grey. Presence values >III are printed in bold. Vegetation unit 111 112 113 210 221 222 223 300 411 412 421 422 423 424 425 Number of plots 4 14 13 10 11 31 10 10 17 10 14 9 9 9 15 Species Species presence and species significance1 Pulsatilla patens III + I h I h II h Pedicularis labradorica III + I + II h Trisetum spicatum III + I h I h I h I h Festuca altaica IV 6 II + III 1 Juniperus communis IV 5 II 3 I h I h II 3 III 5 Salix scouleriana IV 6 II 4 III 4 II 4 I 3 II 2 I + I h Arctostaphylos uva-ursi IV 5 II 4 I 2 I 2 III 5 I h I h II 4 III 6 Delphinium glaucum IV + III + I h IV 4 Geocaulon lividum IV 3 V 2 IV 1 IV 3 I h I h I h Mertensia paniculata III 1 IV 3 IV 2 III 2 IV 3 I h I h I h I h Orthilia secunda III + V 1 III h I h III 1 I 2 II h II h III + I h II h I h II h II + Galium boreale V 3 I h III 1 IV 4 IV 3 II 2 III + IV 1 II + II + II h I + III + Pleurozium schreberi IV 3 IV 7 IV 6 IV 4 I h I + I h III 4 III 4 III + I h I h I h Achillea millefolium III + III + III + IV 1 I h I h III + III h I h II h I h III + III 2 Shepherdia canadensis V 5 V 7 IV 3 I 1 IV 4 IV 4 I 1 I 4 II 4 II 1 I h III 4 I 3 III 5 IV 6 Viburnum edule IV 6 IV 3 III 4 I 2 V 4 V 5 III 4 IV 6 IV 4 I + II 1 Rosa acicularis V 4 V 4 V 3 I 2 V 4 V 5 V 4 IV 5 V 5 IV 4 II 3 II h I h II + Epilobium angustifolium V 6 V 6 IV 3 IV 3 III 2 V 4 IV 3 V 6 III 2 III + I h I h I h II + II + Fragaria virginiana IV + III 2 III 2 IV 2 IV 2 III 1 III 1 III + I h II + II h II 1 IV + III + Linnaea borealis IV 4 V 5 V 5 V 3 V 3 V 4 III 3 III 3 IV + III 4 II + III 4 II 3 II 4 Populus tremuloides V 7 V 7 V 7 V 8 V 8 V 8 V 8 V 8 V 8 V 7 V 8 V 8 V 8 V 8 V 7 Goodyera repens III + II + I h I h Arnica cordifolia V 4 II 2 I 1 I + I h II h II h II 4 IV 4 II + II 1 I h Picea mariana III 4 IV 5 III 4 I 2 I 2 I 2 Hylocomium splendens II h V 7 IV 7 I h I 3 IV 3 I h III 4 I + II + I + I h Cornus canadensis IV 5 IV 6 V 5 II 5 V 6 IV 4 III 2 III 3 IV 3 IV 5 II 5 III 4 Picea glauca II 1 IV 6 IV 5 III 5 V 5 IV 4 III 5 IV 7 V 6 II 3 III 4 II 4 III 4 III 4 I + Lupinus arcticus II 2 II 1 IV 3 II 3 I 2 Mitella nuda III + I h III 2 I h II h I h Petasites frigidus I h IV 3 V 4 III 3 III 3 IV 3 III 2 II + I h I h Ptilium crista-castrensis II 2 III 3 I h I h II 3 III + I h Vaccinium vitis-idaea II 3 I h III 3 V 5 III 3 II 3 Abies lasiocarpa II 2 II 4 I h IV 2 I 1 I h I 2 II 4 I + I + II 4 I 3 Cladina rangiferina IV 4 I t Ledum groenlandicum I 1 II 3 V 7 II 4 II 4 Lycopodium clavatum III 3 I 1 Lycopodium complanatum I h IV 5 I + I h 18 RESU LTS AN D  D ISCU SSIO N Vegetation Classification Scientica Silvica Extension Series, N um ber 27, 2000 Melampyrum lineare IV 2 I h I h I h Peltigera aphthosa II h II 2 II 1 IV 4 I t I h I h I h I h I h I h Polytrichum juniperinum V 3 I h I h Stereocaulon tomentosum II + III 2 Vaccinium myrtilloides V 7 IV 4 I 4 Elymus innovatus III 1 V 5 IV 4 II 1 Maianthemum canadense I + III 3 V 4 IV 3 I + I h Salix sp. IV 3 III 4 V 4 II 3 Pinus contorta II h I 4 II 5 III 3 I h I 2 I 2 I 2 I 2 I 4 III 5 II 4 II 5 IV 5 IV 6 Spiraea betulifolia I + V 3 II 2 II 2 II + I 3 IV 4 I + II 1 IV 1 III 3 III 1 I h Calamagrostis canadensis II h I h III 2 IV 3 III 3 IV 3 II h II h I h III 6 II h IV + I 2 Hedysarum boreale IV 4 Oryzopsis asperifolia I + I h III 4 I + I h II h I 3 Vicia americana I h I h III 3 II 1 I h III + II + II h II + I h II h Lathyrus ochroleucus I + II 2 V 4 V 3 III 3 III 2 III 2 I + II h Amelanchier alnifolia II 1 I h I h III 4 II + III 2 I h IV 4 III + III 2 II + V 6 IV 2 II h Aster conspicuus I + I 3 IV 5 IV 4 III 4 III 3 III 4 I h I h I 1 V 3 III 3 II 3 Pyrola asarifolia I h II 1 V 4 IV 4 I 2 II h III + II + II h Rubus pubescens I + II 2 V 4 III 3 III 2 IV 3 III 1 I + Cornus sericea I + V 4 Galium triflorum I h I h I h V 4 II h II h II h III + IV + IV + IV + Ribes oxyacanthoides I h III 3 Heracleum maximum I h III 4 I 2 I 1 I + I + Equisetum pratense I h I h I 4 II h IV 5 III + I h II h I h II h Populus balsamifera II 2 I 2 I 1 III 5 I 4 I 3 III 5 I 1 I 2 I 4 Viola canadensis I h III 4 II 1 I + I h III 2 II + I h Osmorhiza berteroi II h II + I + I h I h III 2 I h V 2 III + IV 2 IV 1 V 3 IV + I h Actaea rubra I h I + I h V 4 II + III 2 I h I h I h III 4 I 2 Aralia nudicaulis I h I + I 1 II 4 IV 5 II 3 IV 5 V 4 IV 5 II 4 I + I 3 Lonicera involucrata I 2 I + I h II 1 IV 4 III 4 III 4 III 2 I + I h II 5 I h Calamagrostis rubescens I h I 4 III 3 I 1 II 2 III 4 I h V 6 V 6 Thalictrum occidentale I 3 I + III 3 V 2 II 2 I h II 1 V 5 III 3 I + Ribes lacustre I h I h I h II 2 II 3 III 2 I h II 1 II h I h I h Aster ciliolatus I h I h II + I + I h I h III 1 I h II + II h III + II h Disporum hookeri I h III 4 II 2 I 2 II 1 IV 5 II h I h Maianthemum racemosum  I h I + I + I h III 3 III 2 II 3 II + IV 4 III 3 I h Maianthemum stellatum  I 1 I h III 1 II h III 3 IV 2 III + I h Clintonia uniflora I + I h I h III 3 IV 2 III 2 III 4 III 3 I h Cornus stolonifera I h I 2 I h II 3 IV 5 IV 5 III 4 III 2 III 3 II 5 Elymus glaucus I h I h I + I h IV + III + IV 1 IV + III h V 1 II h Rubus parviflorus I h I + IV 5 V 4 III 5 V 4 IV 6 III 4 Symphoricarpos albus II 2 I + II + IV 4 III + IV 3 III + IV 6 IV 5 II + Corylus cornuta I 4 III 6 Rhytidiadelphus triquetrus I 4 I + I h II 2 IV 3 I 3 Vegetation unit 111 112 113 210 221 222 223 300 411 412 421 422 423 424 425 Number of plots 4 14 13 10 11 31 10 10 17 10 14 9 9 9 15 Species Species presence and species significance1 19 RESU LTS AN D  D ISCU SSIO N Vegetation Classification Trem bling Aspen Ecosystem s Thuja plicata III 5 II 6 II 2 II 2 Tsuga heterophylla III 3 I + II 5 Betula papyrifera I h I h II 1 I 2 I + I 2 III 6 III 5 IV 6 I h Paxistima myrsinites  I h II 5 V 7 II 2 III 2 II 5 III 4 II 3 Tiarella trifoliata III + Alnus incana  I h I 1 I 3 II 4 III 5 II 3 II 5 III 5 I 3 Acer glabrum II 4 III 5 III 5 II 3 II 4 I h Ranunculus acris I h I h I h III + I h II h III h Festuca subuliflora I h I h I h I h IV 2 III h II h III + II h Rosa nutkana I h III + III + IV 4 IV 4 III 2 Chimaphila umbellata I + I + III 2 II h I h I 1 Pinus monticola I 2 II 3 III 5 I h Vaccinium caespitosum I + I 3 I 1 I h II h III 6 I 1 Mahonia aquifolium I 3 I h II h III 2 IV 3 IV 4 II 2 Pseudotsuga menziesii I 3 I 2 II 4 I 3 I + IV 6 III 5 IV 5 II 5 Angelica genuflexa I h I h IV 4 I h Lilium columbianum I h II h V + II h I h Senecio pseudaureus I h II + I h II h IV 1 I h Viola renifolia I h II + I h I h I h II + II h III h I h 1 Species presence and significance values as defined in Table 4. Vegetation unit 111 112 113 210 221 222 223 300 411 412 421 422 423 424 425 Number of plots 4 14 13 10 11 31 10 10 17 10 14 9 9 9 15 Species Species presence and species significance1 20 RESULTS AND DISCUSSION Vegetation Classification Scientica Silvica Extension Series, Number 27, 2000 The hierarchy of the proposed classification (Table 3) reflects the distribution of study stands according to regional climates (biogeoclimatic zones). The Mertensia, Elymus, and Thalictrum alliances represent stands located in montane boreal climates (predominantly in the BWBS and SBS zones); and the Symphoricarpos alliance represents stands located predominantly in cool temperate climates (predominantly in the IDF, ICH, and MS zones). This stratification is corroborated by climatic spectra which show two broad groups: the first group including units from 111 through 310 (the units of the Mertensia, Elymus, and Thalictrum alliances) and the second group including units 411 through 425 (the units of the Symphoricarpos alliance) (Figure 2). While the spectra of the first group are dominated by the indicators of montane boreal and cool temperate climates, the spectra of the second group feature also indicators of cool temperate & mesothermal and  cool temperate & semiarid climates. This suggests the stands of the Symphoricarpos alliance are influenced by warmer and milder climates (i.e., cool temperate) than the other stands. Figure 2. Climatic spectra for the 15 basic vegetation units delineated in trembling aspen stands across British Columbia. Codes for vegetation units as in Table 3. Although all study stands, in general, can be considered to represent mid-seral successional stages, some stands featured well-established, regeneration of shade-tolerant conifers while some other stands featured only aspen regeneration in canopy gaps and not conifers (Figure 3). On montane boreal sites the understory conifers were Abies lasiocarpa and Picea mariana; regeneration of Picea glauca was present across the study area. Pinus monticola, Pseudotsuga menziesii, Thuja plicata, and Tsuga heterophylla were established in the understory on cool temperate sites. Montane boreal stands of the Mertensia (100), Elymus (200), and Thalictrum (300) alliances and Viburnum - Spiraea (411) subassociation appear to be floristically aligned with the Picea glauca & mariana order (Krajina 1969) and will likely develop into white spruce and/or black spruce dominated stands, with a variable admixture of subalpine fir in the eastern portion of the BWBS zone and in the SBS zone. The stands of the Symphoricarpos (400) alliance (except for Viburnum - Spiraea (411) subassociation) shows floristic affinities to the interior Tsuga heterophylla order (Krajina 1969), and will likely develop into western hemlock and western redcedar dominated stands in the ICH zone, and Douglas-fir dominated stands in the IDF zone. 0% 20% 40% 60% 80% 100% Relative frequency of climate indicator species Tundra & boreal Subalpine boreal & cool mesothermal Montane boreal & cool temperate Cool mesothermal Cool temperate & mesothermal Cool temperate & semiarid Indicator species groups for climate: 111 112 113 210 221 222 223 310 411 412 421 422 423 424 425 Ve ge ta tio n un it 21RESULTS AND DISCUSSION Vegetation Classification Trembling Aspen Ecosystems While on some sites, aspen may be replaced by conifers within a single aspen generation, replacement on some other sites may be as long as 1,000 years (Perala 1990). Also, the presence of uneven-aged aspen stands in northern Montana, Wyoming, eastern Idaho, Colorado, and North Dakota suggests that under certain conditions, aspen may be self-perpetuating without major disturbance; however, aspen regeneration can fail when apical dominance prevents suckering during gradual deterioration of clones (Mueggler 1985). In the absence of replacement by shade tolerant conifers, aspen stands, especially on moist and nutrient-rich sites, usually gradually deteriorate to shrub-dominated woodlands, with a few scattered aspen suckers and occasional conifers (Perala 1990). Figure 3. Three scenarios encountered in the understory of study stands: 1 - no regeneration of aspen or shade-tolerant conifers, 2 - advance regeneration of shade-tolerant conifers was present, and 3 - natural regeneration of aspen from root suckers was present, providing semi-open canopy conditions. Since a majority of the study stands were young and many stands lacked abundant advance regeneration of conifers, we refrained from explicitly predicting succession trends. Ignoring succession trends might have resulted in framing different vegetation units on ecologically-equivalent sites, i.e., in two different aspen communities that can be differentiated only by the differences in the floristic composition. We also avoided resolving a related issue concerning classification at the order level: could the delineated units form a Populus tremuloides order (similar to the Populus balsamifera order (Krajina 1969)) or should they be attached to the proposed 'coniferous' orders (Krajina 1969) according to the similarity in understory vegetation?  While the constant occurrence of Populus tremuloides was a consequence of the sampling design, several other species, such as Epilobium angustifolium, Fragaria virginiana, Linnaea borealis, Hylocomium splendens, Cornus canadensis, and Picea glauca occurred nearly in all study plots. Somewhat less widespread but frequently occurring species were Achillea milefolium, Galium boreale, Orthilia secunda, Pleurozium schreberi, Shepherdia canadensis, and Viburnum edule (Table 5). When all these commonly occurring species as well as other species with low presence and species significance (e.g., Alnus viridis, Antennaria neglecta, Cladina stellaris, Cladonia ecmocyna, Empetrum nigrum, and others (Table 5)) showed affinity to one or more units vegetation units they were used in the diagnostic table (Table 4) as differential or companion species. The physiognomic appearance of study stands was relatively consistent. Compared to neighbouring coniferous stands, a well developed, frequently luxuriant understory was the characteristic feature of aspen stands. 1 32 22 RESULTS AND DISCUSSION Vegetation Classification Scientica Silvica Extension Series, Number 27, 2000 Regardless of the differences in floristic composition and site characteristics, there were generally minor differences in life forms profiles between the study stands (Figure 4). The understory vegetation was typically dominated by deciduous shrubs (e.g., Shepherdia canadensis, Rosa acicularis, R. nutkana, and Viburnum edule) and herbs (e.g., Epilobium angustifolium, Fragaria virginiana, and Cornus canadensis). Stands in boreal climates had a somewhat higher proportion of mosses and lichens, while stands in drier cool temperate climates had a higher proportion of graminoids. Figure 4. Life from spectra for the 15 basic vegetation units delineated in trembling aspen stands across British Columbia. Codes for vegetation units as in Table 3. The floristic individuality of the delineated vegetation units was described by two sets of similarity indices (Table 6). Vegetation units adjacent in Table 3 were climatically equivalent, and were more similar to each other that the climatically disjunct units that were distant in the table. The most poorly differentiated unit was the Thalictrum (310) association, which was similar to nearly all other units. The Arnica (112) and Petasites (113) subassociations of the Mertensia (110) association were floristically equivalent (Table 5a), and the boreal Festuca (111) subassociation was quite similar to the cool temperate Shepherdia (425) subassociation of the Rosa (420) association. The subassociations of the cool temperate Rosa nutkana (420) association had a high similarity to each other according to both indices. In view of a large number of study stands from climatically and edaphically different environments, it was surprising to frame only 15 units (6 associations and 13 subassociations). It appears that in mid-seral communities the uniform aspen overstory creates favourable light and edaphic conditions for the development of understory vegetation that has similar structure, life forms, and floristic composition over large areas. The major changes in the composition of understory vegetation appear to coincide with major changes in climate and regional flora. 0% 20% 40% 60% 80% 100% Life Form Groups: Coniferous trees Broad-leaved trees Evergreen shrubs Deciduous shrubs Ferns Graminoids Herbs Parasites & saprophytes Mosses Liverworts Lichens Dwarf woody plants Relative frequency of life form groups 111 112 113 210 221 222 223 310 411 412 421 422 423 424 425 Ve ge ta tio n un it 23RESULTS AND DISCUSSION Vegetation Classification Trembling Aspen Ecosystems Table 6. Matrix of floristic similarities for vegetation units delineated in trembling aspen ecosystems across British Columbia. Higher values indicate a greater number of shared species and greater floristic similarity. Codes for vegetation units as in Table 3. A. Sørensen (coincidence) coefficient of floristic similarity based on presence/absence Vegetation unit 111 112 113 210 221 222 223 310 411 412 421 422 423 424 425 Ve ge ta tio n  u n it 111 1.00 112 0.48 1.00 113 0.42 0.70 1.00 210 0.35 0.31 0.32 1.00 221 0.30 0.37 0.46 0.53 1.00 222 0.31 0.42 0.47 0.56 0.61 1.00 223 0.27 0.39 0.46 0.35 0.53 0.67 1.00 310 0.32 0.59 0.65 0.26 0.47 0.47 0.53 1.00 411 0.28 0.55 0.57 0.24 0.44 0.44 0.55 0.69 1.00 412 0.27 0.56 0.53 0.28 0.41 0.44 0.54 0.55 0.67 1.00 421 0.24 0.41 0.48 0.22 0.38 0.43 0.54 0.59 0.61 0.59 1.00 422 0.26 0.45 0.41 0.27 0.33 0.41 0.48 0.52 0.57 0.55 0.68 1.00 423 0.24 0.38 0.41 0.16 0.33 0.38 0.48 0.53 0.60 0.55 0.58 0.65 1.00 424 0.28 0.43 0.43 0.23 0.32 0.38 0.48 0.50 0.52 0.48 0.69 0.63 0.58 1.00 425 0.32 0.41 0.41 0.24 0.31 0.32 0.37 0.50 0.50 0.47 0.55 0.52 0.49 0.65 1.00 B. Sorensen (coincidence) coefficient of floristic similarity based on cover Vegetation unit 111 112 113 210 221 222 223 310 411 412 421 422 423 424 425 Ve ge ta tio n  u n it 111 1.00 112 0.49 1.00 113 0.34 0.67 1.00 210 0.10 0.20 0.23 1.00 221 0.22 0.29 0.28 0.32 1.00 222 0.24 0.29 0.26 0.29 0.52 1.00 223 0.26 0.33 0.31 0.16 0.35 0.44 1.00 310 0.50 0.49 0.41 0.13 0.29 0.28 0.41 1.00 411 0.47 0.41 0.38 0.12 0.28 0.29 0.47 0.63 1.00 412 0.34 0.35 0.34 0.07 0.17 0.15 0.30 0.40 0.54 1.00 421 0.34 0.33 0.35 0.11 0.20 0.20 0.36 0.44 0.51 0.54 1.00 422 0.35 0.37 0.38 0.12 0.19 0.17 0.27 0.41 0.51 0.54 0.59 1.00 423 0.35 0.31 0.29 0.06 0.17 0.10 0.27 0.45 0.59 0.44 0.53 0.51 1.00 424 0.41 0.38 0.37 0.10 0.21 0.17 0.30 0.50 0.57 0.49 0.60 0.58 0.62 1.00 425 0.53 0.39 0.33 0.05 0.20 0.12 0.20 0.44 0.43 0.37 0.40 0.47 0.45 0.66 1.00 24 RESULTS AND DISCUSSION Vegetation Classification Scientica Silvica Extension Series, Number 27, 2000 Cluster analysis using the Sørensen index based on presence/absence showed a hierarchical structure somewhat similar to that based on the tabular analysis (Table 3; Figure 5). The dendrogram shows two major clusters joined at approximately the same distance (0.3), and a smaller cluster joined at a slightly greater distance (0.34). The first cluster joined the units of the montane boreal Mertensia (100) and Elymus (200) alliances. Different from the tabular analysis was the connection of the Thalictrum (300) alliance, with stands occurring in montane boreal and cool temperate climates, to the second cluster, and separation of the Senecio (424) and Shepherdia (425) subassociations of the Rosa nutkana (420) association. These subassociations were connected with the other units at larger distance indicating that they might have been considered to form a different association. Figure 5. Dendrogram showing the groupings of the vegetation units produced by cluster analysis using the Sørensen index based on presence/absence as a distance measure. There were only few significant differences in the mean species diversity among 15 basic vegetation units (Tables 7 and 8). The three units with the highest (>30) mean species diversity were: Viburnum - Spiraea (411), Viburnum - Paxistima (412), and Rosa - Senecio (424) subassociations; the three units with lowest (≤22) mean species diversity were: Rosa - Shepherdia (425) subassociation, Ledum (210) association, and Lathyrus - Hedysarum (221). The most species-diverse Viburnum - Spiraea (411) subassociation a had significantly higher mean species diversity that the Ledum (210) association and Lathyrus - Hedysarum (211) and Lathyrus - typic (222) subassociations; and the least species-diverse, Rosa - Shepherdia (425) subassociation had a significantly lower mean species diversity than the Viburnum - Spiraea (411), Viburnum - Paxistima (412), and the Rosa - Senecio (424) subassociations. Comparison of the most and least species-diverse units seems to indicate that more species-diverse communities develop in wetter cool temperate climate (ICH zone) and less species-diverse communities develop in montane boreal climate and on sites transitional to grasslands. However, despite a few exceptions, the results of species diversity comparisons suggest that species richness in aspen communities is relatively consistent regardless of community type and the type of the associated environment. This inference is corroborated by consistency in the life form spectra (Figure 4) and, to some degree, by floristic similarity of the communities (Table 6). Thus, it can be expected, that the understory vegetation in aspen communities will be similar in life forms, species richness, and floristic composition over large areas, with the major changes in the composition coinciding with major changes in climate and regional flora. 