Whistler has adopted an ecosystem-based approach in its Environmental Strategy (RMOW 2002). The foundation for such an approach is baseline data on the types of ecosystems present within the municipality. The main objective of this project was to provide an ecological framework to support conservation planning. It represents a medium-scale inventory that is appropriate for landscape-level planning applications. More detailed information is required for site-level applications.

2. PROJECT TEAM

The project was conducted for Heather Beresford, Resort Municipality of Whistler. The ecosystem mapping team consisted of Bob Green, Bruce Blackwell, Kevin Haberl, Fiona Steele, and John Davies (B.A. Blackwell and Associates Ltd.). Other project team members included Cherie Stutz and Evelyn Parsons (Chartwell Consultants Ltd. – digitizing and GIS processing), Terry Lewis (Lewis Consulting Ltd. – historic instability mapping) and Karel Klinka (University of British Columbia - quality assurance, classification of wetland ecosystems). Bob Brett (Snowline Ecological Consultants) provided assistance in classification and mapping of alpine and subalpine ecosystems.

3. METHODS

3.1 General Approach

Mapping procedures followed the general methods outlined in Standard for Terrestrial Ecosystem Mapping in British Columbia (RIC, 1998) with some modifications to meet project objectives. Areas encompassing similar ecosystems are delineated on aerial photographs, data is collected in the field to characterize ecological properties, and a set of attributes are then assigned to each delineation based on field data and interpretation of air photos. All the data is compiled in a digital GIS (geographic information system) database. The principal ecological features recognized in delineations include site units, structural stage, and site modifiers. Site units represent different ecosystems as identified in available ecological classification systems (Green and Klinka 1994, Brett et al. 1998, Klinka et al. 1997). These are based on the biogeoclimatic ecosystem classification for British Columbia (Meidinger and Pojar 1991). Structural stage represents the type of vegetation development (e.g. shrub/herb, young forest, old forest, etc.). Site modifiers represent additional information on site properties such as slope, shallow soils, ravines, etc.

3.2 Photo Typing

Photo typing was done on alternate 1:15,000 colour air photos from a 1994 flight. This was the most recent comprehensive coverage available for the RMOW area available at the time. These photos did not cover the upper Fitszimmons Creek area so 1980 1:40,000 scale black and white photos were used to complete this area. Photo typing involved delineation of areas encompassing similar ecosystems that focused on recognizable terrain and landscape properties (physiography, parent materials), and ecological properties (sites, structural stage). Areas showing evidence of historic slope instability[1] were typed prior to delineating the remaining ecological polygons.

3.3 Field Sampling

3.3.1 Sampling strategy

The goal of the field sampling phase was to check as many locations as possible within the budget and time available. The focus was on characterizing ecological composition of mapped polygons, checking polygon boundaries, particularly between biogeoclimatic units, and on characterizing site unit features. This provided data for known points on air photos which was then used for interpreting “photo signatures” when assigning polygon attributes. The sampling program was carried out using a combination of truck, bicycle, and helicopter access with 2 person crews.

A sampling plan was prepared prior to field work. This involved viewing each typed air photo with a stereoscope and marking locations where checking should be aimed. This generally focussed on sites which were representative of the area, or which appeared difficult to interpret from the photos. These pre-marked photos served as a guide to direct sampling in the field. The intent was to sample as many of these sites as possible, while allowing flexibility in checking additional sites as the need was determined by the field crews. The sampling program was facilitated by the 1:30,000 scale Whistler Recreation Map (TerraPro 1998). Outlines of the typed air photos were transferred to the map to assist in photo handling and field orientation.

3.3.2 Field inspection types

Field inspections consisted of three types: ground inspections, visual inspections, and aircall inspections. Ground inspections were used to gather key ecological properties at specific points on the ground, including information on site unit composition in the area around the sample point. Figure 1 shows the data collected on the ground inspection form. Additional data was collected on crown, surface, and ladder fuel loadings that can be used in subsequent fire management planning.

Air calls were conducted from a low flying helicopter for areas that were inaccessible to ground crews. They were used for characterizing site unit composition of polygons and for biogeoclimatic boundary confirmation. In most cases, sufficient features of dominant understory vegetation, tree species, physiography, and tree vigour are visible from hovering just above the canopy, that site unit composition can be reliably estimated. Information recorded for air calls included biogeoclimatic unit, site unit composition, relevant site modifiers, structural stage, tree species composition, and comments relating to features that will aid in photo interpretation. Visual inspections consist of brief photo annotations made while walking or driving through polygons.

Sampling was conducted from July through October, 2003.

FIGURE 1. Data form used to collect ground inspection data.