0.0 0.1 0.2 0.3 0.4 0.5 0.6 Distances 111 112 113 210 221 222 223 310 411 412 421 422 423 424 425 25RESULTS AND DISCUSSION Vegetation Classification Trembling Aspen Ecosystems Table 7. Means and standard deviations of number of species according to the 15 vegetation units. Table 8. Probability in pair-wise comparisons of means of the number of species among the 15 vegetation units (Table 7) based on Tukey HSD test. The values in boldface indicate that two vegetation units in a pair have significantly different means (P≤0.05). Number of species Numerical code Number of plots Mean Standard deviation 111 4 25.75 8.54 112 14 24.50 4.94 113 13 25.92 6.50 210 10 21.90 3.67 221 11 22.00 3.07 222 31 23.74 3.51 223 10 28.20 5.96 310 10 25.80 5.25 411 17 31.24 6.70 412 10 30.60 7.34 421 14 26.86 9.42 422 9 25.67 3.35 423 9 27.33 7.55 424 9 30.89 8.55 425 15 21.47 6.73 Probability Code 111 112 113 210 221 222 223 310 411 412 421 422 423 424 425 111 1.000 112 1.000 1.000 113 1.000 1.000 1.000 210 0.999 0.999 0.964 1.000 221 0.999 1.000 0.964 1.000 1.000 222 1.000 1.000 0.999 1.000 1.000 1.000 223 1.000 0.980 1.000 0.577 0.564 0.789 1.000 310 1.000 1.000 1.000 0.984 0.985 1.000 1.000 1.000 411 0.954 0.127 0.536 0.010 0.008 0.004 0.996 0.633 1.000 412 0.991 0.497 0.887 0.089 0.080 0.117 1.000 0.912 1.000 1.000 421 1.000 1.000 1.000 0.816 0.809 0.961 1.000 1.000 0.801 0.978 1.000 422 1.000 1.000 1.000 0.991 0.992 1.000 1.000 1.000 0.648 0.911 1.000 1.000 423 1.000 0.999 1.000 0.830 0.826 0.967 1.000 1.000 0.967 0.998 1.000 1.000 1.000 424 0.987 0.469 0.862 0.084 0.076 0.116 1.000 0.890 1.000 1.000 0.968 0.889 0.996 1.000 425 0.996 0.992 0.836 1.000 1.000 0.998 0.296 0.919 0.001 0.019 0.525 0.950 0.599 0.019 1.000 26 RESULTS AND DISCUSSION Vegetation-Environment Relationships Scientica Silvica Extension Series, Number 27, 2000 Vegetation-Environment Relationships Considering uncertainties in predicting succession trends, we refrained from deriving site units from delineated vegetation units. Instead, we characterized each basic vegetation units (association or subassociation) by climate (zone) and the range of soil moisture regimes (SMRs) and soil nutrient regimes (SNRs). The climatic and edaphic individuality of each of the 15 basic vegetation units is portrayed on the edatopic grid (Figure 6 and Figure 7) and summarized in the summary environmental table (Table 9). The ranges for each unit were derived by integrating and generalizing the results of environmental and indicator plant analysis for each plot of the unit. Diagnosis of SNRs is also supported by soil chemical analysis (Kayahara et al. 2000). Figure 6. Edatopic grid showing the generalized relationships of the seven vegetation units to soil moisture and soil nutrient regimes in the BWBS zone. The units are named using the generic names of the understory species and vegetation unit numbers in Table 3.  Abbreviations for soil nutrient and moisture regimes are defined in Table 9. VP VD MD SD(f) F(f) M(f) VM(f) W(f) P M R VR Soil nutrient regime So il m oi st ur e re gi m e 223 Lathyrus – Actaea BWBSdk subzone BWBSmw subzone SBS zone SBPS zone grasslands, shrubs, and/or stunted tree  black/white spruce coniferous communities > 50% 20 - 50% < 20% Zone/subzone Distribution of plots according to zone/subzone 113 Mertensia – Petasites210 Ledum 221 Lathyrus – Hedysarum 222 Lathyrus – typic 112 Mertensia – Arnica 111 Mertensia – Festuca 27RESULTS AND DISCUSSION Vegetation-Environment Relationships Trembling Aspen Ecosystems Figure 7. Edatopic grid showing the generalized relationships of the eight vegetation units to soil moisture and soil nutrient regimes in the SBS, MS, ICH, and IDF zones. The units are named using the generic names of the understory species and vegetation unit numbers in Table 3.  Abbreviations for soil nutrient and moisture regimes are defined in Table 9. VP VD MD SD(f) F(f) M(f) VM(f) W(f) P M R VR Soil nutrient regime So il m oi st ur e re gi m e Zone/subzone Distribution of plots according to zone/subzone 425 Rosa – Shepherdia IDF zone MS zone ICH zone SBS zone SBPS zone white/black spruce coniferous communities 422 Rosa – Arnica 424 Rosa – Senecio 423 Rosa – Angelica 310 Thalictrum 421 Rosa – Aralia 412 Viburnum – Paxistima > 50% 20 - 50% < 20% 411 Viburnum – Spirea BWBSdk subzone 28 RESULTS AND DISCUSSION Vegetation-Environment Relationships Scientica Silvica Extension Series, Number 27, 2000 Table 9. Summary environmental table for the vegetation units in aspen ecosystems.  Continuous properties are characterized by mean and range; categorical properties are described by the percentage of the sample plots in each class . Vegetation unit 111 112 113 210 221 222 223 Number of plots 4 14 13 10 11 31 10 Property Zone/subzone BWBSdk - 100 BWBSdk - 86 BWBSdk - 85 BWBSmw -100 BWBSmw - 91 BWBSmw - 100BWBSmw - 90 SBS - 7 SBS - 8 SBS - 9 SBS - 10 SBPS - 7 SBPS - 8 Actual soil moisture regime1 1 Actual moisture regime: VD-very dry, MD-moderately dry, SD-slightly dry, F-fresh, M-moist, VM-moist, f-fluctuating water table MD - 100 MD - 86 SD - 85 SD - 80 SD - 91 SD - 26 M - 80 SD - 14 F - 15 F - 20 M - 9 F - 71 VM - 20 M - 3 Soil nutrient regime2 2 VP-very poor, P-poor, M-medium, R-rich, VR-very rich M - 25 P - 7 P - 15 VP - 60 P - 27 P - 13 R - 90 R -75 M - 71 M - 54 P - 40 M - 73 M - 77 VR - 10 R -21 R - 31 R - 10 Elevation (m) 838 (770-950) 900 (720-1040) 824 (590-900)750 728 (710-790) 632 (450-750) 666 (450-1025) Slope gradient (%) 15 (7-22) 19 (0-33) 12 (0-49) 2 (0-6) 15 (0-40) 4 (0-15) 7 (2-12) Aspect3 3 N-north, E-east, S-south, W-west, F-flat S - 50 E - 36 N - 23 N - 30 S - 45 N - 3 N - 20 W - 50 S - 29 E - 8 W - 10 W - 18 E - 10 S - 50 W - 29 S - 15 F - 60 F - 36 S - 13 W - 10 F - 7 W - 23 W - 26 F - 31 F - 48 Forest floor thickness (cm) 9 (6-11) 12 (5-22) 11 (6-17) 3 (2-4) 7 (3-32) 6 (3-9) 10 (4-14) Textural class4 4 S-sand, SL-sandy loam, LS-loamy sand, L-loam, SiL-silt loam, CL-clay loam, SCL-sandy clay loam, SC-sandy clay, SiCL-silty clay loam, O-organic L -25 L -14 L - 31 LS - 30 LS - 9 LS - 10 SL - 10 LS - 25 LS - 50 SL - 62 SL -20 S - 82 SL - 13 S - 30 SL - 50 SL - 21 SCL - 8 S - 50 SCL - 9 S - 16 SiL - 20 S - 7 SiL - 10 CL - 30 SC - 7 CL - 35 SCL - 10 SiCL - 16 Actual rooting depth (cm) 50 (40-60) 54 (40-70) 59 (30-80) 63 (46-80) 60 (25-80) 49 (20-90) 48 (30-60) Potential rooting depth (cm)59 (40-75) 60 (50-75) 65 (30-80) 63 (46-80) 60 (25-80) 42 (15-90) 47 (26-70) Seepage depth (cm) N/A N/A N/A or >60 N/A N/A or >65 N/A or >30 N/A or 35-85 Soil drainage5 5 R-rapid, W-well, M- moderately well, I-imperfect, P-poor R - 25 R - 7 W - 54 W - 20 R - 9 M - 52 M - 40 W - 25 W - 64 M - 38 M - 60 W - 55 I - 48 I - 60 M - 29 I - 8 I - 20 M -27 I - 9 Humus form group6 6 F-Mor, D-Moder, L-Mull D - 100 R - 57 R - 38 R - 100 R - 18 R - 39 R - 10 D - 43 D - 62 D - 82 D - 61 D - 80 L -10 Soil Order7 7 B-Brunisol, P-Podzol, R-Regosol, O-Organic, L-Luvisol, G-Gleysol B - 50 B - 78 B - 54 B - 100 B - 91 B - 42 B - 70 P - 25 P - 22 P - 31 G - 9 L - 58 L - 30 R - 25 L - 16 Stand age (years @ bh)8 117 (59-152) 124 (67-164) 103 (50-181) 54 (51-58) (>50-154) (>50-70) (>50-96) Site index (m@50 yrs bh)8 8 Site index and stand age data are missing for some plots. See Appendices 10 - 16 for details. 8 (6-9) 12 (10-16) 13 (10-15) 8 (7-10) 13 (11-16) 19 (15-23) 22 (20-25) Tree layer cover (%) 36 (10-70) 47 (21-90) 46 (30-81) 25 (15-36) 36 (27-86) 35 (4-43) 44 (26-100) Shrub layer cover (%) 40 (20-64) 33 (13-77) 20 (4-63) 53 (33-65) 27 (23-47) 35 (4-83) 31 (7-67) Herb layer cover (%) 25 (2-55) 15 (3-32) 17 (1-38) 15 (6-30) 36 (21-58) 33 (11-58) 38 (8-60) Moss layer cover (%) 3 (0-6) 36 (0-92) 55 (0-100) 19 (3-34) 5 (0-50) 2 (0-5) 0 (0-1) 29RESULTS AND DISCUSSION Vegetation-Environment Relationships Trembling Aspen Ecosystems 310 411 412 421 422 423 424 425 10 17 10 14 9 9 9 15 BWBSdk - 10 SBS - 94 ICH - 100 MS - 57 MS - 56 ICH - 67 MS - 44 MS - 13 SBS - 50 ICH - 6 ICH - 29 ICH - 33 IDF - 33 IDF - 56 IDF - 67 SBPS - 20 IDF - 14 IDF - 11 SBPS - 20 IDF - 20 SD - 30 SD - 53 SD - 80 F - 14 MD - 44 SD - 22 MD - 89 VD - 80 F - 50 F - 41 F - 20 M - 71 SD - 56 F - 78 SD - 11 MD - 20 M - 20 M - 6 VM - 14 P - 10  M - 6 M - 50 M - 14 M - 67 M - 22 M -22 P - 40 M - 60 R - 82 R - 50 R - 64 R - 33 R - 67 R - 67 M - 40 R - 30 VR - 12 VR - 22 VR -11 VR - 11 R - 20 891 (595-1115) 860 (390-1025)540 (380-1020) 959 (520-1115) 989 (785-1285) 945 (795-1285) 1073 (1005-1220)1058 (960-1258) 13 (0-67) 6 (0-30) 19 (0-33) 8 (0-33) 36 (0-65) 20 (0-48) 22 (0-59) 22 (0-85) N - 20 N - 18 N - 10 N - 21 N - 44 E - 11 E - 44 E - 7 E - 20 E - 6 E - 10 E - 29 E - 11 S - 67 S - 22 S - 33 S - 10 W - 24 S - 30 W - 7 W - 33 F - 22 W - 22 W - 13 W - 20 F - 53 W - 40 F - 43 F - 11 F - 11 F - 47 F - 30 F - 10 12 (4-40) 9 (4-19) 7 (4-10) 8 (3-30) 6 (3-10) 9 (7-10) 7 (3-13) 6 (3-10) L - 30 4 L - 53 L - 20 L - 14 L - 11 L - 44 LS - 22 L - 20 SL - 30 SL - 24 LS - 50 SL - 29 LS - 56 LS - 11 SL - 56 LS - 20 CL - 20 S - 12 SL - 30 S - 21 SL - 22 SL - 22 S - 11 SL - 33 SCL -10 SCL - 12 SC - 7 S - 11 S - 11 SCL - 11 S - 7 O - 10 SCL - 29 SCL - 11 CL - 7 SCL - 13 71 (30-120) 56 (30-90) 56 (35-70) 54 (30-100) 55 (30-90) 59 (45-70) 71 (40-100) 60 (25-120) 77 (35-120) 62 (30-90) 59 (35-70) 57 (20-100) 55 (30-90) 60 (50-70) 71 (40-100) 61 (25-120) N/A or 60-90 N/A N/A N/A or 20-100 N/A N/A or 55-65 N/A or >75 N/A W - 60 R - 6 W - 60 W - 14 R - 33 W - 67 W - 89 R - 60 M - 20 W - 88 M - 40 M - 36 W - 56 I - 22 M - 11 W - 33 I - 10 M - 6 I - 21 M - 11 P - 11 M - 7 P - 10 P - 29 R - 30 R - 12 R - 10 D - 57 R - 11 D - 33 R - 11 R - 13 D - 70 D - 88 D - 90 L - 43 D - 78 L - 67 D - 22 D - 74 L - 11 L - 67 L - 13 B - 50 B - 88 B - 90 B - 21 B - 22 B - 78 B - 67 B - 94 P - 10 P - 12 P - 10 P - 29 P - 67 L - 22 P - 22 L - 7 L - 30 R - 14 R - 11 L - 11 O - 10 L - 36 73 (46-135) 90 (48-116) 79 (47-103) 70 (56-95) 65 (54-76) 70 (56-100) 75 (57-96) 82 (61-122) 19 (17-22) 16 (12-19) 18 (15-23) 26 (21-31) 23 (20-27) 22 (19-27) 21 (15-25) 12 (9-16) 72 (40-100) 82 (30-100) 63 (20-100) 82 (45-100) 88 (70-100) 74 (42-93) 67 (41-90) 52 (25-95) 33 (5-85) 54 (18-97) 46 (15-95) 26 (1-92) 33 (4-66) 47 (13-84) 37 (3-77) 27 (0-69) 17 (2-84) 15 (2-35) 6 (2-14) 32 (0-80) 18 (2-53) 29 (13-48) 22 (5-78) 18 (0-74) 4 (0-20) 4 (0-35) 2 (0-9) 1 (0-11) 0 0 0 (0-1) 0 (0-2) 30 RESULTS AND DISCUSSION Vegetation-Environment Relationships Scientica Silvica Extension Series, Number 27, 2000 It appears that each delineated vegetation units is not environmentally exclusive: they overlap and cannot be characterized by an exclusive edaphic range. The generalized plots illustrated on the two grids show overlaps in climatic range for some units that is an artifact of placing on one grid units associated with different climates (Figure 5 and Figure 6). For example, two edaphically different units (Lathyrus - Hedysarum (221) and Lathyrus typic (222)) overlap with Mertensia - Petasites (113); however, the former are from the wetter portion of the BWBS zone (BWBSmw subzone) and the latter is from the drier portion of the BWBS zone (BWBSdk subzone). The vegetation units extend from very dry to very moist sites but are infrequent on very poor and poor sites. Except for three units (Mertensia - Arnica (112), Ledum (210), and Thalictrum (310)) all other units occupy medium and richer portion of the grids. In general, indicator plant analysis supported characterization of soil moisture conditions for the units (Figure 8). For example, the Mahonia - Shepherdia (425) subassociation, with the soil moisture range restricted to very dry SMR, has the highest (about 90%) mean relative frequency of very dry to moderately dry indicators. The moderately dry Mertensia - Festuca (111), Mertensia - Arnica (112), and Rosa - Senecio (424) subassociations have lower and similar mean relative frequencies of very dry to moderately dry indicators than the Mahonia - Shepherdia (425) subassociation, and the similar proportion of other indicator species groups in their soil moisture spectra. Similarly, the moist to very moist Lathyrus - Actaea (223) and Rosa - Aralia (421) subassociations have very similar soil moisture spectra that are dominated by indicators of fresh to very moist and very moist to wet soil moisture conditions. Except the Ledum (210) association, the mean relative frequency of nitrogen-rich indicators of all other units is over 40% suggesting rich or very rich SNRs (Figure 9). In general, the units of the cool temperate Symphoricarpos alliance appear to be richer than those of the montane boreal Mertensia (100) and Elymus (200) alliances. However, as soil nutrient spectra reflect nutrient conditions of the forest floor (predominantly Moder humus forms) more strongly than the associated mineral soil, occurrence of very rich sites will likely be infrequent. We made edaphic comparisons of the vegetation units of this study with those recognized by DeLong (1988) in the BWBSmw subzone (Figure 10). The comparison indicates some differences but predominantly similarities, despite different nomenclature, difficulties in comparing actual to relative SMRs, and ambiguous edaphic ranges in DeLong's units. Our Mertensia - Festuca (111) subassociation appears to be edaphically as well as floristically very similar to DeLong's Kinnikinnick unit; similarly, our Ledum (210) association and DeLong's Ledum unit occupy a very similar edaphic range and have the similar floristic composition. Although DeLong's Soopalallie and Creamy Peavine units are considered to be associated predominantly with the medium SNR, they correspond to our medium to rich Lathyrus - Hedysarum (221) and Lathyrus typic (222) subassociations. On moist to very moist, nutrient medium to very rich sites we recognized only one unit (Lathyrus - Actaea (223) subassociation) while DeLong delineated three closely related units: Oak Fern, Black Twinberry, and Cow Parsnip. Our Lathyrus - Actaea (223) subassociation included Lonicera involucrata as a diagnostic species but Gymnocarpium dryopteris and Heracleum sphondylium were very infrequent species. 31RESULTS AND DISCUSSION Vegetation-Environment Relationships Trembling Aspen Ecosystems Figure 8. Soil moisture spectra for the 15 basic vegetation units delineated in trembling aspen stands across British Columbia. Codes for vegetation units as in Table 3. Figure 9. Soil nutrient spectra for the 15 basic vegetation units delineated in trembling aspen stands across British Columbia. Codes for vegetation units as in Table 3. 0% 20% 40% 60% 80% 100% Indicator species groups for soil moisture: Excessively to very dry Very to moderately dry Moderately dry to fresh Fresh to very moist Very moist to wet Wet to very wet Relative frequency of soil moisture indicator species 111 112 113 210 221 222 223 310 411 412 421 422 423 424 425 Ve ge ta tio n Un it 0% 20% 40% 60% 80% 100% 111 112 113 210 221 222 223 310 411 412 421 422 423 424 425  poor  medium  rich Indicator species groups for soil nutrients: Ve ge ta tio n Un it Relative frequency of soil nutrient indicator species 32 RESULTS AND DISCUSSION Vegetation-Environment Relationships Scientica Silvica Extension Series, Number 27, 2000 Figure 10. Edatopic grid showing the relationships to soil moisture and soil nutrient regimes of the seven vegetation units recognized by DeLong (1988) in seral aspen ecosystems in the BWBSmw subzone. The units are named by Trembling Aspen (At) and the common name of one understory species. VP 1 2 3 4 5 6 7 VD MD SD(f) F - M(f) VM(f) W(f) P M R VR Soil nutrient regime So il m oi st ur e re gi m e 01 01 At – Creamy Peavine BWBSmw2 Seral Aspen Units 02 At – Kinnikinnick 03 At – Soopolallie 04 At – Labrador Tea 05 At – Black Twinberry 06 At – Oak Fern 07 At – Cow Parsnip 04 03 02 05 06 07 33RESULTS AND DISCUSSION Description of Plant Associations Trembling Aspen Ecosystems Description of Plant Associations This section expands upon the vegetation classification by emphasizing floristic and stand characteristics of the delineated units. As much of this information is presented in diagnostic, summary, plot vegetation, and plot environmental tables, the description is brief and focused on the most salient features. We describe and illustrate each of the 15 basic vegetation units that represent the lowest level of the hierarchy - either associations or subassociations. Vegetation units are organized according to the order given in Table 3. 111 Populus tremuloides - Mertensia paniculata: Festuca altaica (Mertensia - Festuca) subassociation (References: Tables 3, 4, 5, and 9; Figures 4, 6, 8, 9, 11, 12 and 13; Appendices 2 and 17) Moderately dry, medium to rich (very rich) sites in drier montane boreal climates Mertensia - Festuca communities occur on water-shedding ridge crests or warm-aspect upper slopes, often bordering grassland communities, in the Dry Cool BWBS (BWBSdk) subzone. These water-deficient sites support marginal to poor, often distorted, aspen growth with site index (@ 50 yrs bh) ranging from 6 to 9 m (Figures 11 to 13). The associated soils are shallow, coarse-skeletal, Dystric or Eutric Brunisols, Podzols or Regosols with Mormoder Leptomoder, or Mullmoder (when grass cover is high) humus forms (Table 9). The canopy of the Mertensia - Festuca community is exposed to wind and early frost; however the frost damage is never so severe as on the large, cool air-receiving flats that do not support forest growth. The canopy is usually open and includes only aspen. As a result of the open-canopy conditions, the shrub and herb layers are well developed, but the cover of the moss layer is very low (Table 9, Figures 11, 12 and 13). In order of decreasing presence, the most common shrub species are: Rosa acicularis, Shepherdia  canadensis (a diagnostic species for the Mertensia association), Viburnum edule, and Arctostaphylos uva-ursi and Juniperus communis (both diagnostic species for the Mertensia - Festuca subassociation). The most common species in the herb layer are: Galium boreale and Festuca altaica (both diagnostic species for this subassociation), Epilobium angustifolium, Delphinium glaucum, Fragaria virginiana, Geocaulon lividum, and Linnaea borealis (Tables 4 and 5). Figure 11. An exposed, open-canopy, distorted, stunted, grass-dominated aspen stand on an upper slope in the Atlin Lake area bordering a grassland ecosystem (BWBSdk subzone). This stand represents the driest variation of the Mertensia - Festuca (111) subassociation. 34 RESULTS AND DISCUSSION Description of Plant Associations Scientica Silvica Extension Series, Number 27, 2000 Figure 12. A semi-open canopy, soopalallie-dominated aspen stand on an upper slope in the Atlin Lake area (BWBSdk subzone). This stand represents the typic variation of the Mertensia - Festuca (111) subassociation. Note the white and black spruce understory on the mid-slope (in the background), which is occupied by a Mertensia - Arnica (112) community. Figure 13. A wind-exposed, closed-canopy, cranberry-dominated aspen stand on an upper slope in the Atlin Lake area (BWBSdk subzone). This stand represents the wettest variation of the Mertensia - Festuca (111) subassociation. 35RESULTS AND DISCUSSION Description of Plant Associations Trembling Aspen Ecosystems 112 Populus tremuloides - Mertensia paniculata: Arnica cordifolia (Mertensia - Arnica) subassociation (References: Tables 3, 4, 5, and 9; Figures 4, 6, 8, 9, 14 to 17; Appendices 3 and 18) Moderately dry (slightly dry), (poor) medium to rich sites in drier montane boreal climates Mertensia - Arnica communities occur predominantly on water-shedding mid-slopes, less frequently on flats, in the Dry Cool BWBS (BWBSdk) subzone. These water-deficient sites support low- to medium-productivity aspen growth, with site index (@ 50 yrs bh) ranging from 10 to 16 m. The associated soils are moderately deep, coarse-skeletal, Dystric or Eutric Brunisols or Podzols, with Hemimor, Mormoder, or Leptomoder humus forms (Table 9). The cover of the tree canopy is variable and, in addition to aspen, it may include white spruce, black spruce, and subalpine fir. These shade-tolerant tree species also occur in the understory of many stands (Figures 14, 15,16 and 17). Lodgepole pine occurs very infrequently in the tree layer. All the understory layers may be well developed, with their cover varying from stand to stand (Table 9). In order of decreasing presence, the most common shrub species are Shepherdia canadensis (a diagnostic species for the Mertensia association and this subassociation), Rosa acicularis, Viburnum edule (a diagnostic species for this subassociation), and Salix scouleriana (a diagnostic species for the Mertensia association). The most common herbs are: Arnica cordifolia and Orthilia secunda (the diagnostic species for this subassociation), and Epilobium angustifolium, Geocaulon lividum, Linnaea borealis, Mertensia paniculata (a diagnostic species for the Mertensia association), Cornus canadensis, Delphinium glaucum, Goodyera repens, Achillea millefolium, Fragaria virginiana, Lupinus arcticus, Osmorhiza berteroi, and Festuca altaica. The most common moss species are Hylocomium splendens and Pleurozium schreberi (Tables 4 and 5). Figure 14.  An open-canopy, fireweed-dominated aspen stand on a mid-slope north of Dease Lake (BWBSdk subzone). This stand represents the drier variation of the Mertensia - Arnica (112) subassociation. Figure 15. An semi-open canopy, fireweed- and highbush cranberry-dominated aspen stand on a mid- slope north of Dease Lake (BWBSdk subzone). This stand represents the wetter variation of the Mertensia - Arnica (112) subassociation. 36 RESULTS AND DISCUSSION Description of Plant Associations Scientica Silvica Extension Series, Number 27, 2000 Figure 16. A closed-canopy, grass- and herb-dominated, old-growth aspen stand on a flat in the Atlin Lake area (BWBSdk subzone). This stand represents the drier and richer variation of the Mertensia - Arnica (112) subassociation. Figure 17. An old growth, grass- and herb-dominated aspen stand with large canopy gaps on a flat in the Atlin Lake area (BWBSdk subzone). This stand also represents the drier and richer variation of the Mertensia - Arnica (112) subassociation. Willows and infrequently, white spruce regenerate in canopy gaps. 37RESULTS AND DISCUSSION Description of Plant Associations Trembling Aspen Ecosystems 113 Populus tremuloides - Mertensia paniculata: Petasites frigidus (Mertensia - Petasites) subassociation (References: Tables 3, 4, 5, and 9; Figures 4, 6, 8, 9, 18 and 19; Appendices 4 and 19) Slightly dry to fresh (often with fluctuating water table), (poor) medium to rich sites in drier montane boreal climates More or less water-receiving Mertensia - Petasites communities occur predominantly on lower slopes, with intermittent seepage, less frequently on flats affected by a fluctuating water table, in the Dry Cool BWBS (BWBSdk) subzone. These slightly dry to fresh sites support low- to medium-productivity aspen growth, with site index (@ 50 yrs bh) ranging from 10 to 15 m. The commonly associated soils are moderately deep, sandy loam to loamy, skeletal, occasionally gleyed, Eutric Brunisols or Podzols, with Hemimor, Humimor, Mormoder, or Leptomoder humus forms (Table 9). The cover of the tree canopy is variable and, in addition to aspen, it usually includes shade-intolerant lodgepole pine and shade-tolerant white spruce, black spruce and subalpine fir, with shade-tolerant species also regenerating in the understory of many stands (Figures 18 and 19). All the understory layers are moderately well developed, with the moss layer having the highest average cover (Table 9). In order of decreasing presence the most common shrub species are: Rosa acicularis, Shepherdia  canadensis (a diagnostic species for the Mertensia association), Vaccinium vitis-idaea, Viburnum edule, Empetrum nigrum, and Ledum groelandicum. The most common herb species are: Linnaea borealis, Cornus canadensis, Petasites frigidus (a diagnostic species for this subassociation), Epilobium angustifolium, Geocaulon lividum, Lupinus arcticus (a diagnostic species for this subassociation), Mertensia paniculata (a diagnostic species for the Mertensia association), Achillea millefolium, Festuca altaica, Galium boreale, Fragaria virginiana, Mitella nuda (a diagnostic species for this subassociation), Orthilia secunda, and Goodyera repens. The most common species in the moss layer are: Hylocomium splendens, Pleurozium schreberi, Ptilium crista-castrensis, and Peltigera membranacea (Tables 4 and 5). Figure 18. View of a closed-canopy, dense aspen stand on a lower slope with a scattered understory of white spruce in the Iskut Lake area (BWBSdk subzone). This stand represents the drier variation of the Mertensia - Petasites (113) subassociation. 38 RESULTS AND DISCUSSION Description of Plant Associations Scientica Silvica Extension Series, Number 27, 2000 Figure 19. A closed-canopy, dense aspen stand on a lower slope with a scattered understory of white spruce in the Iskut Lake area (BWBSdk subzone). This stand represents the typic variation of the Mertensia - Petasites (113) subassociation. 39RESULTS AND DISCUSSION Description of Plant Associations Trembling Aspen Ecosystems 210 Populus tremuloides - Ledum groelandicum (Ledum) association (References: Tables 3, 4, 5, and 9; Figures 4, 6, 8, 9, 20, 21 and 22; Appendices 5 and 20) Slightly dry to fresh, very poor to poor sites in wetter montane boreal climates Ledum communities occur most often on very poor and slightly dry sites, and less frequently on poor and fresh sites. They occupy variable mesoslope positions but are most common on flats or very gentle lower slopes. These communities are restricted to wetter subzones of the BWBS zone, and were described from the Dawson Creek area. Aspen productivity is low, with site index (@ 50 yrs bh) ranging from 7 to 10 m. Commonly associated soils are moderately deep, sandy to loamy, skeletal, Dystric Brunisols, with thin Hemimor or Humimor (infrequently Mormoder) humus forms (Table 9). Due to floristic distinctiveness and uniformity, Ledum communities are represented by a single unit at the association level within the Elymus alliance. The cover of the tree layer is variable and, in addition to aspen, it may include shade-intolerant lodgepole pine and shade tolerant white spruce, black spruce, and subalpine fir, with shade-tolerant species also regenerating in the understory of many stands (Figures 20, 21 and 22). All the understory layers are moderately well developed, with the shrub layer having on the average the highest cover (Table 9). In order of decreasing presence, the most common shrub species are: Ledum groelandicum and Spiraea betulifolia (both diagnostic species for this association), Vaccinium myrtilloides, and V. vitis-idaea (a diagnostic species for this association). The most common herb species are: Linnaea borealis, Cornus canadensis, Epilobium angustifolium, Geocaulon lividum, Petasites frigidus (a diagnostic species for the Elymus alliance and this association), Lycopodium complanatum and Melampyrum lineare (both diagnostic species for this association). The most common species in the moss layer are Polytrichum juniperinum (a diagnostic species for this association), Pleurozium schreberi, Cladina rangiferina, and Peltigera aphthosa (Tables 4 and 5). Figure 20. An immature aspen cohort on a gentle upper slope with sparsely developed understory vegetation in the Fort St. John area (BWBSmw subzone). This stand represents the drier variation of the Ledum (210) association. 40 RESULTS AND DISCUSSION Description of Plant Associations Scientica Silvica Extension Series, Number 27, 2000 Figure 21. A closed-canopy, immature aspen stand on a mid-slope with sparsely developed understory vegetation and scattered pine and white spruce in the Fort St. John area (BWBSmw subzone). This stand represents the typic variation of the Ledum (210) association. Figure 22. An immature, Labrador tea-dominated aspen cohort on a flat in the Tumbler Ridge area (BWBSmw subzone). This stand represents the wetter and poorer variation of the Ledum (210) association. 41RESULTS AND DISCUSSION Description of Plant Associations Trembling Aspen Ecosystems 221 Populus tremuloides - Lathyrus ochroleucus: Hedysarum boreale (Lathyrus - Hedysarum) subassociation (References: Tables 3, 4, 5, and 9; Figures 4, 6, 8, 9, 23 and 24; Appendices 6 and 21) Slightly dry, poor to medium sites in wetter montane boreal climates Lathyrus - Hedysarum communities occupy variable mesoslope positions but are most common on warm- aspect, upper or mid-slopes and flats. These communities are restricted to wetter subzones of the BWBS zone, and were described from the Dawson Creek area. Aspen productivity is low to medium, with site index (@ 50 yrs bh) ranging from 11 to 15 m. The associated soils are moderately deep, sandy-skeletal, Dystric or Eutric Brunisols, with or Mor or Mormoder humus forms (Table 9). Lathyrus - Hedysarum communities represent the driest segment of the Lathyrus association (Figure 6). The cover of the tree layer is generally high, and in addition to aspen, it may include shade tolerant white spruce and subalpine fir, which also regenerate in the understory. The shrub and graminoid-dominated herb layers are well developed, but the moss layer is generally absent or very poorly developed (Table 9, Figures 23 and 24). In order of decreasing presence, the most common shrub species are: Rosa acicularis, Vaccinium myrtilloides (the diagnostic species for this subassociation), Shepherdia  canadensis, Amelanchier alnifolia (the diagnostic species for the Lathyrus association), Vaccinium vitis-idaea, and Ledum groelandicum. The most common herb species are: Elymus innovatus (a diagnostic species for the Elymus alliance), Lathyrus ochroleucus (a diagnostic species for the Lathyrus association), Maianthemum canadense, Linnaea borealis, Calamagrostis canadensis, Aster conspicuus (a diagnostic species for the Lathyrus association), Achillea millefolium (a diagnostic species for this subassociation), Galium boreale (a diagnostic species for the Lathyrus association), and Hedysarum boreale (a diagnostic species for this subassociation). Figure 23. An immature, dense aspen stand on a gentle mid-slope in the Dawson Creek area (BWBSmw subzone) dominated by grasses (Calamagrostis canadensis, Elymus innovatus, and Oryzopsis asperifolia). This stand represents the typic variation of the Lathyrus - Hedysarum (221) subassociation. 42 RESULTS AND DISCUSSION Description of Plant Associations Scientica Silvica Extension Series, Number 27, 2000 Figure 24. A closed-canopy, low-productivity, mature aspen stand on a gentle mid-slope in the Dawson Creek area (BWBSmw subzone). The understory is grass-dominated (Calamagrostis canadensis, Elymus innovatus, and Oryzopsis asperifolia) with scattered low shrubs. This stand represents the drier variation of the Lathyrus - Hedysarum (221) subassociation. 43RESULTS AND DISCUSSION Description of Plant Associations Trembling Aspen Ecosystems 222 Populus tremuloides - Lathyrus ochroleucus: typic (Lathyrus typic) subassociation (References: Tables 3, 4, 5, and 9; Figures 4, 6, 8, 9, 25, 26 and 27; Appendices 7 and 22) Slightly dry to fresh (moist), (poor) medium (rich) sites in wetter montane boreal climates Typic Lathyrus communities occur on intermediate sites in the BWBSmw subzone, predominately on slightly dry or fresh, nutrient-medium sites. Occasionally they are found on poor or rich sites and very infrequently on moist sites. They occur most commonly on gentle mid-slopes or flats, and less frequently on lower slopes. This subassociation probably accounts for about half of the aspen communities in the wetter subzones of the BWBS zone, and, unlike the Ledum association and Lathyrus - Hedysarum subassociation, typic Lathyrus typic communities are distributed across the entire Liard Plain (Ft. Nelson, Ft. St. John, and Dawson Creek areas). Aspen productivity is medium, with site index (@ 50 yrs bh) ranging from 15 to 23 m, but timber quality is high as reflected in good growth form and absence of stem rot. The commonly associated soils are moderately deep, sandy to loamy-skeletal, Dystric or Eutric Brunisols and Gray Luvisols with Hemimor or Mormoder humus forms (Table 9). The cover of the tree layer is generally high, and a high stand density is typical for immature stands (Figures 26 and 27). This is the result of prolific suckering after disturbance (Figure 25). In addition to aspen, the tree layer may include white spruce, subalpine fir, lodgepole pine, paper birch, and balsam poplar, with shade- tolerant species occurring in the understory. The shrub and herb layers are very well developed, but the moss layer consistently has a low cover (Table 9). In order of decreasing presence, the most common shrub species are: Rosa acicularis (a diagnostic species for the Lathyrus association), Viburnum edule, and Shepherdia canadensis. The most common herb species are: Cornus canadensis (a diagnostic species for this subassociation), Epilobium angustifolium (Figure 27), Lathyrus ochroleucus (a diagnostic species for the Lathyrus association), Linnaea borealis, Rubus pubescens (a diagnostic species for this subassociation), Pyrola asarifolia (a diagnostic species for the Lathyrus association), Maianthemum canadense, Galium boreale (a diagnostic species for the Lathyrus association), and Elymus innovatus (a diagnostic species for the Elymus alliance). The most common species in the moss layer is Hylocomium splendens (a diagnostic species for this subassociation) (Tables 4 and 5). Figure 25. Vigorous regeneration of aspen following the cutting of conifers on a flat in the Fort St. John area (BWBSmw subzone). This stand represents an early initiation stage in stand development of the Lathyrus typic (222) subassociation. 44 RESULTS AND DISCUSSION Description of Plant Associations Scientica Silvica Extension Series, Number 27, 2000 Figure 26. A dense, immature, herb-dominated aspen stand on a flat in the Fort St. John area (BWBSmw subzone). This stand represents the drier variation of the Lathyrus typic (222) subassociation. Figure 27. A dense, immature, fireweed-dominated aspen stand on a flat in the Fort St. John area (BWBSmw subzone). This stand represents the wetter variation of the Lathyrus typic (222) subassociation. 45RESULTS AND DISCUSSION Description of Plant Associations Trembling Aspen Ecosystems 223 Populus tremuloides - Lathyrus ochroleucus: Actaea rubra (Lathyrus - Actaea) subassociation (References: Tables 3, 4, 5, and 9; Figures 4, 6, 8, 9, and 28, 29, 30, and 31; Appendices 8 and 23) Moist to very moist, rich (very rich) sites in wetter montane boreal climates Lathyrus - Actaea communities represent the wettest segment of the Lathyrus association: in fact, the wettest sites supporting aspen growth in the BWBS zone. On these moist to very moist sites, aspen stands feature a high admixture of balsam poplar, which has a higher tolerance of water-surplus than aspen. Lathyrus - Actaea communities occupy lower slopes, which are often affected by intermittent seepage, or flats, which are often affected by a fluctuating water table. Similar to the Lathyrus typic subassociation, the Lathyrus - Actaea subassociation is distributed in the wetter subzones of the BWBS zone across the entire Laird Plain (Ft. Nelson, Ft. St. John, and Dawson Creek areas). Aspen productivity is high, with site index (@ 50 yrs bh) ranging from 20 to 25 m. Timber quality is also high as reflected in good growth form and absence of stem rot, particularly in the Fort Nelson area. The commonly associated soils are moderately deep, coase to fine-textured, Gleyed Dystric or Eutric Brunisols, occasionally Gleyed Gray Luvisols, with Mormdoder, Hydromoder, Mullmoder, or Vermimull humus forms  (Table 9). The cover of the tree layer is generally high; a high stand density is typical for immature stands (Figures 28 and 29). In addition to aspen, the tree layer usually includes white spruce and paper birch, with shade-tolerant spruce occurring in the understory (Figures 30 and 31). The shrub and herb layers are very well developed, with the moss layer usually absent (Table 9). In order of decreasing presence, the most common shrub species are: Rosa acicularis (a diagnostic species for the Lathyrus association), Viburnum edule, and Cornus sericea and Lonicera involucrata (a diagnostic species for this subassociation). The most common herbs are: Actaea rubra and Aralia nudicaulis (both diagnostic species for this subassociation), Calamagrostis canadensis (a diagnostic species for the Elymus alliance), Epilobium angustifolium, Galium triflorum (a diagnostic species for this subassociation), Pyrola asarifolia (a diagnostic species for the Lathyrus association), Cornus canadensis, Delphinium glaucum (a diagnostic species for this subassociation), Equisetum pratense (a diagnostic species for this subassociation), and Mertensia paniculata (Tables 4 and 5). 46 RESULTS AND DISCUSSION Description of Plant Associations Scientica Silvica Extension Series, Number 27, 2000 Figure 28. A dense, immature aspen stand on a lower slope in early spring in the Fort St. John area (BWBSmw subzone). This stand represents the typic variation of the Lathyrus - Actaea (223) subassociation. Figure 29. A dense, immature, herb-dominated aspen stand on a flat in the Fort St. John area (BWBSmw subzone). This stand represents the wetter variation of the Lathyrus - Actaea (223) subassociation. 47RESULTS AND DISCUSSION Description of Plant Associations Trembling Aspen Ecosystems Figure 30. A semi-open canopy, mature, shrub-dominated aspen stand with scattered white spruce regeneration on an alluvial terrace in the Fort St. John area (BWBSmw subzone). This stand represents the wetter and richer variation of the Lathyrus - Actaea (223) subassociation. Figure 31. A dense cohort of old aspen on a flat with a scattered understory of white spruce in the Fort Nelson area (BWBSdk subzone). This stand representing the wetter and richer variation of the Lathyrus - Actaea (223) subassociation is one of many with high-quality aspen timber in the area. 48 RESULTS AND DISCUSSION Description of Plant Associations Scientica Silvica Extension Series, Number 27, 2000 310 Populus tremuloides - Thalictrum occidentale (Thalictrum) association (References: Tables 3, 4, 5, and 9; Figures 4, 7, 8, 9, 32, 33 and 34; Appendices 9 and 24) Slightly dry to moist (often with fluctuating water table), (poor) medium to rich sites in montane boreal and cool temperate climates The Thalictrum association represents floristically variable communities occurring in montane boreal and cool temperate climates (BWBS, SBS, SBPS, and IDF zones), with most of the communities located in the SBS zone. The floristic variability is indicated by the plot vegetation table, which shows that few species occur in more than 60% of the plots (presence class ≥ IV) (Table 5). This association lacks a diagnostic combination of species, but is defined by the low presence of species diagnostic of other units (Table 4). Thalictrum communities occur over a wide edaphic range, but are most common on fresh, nutrient-medium sites. They occupy various meso-slope positions, depending on climate, but most frequently depressions or flats with a fluctuating water table in drier climates (BWBS, SBPS, and IDF zones) (Figures 32 and 33) or the mid- or lower slopes (affected by intermittent seepage) in wetter climates (SBS zone). In the SBPS zone, Thalictrum communities typically form a narrow fringe in the transition between water surplus sites and water-deficient, upland lodgepole pine forest (Figure 34). Aspen productivity is medium, with site index (@ 50 yrs bh) ranging from 17 to 22 m. The commonly associated soils are shallow to moderately deep, loamy-skeletal, Gleyed Dystric or Eutric Brunisols, occasionally Gleyed Gray Luvisols, with Mormoder, or Leptomdoder humus forms (Table 9). The cover of the tree layer is generally high. In addition to aspen, the tree layer nearly always includes white spruce, occasionally lodgepole pine and black spruce; white spruce, willows, and scrub birch are common in the understory (Table 9). The cover of the understory vegetation decreases in order form the shrub to the herb to the moss layer. In order of decreasing presence, the most common shrub species are: Rosa acicularis, Viburnum edule, Lonicera involucrata, Salix spp., and Ribes lacustre. The most common herbs are: Epilobium angustifolium, Aster conspicuus, Fragaria virginiana, Galium boreale, Thalictrum occidentale, Achillea millefolium, Calamagrostis rubescens, and Cornus canadensis (Tables 4 and 5). Figure 32. An aspen fringe occupying a transitional area between a non-forested, mounded, graminoid community and an 'upland' lodgepole pine forest in the Nimpo Lake area (SBPS zone). The fringe and graminoid community are affected by a fluctuating water table. This stand represents the poorer variation of the Thalictrum (310) association. 49RESULTS AND DISCUSSION Description of Plant Associations Trembling Aspen Ecosystems Figure 33. An immature aspen stand surrounded by lodgepole pine in a shallow depression in the 100 Mile House area (IDF zone). This stand represents the drier and poorer variation of the Thalictrum (310) association on a site with a fluctuating water table. Figure 34. A closed-canopy, mature aspen stand with scattered scrub birch bordering a non-forested, frost-affected wetland (in the background) in the 100 Mile House area (IDF zone). This stand represents the wetter, most productive variation of the Thalictrum (310) association on a site with a fluctuating water table. 