3.3.3 Inspection locations

All field inspections were located on colour photocopies of the typed air photos, and labeled with their inspection numbers. Inspection locations were also collected as waypoints in the field using Garmin 76 GPS units. These labeled waypoints were downloaded and transferred to an ArcInfo plot location layer.

3.4 Digitizing

Chartwell Consultants (North Vancouver, B.C.) undertook digitizing of polygon linework using mono-restitution techniques. A first draft of 1:12,000 check plots was produced for review. These were checked for errors in linework transfer then returned to Chartwell for revisions. A revised second draft of check plots was used for the final attributing phase.

3.5 Final Attributes

3.5.1 Setup

The following items were assembled prior to commencing with the final ecosystem attributing phase:

· basic polygon map. This contained just the polygon linework and numbers and was used for tracking attributing progress and noting revisions.

· contour/inspection/polygons. This contained polygon linework and numbers, inspection locations and numbers, and 100 m contour intervals. Inspection locations were colour coded manually according to the observed biogeoclimatic unit.

· field inspection database sorted by air photo and inspection number

· GIS data for 1994 forest cover inventory with stand age projected to 2003. This data was obtained from the RMOW.

3.5.2 Building the attribute database

Attributing progressed on a photo-by-photo basis across each map sheet. The first step was to add the biogeoclimatic (BGC) unit boundaries to the polygon map. The following information was integrated to locate the BGC boundaries: observed BGC units from field inspections, 100 m contours, original MOF BGC unit boundaries, and interpretation of air photo features. Based on this information, BGC lines were located on the map following existing polygon lines as much as possible. Where required, new lines were added, subdividing existing polygons to ensure correct location of BGC boundaries. In these cases, new reference numbers were added for the new polygons.

The next step was to create final attributes for polygons on each photo. The following information was reviewed prior to deciding on the appropriate attributes: relevant field inspection and supplemental data around each polygon, polygon features from air photo interpretation, final attributes of adjacent polygons, and preliminary attributes for the polygon where noted on the photos. Once decided, the attributes were entered directly into an Excel database on a laptop computer. Structural stage was determined according to the type of site unit. Non-forested site units featured a characteristic structural stage (e.g. Carex-dominated wetlands are characteristically “herb” structural stage, shrub-dominated avalanche tracks are “shrub/herb” structural stage, etc.). For forested site units, structural stage varied according to stand development since the last disturbance (e.g. stand height, age). The forest inventory data was referenced for this information in assigning structural stage as field sampling could not include comprehensive stand age measurements. In some cases, structural stage was based on field observations when they were clearly inconsistent with the forest inventory data. Classes of structural stage used are shown in Table 1. In addition to structural stage, stand composition modifiers were recorded to indicate whether the tree cover layer is dominated by coniferous, deciduous, or mixed species (Table 2).

Once the attributing was completed, the polygon map containing all the new revisions was passed on to Chartwell Consultants so the spatial and attribute databases could be updated accordingly.

TABLE 1. Structural stage classes (RIC, 1998)

Code	Description
Sparse/bryoid	Initial stages of succession; from no vegetative cover to dominant bryoid/lichen cover
Herb	herb dominated communities; <10% tree cover, < 20% shrub cover
Shrub/Herb	communities dominated by shrubby vegetation < 10m tall; tree regeneration may be abundant; tree cover < 10%
Pole/Sapling	trees > 10m tall have overtopped shrub and herb layer; dense stands usually less than 40 yrs since disturbance; includes stagnated older stands
Young Forest	self-thinning evident with canopy layers developed; more open than Pole/Sapling; usually 40-80 yrs since disturbance
Mature Forest	main canopy trees mature; well-developed understory often with advance regeneration; usually 80-250 yrs since disturbance
Old Forest	old structurally complex stands with snags and coarse woody debris; > 250 yrs since disturbance

TABLE 2. Stand composition modifier (RIC 1998)

Code	Description
C	Coniferous
M	Mixed
B	Broadleaf

3.5.3 Editing

Two main editing phases were conducted; a) editing the final attribute database prior to linking it with the spatial polygon data, and b) editing the linked spatial and attribute data. In the first phase, the Excel database of final attributes was thoroughly reviewed using a series of filters and sorts. The following issues were checked and corrected where required:

· inconsistencies and errors in the field codes

· polygon components not summing to 100%

Once the database was correct the resulting data was exported as a dBase file for linking to the spatial data.

Editing of the GIS data was done using ArcView GIS. A series of themes were created from the preliminary GIS data that included BGC unit, structural stage, and site units. These were used to conduct the edit of the GIS data. The BGC and structural stage themes were initially checked for obvious anomalies, then carefully compared against the typed airphotos and the original maps containing the BGC unit boundaries. Polygons with missing attributes were also highlighted on the BGC unit theme and were corrected directly in ArcView.

The results of the above editing were fully incorporated into the GIS database then a final quality check was conducted to identify any outstanding issues. These were corrected to produce the final clean GIS database.

4. RESULTS

4.1 Sampling

A total of 401 inspections were completed for this project, comprised of 59% ground inspections, 17% visual inspections, and 24% air calls. Table 3 summarizes the distribution of inspections by type.

TABLE 3. Distribution of inspections by type.

Inspection Type	Number Completed	Proportion of total (%)
Ground inspections	235	59
Visual inspections	70	17
Air call inspections	96	24
Total inspections	401	100
RMOW area[2]	16,530 ha
Inspection density	41 ha per inspection

The achieved inspection density of 41 ha/inspections exceeded the target density of 60 ha/inspection originally planned. As sampling progressed, it was felt that additional data was required to adequately capture the variability encountered.

4.2 Classification Units

The classification of ecosystems was based on the biogeoclimatic classification (BEC) for British Columbia. An overview of the BEC system can be found in Meidinger and Pojar (1991), and at the following website: http://www.for.gov.bc.ca/hre/becweb/index.htm.

The BEC system groups similar segments of the landscape (ecosystems) into categories of a classification system. For purposes of BEC, an ecosystem is defined as a particular plant community and its associated topography, soil, and climate.

From a practical perspective, the BEC system focuses on two levels of ecosystem variation: climate and site. Geographic areas influenced by similar regional climates are classified into biogeoclimatic units in the climatic component of the BEC system. Within each biogeoclimatic unit, a recurring pattern of sites reflects variation in soil and physiographic properties. These site units have characteristic ecological properties, and are classified based on their potential to produce similar vegetation communities, with the exception of non-vegetated site units that are classified based on their characteristics (e.g. gravel pit, lake, powerline, etc.)

4.2.1 Biogeoclimatic Units

The following biogeoclimatic units occurred in the study area (Figure 2 and Table 4):

Coastal Western Hemlock Zone (CWH)

CWHms1: Southern Moist Submaritime Coastal Western Hemlock Variant. The CWHms1 is distributed from the valley bottom up to about 1200m elevation where it grades into the MH Zone. The climate is transitional between the coast and interior, and is characterized by moist, cool winters and cool but relatively dry summers. Snowfall is relatively heavy, particularly in upper elevations.

Mountain Hemlock Zone (MH)

MHmm2: Leeward Moist Maritime Mountain Hemlock Variant. The MHmm2 occurs above the CWHms1, beginning at about 1200m elevation. It tends to be higher on major warm aspect slopes where it may come in at 1400m. It occurs at lower elevations on plateaus and cold bowls where the subdued topography creates longer duration snowpacks. The climate features long, moist, cold winters and short, cool summers.

MHmmp2: Leeward Moist Maritime Parkland Mountain Hemlock Variant. This variant is characterized by discontinuous forest cover and is distributed where physiography and elevation combine to create snowpacks of sufficient duration to preclude continuous forest cover. The MHmmp2 occurs above the MHmm2. Because of the significant role of topography as it affects snowpack patterns, the distribution of the MHmmp2 is often non-contiguous throughout the study area.

Alpine Tundra Zone (AT)

ATc: The Coastal Alpine Tundra Subzone occurs on upper mountain slopes and peaks where the climate is so harsh that forests cannot establish. It occurs above the MHmmp2.

TABLE 4. Proportion of study area according to biogeoclimatic unit.

Biogeoclimatic unit	Proportion of study area
ATc	12.32%
CWHms1	63.95%
MHmm2	20.14%
MHmmp2	3.60%
Total	100.00%

FIGURE 2. Biogeoclimatic unit distribution within the RMOW.

4.2.2 Site units

The majority of forested site units are recognized in the provincial site series classification (Green and Klinka 1994). A number of predominantly non-forested site units not recognized in the provincial classification were encountered. This reflects the focus of the original BEC program which was forested ecosystems. The new units are summarized in Table 5 with the exception of non-vegetated units that are self-explanatory. The descriptions of these units is based on data and observations collected during field sampling in this and other coastal mapping projects conducted by B.A. Blackwell and Associates, as well as information contained in the listed references. A complete synopsis of site units recognized in the study area can be found in the data dictionary in Appendix A.

TABLE 5. New site units currently not recognized in the provincial BEC classification.