50 RESULTS AND DISCUSSION Description of Plant Associations Scientica Silvica Extension Series, Number 27, 2000 411 Populus tremuloides - Viburnum edule: Spiraea betulifolia (Viburnum - Spiraea) subassociation (References: Tables 3, 4, 5, and 9; Figures 4, 7, 8, 9, 35, 36 and 37; Appendices 10 and 25) Slightly dry to fresh (moist), (medium) rich to very rich sites in wetter montane boreal climates The Viburnum - Spirea subassociation represents a sub-boreal segment of the Symphoricarpos alliance and Viburnum association (Tables 3 and 4). These slightly dry to fresh, nutrient-rich communities occupy flats or warm-aspect, mid- and lower slopes in the SBS zone, and feature a mixture of montane boreal and cool temperate species. The mean area of aspen stands is rather small compared to the BWBS zone. Aspen productivity is medium (Figures 35, 36 and 37), with site index (@ 50 yrs bh) ranging from 12 to 19 m. The commonly associated soils are moderately deep,  well-drained, coarse or fine textured, skeletal, Dystric or Eutric Brunisols, Gray Luvisols, or Humo-Ferric Podzols, with Mormoder, or Mullmoder humus forms (Table 9). The cover of the tree layer is generally high. In addition to aspen, the tree layer nearly always includes white spruce, and occasionally subalpine fir and Douglas-fir. White spruce, subalpine fir, and Sitka alder are common in the understory (Figure 37). The understory vegetation is always well developed; its cover decreases in order from the shrub to the herb to the moss layer (Table 9, Figures 35 and 36). In order of decreasing presence, the most common shrub species are: Rosa acicularis (a diagnostic species for the Viburnum association), Amelanchier alnifolia (a diagnostic species for the Symphoricarpos alliance), Cornus stolonifera (a diagnostic species for the Viburnum association), Spiraea betulifolia, Symphoricarpos albus (a diagnostic species for the Symphoricarpos alliance), Viburnum edule (a diagnostic species for the Viburnum association), and Rubus parviflorus. The most common herbs are: Osmorhiza berteroi and Thalictrum occidentale (both diagnostic species for this subassociation), Aralia nudicaulis (a diagnostic species for the Viburnum association), Elymus glaucus (a diagnostic species for the Symphoricarpos alliance), Galium boreale (a diagnostic species for this subassociation), Linnaea borealis, Epilobium angustifolium, Rubus pubescens, Aster conspicuus and Fragaria virginiana (both diagnostic species for this subassociation), Clintonia uniflora, and Cornus canadensis (Tables 4 and 5). Figure 35. An immature, closed-canopy, herb-dominated aspen stand on a gentle mid-slope north of Vanderhoof (SBS zone). This stand represents the drier variation of the Viburnum - Spiraea (411) subassociation. 51RESULTS AND DISCUSSION Description of Plant Associations Trembling Aspen Ecosystems Figure 36. A late-immature, closed-canopy, shrub- and herb-dominated aspen stand on a flat near Cranberry Junction (ICH zone). This stand represents the wetter variation of the Viburnum - Spiraea (411) subassociation. Figure 37. A late-immature, semi-open canopy, shrub-dominated aspen stand with scattered understory hybrid spruce on flat north of Fort St. James (SBS zone). This stand represents the wetter and richer variation of the Viburnum - Spiraea (411) subassociation. 52 RESULTS AND DISCUSSION Description of Plant Associations Scientica Silvica Extension Series, Number 27, 2000 412 Populus tremuloides - Viburnum edule: Paxistima myrsinites (Viburnum - Paxistima) subassociation (References: Tables 3, 4, 5, and 9; Figures 4, 7, 8, 9, and 38, 39, 40, and 41; Appendices 11 and 26) Slightly dry (fresh), medium to rich sites in wetter cool temperate climates The Viburnum - Paxistima subassociation represents a segment of the Symphoricarpos alliance and Viburnum association that is located entirely within the ICH (Tables 3 and 4). These slightly dry to fresh, nutrient-rich communities occupy variable meso-slope positions but they occur most frequently on warm-aspect mid-slopes (Figures 39, 40 and 41), rarely on flats. Similarly to the Viburnum - Spiraea communities, the Viburnum - Paxistima stands occupy small areas compared to the montane boreal stands. Aspen productivity is medium, with site index (@ 50 yrs bh) ranging from 15 to 23 m. The commonly associated soils are moderately deep, moderately well-drained, coarse or fine textured, skeletal, Eutric Brunisols, with Mormoder or Leptomoder humus forms (Table 9). The cover of the tree layer is variable but generally high (Figures 39, 40 and 41). The tree layer may include paper birch , western redcedar, and western hemlock (all diagnostic species for this subassociation); occasionally balsam poplar, subalpine fir, western white pine, and Douglas-fir. Shade tolerant tree species, Alnus sitchensis, and Corylus cornuta (a diagnostic species for this subassociation) are common in the understory (Table 9, Figure 41). The understory vegetation is always well developed; its cover decreases in order from the shrub to the herb to the moss layer, which has a low cover. In order of decreasing presence, the most common shrub species are: Paxistima myrsinites (a diagnostic species for the Symphoricarpos alliance and Viburnum - Paxistima subassociation), Rubus parviflorus, Cornus stolonifera (a diagnostic species for the Viburnum association), Rosa acicularis, Viburnum edule, and Lonicera involucrata (a diagnostic species for the Viburnum association). The most common herbs are: Aralia nudicaulis (a diagnostic species for the Viburnum association), Clintonia uniflora, Cornus canadensis, Elymus glaucus, Epilobium angustifolium, Linnaea borealis, and Maianthemum racemosum. The most common bryophytes are: Rhytidiadelphus triqetrus (a diagnostic species for this subassociation), Pleurozium schreberi, and Ptilium crista-castrensis (Tables 4 and 5). Figure 38. An immature mixture of aspen and birch dominated by falsebox on a mid-slope in the Horsefly area (ICH zone). This stand represents the drier variation of the Viburnum - Paxistima (412) subassociation. 53RESULTS AND DISCUSSION Description of Plant Associations Trembling Aspen Ecosystems Figure 39. A uniform, immature, closed-canopy, falsebox-dominated aspen stand on a gentle mid-slope near Cranberry Junction (ICH zone). This stand represents the typic variation of the Viburnum - Paxistima (412) subassociation. Figure 40. An immature mixture of aspen, black cottonwood, and birch on a mid-slope near Horsefly (ICH zone). This stand represents the wetter variation of the Viburnum - Paxistima (412) subassociation. Figure 41. A mature aspen with Corylus cornuta in the upper shrub layer stand on a flat near St Marry Lake (ICH zone). This stand represents the wetter and richer variation of the Viburnum - Paxistima (412) subassociation. 54 RESULTS AND DISCUSSION Description of Plant Associations Scientica Silvica Extension Series, Number 27, 2000 421 Populus tremuloides - Rosa nutkana: Aralia nudicaulis (Rosa - Aralia) subassociation (References: Tables 3, 4, 5, and 9; Figures 4, 7, 8, 9, 42, and 43; Appendices 12 and 27) (Fresh) moist to very moist, (medium) rich to very rich sites in wetter cool temperate climates Rosa - Aralia communities are most common on moister and richer sites, but occasionally occur on fresh, or nutrient-medium sites. They are found almost exclusively on cool-aspect lower slopes, sometimes affected by seepage, or on flats influenced by a strongly fluctuating water table. These communities were described from the MS, ICH, and wetter IDF subzones. These water surplus sites support high-productivity aspen growth with site index (@ 50 yrs bh) ranging from 21 to 31 m (Figure 42). The associated soils in the MS and ICH zones include coarse-skeletal Humo-Ferric Podzols, loamy-skeletal Eutric Brunisols or loamy-skeletal Gray Luvisols; the associated humus forms are predominantly Mormoders, Leptomoders or Vermimulls (Table 9). The tree layer of the Rosa - Aralia communities includes frequently hybrid spruce, paper birch, lodgepole pine, and black cottonwood (on very moist sites); the sub-canopy may include hybrid spruce and/or western redcedar (Figure 43). Rosa - Aralia communities usually have well developed shrub and herb layer, but sometimes both of these layers have a very low cover (Table 9). The moss layer is absent or its cover is low. In order of decreasing presence, the most common shrubs are: Symphoricarpos albus (a diagnostic species for the Symphoricarpos alliance), Acer glabrum (an important companion for the Rosa association), Rubus parviflorus, and Cornus stolonifera. The most common species in the herb layer are: Elymus glaucus (a diagnostic species for the Symphoricarpos alliance), Osmorhiza berteroi (an important companion for the Symphoricarpos alliance), Festuca subuliflora (a diagnostic species for the Rosa association), Aralia nudicaulis (a diagnostic species for the Aralia subassociation), Cornus canadensis, Galium triflorum (an important companion for the Rosa association), and Mainathemum stellatum (an important companion for the Symphoricarpos alliance) (Tables 4 and 5). Figure 42. View of the canopy of one of the most productive aspen stands on a moist and rich site in the SBS-ICH transition near Gavin Lake. This stand represents the wetter and richer variation of the Rosa - Aralia (421) subassociation. Figure 43. An open-canopy aspen stand with abundant regeneration of Douglas-fir, hybrid spruce, and subalpine in the understory near Horsefly (ICH zone). This stand represents the drier variation of the Rosa - Aralia (421) subassociation. 55RESULTS AND DISCUSSION Description of Plant Associations Trembling Aspen Ecosystems 422 Populus tremuloides - Rosa nutkana: Arnica cordifolia (Rosa - Arnica) subassociation (References: Tables 3, 4, 5, and 9; Figures 4, 7, 8, 9, and 44; Appendices 13 and 28) Moderately to slightly dry, medium to rich sites in montane cool temperate climates Rosa - Arnica communities occur predominantly on mid-slopes in the MS, ICH, and IDF zones. Although water- deficient, these sites support high-productivity aspen growth, with site index (@ 50 yrs bh) ranging from 20 to 27 m. The associated soils in the MS and ICH zones are typically coarse-skeletal Humo-Ferric Podzols or, in the IDF zone, loamy-skeletal Eutric Brunisols. The associated humus forms are Mormoders and Leptomoders in the MS and ICH zones, and Hemimors in the IDF zone (Table 9). Rosa - Shepherdia communities may include paper birch, and occasionally western white pine and western larch, in the canopy. Douglas-fir may occur in the canopy or sub-canopy in the IDF zone, and hybrid spruce in the MS, ICH, and IDF zones. In the ICH zone, western redcedar and western hemlock can be found in the sub- canopy. Most stands are structurally diversified into well developed, species-rich shrub and herb layers, either layer or both layers may be poorly developed in some cases (Table 9, Figure 44). The moss layer is essentially absent. In order of decreasing presence, the most common shrubs are: Rubus parviflorus, Spiraea betulifolia, Acer glabrum (an important companion for the Rosa association), Mahonia aquifolium (a diagnostic species for the Rosa association), and Shepherdia canadensis. In order of decreasing presence, the most common species in the herb layer are: Osmorhiza berteroi (an important companion for the Symphoricarpos alliance), Arnica cordifolia (a diagnostic species for this subassociation), Galium triflorum (an important companion for the Rosa association), Calamagrostis rubescens, Chimaphila umbellata (a diagnostic species for this subassociation), Clintonia uniflora, and Linnaea borealis (Tables 4 and 5). Figure 44. A mature, small shrub- and herb-dominated aspen stand on a mid-slope on the side of a gully west of Williams Lake (IDF zone). This stand represents the drier variation of the Rosa - Arnica (422) subassociation. 56 RESULTS AND DISCUSSION Description of Plant Associations Scientica Silvica Extension Series, Number 27, 2000 423 Populus tremuloides - Rosa nutkana: Angelica genuflexa (Rosa - Angelica) subassociation (References: TTables 3, 4, 5, and 9; Figures 4, 7, 8, 9, and 45; Appendices 14 and 29) (Slightly dry) fresh, medium to rich (very rich) sites in cool temperate climates Rosa - Angelica communities occur predominantly on south-aspect mid- or lower slopes or on flats affected by intermittent seepage in the ICH and IDF zones. These sites support medium- to high-productivity aspen growth with site index (@ 50 yrs bh) ranging from 19 to 26 m. The associated soils are typically sandy to loamy-skeletal Eutric Brunisols, occasionally Gray Luvisols, with Vermimull or Moder humus forms (Table 9). In the IDF zone, Rosa - Angelica communities may include Douglas-fir in the canopy or sub-canopy while hybrid spruce can be present in both the IDF and ICH zones (Figure 45). Lodgepole pine in the canopy and western hemlock in the sub-canopy are infrequent. The stand structure is typically diversified into well developed, species-rich shrub and herb layers, but the moss layer is essentially absent (Table 9). In order of decreasing presence, the most common shrubs are: Amelanchier alnifolia (a diagnostic species for this subassociation), Sympricarpos albus (a diagnostic species for the Symphoricarpos alliance), Rubus parviflorus, Cornus stolonifera, Lonicera involucrata, and L. utahensis (an important companion for the Rosa association). The common herbs include: Actaea rubra, Angelica genuflexa, Aster conspicuus, Disporum hookeri, Lilium columbianum, and Thalictrum occidentale (all diagnostic species for this subassociation) (Tables 4 and 5). Figure 45. An immature, open-canopy, clumpy aspen stand with western hemlock and hybrid spruce in the understory on a flat near Horsefly (ICH zone). This stand represents the typic variation of the Rosa - Angelica (423) subassociation associated with a fluctuating water table. 57RESULTS AND DISCUSSION Description of Plant Associations Trembling Aspen Ecosystems 424 Populus tremuloides - Rosa nutkana: Senecio pseudoaureus (Rosa - Senecio) subassociation (References: Tables 3, 4, 5, and 9; Figures 4, 7, 8, 9, and 46; Appendices 15 and 30) Moderately dry (slightly dry), (medium) to rich (very rich) sites in drier cool temperate climates Rosa - Senecio communities occur on water-deficient sites, typically on upper or mid-slopes or on flats associated with fluvial deposits in the IDF and MS zones. While most common on moderately dry and rich sites, these communities are occasionally found on slightly dry and on medium or very rich sites. Although dry, these sites represent medium- to high-productivity conditions for aspen growth with site index @ 50 yrs bh ranging from 15 to 25 m; however, there is a high incidence of stem rot. The associated soils are loamy-skeletal Eutric Brunisols, occasionally Humo-Ferric Podzols or Grey Luvisols, with Vermimull or Leptomoder humus forms (Table 9). Rosa - Senecio communities may include lodgepole pine in the upper canopy or Douglas-fir (in the IDF zone) or hybrid spruce (in the MS zone) in the canopy or sub-canopy, or western redcedar in the sub-canopy (in the IDF zone). The stand structure is usually simple, with either the shrub or herb layer (or both) being poorly developed (Table 9, Figure 46). The moss layer is essentially absent. Common shub species include: Amelanchier alnifolia (a diagnostic species for the Symphoricarpos alliance), Mahonia aquifolium (a diagnostic species for the Rosa association), Rosa nutkana, Paxistima myrsinites and Symphoricarpos albus (both diagnostic species for the Symphoricarpos alliance). Calamagrostis rubescens and Elymus glaucus (a diagnostic species for the Symphoricarpos alliance) are constant dominants, and Senecio pseudoaureus (a diagnostic species for this subassociation) and Fragaria virginiana are other common herbs. The Rosa - Senecio subassociation has only one, albeit weak, diagnostic species (Senecio pseudoaureus). This means that these communities are identified by the absence of diagnostic species identified for the other four subassociations of the Rosa nutkana association (Tables 4 and 5). Figure 46. A uniform, closed-canopy mature aspen stand with a shrub (Shepherdia canadensis), grass (Calamagrostis rubescens), and herb-dominated understory near Yahk (MS zone). This stand represents the poorer variation of the Rosa - Senecio (424) subassociation. 58 RESULTS AND DISCUSSION Description of Plant Associations Scientica Silvica Extension Series, Number 27, 2000 425 Populus tremuloides - Rosa nutkana: Shepherdia  canadensis (Rosa - Shepherdia) subassociation (References: Tables 3, 4, 5, and 9; Figures 4, 7, 8, 9, and 47; Appendices 16 and 31) Very dry (moderately dry), poor to rich sites in drier cool temperate climates The Rosa - Shepherdia subassociation represents aspen communities characterized by severe water deficit. They occur on the driest and warmest sites, which are mostly very dry, and occasionally moderately dry, but have a wide range of nutrient conditions. These communities are typically found on ridge crests and warm- aspect, upper slopes in the IDF, SBPS, and MS zones, often bordering grassland communities, but sometimes occur on flats. The marginal environmental conditions for aspen growth are indicated by the occasional presence of Juniperus scopulorum. In the driest IDF subzones, Rosa - Shepherdia communities are located in gullies that feature ephemeral streams. The associated soils are typically loamy-skeletal Eutric Brunisols, occasionally Luvisols, with thin Leptomoder or Mull (when the cover of graminoids is high) humus forms. Small patches of exposed mineral soil are common, especially on steep slopes. Aspen growth is poor to medium (site index (@ 50 yrs bh) ranges form 8 to 16 m), often with a distorted growth form  and a high incidence of stem rot (Table 9, Figure 47). Rosa - Shepherdia communities may include lodgepole pine in the upper canopy or Douglas-fir in the canopy or sub-canopy. The stand structure is variable, typically both a shrub and herb layer are present, but either, or both may be poorly developed (Table 9). The cover of mosses is very low. Shepherdia canadensis and Arctostaphylos uva-ursi (a dominant differential species for this subassociation), Rosa nutkana (diagnostic for the Rosa association) and Juniperus communis ursi (a dominant differential species for this subassociation) are the most common shrubs. Calamagrostis rubescens is a constant dominant understory species; other associated grasses may include Elymus glaucus, E. repens, Festuca subuliflora, Poa nemoralis, Oryzopsis asperifolia, and Stipa richardsonii. Common forb species include: Achillea millefolium, Fragaria virginiana, and Galium boreale (an important companion for this subassociation) (Tables 4 and 5). Figure 47. A distorted, mature aspen stand with a graminoid-dominated (Calamagrostis rubescens) understory on an upper slope near Dog Creek (IDF zone). This stand represents the drier and richer variation of the Rosa - Shepherdia (425) subassociation. 59REFERENCES Trembling Aspen Ecosystems REFERENCES Agriculture Canada Expert Committeee on Soil Survey. 1987. The Canadian system of soil classification. 2nd ed. Agric. Can. Publ. 1646. Agriculture Canada, Ottawa, ON. 164 pp. Banner, A., W. MacKenzie, S. Haeussler, S. Thomson, J. Pojar, and R. Trowbridge. 1993. A field guide to site identification and interpretation for the Prince Rupert Forest Region. Land Management Handbook No 26. B.C. Min. For., Victoria, B.C. Barkman, J.J., J. Moravec, and S. Rauschert. 1976. Code of phytosociological nomenclature. Vegetatio 32:131-185. BC Ministy of Forests. no date. Biogeoclimatic units of the Prince George Forest Region. Map, scale 1:800,000. B.C. Min. For., Prince George, B.C. BC Ministy of Forests. 1988. Biogeoclimatic and ecoregion units of the Prince Rupert Forest Region. Map, scale 1:500,000. B.C. Min. For., Prince George, B.C. BC Ministry of Forests. 1997. Site index estimates by site series for coniferous tree species in British Columbia. Forest Renewal BC and BC Ministry of Forests, Victoria, B.C. 265 pp. Becking, R.W. 1957. The Zurich-Montepellier School of phytosociology. Bot. Rev. 23:411-488. Brooke, R.C., E.B. Peterson, and V.J. Krajina. 1970. The subalpine Mountain Hemlock zone. Ecol. Western N. Amer. 2:148-349. Chen, H.Y.H., K. Klinka, and R.D. Kabzems. 1998a. Height growth and site index models for trembling aspen (Populus tremuloides (Michx.) in northern British Columbia. For. Ecol. Manage. 102: 157-165. Chen, H.Y.H., K. Klinka, and R.D. Kabzems. 1998b. Site index, site quality, and foliar nutrients of trembling aspen: relationships and predictions. Can. J. For. Res. 28:1743-1755. DeLong, C. 1988. A field guide for identification of seral aspen ecosystems of the BWBSc1, Prince George Forest Region. Land Manage. Handbook No. 16., BC Ministry of Forests, Victoria BC. 36 pp. Emanuel, J. 1999. VTAB Ecosystem Reporter Revision 199907a. Department of Forest Sciences, University of British Columbia, Vancouver, B.C. Fons, J., K. Klinka, and R.D. Kabzems. 1998. Humus forms of trembling aspen ecosystems in northeastern British Columbia. Forest Ecol. Manage. 105: 241-250.  Green, R.N., R.L. Towbridge, and K. Klinka. 1993. Towards a taxonomic classification of humus forms. For. Sci. Monog. 29. 49pp. Green, R.N. and K. Klinka. 1994. A field guide to site identification and interpretaion for the Vancouver Forest Region. B.C. Min. For., Victoria, B.C. 285 pp. Hill, M.O. 1979. TWINSPAN - a FORTRAN program for arranging multivariate data in an ordered two-way table by classification of the individuals and attributes. Cornell University, Ithaca, N.Y. 60 REFERENCES Scientica Silvica Extension Series, Number 27, 2000 Kayahara, G.J., K. Klinka, P.V. Krestov, and H. Qian. 2000. Comparison of vegetation and soil nutrient properties between black spruce and trembling aspen ecosystems in the boreal black and white spruce zone of British Columbia. Submitted for publication in Can. J. For. Res. Klinka, K., V.J. Krajina, A. Ceska and A.M. Scagel. 1989. Indicator plants of coastal British Columbia. University of British Columbia Press, Vancouver, B.C. 138 pp. Klinka, K., H. Qian, J. Pojar, and D.V. Meidinger. 