BGC unit	Name	Description
CWH	CwSs - Red-osier dogwood - Skunk cabbage	Wet, nutrient rich sites on poorly drained alluvial soils; features Cornus sericea, Vibernum edule, Lonicera involucrata, Oplopanax horridus, Lysichitum americanum, and related species; productive hybrid spruce (Picea sitchensis x engelmannii) on raised microsites.
CWH	Cw - Spirea	Wet to very wet, open canopy swamp forest transitional between “CwSs - Skunk cabbage” and non-forested wetlands; features Carex spp., Spiraea douglasii , Lysichitum americanum, Sphagnum spp., Vibernum edule, Calamagrostis canadensis, and related species; with stands of open, low vigour western redcedar (Thuja plicata) and red alder (Alnus rubra); located in poorly drained depressions and along margins of wetlands.
CWH	Cw – Fern bluffs	Precipitous bluffs and cliffs; extreme microsite variation due to crevices, ledges and other irregularities, combined with intermittent surface seepage; irregularly stocked coniferous stands rooted in crevices, and very thin organic and colluvial parent material; typically includes Adiantum aleuticum, Polystichum munitum, and/or Polypodium glycyrrhiza.
MHmm2	HmYc – Blueberry – Mountain heather	Fresh, nutrient poor to medium late snow-lie sites with open canopies; generally on subdued topography; late snow melt associated with this topography results in open canopy stands; generally hummocky microtopography with common moist to wet depressions.
MHmm2	Bl-Rhododendron	Fresh, nutrient poor to medium, strong warm-aspect sites with subcontinental local climate influence; features subalpine fir (Abies lasiocarpa), whitebark pine (Pinus albicaulis), Vaccinium membranaceum, Rhododendron albiflorum, Valeriana sitchensis, Dicranum spp., Rhytidiopsis robusta, and associated species; related to “Vaccinium membranaceum” alliance in Brooke et al. (1970).
MHmm2	Yc – Rhacomitrium bluffs	Precipitous bluffs, cliffs, and extremely steep (>100%) rocky slopes featuring scrubby conifers rooted in crevices and very thin organic and colluvial parent material.
AT/MHmmp	Penstemon - Juniper	Dry lithic alpine/subalpine habitats; steep rocky sites supporting xerophytic species together with talus and rock; related to “Penstomen davidsonii – Juniperus communis” in Brett et al. (1998).
AT/MHmmp	Bl -Phyllodoce	Krummholz community featuring patches of scrubby subalpine fir (occasionally mountain hemlock (Tsuga mertensiana) and whitebark pine); typically on steep, rocky sites but may occur on deeper soils; related to “Phyllodoce emptriformis – Abies lasiocarpa” in Brett et al. (1998).
AT/MHmmp	Bl – Black huckleberry	Tree island community; relatively small but distinct closed forest stands surrounded by alpine or parkland communities; features subalpine fir, mountain hemlock (on cool aspects) , Vaccinium membranaceum, Rhododendron albiflorum, Valeriana sitchensis, Luetkea pectinata, Phyllodoce empetriformis, and related species; generally on steep, snow-shedding slopes.
AT/MHmmp	Cassiope - Phyllodoce	Heath community; alpine heather-dominated heath featuring a dense and matted cover of low shrubs and herbs dominated by Phyllodoce empetriformis and Cassiope mertensiana; related to “Cassiope mertensiana – Phyllodoce empetriformis” in Brett et al. (1998).
AT/MHmmp	Hm - Cassiope	Heath community; alpine heather-dominated heath featuring a dense and matted cover of low shrubs and herbs dominated by Phyllodoce empetriformis and Cassiope mertensiana, with common dwarf-sized (<50cm) mountain hemlock and subalpine fir; related to “Cassiope mertensiana – Tsuga mertensiana” in Brett et al. (1998).
AT/MHmmp	Parkland - heath	Parkland community; a discontinuously forested complex of small islands of tree-sized subalpine fir, mountain hemlock (cool aspects), and occasionally whitebark pine (warm aspects), with a surrounding matrix dominated by heath-like species (Phyllodoce empetriformis , Cassiope mertensiana).
AT/MHmmp	Parkland – dry herbaceous	Parkland community; a discontinuously forested complex of small islands of tree-sized subalpine fir, mountain hemlock (cool aspects), and occasionally whitebark pine (warm aspects), with a surrounding matrix dominated by dry alpine herbaceous species such as Lupinus arcticus, Phlox diffusa, Valeriana sitchensis, Pedicularis racemosa, Hieracium gracile, and related species.
AT/MHmmp	Parkland – lush herbaceous	Parkland community; a discontinuously forested complex of small islands of tree-sized subalpine fir, mountain hemlock (cool aspects), and occasionally whitebark pine (warm aspects), with a surrounding matrix dominated by lush, floristically diverse alpine herbaceous species such as Valeriana sitchensis, Heracleum maximum, Veratrum viride, Carex spectabilis, Lupinus arcticus, Arnica latifolia, and related species.
AT/MHmmp	Caltha - Leptarrhena	Very moist to wet, moisture collecting habitats; floristically diverse herb-dominated communities occurring on seepage and moisture collecting sites; features Caltha leptosepala, Leptarrhena pyrolifolia, Valeriana sitchensis, Parnassia fimbriata, Philonotis fontana, Senecio triangularis, and related species; encompasses the “Philonotis Fontana order” in Brett et al. (1998).
AT/MHmmp	Valeriana meadows	Moist to very moist nutrient rich habitats; floristically diverse herb-dominated communities featuring a variety of herbs, graminoids, and mosses, including Valeriana sitchensis, Heracleum maximum, Veratrum viride, Carex spectabilis, Lupinus arcticus, Arnica latifolia, and related species; encompasses the “Valeriana sitchensis order” in Brett et al. (1998).
AT/MH	Carex - Eriophorum	Subalpine/alpine wetland community; includes the group of sedge/bryophyte communities that occupy water-collecting subalpine/alpine basins; encompasses the “Eriophorum angustifolium order” in Brett et al. (1998).
AT/MHmmp	Carex nigricans	Snow basin habitats; includes communities that form in cold-air-ponding swales where snowpacks persist late into the growing season; encompasses the “Carex nigricans” and “Marsupella brevissima” orders in Brett et al. (1998).
AT/MHmmp	Carex spectabilis	Moist fragmental habitats: Carex spectabilis dominated communities occurring on stony parent materials featuring abundant moisture from melting snow; related to “Carex spectabilis” in Brett et al. (1998).
AT/MHmmp	Dry herbaceous	Alpine meadows dominated by dry alpine herbaceous species such as Lupinus arcticus, Phlox diffusa, Valeriana sitchensis, Carex species, Pedicularis racemosa, Hieracium gracile, and related species.
CWH/MH	Ledum-Sphagnum	Bog[3] wetland; features a dominant cover of Sphagnum species with Ledum groenlandicum, Drosera rotundifolia, Kalmia microphylla, Oxycoccus oxycoccos, and related species; related to “Ledum groenlandicum – Sphagnum association” in Klinka et al. (1997).
CWH	Myrica-Sphagnum	Bog wetland; features a dominant cover of Sphagnum species with Myrica gale, Carex species (C. sitchensis, C. lasiocarpa, etc.), Drosera rotundifolia and related species; similar to “Ledum groenlandicum – Sphagnum – Myrica gale subassociation” in Klinka et al. (1997).
CWH/MH	Carex fen	Fen wetland; features a dominant cover of Carex aquatilis, Carex sitchensis, Calamagrostis canadensis, and related species; encompassed by “Spiraea douglasii – Carex sitchensis order” in Klinka et al. (1997).
CWH	Spirea fen	Fen wetland; features a dominant shrub layer of Spiraea douglasii with Calamgrostis canadensis and varying amounts of Lonicera involucrata, Carex sitchensis, Salix lasiandra, and related species; related to “Spiraea douglasii – Carex sitchensis association” in Klinka et al. (1997).
CWH	Juncus-Typha	Marsh wetland; features a dominant cover of Juncus ensifolius with Myrica gale, Typha latifolia, and related species; related to “Juncus ensifolius – Typha latifolia association” in Klinka et al. (1997).
CWH	Typha	Marsh wetland; dominated by Typha latifolia with Scirpus microcarpus, Oenanthe sarmentosa, and related species; related to “Oenanthe sarmentosa – Typha latifolia association” in Klinka et al. (1997).
CWH	Equisteum	Shallow water wetland; aquatic community dominated by Equisetum species limited to lakeshore fringes; very limited distribution (e.g. Rainbow Park).
CWH	Menyanthes	Shallow water wetland; aquatic community dominated by Menyanthes trifoliata and related species; related to “Menyanthes trifoliate - Dulichium arundinaceum association” in Klinka et al. (1997).
CWH	Nuphar	Shallow water wetland; aquatic community dominated by Nuphar polysepala; related to “Nuphar polysepala association” in Klinka et al. (1997).
CWH	DrWi-Skunk cabbage	Swamp wetland; shrub dominated community on inundated alluvial sites featuring low vigour red alder, with Salix lasiandra, Salix sitchensis, Lysichitum americanum, Lonicera involucrata, Cornus sericea, Vibernum edule, and related species; related to “Lysichitum americanum – Salix lasiandra & sitchensis association” in Klinka et al. (1997).
CWH	Shrub carr	Swamp wetland; shrub dominated community featuring Alnus sinuata, shrubby red alder, Salix sitchensis, Spiraea douglasii, Carex obnupta, Calamagrostis canadensis, Lysichitum americanum, and related species.
CWH/MH	Sitka alder – Salmonberry avalanche	Frequently disturbed avalanche tracks dominated by Alnus sinuata; may include patches of Hm and Yc; typically a complex pattern of plant communities of the Alnus sinuata order. (Klinka et al. 1997).
CWH/MH	Valerian – Hellebore avalanche	Frequently disturbed avalanche tracks dominated by Valeriana sitchensis and related herbaceous species; typically a complex pattern of plant communities of the “Valeriana sitchensis” order. (Klinka et al. 1997)
MH	Ba – Copperbush avalanche	Infrequently disturbed avalanche tracks dominated by young conifer regeneration; typically a complex pattern of plant communities.
CWH/MH	Brushy talus	Blocky talus slopes dominated by Alnus sinuata, Sambucus racemosa and other brush species; not directly influenced by snow avalanching.
RV	Bedrock – vegetated	Lichen and bryophyte dominated bedrock in alpine/subalpine environments; featuring Rhizocarpon geographicum and Umbilicaria proboscidea; related to “Rhizocarpon geographicum order” in Brett et al. (1998); indicates relatively long period of time since significant disturbance.
TV	Talus - vegetated	Lichen and bryophyte dominated talus in alpine/subalpine environments; featuring Rhizocarpon geographicum and Umbilicaria proboscidea; related to “Rhizocarpon geographicum order” in Brett et al. (1998); indicates relatively long period of time since significant disturbance.