1996. Classification of natural forest communities of coastal British Columbia, Canada. Vegetatio 125: 149-168. Krajina, V.J. 1969. Ecology of forest trees in British Columbia. Ecol. Western N. Amer. 2:1-146. Little, E.L. Jr. 1979. Checklist of United States Trees. USDA For. Serv. Agricultural Handbook 541. Washington, D.C., 373 pp. Luttmerding, H.A, D.A. Demarchi. E.C. Lea, D.V. Meidinger and T. Vold (eds.) 1990. Describing ecosystems in the field. 2nd ed. B.C. Min. For., Victoria, B.C. Magurran, A.E. 1988. Ecological diversity and its measurement. Princeton University Press, Princeton, N.Y. 179 pp. Meidinger, D.V. and J. Pojar (eds.) 1991. Ecosystems of British Columbia. Special Rep. Series no. 6, B.C. Min. For., Victoria, B.C. Mueggler, W.F. Vegetation associations. Pp. 45-55 in N.V. DeByle and R.P. Vinokur (editors). Aspen: Ecology and management in the western  United States. USDA For. Serv. General Technical Report RM- 119, Rocky Mountain For. and Range Exp. Stat., Fort Collins, Colorado. Mueller-Dombois, D., and H. Ellenberg. 1974. Aims and methods of vegetation ecology. John Wiley and Sons, Toronto, ON. New, D. 1999. Productivity of western larch in relation to categorical measures of climate, soil moisture, and soil nutrients. M.Sc.Thesis, Faculty of Forestry, University of British Columbia. 47 pp. Nigh, G.D. 1996. Growth intercept models for species without distinct annual branch whorls: western hemlock. Can. J. For. Res. 26:1407-1415. Oliver, C.D. and B.C. Larson. 1996. Forest stand dynamics. McGraw-Hill, Inc., New York. 467 pp. Perala, D.A. 1990. Populus tremuloides (Michx). Pp. 555 -569 in R.M. Burns and B.H. Honkala (editors). Silvics of North America. Vol. 2. Hardwoods. USDA For. Serv. Agri. Handbook 445, Washington, D.C. 877 pp. Pojar, J. , K. Klinka, and D.V. Meidinger. 1987. Biogeoclimatic ecosystem classification in British Columbia. For. Ecol. Manage. 22:119-154. Poore, M.E.D. 1962. The methods of successive approximation in descriptive ecology. Adv. Ecol. Res. 1:35-68. Qian, H. and K. Klinka. 1998. Plants of British Columbia: scientific and common names of vascular plants, bryophytes, and lichens. University of British Columbia Press, Vancouver, B.C. 534 pp. Qian, H., K. Kinka, and B. Sivak. 1997. Diversity of the understory vascular vegetation in 40 year-old and old- growth forest stands on Vancouver Island, British Columbia. J. Veg. Sci. 8:773-780. 61REFERENCES Trembling Aspen Ecosystems Wang, Q. 1992. Ecological and height growth analysis of some sub-boreal immature lodgepole pine stands in central British Columbia. Ph.D. thesis, Fac. For., Univ. B.C. Vancouver, B.C. 207 pp. Wang, Q., G.G. Wang, K.D. Coates, and K. Klinka. 1994. Use of site factors to predict lodgepole pine and interior spruce site index in the Sub-Boreal Spruce Zone. Research Note No. 114, B.C. Min. For., Victoria, B.C. Westhoff, V. and E. van der Maarel. 1980. The Braun-Blanquet approach. In: R.H. Whittaker (ed). Classification of Plant Communities. Edited by R.H. Whittaker. Dr. Junk bv Publishers, The Hague. 62 Scientica Silvica Extension Series, Number 27, 2000 63 APPEN D ICES A ppendix 1 Trem bling Aspen Ecosystem s APPENDICES Appendix 1. Summary vegetation table (in alphabetical order) for vegetation units delineated in trembling aspen ecosystems in British Columbia. This table presents non-diagnostic species and those that occur with the presence ≤40% (= presence class ≤II) in one or more columns. Weak diagnostic species (usually important companion species) that were used in the diagnostic combinations of species (Table 4 on page 12) are shaded in grey. Codes for vegetation units as in Table 3 on page 11. Code 111 112 113 210 221 222 223 310 411 412 421 422 423 424 425 Number of sample plots 4 14 13 10 11 31 10 10 17 10 14 9 9 9 15 Number of plant species 62 101 111 41 72 78 87 103 119 102 112 87 81 115 103 Species Species presence and species significance1 Aconitum columbianum II + Adenocaulon bicolor II 4 II 2 II + I h Adoxa moschatellina I h I h II h Agoseris aurantiaca I h I h Agropyron pauciflorum I h Agrostis mertensii I h I h Alectoria sarmentosa I h Allium cernuum I h II + Alnus viridis I h I 4 I 1 I 2 II 4 II 3 I 4 I 2 II 4 I 1 Anaphalis margaritacea II h II h I h Anemone multifida II + Anemone parviflora I h Antennaria microphylla I h Antennaria neglecta II h I h II + Antennaria pulcherrima I h Apocynum androsaemifolium I 3 I h II 2 Aquilegia brevistyla I t I 1 Aquilegia formosa II h I h II h I h II 1 Arabis holboellii I h Arctostaphylos alpina I h I h Asplenium viride I h Aster engelmannii I + Aster modestus I h I h Aster sibiricus II h I h I h II 1 I + I 1 II + Asterella lindenbergiana I + Athyrium filix-femina I h II + II h Aulacomnium palustre I h Betula nana II h I 3 I + Botrychium lunaria I h I h I h Botrychium virginianum I h II h Bromus inermis II 1 I h II 1 I h I h I h Calliergon giganteum I h II h II h I h Calliergon stramineum I 3 I h II 1 I h I h II h I h I h Calochortus apiculatus I h Calypso bulbosa I h I h Campanula rotundifolia I h I h I h I h Carex concinna I h Carex disperma I h I h I h 64 APPEN D ICES A ppendix 1 Scientica Silvica Extension Series, N um ber 27, 2000 Carex obtusata I h Carex rossii I 2 Carex spectabilis I h I h Castilleja hyetophila I h II + Castilleja miniata I h I h I h I h I + Castilleja sulphurea I h Ceanothus velutinus I h Cerastium arvense I h Cinna latifolia I h I h I h I h I h Cladina arbuscula II h I h Cladina stellaris II h I h I h Cladonia borealis  II 1 Cladonia cornuta II h I h Cladonia crispata II h I h Cladonia ecmocyna II h I h I h Cladonia gracilis II h Cladonia multiformis I h I h I h I h I h Cladonia ochrochlora II h Cladonia phyllophora II h I h Cladonia pyxidata II h Clematis occidentalis I h I h Coeloglossum viride I h Corallorhiza maculata I h Corallorhiza trifida I h I h I h II h II h I h Crataegus douglasii I h Cypripedium montanum I h I h Dactylis glomerata I h II 1 Deschampsia cespitosa I h I h Dicranella palustris II h I + I h I h I h Dicranum fragilifolium I h Dicranum fuscescens I h I h I h I h I h I h I h I h I h Dicranum polysetum I + I h Dicranum scoparium I h I h I h I h I h Disporum trachycarpum I h Dryopteris expansa I h Dryopteris fragrans I h I h Elymus repens I h II h I h I 1 Elymus smithii I h Empetrum nigrum II h I h II 2 Epilobium ciliatum I + I h I h Equisetum arvense I h I t I h I h I h Equisetum hyemale I h Equisetum scirpoides I h I h I h Equisetum sylvaticum I h I h I h II h Eurhynchium pulchellum I h I h Festuca brachyphylla I h Festuca occidentalis I h I h I h I h I h Flavocetraria nivalis II h Code 111 112 113 210 221 222 223 310 411 412 421 422 423 424 425 Number of sample plots 4 14 13 10 11 31 10 10 17 10 14 9 9 9 15 Number of plant species 62 101 111 41 72 78 87 103 119 102 112 87 81 115 103 Species Species presence and species significance1 65 APPEN D ICES A ppendix 1 Trem bling Aspen Ecosystem s Frangula purshiana I + Fritillaria affinis I h I h Gentianella amarella II h I h I h I h Geranium richardsonii I h II + I h Geum macrophyllum I h Glyceria elata I h I + Goodyera oblongifolia I h I h I h II h I h I h II h I h Gymnocarpium dryopteris I 3 I 4 I 3 I h Hedysarum sulphurescens I h Hieracium scouleri I h II h I h II h II h Hieracium umbellatum I h Hypopitys monotropa I h Juniperus horizontalis I + Juniperus scopulorum I 2 Larix occidentalis I 3 I 3 II 4 Lathyrus nevadensis I h II h I h I 2 I + I h Letharia vulpina I h I h Leucanthemum vulgare II h Leymus innovatus I 3 I 2 Listera convallarioides I h Listera cordata I h Lobaria pulmonaria I h I h I h Lonicera utahensis I h II 4 I h II 4 II 4 I h Lycopodium annotinum I 2 I h I 2 I h I 1 Lycopodium dendroideum I h Lycopodium obscurum II 2 I 2 Maianthemum racemosum I h I 1 Maianthemum stellatum I h I h Maianthemum trifoliatum  I h Malus fusca I h I + Matteuccia struthiopteris I h Medicago sativa II 2 I 3 Mnium spinulosum I h Moehringia lateriflora II h Moneses uniflora I 1 Oplopanax horridus I + I h Parmelia saxatilis II h Pedicularis bracteosa I h Pedicularis racemosa I h I 1 Peltigera malacea I + I h I h I h Peltigera membranacea II h II h II 2 I h Peltigera praetextata I h I h I h I h II h I h Peltigera scabrosa I h I h Penstemon procerus  I h I h Petasites sagittatus I h Phleum pratense I h I h I h Piperia unalascensis I h I h I h Plagiomnium ciliare II h Code 111 112 113 210 221 222 223 310 411 412 421 422 423 424 425 Number of sample plots 4 14 13 10 11 31 10 10 17 10 14 9 9 9 15 Number of plant species 62 101 111 41 72 78 87 103 119 102 112 87 81 115 103 Species Species presence and species significance1 66 APPEN D ICES A ppendix 1 Scientica Silvica Extension Series, N um ber 27, 2000 Plagiomnium drummondii I 4 I h I h I h I h I h Plagiomnium medium I h I h Platanthera obtusata II h I h I h Platanthera orbiculata I h I h I + I t I h I h I h Poa nemorosa I h II h Poa palustis  I h I h II h I h Pogonatum contortum I h Polemonium boreale II + Polemonium caeruleum I h Polytrichum strictum I h II h II h Potentilla glandulosa I h I h Prunella vulgaris II 2 II h I h Prunus virginiana I 1 Pteridium aquilinum II 3 II 3 II 4 Ptilidium pulcherrimum II h Pyrola chlorantha I h I h I h Pyrola elliptica II h I h I h Pyrola minor II + II h I h I h I h Ranunculus eschscholtzii I h Rhododendron albiflorum I h Rhytidiadelphus squarrosus I h I + I h Ribes triste I h I h I h I 2 I + Rubus idaeus I h I + II 2 I 2 I h I h II + II 2 I h Rubus pedatus I + Salix bebbiana I + I + I 3 I 2 I h Salix glauca I 3 I 6 I h II 1 Salix lucida I 2 II h Salix myrtillifolia I h Salix sitchensis I 1 Sambucus racemosa I h Sanicula marilandica I h Sanionia uncinata II 2 I h I h I h I h II h Saxifraga nelsoniana I h Saxifraga tricuspidata II + Schizachne purpurascens I h I + Senecio triangularis I 1 Silene menziesii I h I h Solidago canadensis I h I h II + I h I h I h Solidago spathulata II h I h I h I h I h Sorbus scopulina I + II h II + II + Spiraea douglasii I 1 Stellaria calycantha I h I h I h I h II h I h Stenanthium occidentale I h I h Stipa richardsonii I h Streptopus amplexifolius I h Taraxacum officinale I h I h I + I h I h I h II h II + Thalictrum venulosum II 2 Thamnolia vermicularis II h I h Code 111 112 113 210 221 222 223 310 411 412 421 422 423 424 425 Number of sample plots 4 14 13 10 11 31 10 10 17 10 14 9 9 9 15 Number of plant species 62 101 111 41 72 78 87 103 119 102 112 87 81 115 103 Species Species presence and species significance1 67 APPEN D ICES A ppendix 1 Trem bling Aspen Ecosystem s Tomentypnum nitens II h Tortula ruraliformis II h I h Trifolium pratense I h I + Trifolium repens I h II h I h Trillium ovatum I h I h Trimorpha acris  I h Trisetum cernuum I h I h I h I h I + I h II h I h Urtica dioica I + Vaccinium membranaceum I h I h I h II + I h I h I h I h Vaccinium scoparium I 2 Viola lanceolata I h Viola orbiculata I h I h I h Viola palustris I h I h I h I h Viola septentrionalis I h I h II h Vulpia microstachys I h I h Zigadenus elegans I h 1 Species presence and significance classes defined in Table 4 on pag e12. Code 111 112 113 210 221 222 223 310 411 412 421 422 423 424 425 Number of sample plots 4 14 13 10 11 31 10 10 17 10 14 9 9 9 15 Number of plant species 62 101 111 41 72 78 87 103 119 102 112 87 81 115 103 Species Species presence and species significance1 68 APPENDICES Appendix 2 Scientica Silvica Extension Series, Number 27, 2000 Appendix 2. Plot vegetation table for the 111 Populus tremuloides – Mertensia paniculata: Festuca altaica subassociation. Species are arranged in order of decreasing presence and alphabetically. Plot number1 1 Plot numbers have been simplified in this report. See Appendix 32 on page 112 for original plot codes. 1 2 3 4 Species Species significance2 2 Species significance classes see Table 4 on page12 . Epilobium angustifolium 7 + + 4 Galium boreale + 2 4 2 Populus tremuloides 7 7 6 9 Rosa acicularis 4 3 + 4 Shepherdia canadensis 6 3 6 5 Arctostaphylos uva-ursi 4 4 6 Delphinium glaucum + + 2 Festuca altaica 2 8 4 Fragaria virginiana + + + Geocaulon lividum 4 2 + Juniperus communis 6 6 5 Linnaea borealis 5 3 3 Pleurozium schreberi 4 4 2 Salix scouleriana 4 4 7 Viburnum edule 5 3 7 Achillea millefolium + + Mertensia paniculata + 3 Orthilia secunda + + Pulsatilla patens + + Pedicularis labradorica + + Trisetum spicatum + + Abies lasiocarpa 4 Amelanchier alnifolia 3 Antennaria neglecta + Aquilegia formosa + Aster sibiricus + Cladonia borealis  3 Calamagrostis canadensis + Cladina arbuscula ssp. mitis + Cladina stellaris + Cladonia cornuta + Cladonia crispata + Cladonia ecmocyna + Cladonia gracilis + Cladonia ochrochlora + Cladonia phyllophora + Cladonia pyxidata + Drepanocladus uncinatus 4 Empetrum nigrum + Flavocetraria nivalis + Gentianella amarella + Hylocomium splendens + Lupinus arcticus 4 Moehringia lateriflora + Osmorhiza berteroi  + Parmelia saxatilis + Peltigera aphthosa + Peltigera membranacea + Picea glauca 3 Pinus contorta + Plagiomnium ciliare + Polemonium boreale 2 Ptilidium pulcherrimum + Rhizomnium glabrescens + Saxifraga tricuspidata 2 Solidago spathulata + Stereocaulon tomentosum 1 Thamnolia vermicularis + Tomentypnum nitens + Vaccinium vitis-idaea 5 69APPENDICES Appendix 3 Trembling Aspen Ecosystems Appendix 3. Plot vegetation table for the 112 Populus tremuloides – Mertensia paniculata:  Arnica cordifolia subassociation. Species are arranged in order of decreasing presence and alphabetically. Plot number1 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Species Species significance2 Hylocomium splendens 6 8 7 + 7 2 3 7 7 7 6 + + 6 Populus tremuloides 8 7 6 7 7 8 7 6 7 8 7 7 8 6 Shepherdia canadensis 4 7 5 7 6 6 8 6 5 7 7 6 5 Arnica cordifolia 4 + 5 + + + 3 6 + + + + Epilobium angustifolium 3 + 7 3 7 7 4 2 + 6 2 + Geocaulon lividum 4 + 3 + + + + 3 3 + + + Linnaea borealis 5 4 7 5 + 3 4 + 5 6 2 + Orthilia secunda 4 + + + + + + + + + + + Rosa acicularis 2 + 3 3 3 5 2 5 + 4 6 + Picea glauca 6 7 6 4 5 4 5 7 6 6 5 Mertensia paniculata 3 + + + 3 5 3 3 + 4 Pleurozium schreberi 7 7 8 + + 5 6 7 4 9 Viburnum edule 5 4 3 4 3 4 3 + 4 + Cornus canadensis + 4 7 3 5 5 5 5 + Delphinium glaucum + + + + + 3 + + Goodyera repens + + + + + + + + Achillea millefolium + + + + + + + Picea mariana 5 4 4 4 5 5 4 Fragaria virginiana + 5 + + + + Lupinus arcticus + + 4 + 3 Osmorhiza berteroi + + + + 3 Salix scouleriana 2 3 + 7 5 Abies lasiocarpa 6 5 5 3 Festuca altaica + + + 3 Juniperus communis + 5 + 6 Peltigera aphthosa + + 4 4 Arctostaphylos uva-ursi 4 4 7 Dicranella palustris + + + Peltigera membranacea 2 + + Platanthera obtusata + + + Populus balsamifera + 3 5 Ptilium crista-castrensis 5 + + Pyrola elliptica + + + Pyrola minor + + 3 Rhizomnium glabrescens + + + Actaea rubra + + Amelanchier alnifolia + + Castilleja sulphurea + + Cladonia ecmocyna + + Corallorhiza trifida + + Dicranum scoparium + + Elymus glaucus + + Empetrum nigrum + + Galium boreale + + Goodyera oblongifolia + + Ledum groenlandicum 4 3 Lobaria pulmonaria + + Lycopodium annotinum + 5 Oryzopsis asperifolia + 3 Pedicularis labradorica 3 + Peltigera scabrosa + + Pinus contorta 4 7 Rhytidiadelphus triquetrus 7 + Ribes lacustre + + Spiraea betulifolia 4 + Alnus viridis 2 Adoxa moschatellina + 70 APPENDICES Appendix 3 Scientica Silvica Extension Series, Number 27, 2000 Aralia nudicaulis + Arctostaphylos alpina + Aster conspicuus 3 Aster sibiricus + Calamagrostis canadensis + Calamagrostis rubescens + Carex spectabilis + Castilleja miniata + Cerastium arvense + Cladina arbuscula + Cladina stellaris + Cladonia multiformis + Clintonia uniflora 3 Deschampsia cespitosa + Dicranum fragilifolium + Dicranum fuscescens + Dicranum polysetum 4 Drepanocladus uncinatus + Equisetum scirpoides + Festuca occidentalis + Galium trifidum + Juniperus horizontalis 3 Leymus innovatus 6 Lonicera involucrata 5 Lycopodium complanatum + Maianthemum racemosum 1 Pulsatilla patens + Peltigera praetextata + Petasites frigidus + Platanthera orbiculata + Pseudotsuga menziesii 6 Salix bebbiana 3 Salix glauca 6 Solidago spathulata + Stellaria calycantha + Trisetum cernuum + Vaccinium caespitosum 4 Vaccinium membranaceum + Vaccinium scoparium 5 Vaccinium vitis-idaea 2 Vicia americana + Zigadenus elegans + 1 Plot numbers have been simplified in this report. See Appendix 32 on page 112 for original plot codes. 2 Species significance classes defined in Table 4 on page 12. Plot number1 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Species Species significance2 71APPENDICES Appendix 4 Trembling Aspen Ecosystems Appendix 4. Plot vegetation table for the 113 Populus tremuloides – Mertensia paniculata: Petasites frigidus subassociation. Species are arranged in order of decreasing presence and alphabetically. Plot number1 19 20 21 22 23 24 25 26 27 28 29 30 31 Species Species significance2 Populus tremuloides 5 7 7 6 6 9 6 7 8 7 5 9 7 Linnaea borealis 2 4 4 5 5 5 7 2 3 4 + Rosa acicularis + + + + + 2 4 6 + 2 2 Hylocomium splendens 6 7 9 9 7 8 7 8 9 5 Shepherdia canadensis 4 + + + 3 4 + + 5 2 Cornus canadensis 7 7 7 6 + 6 6 + 4 Petasites frigidus + 3 3 3 3 2 + 6 4 Pleurozium schreberi 7 8 7 5 6 6 6 7 6 Epilobium angustifolium 6 3 3 3 3 + + 3 Geocaulon lividum + 4 + + + + + 3 Lupinus arcticus 3 5 4 4 4 4 + 2 Mertensia paniculata 4 3 + 3 3 + + + Picea glauca 5 6 3 4 7 6 5 3 Picea mariana 7 6 6 4 3 6 5 5 Achillea millefolium + + 3 + + + + Festuca altaica + 3 3 + + 2 + Galium boreale + + + 3 + 3 + Salix scouleriana 5 3 3 5 5 4 4 Vaccinium vitis-idaea 2 5 4 3 4 + 4 Viburnum edule 3 3 3 7 4 + 3 Fragaria virginiana + + 4 + 4 2 Mitella nuda + + + + 3 + Orthilia secunda + + + + + + Ptilium crista-castrensis 5 3 + 5 + 4 Goodyera repens 3 + + + + Peltigera membranacea 1 1 5 4 2 Pinus contorta 6 7 6 6 5 Arnica cordifolia + 3 4 4 Empetrum nigrum 3 + + 5 Ledum groenlandicum 4 5 5 + Pedicularis labradorica + + + + Peltigera aphthosa + + 3 4 Pyrola minor + + + + Betula nana + + + Abies lasiocarpa 1 + Arctostaphylos alpina + + Arctostaphylos uva-ursi 5 + Aster conspicuus 5 6 Aulacomnium palustre + + Calypso bulbosa + + Cladina stellaris + + Delphinium glaucum 2 + Dicranella palustris 3 + Equisetum scirpoides + + Galium triflorum + + Leymus innovatus 4 5 Platanthera obtusata + + Platanthera orbiculata + + Populus balsamifera 5 + Pyrola elliptica + + Rubus pedatus 3 + Rubus pubescens 3 + Salix bebbiana 3 3 Thamnolia vermicularis + + Vaccinium caespitosum 6 5 Viola lanceolata + + Alnus incana 2 72 APPENDICES Appendix 4 Scientica Silvica Extension Series, Number 27, 2000 Alnus viridis 7 Actaea rubra 3 Amelanchier alnifolia 2 Aralia nudicaulis 4 Aster ciliolatus 1 Aster sibiricus + Betula papyrifera 2 Botrychium virginianum + Calamagrostis rubescens 7 Cladonia cornuta + Cladonia ecmocyna + Cladonia multiformis 1 Corallorhiza trifida + Cornus stolonifera + Dicranum polysetum + Elymus glaucus + Elymus repens + Elymus smithii + Epilobium ciliatum 4 Equisetum arvense + Equisetum pratense + Equisetum sylvaticum + Festuca subuliflora + Geranium richardsonii 2 Goodyera oblongifolia + Juniperus communis + Lathyrus nevadensis + Lathyrus ochroleucus 3 Lonicera involucrata 3 Lycopodium annotinum + Maianthemum racemosum 4 Maianthemum canadense 4 Osmorhiza berteroi 4 Oryzopsis asperifolia + Poa palustris + Peltigera scabrosa 2 Polemonium caeruleum + Pyrola asarifolia + Pyrola chlorantha + Rhytidiadelphus squarrosus + Rhytidiadelphus triquetrus 4 Ribes lacustre 2 Ribes triste 2 Rubus idaeus + Salix sp. 2 Salix myrtillifolia + Solidago spathulata + Taraxacum officinalis + Thalictrum occidentale 6 Trisetum cernuum + Vaccinium membranaceum + Vicia americana + Viola palustris + 1 Plot numbers have been simplified in this report. See Appendix 32 on page112  for original plot codes. 2 Species significance classes defined in Table 4 on page12 . Plot number1 19 20 21 22 23 24 25 26 27 28 29 30 31 Species Species significance2 73APPENDICES Appendix 5 Trembling Aspen Ecosystems Appendix 5. Plot vegetation table for the 210 Populus tremuloides – Ledum groenlandicum association. Species are arranged in order of decreasing presence and alphabetically. Plot number1 1 Plot numbers have been simplified in this report. See Appendix 32 on page 112 for original plot codes. 