5. Maintaining the GIS Data

5.1 Updating to current conditions

The mapping for this project was done using 1994 air photos. As a result, the database should be updated to reflect changes that have taken place over the past nine years. The two major types of changes include those that have taken place to site units, and those that have taken place in structural stage of forested ecosystems.

5.1.1 Site unit changes

These relate to changes that have taken place to the mapped site units. The most significant of these include expansion of Urban, Ski Development, Golf Course, Gravel Pit, Reservoir, and Road Surface site units. Minor changes may also have taken place in the Buildings/parking, Exposed Soil, Gravel Bar, and Sports Facilities site units. An example of changes in Ski Development is shown in Figure 3 where new ski runs on Whistler Creekside are visible adjacent to mapped ski runs from 1994 air photos.

FIGURE 3. Recent ski runs not shown in mapped Ski Development site unit (mapped ski runs shown in purple).

The most accurate method to update the database is to obtain recent air photos when they become available, map changes which are evident from comparing old and new photos, digitize changes and append them to the GIS data, and update the attribute database. As an alternative, if the changed features are available as an accurate GIS database (e.g. mapped ski runs and gravel pits, development boundaries, etc.), they could be integrated into the TEM GIS database, followed by associated attribute database update.

5.1.2 Structural stage changes

The structural stage of forested ecosystems is a dynamic feature and continuously changing. For example, the 01 (HwBa – Step moss) site unit in the CWHms1 represents site conditions that result in a slightly dry to fresh soil moisture regime and medium soil nutrient regime. The vegetation that develops on this site varies depending on the time since the last disturbance (Figure 4). The structural stage of non-forested ecosystems is relatively stable within the time frame relevant to the applications of this data (e.g. Carex fens remain in a “herb” structural stage unless something changes in the basic site properties). An exception to this includes exposed soil units that eventually revegetate over time.

FIGURE 4. Example of structural stage changes that can occur on a CWHms1/01 site unit. Weeds and grasses represent the “herb” stage soon after disturbance (e.g. harvesting), while the “mature forest” stage occurs approximately 80-250 years after disturbance (image source: www.mainetreefoundation.org).

The structural stage changes that require updating are primarily associated with post-1994 harvesting that has taken place in the southwest portion of the RMOW (Figure 5). These can be updated in the GIS database using two approaches. The first is to use the same method using new air photos as described for site unit changes. New cutblock boundaries are typed on the new photos, digitized and appended to the GIS data, and attributes adjusted. In this case, only the attributes that relate to structural stage are changed (fuel loading classes, structural stage, stand composition modifier, significant pine composition). The other option is to obtain cutblock boundaries in digital format from the licensee or Ministry of Forests, then append and adjust the data as before.

FIGURE 5. Example of structural stage changes associated with recent harvesting. The hatched area is mapped “old forest” structural stage; the newly created “shrub/herb” stage of the recent cutblock is visible below. Given sufficient time, this will shift back to an old forest stage.