32 33 34 35 36 37 38 39 40 41 Species Species significance2 2 Species significance classes defined in Table 4 on page12 . Populus tremuloides 8 9 9 8 8 7 7 7 9 9 Cornus canadensis 4 4 4 4 5 6 6 5 5 4 Ledum groenlandicum 6 4 6 7 7 6 7 7 6 7 Petasites palmatus 2 2 + 4 4 4 4 4 3 3 Spiraea betulifolia 3 3 3 4 3 3 4 + 2 4 Vaccinium myrtilloides 7 7 7 7 6 5 5 5 7 7 Vaccinium vitis-idaea 5 5 5 4 4 4 4 2 5 5 Linnaea borealis 2 2 2 3 4 4 3 2 3 Polytrichum juniperinum 4 3 4 + + 3 3 4 3 Epilobium angustifolium 2 3 + 2 4 5 2 2 Geocaulon lividum 3 3 2 3 3 3 4 3 Lycopodium complanatum 4 4 4 5 4 5 6 5 Pleurozium schreberi 4 3 5 4 4 3 4 4 Abies lasiocarpa 3 2 2 2 2 2 + Cladina rangiferina 5 4 5 5 3 4 5 Melampyrum lineare 2 2 + 3 2 3 + Peltigera aphthosa 4 4 4 4 3 4 4 Salix sp. 2 2 2 3 3 4 3 Picea glauca 6 5 4 6 5 4 Picea mariana 4 4 4 4 4 4 Calamagrostis canadensis + 2 3 3 4 Elymus innovatus 3 2 2 3 + Lycopodium clavatum 4 4 4 3 5 Maianthemum canadense 3 + 4 4 3 Pinus contorta 4 4 2 4 4 Stereocaulon tomentosum 3 3 + 3 4 Lathyrus ochroleucus 3 2 4 4 Tortula ruraliformis + + + + Lycopodium obscurum 4 + 4 Alnus viridis 3 3 Arctostaphylos uva-ursi 4 4 Rosa acicularis 3 4 Aster ciliolatus + Betula papyrifera + Castilleja hyetophila + Cladonia crispata 2 Equisetum pratense + Hylocomium splendens + Juniperus communis + Shepherdia canadensis 4 Vaccinium caespitosum 4 74 APPENDICES Appendix 6 Scientica Silvica Extension Series, Number 27, 2000 Appendix 6. Plot vegetation table for the 221 Populus tremuloides – Lathyrus ochroleucus: Hedysarum boreale subassociation. Species are arranged in order of decreasing presence and alphabetically. Plot number1 42 43 44 45 46 47 48 49 50 51 52 Species Species significance2 Populus tremuloides 7 9 8 9 9 8 9 8 8 8 9 Elymus innovatus 6 4 6 4 6 6 6 3 4 3 Lathyrus ochroleucus 5 3 4 3 4 4 4 3 3 4 Maianthemum canadense 4 2 3 2 4 5 4 4 4 2 Linnaea borealis 4 2 + 2 + + 4 4 + Picea glauca 5 5 6 4 3 4 4 4 6 Rosa acicularis 4 4 3 4 4 4 4 4 4 Aster conspicuus 6 3 3 3 4 7 4 4 Calamagrostis canadensis 2 4 4 2 2 4 4 3 Galium boreale 4 4 4 4 4 4 5 4 Vaccinium myrtilloides 6 5 4 3 4 4 5 4 Achillea millefolium 2 2 2 + 2 3 + Fragaria virginiana 2 2 2 3 3 4 2 Hedysarum boreale 4 + 4 3 6 4 3 Salix sp. 4 5 4 4 3 4 6 Shepherdia canadensis 4 5 3 4 4 4 4 Amelanchier alnifolia 4 2 6 5 4 4 Oryzopsis asperifolia 4 5 4 5 4 4 Vaccinium vitis-idaea + 2 3 3 5 3 Vicia americana 4 2 + 2 5 4 Arctostaphylos uva-ursi 6 4 6 5 6 Epilobium angustifolium 3 2 2 4 4 Petasites frigidus 4 2 4 4 + Aster ciliolatus 2 + 3 2 Cornus canadensis 4 7 6 + Ledum groenlandicum 4 6 6 6 Spiraea betulifolia 3 3 2 4 Anemone multifida 2 + + Bromus inermis 3 4 + Castilleja hyetophila 2 2 2 Pyrola asarifolia 3 2 3 Rubus pubescens 2 4 4 Symphoricarpos albus 3 2 4 Abies lasiocarpa 4 3 Alnus viridis ssp. fruticosa 4 4 Asterella lindenbergiana 3 2 Hylocomium splendens + 6 Lycopodium obscurum 4 4 Platanthera orbiculata 3 + Apocynum androsaemifolium 6 Arabis holboellii + Aralia nudicaulis 4 Aster modestus 2 Calliergon stramineum 6 Calypso bulbosa + Carex disperma + Cinna latifolia + Coeloglossum viride + Cornus stolonifera 5 Epilobium ciliatum + Equisetum pratense 7 Geum macrophyllum 2 Lonicera involucrata + Maianthemum stellatum + Melampyrum lineare 2 Mitella nuda + Osmorhiza berteroi + 75APPENDICES Appendix 6 Trembling Aspen Ecosystems Orthilia secunda + Picea mariana 5 Pinus contorta 2 Plagiomnium drummondii 7 Platanthera obtusata + Pleurozium schreberi + Ranunculus eschscholtzii + Ribes triste 2 Schizachne purpurascens 2 Tortula ruraliformis + Viburnum edule 5 Viola renifolia + 1 Plot numbers have been simplified in this report. See Appendix 32 on pag e112 for original plot codes. 2 Species significance classes defined in Table 4 on page12 . Plot number1 42 43 44 45 46 47 48 49 50 51 52 Species Species significance2 76 APPEN D ICES A ppendix 7 Scientica Silvica Extension Series, N um ber 27, 2000 Appendix 7. Plot vegetation table for the 222 Populus tremuloides – Lathyrus ochroleucus: typic subassociation. Species are arranged in order of decreasing presence and alphabetically. Plot number1 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 Species Species significance2 Populus tremuloides 8 9 7 8 9 8 8 7 9 9 8 7 7 9 9 9 7 9 7 8 9 8 7 7 7 8 8 8 9 7 7 Rosa acicularis 6 6 5 6 3 4 4 5 7 4 6 6 6 6 6 5 4 4 6 6 6 5 5 5 4 4 5 3 4 5 4 Cornus canadensis 3 6 4 4 5 4 4 4 5 5 5 5 4 4 7 6 7 5 5 5 5 7 6 4 4 3 7 6 4 Epilobium angustifolium 4 6 2 3 4 3 5 5 4 4 6 2 4 4 4 3 3 6 4 4 4 4 4 5 5 5 5 4 2 Lathyrus ochroleucus 5 3 4 3 2 4 4 3 4 3 3 3 + + 3 3 2 4 3 + 3 3 3 3 3 3 3 3 3 Linnaea borealis 4 2 + 3 3 3 3 4 4 4 4 4 4 4 4 4 4 4 4 3 4 4 3 2 3 5 3 4 Viburnum edule 4 5 5 5 4 4 4 5 4 4 5 5 5 5 3 4 + 3 4 4 6 6 4 4 2 3 5 5 Rubus pubescens 2 2 4 4 3 2 4 4 4 4 3 4 4 3 4 4 4 4 3 4 4 4 4 3 3 3 4 Salix sp. 3 4 4 4 3 4 3 4 6 5 4 4 5 4 4 5 3 4 4 4 3 4 4 3 4 3 5 Pyrola asarifolia 2 3 4 4 3 4 2 3 3 5 3 4 2 4 4 4 5 4 4 4 4 2 3 6 3 2 Maianthemum canadense 4 2 + 4 4 2 2 + 2 4 5 4 4 3 3 3 4 3 5 4 4 4 3 2 Shepherdia canadensis 5 5 4 4 2 5 4 4 4 5 5 5 4 5 5 4 3 5 4 6 4 2 3 2 Galium boreale 3 2 4 2 4 3 3 2 3 3 3 2 3 3 2 3 2 4 3 3 3 4 Hylocomium splendens 2 3 2 + 4 3 3 3 4 5 5 4 2 2 3 5 4 4 + 4 3 Picea glauca 4 5 4 4 4 6 2 4 4 6 4 5 3 3 4 5 4 4 + 2 5 Elymus innovatus 5 4 2 + + 6 3 3 5 4 5 4 4 4 4 4 5 5 5 5 Aster conspicuus 4 4 4 5 2 6 4 3 2 2 + 3 3 6 5 4 4 5 3 Fragaria virginiana + + 3 3 4 4 4 3 3 3 3 3 + 2 2 4 2 3 3 Calamagrostis canadensis + 4 2 + 3 4 2 3 4 4 4 2 3 4 3 4 4 3 Orthilia secunda + + 2 2 3 2 2 + 3 3 3 + + 3 3 + + Petasites frigidus 3 3 3 4 6 4 4 4 2 2 4 3 3 4 2 2 4 Mertensia paniculata 4 + 4 3 2 4 3 2 2 2 4 4 2 3 Alnus viridis 3 5 6 5 4 5 4 5 3 4 4 4 Aralia nudicaulis 5 7 6 4 5 + 5 4 4 5 4 4 Ledum groenlandicum + 4 6 + 6 6 6 6 + 5 + 2 Vaccinium vitis-idaea + 3 3 + 2 4 4 4 4 4 5 4 Lonicera involucrata 2 + 2 3 + + + + + 5 + Spiraea betulifolia 4 5 4 + 3 4 4 4 + 2 3 Vicia americana 4 + + 4 + + + 2 + + 2 Amelanchier alnifolia + + + 2 2 2 + 3 2 Betula papyrifera 3 3 3 4 4 2 3 + Viola renifolia + 3 4 3 + + + 2 Equisetum pratense + + 2 2 2 + + Achillea millefolium + 2 + + 2 + Arnica cordifolia 4 3 3 3 3 4 Lycopodium clavatum 2 3 3 4 4 4 Symphoricarpos albus 3 2 2 3 3 + Vaccinium myrtilloides 5 3 7 7 6 6 Corallorhiza maculata + + + + + Cornus sericea + 3 2 + 2 77 APPEN D ICES A ppendix 7 Trem bling Aspen Ecosystem s  Rubus idaeus + 4 2 + 2 Aster ciliolatus 2 + 4 + Pinus contorta 2 5 5 3 Populus balsamifera 3 4 4 4 Galium triflorum + + + Picea mariana 4 6 5 Pleurozium schreberi + 3 4 Ribes oxyacanthoides 3 + 2 Ribes triste 2 + + Vaccinium caespitosum 3 2 2 Actaea rubra + + Aster engelmannii 4 2 Elymus glaucus 4 4 Lycopodium annotinum 6 4 Maianthemum racemosum + + Oryzopsis asperifolia 4 3 Ptilium crista-castrensis 3 3 Ribes lacustre + 3 Sorbus scopulina 3 4 Taraxacum officinale + 2 Viola canadensis 3 + Abies lasiocarpa 2 Aquilegia brevistyla + Arctostaphylos uva-ursi 2 Cladina rangiferina + Equisetum arvense + Heracleum maximum 2 Lycopodium complanatum 5 Osmorhiza berteroi 2 Peltigera aphthosa + Platanthera orbiculata + Rubus parviflorus 2 Schizachne purpurascens 4 1 Plot numbers have been simplified in this report. See Appendix 32 on pag e112 for original plot codes. 2 Species significance classes as defined in Table 4 on page 12. Plot number1 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 Species Species significance2 78 APPENDICES Appendix 8 Scientica Silvica Extension Series, Number 27, 2000 Appendix 8. Plot vegetation table for the 223 Populus tremuloides – Lathyrus ochroleucus: Actaea rubra subassociation. Species are arranged in order of decreasing presence and alphabetically. Plot number1 84 85 86 87 88 89 90 91 92 93 Species Species significance2 Populus tremuloides 9 9 7 9 8 8 8 8 7 9 Actaea rubra + 5 4 4 3 3 3 2 2 Cornus sericea 3 4 + 3 5 5 6 4 5 Galium triflorum 3 4 3 4 4 4 3 4 + Rosa acicularis 4 4 4 4 5 4 4 5 + Viburnum edule 5 4 4 5 5 6 6 6 4 Aralia nudicaulis 4 6 4 4 4 5 4 6 Calamagrostis canadensis 3 3 2 3 3 4 4 4 Epilobium angustifolium 3 4 3 4 3 2 4 4 Lonicera involucrata 6 2 3 3 3 2 5 4 Pyrola asarifolia 3 3 4 4 4 4 4 + Cornus canadensis 2 4 3 4 5 5 3 Delphinium glaucum 4 5 3 4 3 4 4 Equisetum pratense + 3 3 2 5 3 7 Mertensia paniculata 5 4 2 3 3 3 4 Petasites frigidus 3 4 3 3 4 4 + Aster conspicuus 4 4 5 4 5 5 Lathyrus ochroleucus 3 4 4 + 2 4 Picea glauca 3 4 4 3 + 7 Rubus pubescens 4 4 5 2 4 2 Amelanchier alnifolia + 2 4 4 + Fragaria virginiana 2 3 3 + + Heracleum maximum 6 4 6 4 + Linnaea borealis + 3 4 4 4 Mitella nuda + 3 2 4 4 Osmorhiza berteroi 4 4 3 2 3 Populus balsamifera 5 2 4 4 7 Ribes oxyacanthoides 3 4 5 3 4 Viola canadensis 5 6 6 3 3 Elymus innovatus + 4 2 + Galium boreale 2 + 4 3 Ribes lacustre 4 4 3 + Alnus viridis 5 5 4 Botrychium virginianum + + + Rubus idaeus 4 4 + Salix sp. 5 4 4 Spiraea betulifolia + 3 + Symphoricarpos albus 2 3 + Thalictrum venulosum 3 + 4 Agropyron pauciflorum 2 + Aquilegia brevistyla 3 3 Maianthemum canadense 2 3 Maianthemum racemosum 4 2 Maianthemum stellatum + 2 Orthilia secunda 4 4 Ribes triste 4 4 Taraxacum officinale + 3 Alnus incana 4 Achillea millefolium 2 Arnica cordifolia 3 Aster ciliolatus 2 Betula papyrifera 5 Betulaceae 4 Bromus inermis + Calliergon stramineum + Clintonia uniflora + Cornus stolonifera 1 79APPENDICES Appendix 8 Trembling Aspen Ecosystems Dicranum scoparium + Disporum trachycarpum 2 Drepanocladus uncinatus + Equisetum sylvaticum + Festuca subuliflora + Gymnocarpium dryopteris 6 Hylocomium splendens 2 Maianthemum racemosum 3 Maianthemum stellatum 4 Matteuccia struthiopteris + Moneses uniflora 4 Paxistima myrsinites + Peltigera aphthosa + Pinus contorta 5 Plagiomnium drummondii + Pleurozium schreberi + Pseudotsuga menziesii 5 Ranunculus acris + Rubus parviflorus 3 Shepherdia canadensis 4 Solidago canadensis + Thalictrum occidentale 3 Vicia americana + Viola renifolia 2 1 Plot numbers have been simplified in this report. See Appendix 32 on page 112 for original plot codes. 2 Species significance classes defined in Table 4 on page12 . Plot number1 84 85 86 87 88 89 90 91 92 93 Species Species significance2 80 APPENDICES Appendix 9 Scientica Silvica Extension Series, Number 27, 2000 Appendix 9. Plot vegetation table for the 310 Populus tremuloides – Thalictrum occidentale association. Species are arranged in order of decreasing presence and alphabetically. Plot number1 94 95 96 97 98 99 100 101 102 103 Species Species significance2 Populus tremuloides 8 9 9 8 9 8 7 7 7 8 Epilobium angustifolium + 3 + 6 4 + 3 9 + Picea glauca 6 6 9 3 6 7 7 7 Rosa acicularis 4 6 4 5 6 5 4 3 Aster conspicuus 6 3 3 3 + + Fragaria virginiana + 3 + 2 + + Galium boreale + + + + + + Thalictrum occidentale + + + 5 4 2 Viburnum edule 6 + 5 5 1 + Achillea millefolium + + + + + Calamagrostis rubescens + + 3 + 6 Cornus canadensis + + 4 4 + Equisetum pratense + + + + + Hylocomium splendens 4 + 3 3 6 Linnaea borealis 4 + 5 3 + Lonicera involucrata + 5 + 7 1 Petasites frigidus + + + 5 + Pleurozium schreberi 2 + 2 5 6 Rubus pubescens + 4 + 4 + Vicia americana + + 1 + + Actaea rubra + + 2 3 Aster sibiricus + + 4 + Elymus repens + + + + Lathyrus nevadensis + + + + Ribes lacustre + 3 6 2 Aralia nudicaulis 2 6 4 Bromus inermis 4 + + Calamagrostis canadensis + + + Calliergon stramineum + + 4 Cornus stolonifera 2 + 6 Galium triflorum + + + Geranium richardsonii 3 + 2 Orthilia secunda + + + Salix scouleriana 4 5 6 Viola canadensis + + 4 Alnus incana 4 5 Arnica cordifolia + + Betula nana 6 + Carex disperma + + Disporum hookeri + 2 Elymus glaucus + + Equisetum scirpoides + + Festuca subuliflora + + Hieracium umbellatum + + Maianthemum racemosum + 2 Maianthemum stellatum + + Mitella nuda 1 + Osmorhiza berteroi + + Poa palustris + + Populus balsamifera 2 7 Pyrola asarifolia 3 4 Rhytidiadelphus triquetrus + + Salix glauca 8 7 Senecio pseudaureus + + Shepherdia canadensis 7 + Abies lasiocarpa 5 Amelanchier alnifolia + 81APPENDICES Appendix 9 Trembling Aspen Ecosystems Antennaria pulcherrima 2 Aquilegia formosa + Arctostaphylos uva-ursi + Aster ciliolatus + Betula papyrifera 3 Carex obtusata        + Carex rossii  5 Carex spectabilis   + Castilleja miniata      + Clintonia uniflora           + Dicranella palustris 2 Dicranum fuscescens     + Drepanocladus uncinatus           + Epilobium ciliatum   + Gentianella amarella   + Glyceria elata   + Goodyera oblongifolia           + Goodyera repens     + Heracleum maximum         5 Lycopodium annotinum  + Maianthemum trifolium   + Maianthemum canadense  + Mertensia paniculata  + Oryzopsis asperifolia    + Pulsatilla patens    + Peltigera praetextata     + Petasites sagittatus    + Picea mariana          5 Pinus contorta          5 Platanthera orbiculata  + Ptilium crista-castrensis         + Pyrola minor   + Ranunculus acris        + Rubus idaeus         5 Salix sp.       6 Salix bebbiana  6 Salix lucida   5 Salix sitchensis      4 Spiraea betulifolia          6 Stellaria calycantha         + Taraxacum officinalis    + Trisetum cernuum      + Vaccinium membranaceum           + Viola palustris   + Viola renifolia   + 1 Plot numbers have been simplified in this report. See Appendix 32 on page 112 for original plot codes. 2 Species significance classes defined in Table 4 on page12 . Plot number1 94 95 96 97 98 99 100 101 102 103 Species Species significance2 82 APPENDICES Appendix 10 Scientica Silvica Extension Series, Number 27, 2000 Appendix 10. Plot vegetation table for the 411 Populus tremuloides – Viburnum edule: Spiraea betulifolia subassociation. Species are arranged in order of decreasing presence and alphabetically. Plot number1 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 Species Species significance2 Populus tremuloides 9 8 8 9 9 9 9 9 8 9 7 7 7 9 7 8 9 Rosa acicularis 5 2 1 4 6 4 5 6 4 6 5 7 + 3 6 Osmorhiza berteroi + 4 4 + 4 + + + + + + + + + Picea glauca 5 7 5 5 6 5 6 + 7 3 6 7 8 5 Thalictrum occidentale 4 3 2 3 + + 3 4 + + + + + + Amelanchier alnifolia + 3 3 6 5 3 6 6 5 5 3 + + Aralia nudicaulis 7 6 4 4 6 4 6 3 5 3 6 4 3 Elymus glaucus + + + + + + + + + + + + + Cornus stolonifera 5 5 4 5 5 7 6 4 4 + 3 5 Spiraea betulifolia 7 2 3 5 6 4 3 + + + 3 2 Symphoricarpos albus 3 + 4 2 3 3 5 + 4 6 5 4 Viburnum edule 7 7 3 7 6 7 7 4 + + 2 5 Galium boreale 4 1 2 + + + + + + + + Linnaea borealis 3 1 + + + + + + + + + Rubus parviflorus 5 6 6 3 3 4 + + 5 2 7 Rubus pubescens 4 5 1 3 3 3 1 + + + + Aster conspicuus 6 4 5 5 2 3 5 + + 6 Clintonia uniflora 6 1 4 3 + 5 + + 2 + Cornus canadensis 5 2 3 4 4 3 + + + + Disporum hookeri + 4 5 5 2 + 4 6 + + Fragaria virginiana 2 + + + 3 + + + + + Lonicera involucrata 2 7 4 5 4 1 + 5 + 2 Maianthemum racemosum 4 5 + 2 4 4 3 + 4 4 Epilobium angustifolium + 2 4 2 4 3 + + 4 Maianthemum stellatum + 4 1 + 2 + + + + Pleurozium schreberi 5 5 3 3 2 3 + 6 5 Ribes lacustre 1 4 4 3 3 + + + Achillea millefolium + + + + + + + Actaea rubra 2 + 4 1 2 5 + Aster ciliolatus 4 2 2 + + + + Lathyrus ochroleucus 4 1 4 + 4 2 2 Abies lasiocarpa 2 5 6 6 5 5 Mitella nuda + + + + + + Pyrola asarifolia + + + + + + Shepherdia canadensis 7 5 4 + 2 5 Calamagrostis canadensis + 1 + + + Galium triflorum + + + + + Oryzopsis asperifolia + + + + + Petasites frigidus 2 1 + 2 1 Vicia americana + + 4 + + Alnus incana 5 5 5 6 Aquilegia formosa + + + + Arnica cordifolia + + + + Goodyera oblongifolia + + + + Orthilia secunda + 2 + + Paxistima myrsinites 7 + 8 5 Pseudotsuga menziesii 5 6 7 5 Ptilium crista-castrensis 4 2 6 3 Rhytidiadelphus triquetrus 1 + 2 6 Sorbus scopulina + + + 2 Vaccinium membranaceum 1 2 4 + Alnus viridis 6 6 6 Calamagrostis rubescens + + 5 Cinna latifolia + + + Heracleum maximum + 4 4 Salix scouleriana 2 6 4 Viola canadensis + + 4 Aster modestus 1 + Aster sibiricus 3 + Betula papyrifera 6 2 83APPENDICES Appendix 10 Trembling Aspen Ecosystems Bromus inermis + + Equisetum arvense + + Eurhynchium pulchellum + + Festuca occidentalis + + Festuca subuliflora + + Gymnocarpium dryopteris 7 5 Hylocomium splendens 4 3 Lathyrus nevadensis + + Lilium columbianum + + Lycopodium annotinum 5 + Mahonia aquifolium 6 6 Malus fusca + + Ribes triste 3 3 Rubus idaeus + + Sambucus racemosa + + Trisetum cernuum + + Viola palustris + 2 Adoxa moschatellina + Angelica genuflexa + Apocynum androsaemifolium + Athyrium filix-femina 3 Calliergon stramineum + Carex disperma + Castilleja miniata 1 Clematis occidentalis + Corylus cornuta 7 Deschampsia cespitosa + Dicranella palustris + Dicranum fuscescens + Drepanocladus uncinatus + Equisetum pratense + Fritillaria affinis + Geocaulon lividum + Geranium richardsonii + Listera cordata + Lobaria pulmonaria + Lonicera utahensis + Mertensia paniculata + Oplopanax horridus 4 Peltigera aphthosa + Peltigera praetextata + Pinus contorta 6 Plagiomnium drummondii 1 Plagiomnium medium + Platanthera orbiculata + Prunus virginiana 5 Pyrola minor + Ranunculus acris + Rhytidiadelphus squarrosus 4 Salix bebbiana 6 Solidago canadensis + Spiraea douglasii 5 Stellaria calycantha + Streptopus amplexifolius 1 Taraxacum officinalis + Trifolium pratense + Viola septentrionalis 2 Vulpia microstachys + 1 Plot numbers have been simplified in this report. See Appendix 32 on pag e112 for original plot codes. 2 Species significance classes defined in Table 4 on pag e12. Plot number1 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 Species Species significance2 84 APPENDICES Appendix 11 Scientica Silvica Extension Series, Number 27, 2000 Appendix 11. Plot vegetation table for the 412 Populus tremuloides – Viburnum edule: Paxistima myrsinites subassociation. Species are arranged in order of decreasing presence and alphabetically. Plot number1 121 122 123 124 125 126 127 128 129 130 Species Species Significance2 Paxistima myrsinites 6 7 8 5 6 7 7 5 5 5 Populus tremuloides 7 7 8 9 7 7 7 7 6 7 Aralia nudicaulis + 4 6 3 4 + + 2 3 Rubus parviflorus + 3 5 + 6 5 4 5 4 Clintonia uniflora + + + + 3 + 4 2 Cornus canadensis + + + 3 + 5 3 2 Cornus stolonifera 3 6 7 4 6 3 5 + Rosa acicularis 3 3 + 4 4 6 4 5 Viburnum edule 5 3 3 4 3 3 5 + Rhytidiadelphus triquetrus + 1 + 3 + + 5 Betula papyrifera + 8 5 7 5 6 Elymus glaucus + + + + + + Epilobium angustifolium + + + + + + Linnaea borealis + 3 3 7 + 4 Lonicera involucrata 4 2 + 3 3 + Maianthemum racemosum + 4 3 4 + + Osmorhiza berteroi + + 3 + + + Pyrola asarifolia + + + 3 + + Symphoricarpos albus + + + 3 + + Amelanchier alnifolia 2 + + 3 + Corylus cornuta 7 7 7 5 3 Lathyrus ochroleucus 4 3 3 3 + Orthilia secunda + + + + + Pleurozium schreberi + 2 3 + + Ptilium crista-castrensis + + + + + Rubus pubescens + + + 3 3 Thuja plicata + 6 3 6 7 Tsuga heterophylla 3 5 3 5 2 Acer glabrum 2 2 5 6 Adoxa moschatellina + + + + Arnica cordifolia + + + + Hylocomium splendens + + + 2 Picea glauca 3 3 4 4 Sorbus scopulina + 2 3 + Disporum hookeri 4 4 3 Galium boreale + 3 + Galium triflorum + + + Maianthemum stellatum + + + Shepherdia canadensis 3 + 3 Thalictrum occidentale + 4 3 Vicia americana + + + Abies lasiocarpa 2 2 Aster ciliolatus + + Aster conspicuus + + Calamagrostis canadensis + + Fragaria virginiana + + Goodyera oblongifolia + + Goodyera repens + + Lobaria pulmonaria + + Lycopodium complanatum + + Mahonia aquifolium + 1 Mitella nuda + + Petasites frigidus + + Platanthera orbiculata + + Pyrola elliptica + + Sanicula marilandica + + Vaccinium membranaceum + + 85APPENDICES Appendix 11 Trembling Aspen Ecosystems Alnus viridis 5 Actaea rubra + Alectoria sarmentosa + Aster sibiricus 4 Chimaphila umbellata 3 Cinna latifolia + Dicranella palustris + Dicranum fuscescens + Dicranum scoparium + Equisetum sylvaticum + Eurhynchium pulchellum + Festuca occidentalis + Geocaulon lividum + Gymnocarpium dryopteris 6 Hypopitys monotropa + Larix occidentalis 6 Lathyrus nevadensis 5 Lycopodium dendroideum + Malus fusca 3 Melampyrum lineare + Pedicularis racemosa 2 Peltigera aphthosa + Peltigera malacea 3 Peltigera membranacea + Pinus contorta 7 Pinus monticola 5 Plagiomnium drummondii + Populus balsamifera 6 Pseudotsuga menziesii 6 Rhizomnium glabrescens + Rhododendron albiflorum + Rhytidiadelphus squarrosus + Ribes lacustre + Rosa nutkana 2 Rubus idaeus + Salix glauca + Spiraea betulifolia 3 Stellaria calycantha + Stenanthium occidentale + Trisetum cernuum 3 Viola orbiculata + Viola renifolia + Viola septentrionalis + Vulpia microstachys + 1 Plot numbers have been simplified in this report. See Appendix 32 on page 112 for original plot codes. 