5.2 Updating over the long term

Maintaining structural stage as an integrated part of the TEM database over the long term creates data maintenance problems. In essence, the data becomes outdated as the stands age and structural stages change over time. As there are no stand age data, there is no way to shift structural stage to older classes over time. The best way to overcome this is to separate the dynamic structural stage from the more static site data. The delivered TEM database is designed with this in mind. A GIS database of site unit polygons only can be created through GIS processing. This involves running a “dissolve” of the original TEM database using the following fields:

POLY_NBR, SOURCE, BGCUNIT, ASP, SG, ECO1_DEC, ECO1_SS, ECO1_SM1, ECO1_SM2, ECO1_SM3, ECO2_DEC, ECO2_SS, ECO2_SM1, ECO2_SM2, ECO2_SM3, ECO3_DEC, ECO3_SS, ECO3_SM1, ECO3_SM2, ECO3_SM3, INSTAB, BASALT.

This will create a new GIS coverage of site unit polygons that will serve as a long term database of the more stable ecological components. The original digitized linework differentiated the “soft” structural stage lines from the “hard” site unit lines using unique feature codes. This facilitates error-checking of the dissolve coverage. Subsequent updates are only required for new polygons associated with development (e.g. urban, ski runs, etc.). A separate coverage of structural stage is created and maintained from the forest cover database available from the Ministry of Forests. Structural stage polygons are created using an algorithm that assigns the appropriate class according to attributes in the forest cover data (e.g. stand age, stand height, species composition, etc.). This coverage can then be overlain with the site unit coverage using GIS processing for planning applications. The structural stage coverage can be maintained be re-processing the algorithm as revised forest cover data becomes available. This approach is commonly used with large-scale operational TEM databases. It ensures that combined site and structural stage data remains current over the long term.

6. REFERENCES

Brett, R.B., K. Klinka, and H. Qian. 1998. Classification of high elevation, non-forested plant communities in coastal British Columbia. Forest Sciences Dept., The University of B.C.

Brooke, R.C., E.B. Peterson, and V.J. Krajina. 1970. The Subalpine Mountain Hemlock Zone. Subalpine vegetation in southwestern B.C., its climatic characteristics, soils, ecosystems and environmental relationships. Ecol. of West. North Amer. 2:147-349.

Green, R.N. and K. Klinka. 1994. A field guide to site identification and interpretation for the Vancouver Forest Region. Land Manag. Hnbk. No. 28. B.C. Min. For., Victoria, B.C.

Klinka, K., H. Qian, and A. Ceska. 1997. Provisional classification of non-forested plant communities in coastal British Columbia.

Meidinger, D.V. and J. Pojar (eds.). 1991. Ecosystems of British Columbia. Special Report Series No. 6, B.C. Min. For., Victoria, B.C.

Resources Inventory Committee (RIC) 1998. Standard for terrestrial ecosystem mapping in British Columbia. B.C. Res. Inc. Comm., Victoria, B.C.

RMOW 2002. Whistler Environmental Strategy.

TerraPro GPS Surveys 1998. Whistler recreation map. TerraPro Recmaps, Whistler, B.C. (1:30,000 colour map).

7. APPENDIX A: Database Dictionary – Resort Municipality of Whistler

Data Fields

Code

Description

AREA

Polygon area (m²)

PERIMETER

Polygon perimeter (m)

TER_

ArcGIS reference field

TER_ID

ArcGIS reference field

FCODE

ArcGIS reference field

TER_TAG

ArcGIS reference field

POLY_NBR

Polygon number

SOURCE

Data source

BGCUNIT

Biogeoclimatic unit (combined BGC zone/subzone/variant)

ASP

Aspect

FUEL_CR

Crown fuel loading class

FUEL_SU

Surface fuel loading class

FUEL_LD

Ladder fuel loading class

FUEL_AL

Combined fuel loading class

Site group

ECO1_DEC

1^st ecosystem component - % decile

ECO1_SS

1^st ecosystem component - site series

ECO1_SM1

1^st ecosystem component - 1^st site modifier

ECO1_SM2

1^st ecosystem component - 2^nd site modifier

ECO1_SM3

1^st ecosystem component - 3^rd site modifier

ECO1_STR

1^st ecosystem component - structural stage

ECO1_STD

1^st ecosystem component – stand composition modifier

ECO2_DEC

2^nd ecosystem component - % decile

ECO2_SS

2^nd ecosystem component - site series

ECO2_SM1

2^nd ecosystem component - 1^st site modifier

ECO2_SM2

2^nd ecosystem component - 2^nd site modifier

ECO2_SM3

2^nd ecosystem component - 3^rd site modifier

ECO2_STR

2^nd ecosystem component - structural stage

ECO2_STD

2^nd ecosystem component - stand composition modifier

ECO3_DEC

3^rd ecosystem component - % decile

ECO3_SS

3^rd ecosystem component - site series

ECO3_SM1

3^rd ecosystem component - 1^st site modifier

ECO3_SM2

3^rd ecosystem component - 2^nd site modifier

ECO3_SM3

3^rd ecosystem component - 3^rd site modifier

ECO3_STR

3^rd ecosystem component - structural stage

ECO3_STD

3^rd ecosystem component - stand composition modifier

INSTAB

Evidence of historic instability

PINE

Significant lodgepole pine composition

BASALT

Columnar basal present within or directly adjacent to polygon

Field Descriptions

Source

Code	Description
A	Air call – data recorded from low flying helicopter
G	Ground inspection plot – data recorded on plot cards from the ground
P	Photo interpretation – data interpreted from air photo
V	Visual inspection – data noted on air photos