2 Species significance classes defined in Table 4 on page12 . Plot number1 121 122 123 124 125 126 127 128 129 130 Species Species Significance2 86 APPENDICES Appendix 12 Scientica Silvica Extension Series, Number 27, 2000 Appendix 12. Plot vegetation table for the 421 Populus tremuloides – Rosa nutkana: Aralia nudicaulis subassociation. Species are arranged in order of decreasing presence and alphabetically. Plot number1 131 132 133 134 135 136 137 138 139 140 141 142 143 144 Species Species significance2 Populus tremuloides 7 8 7 8 9 9 9 9 9 8 8 8 7 7 Elymus glaucus 3 + + + + + 3 + + + Festuca subuliflora + + + + + 2 3 5 2 + Osmorhiza berteroi + 3 + + 1 + + + 4 4 Aralia nudicaulis 5 7 7 6 2 2 1 1 6 Cornus canadensis 3 5 + 2 7 5 7 + 6 Symphoricarpos albus + 5 4 + 4 + 4 + + Acer glabrum + 3 7 5 + 3 7 + Clintonia uniflora 3 1 3 3 3 + + + Rubus parviflorus 6 5 7 3 + + 6 7 Alnus incana 6 5 6 4 5 6 6 Cornus stolonifera 6 3 + 3 3 + 6 Galium trifidum 3 + + + + + + Maianthemum stellatum 3 + + 6 3 2 + Picea glauca 5 5 5 5 5 5 6 Populus balsamifera 7 6 6 6 6 6 6 Ranunculus acris + + + 2 + 2 + Rosa nutkana + + + 2 + + + Amelanchier alnifolia + 3 4 + + 3 Betula papyrifera 6 7 6 3 4 2 Calamagrostis canadensis 7 7 9 6 8 + Pinus contorta 4 7 5 6 7 5 Tiarella trifoliata + 2 + + + + Adenocaulon bicolor 6 + + 4 6 Arnica cordifolia 2 7 3 + 2 Athyrium filix-femina + 2 2 3 + Calamagrostis rubescens 5 3 + 2 + Equisetum pratense + + + 1 + Fragaria virginiana + + + + 2 Linnaea borealis 3 + + + + Solidago canadensis + 2 + + + Spiraea betulifolia + + + 4 3 Thuja plicata 3 7 8 9 5 Pteridium aquilinum 5 6 3 + Pyrola asarifolia 2 3 3 + Ribes lacustre 4 + + 3 Senecio pseudaureus + + 4 + Viola renifolia + + 4 + Aconitum columbianum + + 3 Anaphalis margaritacea + + 2 Equisetum sylvaticum + + + Galium boreale 4 + + Lonicera utahensis 5 7 3 Maianthemum racemosum 6 + + Mahonia aquifolium 1 + + Paxistima myrsinites 5 2 + Poa palustris + + 2 Pinus monticola 4 5 5 Prunella vulgaris + + 5 Rosa acicularis 4 4 5 Rubus idaeus 2 + 2 Vaccinium caespitosum + 2 + Vicia americana 4 + + Actaea rubra + + Agrostis mertensii + + Calliergon giganteum + + Chimaphila umbellata + 3 87APPENDICES Appendix 12 Trembling Aspen Ecosystems Dicranum fuscescens + + Disporum hookeri 5 + Epilobium angustifolium + + Equisetum arvense + + Frangula purshiana + 4 Heracleum maximum 3 3 Larix occidentalis 5 6 Lonicera involucrata 3 3 Peltigera praetextata + + Phleum pratense + + Pseudotsuga menziesii 4 + Rhytidiadelphus triquetrus 6 + Taraxacum officinalis + + Thalictrum occidentale + 2 Trillium ovatum + + Trisetum cernuum + + Trisetum spicatum + + Abies lasiocarpa 4 Achillea millefolium + Aster conspicuus + Botrychium lunaria + Bromus inermis + Calliergon stramineum + Campanula rotundifolia + Cladonia phyllophora + Corallorhiza trifida + Crataegus douglasii 2 Dactylis glomerata + Glyceria elata 3 Gymnocarpium dryopteris + Hieracium scouleri + Hylocomium splendens 3 Lathyrus nevadensis 3 Oplopanax horridus + Orthilia secunda + Plagiothecium sp. + Poa nemoralis + Peltigera aphthosa + Petasites frigidus + Piperia unalascensis + Plagiomnium drummondii + Plagiomnium medium + Pleurozium schreberi 2 Polytrichum strictum + Ptilium crista-castrensis 1 Rubus pubescens 3 Salix sp. + Shepherdia canadensis + Trifolium repens + Tsuga heterophylla 3 Vaccinium membranaceum + Viburnum edule 4 1 Plot numbers have been simplified in this report. See Appendix 32 on page112  for original plot codes. 2 Species significance classes defined in Table 4 on page12 . Plot number1 131 132 133 134 135 136 137 138 139 140 141 142 143 144 Species Species significance2 88 APPENDICES Appendix 13 Scientica Silvica Extension Series, Number 27, 2000 Appendix 13. Plot vegetation table for the 422 Populus tremuloides – Rosa nutkana: Arnica cordifolia subassociation. Species are arranged in order of decreasing presence and alphabetically. Plot number1 145 146 147 148 149 150 151 152 153 Species Species significance2 Populus tremuloides 8 7 7 8 7 7 9 7 9 Rubus parviflorus 4 3 + 2 6 6 + 4 Osmorhiza berteroi 3 + + + + + 3 Pseudotsuga menziesii 5 4 6 6 6 4 7 Arnica cordifolia 6 3 5 4 + + Betula papyrifera 6 + 7 7 6 + Elymus glaucus + + + + + + Galium trifidum + + + + + + Spiraea betulifolia 2 + 3 2 + 1 Acer glabrum 4 + 3 7 6 Calamagrostis rubescens 6 5 4 + 6 Chimaphila umbellata 2 + + + 5 Clintonia uniflora + 5 5 4 + Linnaea borealis + 5 5 5 + Mahonia aquifolium 4 + 2 + + Shepherdia canadensis 3 4 3 6 3 Cornus stolonifera 3 4 + 3 Festuca subuliflora + + + + Paxistima myrsinites + 2 4 3 Pinus monticola 6 7 6 + Rosa nutkana 3 2 + + Symphoricarpos albus + + + 2 Vaccinium caespitosum 2 6 8 8 Alnus incana 3 2 6 Alnus viridis 5 6 6 Adenocaulon bicolor 4 4 + Amelanchier alnifolia + 3 2 Apocynum androsaemifolium 4 2 3 Cornus canadensis 7 5 6 Hieracium scouleri + + + Larix occidentalis 6 6 5 Peltigera praetextata + + + Picea glauca 5 6 6 Pinus contorta 6 6 5 Abies lasiocarpa 2 7 Achillea millefolium + + Anaphalis margaritacea + + Aralia nudicaulis 6 6 Aster ciliolatus 3 + Calamagrostis canadensis + + Calliergon giganteum + + Calliergon stramineum + + Corallorhiza trifida + + Disporum hookeri 4 1 Fragaria virginiana + + Lilium columbianum + + Maianthemum racemosum 3 2 Orthilia secunda + + Polytrichum strictum + + Pteridium aquilinum 5 4 Rosa acicularis + + Thalictrum occidentale + 4 Thuja plicata + 5 Tsuga heterophylla 6 7 Viola renifolia + + Actaea rubra 1 Anemone parviflora + 89APPENDICES Appendix 13 Trembling Aspen Ecosystems Angelica genuflexa + Aquilegia formosa + Aster conspicuus 4 Castilleja miniata + Ceanothus velutinus 2 Cladonia multiformis + Dicranum fuscescens + Dicranum scoparium + Epilobium angustifolium + Equisetum arvense + Geocaulon lividum + Goodyera oblongifolia + Lonicera involucrata + Lonicera utahensis + Mertensia paniculata + Peltigera malacea + Pleurozium schreberi + Polytrichum juniperinum + Populus balsamifera 4 Pyrola minor + Ranunculus acris + Senecio pseudaureus + Solidago canadensis + Trillium ovatum + Trisetum spicatum + Vaccinium membranaceum + Viola canadensis + Viola orbiculata + 1 Plot numbers have been simplified in this report. See Appendix 32 on page 112 for original plot codes. 2 Species significance classes as defined in Table 4 on page 12. Plot number1 145 146 147 148 149 150 151 152 153 Species Species significance2 90 APPENDICES Appendix 14 Scientica Silvica Extension Series, Number 27, 2000 Appendix 14. Plot vegetation table for the 423 Populus tremuloides – Rosa nutkana: Angelica genuflexa subassociation. Species are arranged in order of decreasing presence and alphabetically. Plot number1 154 155 156 157 158 159 160 161 162 Species Species significance2 Populus tremuloides 8 8 9 9 9 8 8 7 8 Amelanchier alnifolia 5 6 6 6 7 6 5 2 Aster conspicuus 3 + + 4 4 + 2 + Lilium columbianum + + + + + 2 + + Osmorhiza berteroi + + 2 4 5 2 + 2 Thalictrum occidentale 4 6 4 5 4 5 6 5 Angelica genuflexa 2 2 + 3 + 6 6 Maianthemum racemosum + 5 3 3 4 4 4 Maianthemum stellatum + + + + + 2 4 Symphoricarpos albus 3 6 7 4 6 6 1 Calamagrostis canadensis + + + + + + Disporum hookeri 5 6 5 5 6 3 Galium triflorum + + + 3 + + Mahonia aquifolium 5 2 3 + + 2 Rosa nutkana 2 3 6 4 + 2 Rubus parviflorus 7 7 7 6 6 3 Actaea rubra 4 5 3 5 + Clintonia uniflora + 2 6 1 + Pseudotsuga menziesii 6 7 6 3 6 Viola canadensis 4 2 + + + Cornus stolonifera + 5 4 4 Elymus glaucus + + + + Picea glauca 5 6 5 3 Spiraea betulifolia 3 2 + 5 Acer glabrum 5 3 + Arnica cordifolia 3 + + Aster ciliolatus + + + Calliergon giganteum + 1 + Festuca subuliflora + + + Fragaria virginiana 2 4 + Lonicera involucrata 4 7 + Lonicera utahensis 4 6 1 Trisetum cernuum + + + Alnus incana 6 7 Adenocaulon bicolor 1 2 Aquilegia formosa 4 + Chimaphila umbellata + + Galium boreale + + Goodyera oblongifolia + + Paxistima myrsinites 5 7 Pinus contorta 4 7 Pteridium aquilinum 6 5 Pyrola asarifolia + + Ranunculus acris + + Ribes lacustre + + Rubus idaeus + 5 Salix lucida + + Salix scouleriana 2 5 Senecio pseudaureus + + Sorbus scopulina + 2 Viburnum edule 3 3 Viola septentrionalis + + Alnus viridis 4 Abies lasiocarpa 6 Achillea millefolium + Aralia nudicaulis 3 Calamagrostis rubescens + 91APPENDICES Appendix 14 Trembling Aspen Ecosystems Calliergon stramineum + Campanula rotundifolia + Cinna latifolia + Clematis occidentalis 2 Cypripedium montanum + Dicranum fuscescens + Epilobium angustifolium 2 Equisetum pratense + Festuca occidentalis + Hieracium scouleri + Listera convallarioides + Orthilia secunda 1 Pedicularis bracteosa + Pedicularis racemosa 4 Peltigera malacea + Populus balsamifera 5 Pyrola chlorantha + Salix bebbiana 2 Senecio triangularis 4 Shepherdia canadensis 6 Solidago canadensis + Urtica dioica 3 Viola palustris + 1 Plot numbers have been simplified in this report. See Appendix 32 on page 112 for original plot codes. 2 Species significance classes defined in Table 4 on pag e12. Plot number1 154 155 156 157 158 159 160 161 162 Species Species significance2 92 APPENDICES Appendix 15 Scientica Silvica Extension Series, Number 27, 2000 Appendix 15. Plot vegetation table for the 424 Populus tremuloides – Rosa nutkana: Senecio pseudoaureus subassociation. Species are arranged in order of decreasing presence and alphabetically. Plot number1 163 164 165 166 167 168 169 170 171 Species Species significance2 Populus tremuloides 9 8 9 7 7 7 7 8 9 Calamagrostis rubescens 4 6 8 6 6 2 + 6 Elymus glaucus + + + + + 2 + 2 Amelanchier alnifolia 2 2 + + + 4 + Mahonia aquifolium + 4 6 2 + + 1 Pseudotsuga menziesii 5 3 + 2 7 6 6 Rosa nutkana 3 2 2 + + + 6 Senecio pseudaureus + + + + 3 + + Fragaria virginiana + + 3 + + + Galium trifidum + + + + + + Osmorhiza berteroi + + + + 1 + Pinus contorta 4 5 7 6 2 5 Symphoricarpos albus 5 2 6 4 6 5 Alnus viridis 3 + 7 6 3 Festuca subuliflora + 2 2 + 1 Paxistima myrsinites + 4 2 6 + Spiraea betulifolia 3 2 + + 2 Thalictrum occidentale 5 2 3 + 5 Achillea millefolium + + + 3 Aster ciliolatus 2 2 2 + Aster conspicuus + 3 5 2 Cornus canadensis 5 6 4 + Maianthemum racemosum 1 3 6 1 Maianthemum stellatum + 1 + 2 Picea glauca 5 3 6 6 Ranunculus acris + + + + Rubus parviflorus + 6 6 + Shepherdia canadensis + + + 8 Viola renifolia + + + + Acer glabrum 1 7 2 Cornus stolonifera + 7 7 Hieracium scouleri + + + Juniperus communis 5 5 2 Linnaea borealis 2 6 + Viola canadensis + + 2 Arctostaphylos uva-ursi 6 4 Arnica cordifolia 4 + Athyrium filix-femina + + Corallorhiza trifida + + Dactylis glomerata + 4 Disporum hookeri + 1 Drepanocladus uncinatus 1 + Epilobium angustifolium 2 + Equisetum pratense + + Leucanthemum vulgare + + Lilium columbianum + + Lonicera utahensis 5 6 Lupinus arcticus 4 5 Medicago sativa + 5 Orthilia secunda + + Polytrichum strictum + + Prunella vulgaris + + Stellaria calycantha + + Taraxacum officinalis + + Thuja plicata 5 2 Trifolium repens + + Actaea rubra 5 93APPENDICES Appendix 15 Trembling Aspen Ecosystems Adenocaulon bicolor + Agoseris aurantiaca + Allium cernuum + Anaphalis margaritacea + Angelica genuflexa + Antennaria microphylla + Antennaria neglecta + Aralia nudicaulis 6 Asplenium viride + Betula papyrifera + Botrychium lunaria + Calamagrostis canadensis 5 Calliergon giganteum + Calochortus apiculatus + Campanula rotundifolia + Carex concinna + Chimaphila umbellata + Cinna latifolia + Cladonia multiformis + Clintonia uniflora + Cypripedium montanum + Dicranum fuscescens + Dicranum scoparium + Dryopteris expansa + Dryopteris fragrans + Elymus repens + Equisetum hyemale + Galium boreale 3 Gentianella amarella + Heracleum maximum + Lathyrus ochroleucus 3 Letharia vulpina + Lonicera involucrata + Mertensia paniculata + Penstemon procerus + Poa palustris + Peltigera aphthosa + Peltigera praetextata + Phleum pratense + Pinus monticola 2 Piperia unalascensis + Plagiomnium drummondii + Populus balsamifera 7 Potentilla glandulosa + Pyrola chlorantha + Ribes lacustre 2 Rosa acicularis + Salix scouleriana 3 Saxifraga nelsoniana + Silene menziesii + Solidago spathulata 2 Trisetum cernuum + Trisetum spicatum + Vaccinium caespitosum 4 Vicia americana 2 1 Plot numbers have been simplified in this report. See Appendix 32 on page 112 for original plot codes. 2 Species significance classes as defined in Table 4 on page 12. Plot number1 163 164 165 166 167 168 169 170 171 Species Species significance2 94 APPENDICES Appendix 16 Scientica Silvica Extension Series, Number 27, 2000 Appendix 16. Plot vegetation table for the 425 Populus tremuloides – Rosa nutkana: Shepherdia canadensis subassociation. Species are arranged in order of decreasing presence and alphabetically. Plot number1 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 Species Species significance2 Populus tremuloides 7 7 8 9 7 6 6 9 7 7 8 9 7 7 7 Calamagrostis rubescens + 8 4 2 + 2 + 5 4 5 7 8 + 7 Pinus contorta 7 6 4 6 6 6 3 5 6 7 7 Shepherdia canadensis 8 + 3 5 6 2 3 4 6 6 7 Arctostaphylos uva-ursi 6 1 + 7 5 4 6 8 7 Rosa nutkana 3 + + + 4 3 2 + + Achillea millefolium + + 3 + + 5 + + Fragaria virginiana + + + + 2 + + + Galium boreale + + 3 2 2 + + + Juniperus communis 3 7 6 6 + 6 7 3 Linnaea borealis + + 7 2 + + Orthilia secunda 3 + + + 2 + Taraxacum officinalis + 3 + + + + Antennaria neglecta + + 3 + + Aster conspicuus + 2 2 6 2 Elymus glaucus + + + + + Pseudotsuga menziesii 7 6 7 5 3 Rosa acicularis 3 + + + 2 Salix glauca 2 3 3 3 2 Vicia americana + + + + + Allium cernuum + 3 + + Amelanchier alnifolia + + + + Aster ciliolatus + 2 + + Aster sibiricus 2 3 + + Epilobium angustifolium 3 + + + Festuca subuliflora + + + + Hieracium scouleri + + + + Lathyrus ochroleucus + + + 2 Mahonia aquifolium 4 4 3 + Paxistima myrsinites 2 + 4 6 Poa nemoralis + + + + Pulsatilla patens + 2 + + Symphoricarpos albus + + 3 3 Agoseris aurantiaca + + 1 Castilleja miniata + 3 3 Chimaphila umbellata + 3 4 Elymus repens 4 + 3 Gentianella amarella + + + Lupinus arcticus 5 4 4 Maianthemum racemosum + + + Oryzopsis asperifolia 6 3 5 Salix scouleriana + + + Senecio pseudaureus + + + Stipa richardsonii 2 + + Thalictrum occidentale + + 3 Agrostis mertensii + + Arnica cordifolia + 1 Campanula rotundifolia + + Dicranum fuscescens + + Dryopteris fragrans + + Goodyera oblongifolia + + Juniperus scopulorum 2 5 Letharia vulpina + + Lonicera utahensis + + Medicago sativa 6 + Osmorhiza berteroi + + Penstemon procerus 2 + 95APPENDICES Appendix 16 Trembling Aspen Ecosystems Piperia unalascensis + + Pleurozium schreberi + + Potentilla glandulosa + + Solidago canadensis 2 + Solidago spathulata + + Spiraea betulifolia + + Trisetum spicatum + + Viola canadensis + + Viola renifolia + + Alnus incana 6 Acer glabrum 2 Betula nana 4 Botrychium lunaria + Bromus inermis + Calliergon stramineum 2 Cladonia multiformis 2 Corallorhiza trifida + Disporum hookeri + Festuca brachyphylla + Festuca occidentalis + Fritillaria affinis + Hedysarum sulphurescens 2 Hylocomium splendens + Lathyrus nevadensis 1 Lilium columbianum + Maianthemum stellatum + Melampyrum lineare + Peltigera aphthosa 2 Peltigera malacea + Phleum pratense + Picea glauca 4 Pogonatum contortum + Polytrichum juniperinum + Prunella vulgaris + Ribes lacustre + Rubus idaeus + Silene menziesii + Stellaria calycantha + Stenanthium occidentale + Trimorpha acris + Trifolium pratense 4 Trifolium repens + Vaccinium membranaceum + Viola orbiculata + 1 Plot numbers have been simplified in this report. See Appendix 32 on page112  for original plot codes. 2 Species significance classes defined in Table 4 on pag e12. Plot number1 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 Species Species significance2 96 APPENDICES Appendix 17 Scientica Silvica Extension Series, Number 27, 2000 Appendix 17. Selected environmental characteristics for plots of the 111 Populus tremuloides – Mertensia paniculata: Festuca altaica subassociation. Plot number1 1 Plot numbers have been simplified in this report.  See Appendix 32 on pag e112 for original plot codes. 1 2 3 4 Zone/subzone BWBS dk BWBS dk BWBS dk BWBS dk Soil moisture regime2 2 Relative soil moisture regime: 1-xeric, 2-subxeric, 3-submesic, 4-mesic, 5-subhygric, 6-hygric Actual soil moisture regime: VD-very dry, MD-moderately dry, SD-slightly dry, F-fresh, M-moist, VM-very moist, f-fluctuating water table 2/MD 2/MD 2/MD 2/MD Soil nutrient regime3 3 VP-very poor, P-poor, M-medium, R-rich, VR-very rich R M R R Elevation (m) 950 850 780 770 Slope gradient (%) 18 22 11 7 Aspect4 4 N-north, E-east, S-south, W-west, F-flat S S W W Forest floor thickness (cm) 9 11 6 9.5 Textural class5 5 S-sand, SL-sandy loam, LS-loamy sand, L-loam, SiL-silt loam, CL-clay loam, SCL-sandy clay loam, SC-sandy clay, SiCL-silty clay loam, O-organic SL L SL LS Actual rooting depth (cm) 60 40 40 60 Potential rooting depth (cm) 65 40 55 75 Seepage depth (cm) N/A6 6 N/A - not applicable; N/D - not determined N/A N/A N/A Soil drainage7 7 R-rapid, W-well, M- moderately well, I-imperfect, P-poor W R W W Humus form group8 8 HR-Hemimor, UR-Humimor, YR-Hydromor, RD-Mormoder, TD-Leptomoder, MD-Mullmoder, YD-Hydromoder, VL-Vermimull, YL-Hydromull TD RD TD TD Soil great group9 9 EB-Eutric Brunisol, DYB-Dystric Brunisol, MB-Melanic Brunisol, SB-Sombric Brunisol, GL-Grey Luvisol, GBL- Grey Brown Luvisol, HG-Humic Gleysol, G-Gleysol, LG-Luvic Gleysol, HFP-Humo-Ferric Podzol, FHP-Ferro-Humic Podzol, R-Regosol, HR-Humic Regosol, H-Humisol EB R DYB FHP Stand age (years @ bh) 152 114 59 144 Site index (m @ 50 yrs bh) 8 8.8 5.5 9.1 Tree layer cover (%) 44 20 10 70 Shrub layer cover (%) 43 33 20 64 Herb layer cover (%) 33 2 55 11 Moss layer cover (%) 6 5 0 1 97APPENDICES Appendix 18 Trembling Aspen Ecosystems Appendix 18. Selected environmental characteristics for plots of the 112 Populus tremuloides – Mertensia paniculata: Arnica cordifolia subassociation.  * Abbreviations defined in Appendix 17 on pag e96. Plot number1 1 Plot numbers have been simplified in this report. See Appendix 32 on page112  for original plot codes. 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Zone/subzone SBS dw BWBS dk BWBS dk BWBS dk BWBS dk BWBS dk BWBS dk BWBS dk BWBS dk BWBS dk BWBS dk BWBS dk BWBS dk SBPS xc Soil moisture regime* 3/SD 2/MD 2/MD 2/MD 2/MD 2/MD 2/MD 2/MD 2/MD 2/MD 2/MD 3/SD 2/MD 3/MD Soil nutrient regime* M M M R M R R M M M M M M P Elevation (m) 890 930 930 930 1005 970 980 910 950 720 800 780 770 1040 Slope gradient (%) 4 27 18 33 33 27 31 27 0 4 18 31 9 7 Aspect* E W W S S E E S F E S W W E Forest floor thickness (cm) 13 22 12 12 14 17 18 13 8 5.5 5 9 8 5 Textural class* L LS LS LS LS LS SL SL SL SC LS L S LS Actual rooting depth (cm) 50 60 60 70 60 60 60 60 40 50 40 40 60 50 Potential rooting depth (cm) 60 60 60 70 60 60 60 60 50 55 55 58 75 50 Seepage depth (cm) N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Soil drainage* W W W M M M W M W W W W W R Humus form group* HR UR HR TD RD TD TD RD HR HR HR RD HR HR Soil great group* HFP EB EB EB EB EB EB EB EB HFP FHP DYB DYB EB Stand age (years @ bh) 120 151 N/D 139 N/D 160 164 154 90 94 67 138 143 69 Site index (m @ 50 yrs bh) 14.8 10.5 N/D 10 N/D 11.5 11.5 12.9 11.9 14.8 12.9 10.4 11.5 15.5 Tree layer cover (%) 90 48 27 30 35 72 38 21 60 63 40 40 50 41 Shrub layer cover (%) 14 13 25 29 37 19 17 52 13 16 51 77 76 24 Herb layer cover (%) 8 13 32 31 3 27 31 15 19 11 3 13 3 3 Moss layer cover (%) 41 86 90 0 61 1 6.2 37 62 23 10 0 0 92 98 APPENDICES Appendix 19 Scientica Silvica Extension Series, Number 27, 2000 Appendix 19. Selected environmental characteristics for plots of the 113 Populus tremuloides – Mertensia paniculata: Petasites frigidus subassociation. * Abbreviations defined in Appendix 17 on pag e96. Plot number1 1 Plot numbers have been simplified in this report. See Appendix 32 on pag e112 for original plot codes. 19 20 21 22 23 24 25 26 27 28 29 30 31 Zone/subzone SBS dw BWBS dk BWBS dk BWBS dk BWBS dk BWBS dk BWBS dk BWBS dk BWBS dk BWBS dk BWBS dk BWBS dk SBPS xc Soil moisture regime* 4/Ff 4/SDf 4/SD 3/SD 3/SD 3/SDf 3/SDf 3/SDf 3/SD 3/SDf 3/SD 3/SD 5/F Soil nutrient regime* R M M M M R P M M P M R R Elevation (m) 870 900 805 790 780 810 840 850 860 890 850 590 880 Slope gradient (%) 0 2 18 18 18 0 0 4 49 4 11 16 18 Aspect* F F E N N F F W S N W S W Forest floor thickness (cm) 16.5 13 6 9 11 13 9 12 10 12 9 9 8 Textural class* L SCL L SL SL SL SL SL L SL SL SL L Actual rooting depth (cm) 30 60 60 60 60 60 60 60 60 60 60 80 60 Potential rooting depth (cm) 30 70 60 70 70 70 60 70 70 65 72 80 60 Seepage depth (cm) N/A N/A N/A N/A N/A N/A 60 N/A N/A N/A N/A N/A N/A Soil drainage* W I M W W W M M W M M W W Humus form group* MD MD RD HR HR RD HR TD HR RD HR RD RD Soil great group* EB GBL EB EB EB EB EB GL HFP HFP HFP HFP EB Stand age (years @ bh) 97 157 66 63 63 145 102 62 68 181 156 124 50 Site index (m @ 50 yrs bh) 10.5 11 9.6 13.8 14.4 14.4 12.7 15.4 15.1 10.8 10.8 15.4 N/D Tree layer cover (%) 40 30 35 35 48 74 40 40 70 35 30 81 41 Shrub layer cover (%) 63 5 15 16 5 51 18 16 35 15 5 17 4 Herb layer cover (%) 13 36 38 17 9 9 19 26 1 4 4 14 33 Moss layer cover (%) 40 97 42 100 95 40 70 41 0 93 97 5 0 99APPENDICES Appendix 20 Trembling Aspen Ecosystems Appendix 20. Selected environmental characteristics for plots of the 210 Populus tremuloides – Ledum groenlandicum association. * Abbreviations defined in Appendix 17 on page96 . Plot number1 1 Plot numbers have been simplified in this report. See Appendix 32 on page112  for original plot codes. 32 33 34 35 36 37 38 39 40 41 Zone/subzone BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw Soil moisture regime* 4/SD 4/SD 4/SD 5/F 4/SD 4/SD 4/SD 5/F 4/SD 4/SD Soil nutrient regime* VP VP VP P VP P P P VP VP Elevation (m) 750 750 750 750 750 750 750 750 750 750 Slope gradient (%) 0 0 0 5 0 5 4 6 0 0 Aspect* F F F N F W N N F F Forest floor thickness (cm) 4 2 3 4 4 2 3 3.5 3 2.5 Textural class* LS S LS SL SL S S LS S S Actual rooting depth (cm) 60 50 70 60 80 60 80 70 55 46 Potential rooting depth (cm) 60 50 70 60 80 60 80 70 55 46 Seepage depth (cm) N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Soil drainage* M M M M M W W I M I Humus form group* UR UR UR UR UR HR HR HR UR UR Soil great group* DYB DYB DYB DYB DYB DYB DYB DYB DYB DYB Stand age (years @ bh) 54 51 54 55 55 52 58 52 53 57 Site index (m @ 50 yrs bh) 9 8 6.6 9.3 7.6 8.8 9.9 10.2 8.6 6.9 Tree layer cover (%) 23 22 23 26 30 18 36 33 15 24 Shrub layer cover (%) 62 55 60 54 51 40 33 48 58 65 Herb layer cover (%) 7 7 6 11 15 22 30 26 13 8 Moss layer cover (%) 21 16 27 34 17 8 3 18 22 21 100 APPENDICES Appendix 21 Scientica Silvica Extension Series, Number 27, 2000 Appendix 21. Selected environmental characteristics for plots of the 221 Populus tremuloides – Lathyrus ochroleucus: Hedysarum boreale subassociation. * Abbreviations defined in Appendix 17 on pag e96. Plot number1 1 Plot numbers have been simplified in this report.  See Appendix 32 on page112  for original plot codes. 42 43 44 45 46 47 48 49 50 51 52 Zone/subzone BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw SBS dw Soil moisture regime* 3/SD 3/SD 3/SD 4/SD 3/SD 3/SD 3/SD 3/SD 3/SD 3/SD 5/Mf Soil nutrient regime* M M M M M M M P P P M Elevation (m) 710 710 710 710 710 710 710 750 750 750 790 Slope gradient (%) 2 2 5 2 30 40 35 40 5 5 0 Aspect* F F S F S S S S W W F Forest floor thickness (cm) 4 4.5 6 6.5 5 5 7.5 3 4.5 3 32 Textural class* S S S S S LS S S S S SCL Actual rooting depth (cm) 60 60 60 70 75 60 50 80 52 65 25 Potential rooting depth (cm) 60 60 60 70 75 60 50 80 52 65 25 Seepage depth (cm) N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 65 Soil drainage* M M W M R W W W W W I Humus form group* RD RD RD RD RD RD RD RD HR RD YR Soil great group* DYB DYB EB DYB DYB DYB DYB EB DYB DYB GL Stand age (yrs @ bh) >50 >50 >50 53 >50 52 53 52 56 56 154 Site index (m 50 yr bh) N/D N/D N/D 15.5 N/D 15 13.1 10.8 13.1 12.4 12.2 Tree layer cover (%) 38 35 30 27 28 28 28 30 35 33 86 Shrub layer cover (%) 26 25 25 47 23 28 23 25 29 26 25 Herb layer cover (%) 58 26 28 21 41 53 38 37 39 26 25 Moss layer cover (%) 0 0 0 1 0 0 0 0 3 2 50 10 1 APPEN D ICES A ppendix 22 Trem bling Aspen Ecosystem s Appendix 22. Selected environmental characteristics for plots of the 222 Populus tremuloides – Lathyrus ochroleucus: typic subassociation. Plot number 1 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 Subzone/Variant BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw Soil moisture regime* 5/F 5/F 5/M 5/F 5/F 5/F 5/F 5/F 5/F 5/F 4/SD 4/SD 5/F 5/F 5/F 5/F Soil nutrient regime* M M M R P P M M R P R M M M M M Elevation (m) 645 630 630 630 750 710 740 740 645 750 525 525 480 465 465 450 Slope gradient (%) 0 5 0 6 4 6 1 3 3 0 2 1 0 2 3 0 Aspect* F S F E S S F W E F F F F F S F Forest floor thickness (cm) 9 6 7 6 6 5.5 4.5 5.5 8 7 4 5 3 5 4.5 6 Textural class* SL CL CL SiL CL LS SL CL CL LS SL LS CL SiL SiCL S Actual rooting depth (cm) 40 50 20 50 25 80 60 50 50 30 85 70 40 40 40 35 Potential rooting depth (cm) 30 20 15 50 25 80 35 20 50 30 85 70 40 25 20 55 Seepage depth (cm) N/A N/A N/A N/A N/A N/A N/A N/A N/A 30 N/A N/A N/A N/A N/A N/A Soil drainage* M I I M I M I I I I M M M M M I Humus form group* RD TD RD RD HR RD RD RD RD HR HR HR HR HR HR RD Soil great group* GL GL GL EB EB DYB GL GL EB DYB DYB DYB GL GL GL DYB Stand age (years @ bh) 70 >50 >50 55 52 53 64 65 69 67 >50 >50 >50 >50 >50 >50 Site index (m @ 50 yrs bh) 17.6 N/D N/D 18.9 18.2 17.4 20.3 16.8 19.5 14.8 N/D N/D N/D N/D N/D N/D Tree layer cover (%) 40 40 35 38 25 43 40 4 35 33 35 28 35 32 38 34 Shrub layer cover (%) 27 21 18 36 65 20 15 18 38 83 50 30 31 30 38 65 Herb layer cover (%) 35 27 22 42 18 51 32 29 46 24 40 36 22 20 18 45 Moss layer cover (%) 1 1 1 0 1 0 1 0 0 2 0 1 1 1 1 3 10 2 APPEN D ICES A ppendix 22 Scientica Silvica Extension Series, N um ber 27, 2000 * Abbreviations defined in Appendix 17 on page96 . Plot number1 1 Plot numbers have been simplified in this report.  See Appendix 32 on pag e112 for original plot codes. 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 Subzone/Variant BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw Soil moisture regime* 5/F 5/F 4/SD 4/SD 4/SD 5/F 4/SD 4/SD 5/F 5/F 5/F 5/F 5/F 4/SD 5/F Soil nutrient regime* P M M M M M M M M M M M M M M Elevation (m) 450 465 525 525 525 750 750 750 750 720 720 720 700 700 750 Slope gradient (%) 0 3 2 2 2 0 15 4 7 5 4 1 15 9 4 Aspect* F W F F F F E W W N W F W W W Forest floor thickness (cm) 6 6 4.5 6.5 5 5 7 5 6 4 4 4 7 6 4.5 Textural class* S SL S S S CL SiCL SiCL SiL SiCL CL CL CL CL SiCL Actual rooting depth (cm) 45 32 90 55 70 25 60 40 60 50 35 60 50 50 45 Potential rooting depth (cm) 45 32 90 55 70 25 60 30 60 50 35 20 45 20 30 Seepage depth (cm) N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Soil drainage* I I M M M M M M I I I I M M I Humus form group* RD RD HR RD RD HR RD RD RD RD RD HR HR HR RD Soil great group* DYB DYB GL DYB DYB GL EB GL GL GL GL GL GL GL GL Stand age (years @ bh) >50 >50 >50 49 >50 66 >50 >50 >50 >50 >50 >50 >50 >50 50 Site index (m @ 50 yrs bh) N/D N/D N/D 22.7 N/D 21.1 N/D N/D N/D N/D N/D N/D N/D N/D 18.6 Tree layer cover (%) 25 26 35 40 40 35 37 35 40 36 40 42 36 43 30 Shrub layer cover (%) 59 60 37 27 42 44 38 38 9 21 14 4 34 55 23 Herb layer cover (%) 32 50 35 36 33 39 48 37 24 32 29 21 58 11 23 Moss layer cover (%) 5 5 3 1 1 2 5 3 4 0 0 4 1 1 2 103APPENDICES Appendix 23 Trembling Aspen Ecosystems Appendix 23. Selected environmental characteristics for plots of the 223 Populus tremuloides – Latyrus ochrocleucus: Actaea rubra subassociation. * Abbreviations defined in Appendix 17 on page96 . Plot number1 1 Plot numbers have been simplified in this report.  See Appendix 32 on page 112 for original plot codes. 84 85 86 87 88 89 90 91 92 93 Zone/subzone BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw BWBS mw SBS dw Soil moisture regime* 5/M 5/M 5/M 6/VM 5/M 6/VM 5/M 5/M 5/M 5/M Soil nutrient regime* R R R R R R R R R VR Elevation (m) 630 750 750 750 450 450 450 700 700 1025 Slope gradient (%) 3 2 8 4 10 12 12 8 4 2 Aspect* S F S N S S S W N F Forest floor thickness (cm) 11 12 6 8.5 9 13 10 12 14 4 Textural class* CL SiL S SL S S SiL CL CL SCL Actual rooting depth (cm) 70 40 45 35 60 60 60 50 30 50 Potential rooting depth (cm) 70 40 45 35 60 60 60 26 30 70 Seepage depth (cm) N/A N/A N/A 45 N/A 35 N/A N/A N/A 85 Soil drainage* I M M I I I M I M I Humus form group* MD RD RD RD RD RD RD HR RD VL Soil great group* MB EB DYB DYB DYB DYB EB GL GL GBL Stand age (years @ bh) 57 56 52 55 N/D N/D N/D 57 N/D 96 Site index (m @ 50 yrs bh) 25.1 21.2 23.0 19.7 N/D N/D N/D 20.1 N/D 23.7 Tree layer cover (%) 26 30 40 30 45 46 45 43 39 100 Shrub layer cover (%) 28 14 26 24 27 27 40 67 45 7 Herb layer cover (%) 25 60 36 57 45 35 44 35 36 8 Moss layer cover (%) 0 0 0 0 0 0 0 1 0 1 104 APPENDICES Appendix 24 Scientica Silvica Extension Series, Number 27, 2000 Appendix 24. Selected environmental characteristics for plots of the 310 Populus tremuloides – Thalictrum occidentale  association. * Abbreviations defined in Appendix 17 on page96 . Plot number1 1 Plot numbers have been simplified in this report.  See Appendix 32 on page 112 for original plot codes. 94 95 96 97 98 99 100 101 102 103 Zone/subzone BWBS dk IDF xm IDF dk SBPS dc SBPS dc SBS dw SBS dw SBS dw SBS dw SBS dw Soil moisture regime* 4/SD 5/SDf 5/SDf 5/Ff 5/Ff 4/F 5/Mf 4/F 5/Mf 4/Ff Soil nutrient regime* M R P M M M M R R M Elevation (m) 595 1115 960 900 870 880 880 885 900 920 Slope gradient (%) 13 0 0 25 5 17 3 67 3 0 Aspect* S F F W W E N E N F Forest floor thickness (cm) 6.5 21 6 5 4 9 40 9 8 9 Textural class* SL SCL CL CL L SL O L L SL Actual rooting depth (cm) 100 70 30 80 90 35 70 60 120 50 Potential rooting depth (cm) 100 70 90 80 90 35 70 60 120 50 Seepage depth (cm) N/A 75 90 N/A N/A N/A 60 N/A N/A N/A Soil drainage* W M I M W W P W W W Humus form group* HR MD RD RD TD HR YR RD TD TD Soil great group* HFP GBL GL GL EB EB H EB EB EB Stand age (years @ bh) 135 68 48 50 75 63 87 61 46 99 Site index (m @ 50 yrs bh) 18.4 16.8 N/D 18.3 22.4 18.5 20 18.3 N/D 16.7 Tree layer cover (%) 71 80 70 100 76 60 51 70 40 100 Shrub layer cover (%) 19 85 32 5 23 47 53 20 19 31 Herb layer cover (%) 2 9 8 11 15 8 8 20 84 4 Moss layer cover (%) 4 0 0 1 1 0 4 6 0 20 10 5 APPEN D ICES A ppendix 25 Trem bling Aspen Ecosystem s Appendix 25. Selected environmental characteristics for plots of the 411 Populus tremuloides – Viburnum edule: Spiraea betulifolia subassociation. * Abbreviations defined in Appendix 17 on pag e96. Plot number1 1 Plot numbers have been simplified in this report.  See Appendix 32 on pag e112 for original plot codes. 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 Zone/subzone SBS dw SBS dw SBS dw SBS dw SBS dw SBS dw SBS dw SBS dw SBS dk SBS dk ICH mc SBS dw SBS dw SBS dw SBS dw SBS dw SBS dw Soil moisture regime* 3/SD 3/SD 3/SD 3/SD 3/SDf 4/Ff 4/F 4/F 4/F 3/SD 4/F 4/F 3/SD 3/SD 4/Ff 5/Mf 3/SD Soil nutrient regime* R R VR R R VR R R R R R R R R M R R Elevation (m) 920 880 890 870 900 900 890 890 880 810 390 1025 855 850 885 880 900 Slope gradient (%) 2 7 7 0 0 0 2 0 0 4 11 14 11 16 0 0 30 Aspect* F N N F F F F F F W W N W W F F E Forest floor thickness (cm) 5 5.5 12.5 10 10 19 10 13 6.5 9.5 8.5 6 5 4 7.5 7 8 Textural class* L L L L L L L L SL L SL SCL SL SL S S SCL Actual rooting depth (cm) 30 60 60 50 50 50 60 60 60 60 60 30 30 90 70 80 60 Potential rooting depth (cm) 30 60 70 60 60 60 70 70 70 70 70 30 30 90 70 80 60 Seepage depth (cm) N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Soil drainage* W W W W W W W W W W W M W W R W W Humus form group* RD RD MD TD TD MD MD MD UR MD TD TD RD RD RD HR RD Soil great group* HFP HFP DYB EB DYB EB EB EB EB EB EB EB EB EB EB EB EB Stand age (years @ bh) N/D 104 105 101 103 112 N/D N/D 81 103 72 116 85 65 83 81 48 Site index (m @ 50 yrs bh) N/D 18.6 18.6 12.1 18.9 19.4 N/D N/D 16.7 15.2 13 17.3 15.2 18.1 13.6 15.6 N/D Tree layer cover (%) 96 100 75 95 95 85 70 85 70 90 30 95 91 86 55 100 85 Shrub layer cover (%) 55 65 85 59 52 48 97 48 54 39 50 18 38 59 67 67 22 Herb layer cover (%) 24 35 22 11 35 22 5 8 21 29 4 2 3 5 2 2 20 Moss layer cover (%) 0 12 7 1 1 1 0 0 0 0 1 2 0 0 35 6 0 106 APPENDICES Appendix 26 Scientica Silvica Extension Series, Number 27, 2000 Appendix 26. Selected environmental characteristics for plots of the 412 Populus tremuloides – Viburnum edule: Paxistima myrsinites subassociation. * Abbreviations defined in Appendix 17 on pag e96. Plot number1 1 Plot numbers have been simplified in this report. See Appendix 32 on page 112 for original plot codes. 121 122 123 124 125 126 127 128 129 130 Zone/subzone ICH mc ICH mc ICH mc ICH mc ICH mc ICH mc ICH mc ICH mc ICH mw ICH dw Soil moisture regime* 3/SD 3/SD 3/SD 3/SD 4/F 3/SD 3/SD 3/SD 4/F 3/SD Soil nutrient regime* R R R R R M M M M M Elevation (m) 390 380 380 420 500 500 500 520 790 1020 Slope gradient (%) 11 27 18 33 0 22 27 11 25 16 Aspect* W S N W F W W S S E Forest floor thickness (cm) 7.5 10 8 8.5 6 8.5 7 5 3.5 8 Textural class* L SL LS LS LS LS LS SL L SL Actual rooting depth (cm) 40 60 70 70 70 70 40 50 50 35 Potential rooting depth (cm) 50 70 70 70 70 70 40 60 50 35 Seepage depth (cm) N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Soil drainage* W W M W M M M W W W Humus form group* TD RD TD TD TD HR TD TD RD RD Soil great group* DYB EB EB EB EB EB EB EB HFP EB Stand age (years @ bh) 103 99 N/D N/D 63 71 71 N/D 47 96 Site index (m @ 50 yrs bh) 16.9 14.8 N/D N/D 22.5 16.6 20.3 N/D N/D N/D Tree layer cover (%) 20 40 100 70 52 50 79 71 74 75 Shrub layer cover (%) 54 63 95 37 41 50 54 31 15 18 Herb layer cover (%) 8 6 14 6 10 2 6 2 8 2 Moss layer cover (%) 0 0 1 0 2 1 1 9 0 1 107APPENDICES Appendix 27 Trembling Aspen Ecosystems Appendix 27. Selected environmental characteristics for plots of the 421 Populus tremuloides – Rosa nutkana: Aralia nudicaulis subassociation. * Abbreviations defined in Appendix 17 on page96 . Plot number1 1 Plot numbers have been simplified in this report. See Appendix 32 on page112  for original plot codes. 131 132 133 134 135 136 137 138 139 140 141 142 143 144 Zone/subzone ICH mc MS dk MS dk MS dk MS dk MS dk MS dk MS dk MS dk ICH dw ICH dw ICH mw IDF dm IDF dm Soil moisture regime* 5/M 6/Mf 6/Mf 6/M 6/M 6/M 6/Mf 6/Mf 6/M 5/M 6/VM 6/VM 6/F 6/F Soil nutrient regime* R VR R R R M R R R R VR VR R M Elevation (m) 520 815 980 990 1045 1035 1020 1040 1040 850 850 1025 1100 1115 Slope gradient (%) 22 0 0 33 13 7 0 2 8 0 0 6 6 8 Aspect* N F F E E N F F W F F N E E Forest floor thickness (cm) 7 10 2.5 7 4 8 2.5 3 3 5 30 17 6 10 Textural class* SL SC S SL L S SCL SL SCL S L SCL SCL SL Actual rooting depth (cm) 70 30 80 50 30 60 45 45 45 100 90 38 40 35 Potential rooting depth (cm) 70 60 80 50 30 80 55 45 65 100 90 38 20 35 Seepage depth (cm) 100 60 N/A N/A N/A N/A 55 N/A 65 70 45 45 20 N/A Soil drainage* M I M M M M P W P I I P P W Humus form group* TD TD VL TD MD TD VL VL VL RD YL YD VL RD Soil great group* EB GL HFP EB HFP R GL HFP GL HFP HR GL GL EB Stand age (years @ bh) 95 N/D 58 56 59 58 75 73 74 80 80 81 63 62 Site index (m @ 50 yrs bh) 28.3 N/D 29.6 26.4 26.6 26.8 26.6 24.8 24.5 29.3 30.7 24.1 20.6 22.3 Tree layer cover (%) 54 100 60 78 100 91 80 97 85 79 100 100 75 45 Shrub layer cover (%) 27 44 46 57 12 14 17 9 3 2 1 1 92 35 Herb layer cover (%) 15 26 44 11 25 78 80 49 70 3 3 0 15 32 Moss layer cover (%) 11 0 0 0 0 0 0 1 0 0 0 0 0 1 108 APPENDICES Appendix 28 Scientica Silvica Extension Series, Number 27, 2000 Appendix 28. Selected environmental characteristics for plots of the 422 Populus tremuloides – Rosa nutkana: Arnica cordifolia subassociation. * Abbreviations defined in Appendix 17 on page 96. Plot number1 1 Plot numbers have been simplified in this report. See Appendix 32 on pag e112 for original plot codes. 145 146 147 148 149 150 151 152 153 Zone/subzone MS dk MS dk MS dk MS dk ICH dw ICH dw ICH dw MS dk IDF dm Soil moisture regime* 3/SD 2/MD 3/SD 2/MD 3/SD 3/SD 3/SD 2/MD 4/MD Soil nutrient regime* M M M M R R R M M Elevation (m) 980 980 1020 1030 785 805 800 1285 1215 Slope gradient (%) 40 48 21 27 42 65 65 0 16 Aspect* N N N N W W W F E Forest floor thickness (cm) 8 7 3 7 6 7 6 4 10 Textural class* LS LS S L LS SL LS LS SL Actual rooting depth (cm) 80 60 35 45 70 90 30 45 40 Potential rooting depth (cm) 80 60 35 45 70 90 30 45 40 Seepage depth (cm) N/A N/A N/A N/A N/A N/A N/A N/A N/A Soil drainage* W W M W R R R W W Humus form group* TD TD VL TD RD TD TD RD HR Soil great group* HFP HFP EB HFP HFP HFP R HFP EB Stand age (years @ bh) 58 58 54 55 73 73 75 76 N/D Site index (m @ 50 yrs bh) 26.7 25.3 26.1 21.8 20 24.1 20.4 20.5 N/D Tree layer cover (%) 95 70 80 100 85 75 93 90 100 Shrub layer cover (%) 8 27 57 66 16 57 42 4 16 Herb layer cover (%) 53 7 26 22 15 11 4 2 17 Moss layer cover (%) 0 0 0 0 0 0 0 0 0 109APPENDICES Appendix 29 Trembling Aspen Ecosystems Appendix 29. Selected environmental characteristics for plots of the 423 Populus tremuloides – Rosa nutkana: Angelica genuflexa subassociation. * Abbreviations defined in Appendix 17 on pag e96. Plot number1 1 Plot numbers have been simplified in this report.  See Appendix 32 on page 112 for original plot codes. 154 155 156 157 158 159 160 161 162 Zone/subzone ICH mw ICH mw ICH mw ICH mw ICH mw ICH mw IDF dm IDF dm IDF dm Soil moisture regime* 4/F 4/F 4/F 4/F 4/F 4/F 6/F 5/SD 5/SD Soil nutrient regime* R R VR R R R M R M Elevation (m) 795 795 800 800 805 805 1210 1210 1285 Slope gradient (%) 48 18 32 27 30 21 4 0 0 Aspect* S S S S S S E F F Forest floor thickness (cm) 7 10 10 8 10 9.5 8 8 9 Textural class* SL L L L L SL LS SCL S Actual rooting depth (cm) 50 50 70 70 70 60 65 45 50 Potential rooting depth (cm) 50 50 70 70 70 60 65 55 50 Seepage depth (cm) N/A N/A N/A N/A N/A N/A 65 55 60 Soil drainage* W W W W W W P I I Humus form group* VL VL TD VL VL VL TD VL RD Soil great group* EB EB EB EB EB EB GL GL DYB Stand age (years @ bh) 76 100 59 56 65 77 65 67 66 Site index (m @ 50 yrs bh) 19.6 19.3 23.7 20.4 27 21 20.2 22.3 20 Tree layer cover (%) 85 85 70 80 70 70 68 42 93 Shrub layer cover (%) 48 72 58 23 70 28 27 84 13 Herb layer cover (%) 16 28 19 45 27 48 30 35 13 Moss layer cover (%) 0 0 0 0 0 0 0 0 0 110 APPENDICES Appendix 30 Scientica Silvica Extension Series, Number 27, 2000 Appendix 30. Selected environmental characteristics for plots of the 424 Populus tremuloides – Rosa nutkana: Senecio pseudoaureus subassociation. * Abbreviations defined in Appendix 17 on page 96. Plot number1 1 Plot numbers have been simplified in this report. See Appendix 32 on pag e112 for original plot codes. 163 164 165 166 167 168 169 170 171 Zone/subzone IDF dm MS dk MS dk MS dk MS dx IDF dw IDF xm IDF xm IDF xm Soil moisture regime* 4/MD 3/SD 2/MD 2/MD 2/MD 4/MD 4/MD 4/MD 4/MD Soil nutrient regime* VR R R M R R R R M Elevation (m) 1005 1025 1035 1040 1055 1010 1050 1215 1220 Slope gradient (%) 0 8 45 5 59 48 5 12 15 Aspect* F E S W S W E E E Forest floor thickness (cm) 7 3 2.5 9 3 9 4 13 9 Textural class* SL SL SL SL LS LS S SCL SL Actual rooting depth (cm) 100 90 100 40 40 80 80 70 40 Potential rooting depth (cm) 100 90 100 40 40 80 80 70 40 Seepage depth (cm) N/A N/A N/A N/A N/A N/A N/A 75 N/A Soil drainage* W W W W W W W M W Humus form group* VL VL VL VL VL TD VL TD HR Soil great group* EB HFP EB HFP EB EB EB GL EB Stand age (years @ bh) 96 74 61 72 57 89 75 69 86 Site index (m @ 50 yrs bh) 20.2 24.9 20.7 17.9 15.2 24.6 20.6 23.8 19.1 Tree layer cover (%) 70 63 88 75 41 56 41 90 80 Shrub layer cover (%) 9 23 3 6 28 59 77 55 69 Herb layer cover (%) 13 19 78 16 18 10 5 22 18 Moss layer cover (%) 0 1 0 1 0 0 0 0 0 111 APPEN D ICES A ppendix 31 Trem bling Aspen Ecosystem s Appendix 31. Selected environmental characteristics for plots of the 425 Populus tremuloides – Rosa nutkana: Shepherdia canadensis subassociation. * Abbreviations defined in Appendix 17 on page96 . Plot number1 1 Plot numbers have been simplified in this report. See Appendix 32 on pag e112 for original plot codes. 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 zone/subzone IDF xm IDF xm IDF xm IDF xm IDF xm SBPS dc SBPS dc SBPS dc MS dk MS dk IDF dm IDF dm IDF dm IDF dm IDF dm Soil moisture regime* 2/VD 2/VD 2/VD 3/VD 3/VD 4/MDf 4/MDf 2/VD 1/VD 1/VD 2/VD 2/VD 2/VD 2/VD 4/MD Soil nutrient regime* M M R M P M R R M P P M P P P Elevation (m) 1095 1100 1040 965 980 960 960 970 1060 1060 1040 1080 1065 1285 1210 Slope gradient (%) 0 14 48 0 0 0 0 4 35 85 38 38 67 0 2 Aspect* F E W F F F F W S S S S S F F Forest floor thickness (cm) 5 7 3 9 5 9 3 6 9 4 5 10 4 6 4 Textural class* L SL SL L LS SCL SCL CL LS L SL SL S LS SL Actual rooting depth (cm) 80 45 40 70 45 70 70 65 40 120 25 55 80 30 70 Potential rooting depth (cm) 80 45 45 70 45 70 70 65 40 120 25 55 80 30 70 Seepage depth (cm) N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Soil drainage* W R R W R W W M R R R R R R W Humus form group* TD RD VL TD HR VL TD TD TD TD TD TD TD TD HR Soil great group* EB EB EB EB EB SB EB GL DYB EB EB EB DYB DYB EB Stand age (years @ bh) 70 63 63 122 113 95 65 117 61 62 86 95 75 68 74 Site index (m @ 50 yrs bh) 12.6 13.1 8.7 10.2 9.8 10.2 11.2 10.3 14.1 12.7 14.6 10.2 14.8 N/D 16.2 Tree layer cover (%) 60 30 50 82 40 25 25 80 44 25 70 95 25 66 60 Shrub layer cover (%) 62 1 0 1 4 53 51 18 15 69 42 33 5 13 37 Herb layer cover (%) 4 51 12 1 2 16 7 14 35 9 22 74 0 4 25 Moss layer cover (%) 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 112 APPENDICES Appendix 32 Scientica Silvica Extension Series, Number 27, 2000 Appendix 32. Conversion of the plot numbers used in this report to the plot codes used in the original data set (AtKK.MDB) on file with the British Columbia Ministry of Forests, Research Branch, in the VENUS data base. plot number plot code plot number plot code plot number plot code plot number plot code 1 97--040 48 95--115 95 98--007 142 98--254 2 97--068 49 95--118 96 98--026 143 98--277 3 97--107 50 95--124 97 98--095 144 98--278 4 97--111 51 95--125 98 98--097 145 98--217 5 97--015 52 98--114 99 98--099 146 98--218 6 97--036 53 95--101 100 98--100 147 98--221 7 97--037 54 95--102 101 98--102 148 98--222 8 97--042 55 95--103 102 98--104 149 98--235 9 97--047 56 95--104 103 98--111 150 98--236 10 97--048 57 95--107 104 97--003 151 98--237 11 97--051 58 95--109 105 97--005 152 98--283 12 97--053 59 95--116 106 97--007 153 98--286 13 97--059 60 95--117 107 97--009 154 98--206 14 97--089 61 95--129 108 97--010 155 98--207 15 97--102 62 95--131 109 97--011 156 98--209 16 97--103 63 95--201 110 97--017 157 98--210 17 97--109 64 95--202 111 97--018 158 98--211 18 98--093 65 95--203 112 97--019 159 98--213 19 97--008 66 95--204 113 97--020 160 98--279 20 97--056 67 95--205 114 97--023 161 98--280 21 97--063 68 95--206 115 98--063 162 98--281 22 97--065 69 95--207 116 98--067 163 98--010 23 97--066 70 95--208 117 98--068 164 98--226 24 97--067 71 95--212 118 98--071 165 98--227 25 97--069 72 95--213 119 98--073 166 98--229 26 97--076 73 95--214 120 98--103 167 98--232 27 97--082 74 95--215 121 97--024 168 98--267 28 97--116 75 95--216 122 97--025 169 98--275 29 97--117 76 95--217 123 97--026 170 98--285 30 97--121 77 95--301 124 97--027 171 98--287 31 98--096 78 95--302 125 97--028 172 98--002 32 95--119 79 95--303 126 97--029 173 98--003 33 95--120 80 95--304 127 97--031 174 98--008 34 95--121 81 95--306 128 97--032 175 98--023 35 95--122 82 95--307 129 98--203 176 98--024 36 95--123 83 95--309 130 98--253 177 98--025 37 95--126 84 95--105 131 97--034 178 98--027 38 95--127 85 95--106 132 98--216 179 98--028 39 95--132 86 95--128 133 98--219 180 98--233 40 95--133 87 95--130 134 98--220 181 98--234 41 95--134 88 95--209 135 98--223 182 98--269 42 95--108 89 95--210 136 98--224 183 98--270 43 95--110 90 95--211 137 98--225 184 98--276 44 95--111 91 95--305 138 98--228 185 98--282 45 95--112 92 95--308 139 98--230 186 98--284 46 95--113 93 98--075 140 98--251 47 95--114 94 97--120 141 98--252

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