Biogeoclimatic Unit (Zone/Subzone/Variant)

Code	Description
CWHms1	Southern Moist Submaritime Coastal Western Hemlock Variant
MHmm2	Leeward Moist Maritime Mountain Hemlock Variant
MHmmp2	Leeward Parkland Moist Maritime Mountain Hemlock Variant
ATc	Coastal Alpine Tundra Subzone

Aspect

Code	Name	Description
W	Warm	slopes >35% and between 135⁰ to 285⁰
C	Cool	slopes >35% and between 285⁰ to 135⁰
G	Gentle	slopes < 35%

Site Group [4]

Code	Name	Description
AH	Alpine heath	Heather dominated alpine heath site units
AK	Alpine krummholz	Alpine krummholz site units
AM	Alpine meadows	Dry to wet alpine/subalpine herbaceous meadow site units
AV	Avalanche	Snow avalanche site units
DR	Dry	Forested dry site units
FL	Floodplains	Forested floodplain site units
GC	Golf course	Golf course and sports field site units
IC	Ice	Glaciers and permanent snow site units
MP	Moist – poor	Forested moisture and/or nutrient enhanced – poor productivity site units
MR	Moist – rich	Forested moisture and/or nutrient enhanced – productive site units
PK	Parkland	Subalpine parkland and transition parkland site units
RO	Rock and talus	Bedrock, talus, recent moraines, and rubble site units
SK	Ski development	Ski developments including runs, lifts, and buildings
SO	Soil	Exposed soil site units
UR	Urban	Urban development site units
UT	Utilities	Utilities and transportation site units
WA	Water	Water units
WE	Wetlands	Wetland, swamp, and bog woodland site units
ZO	Zonal	Forested zonal (average moisture and nutrients) site units

Site Units

Note coding sequence:

01-19 : recognized site series in BEC system (Green and Klinka 1994)

20-29 : new forested site units (CWH/MHmm2)

30-40’s : wetland units (CWH/MHmm2)

50’s : avalanche tracks (all BGC units)

60-70’s : alpine/parkland units (ATc, MHmmp2)

Code	Site Group	Name	Comments
CWHms1 units
01	ZO	HwBa – Step moss	slightly dry to fresh/poor to medium sites (zonal)
02	DR	FdPl - Kinnikinnick	very dry/poor sites on bedrock or very thin soils
03	DR	FdHw – Falsebox	moderately dry/poor to medium sites on shallow and/or very coarse soils
04	MR	BaCw – Oak fern	slightly dry to fresh/rich sites
05	MR	HwBa – Queen’s cup	moist to very moist/poor to medium sites
06	MR	BaCw – Devil’s club	moist to very moist/rich sites
07	FL	Ss - Salmonberry	high bench floodplain sites
08	FL	Act – Red-osier dogwood	medium bench floodplain sites
09	FL	Act - Willow	low bench floodplain sites
10	WE	Pl - Sphagnum	wet/poor sparsely forested bog
11	MP	CwSs – Skunk cabbage	wet/medium to rich sites on poorly drained soils
22	FL	CwSs - Red-osier dogwood - Skunk cabbage	wet/rich sites on poorly drained alluvial soils
23	WE	Cw - Spirea	very wet/medium to rich swamp forest
20	DR	Cw – Fern bluffs	dry to moist/poor to medium sites on forested bluffs and cliffs (extreme microsite variation)
MHmm2 units
01	ZO	HmBa - Blueberry	fresh/poor to medium sites (zonal)
24	PK	HmYc – Blueberry – Mountain heather	fresh/poor to medium, late snow-lie sites with open canopy forests
25	ZO	Bl-Rhododendron	fresh/poor to medium, warm-aspect sites with strong subcontinental features
02	DR	HmBa - Mountain-heather	slightly dry/poor to medium sites on bedrock or very shallow soils
03	MR	BaHm – Oak fern	fresh/rich sites
04	MR	HmBa - Bramble	moist/poor to medium sites
05	MR	BaHm - Twisted stalk	moist/rich sites
06	MP	HmYc – Deer cabbage	very moist/poor to rich sites with open canopy forests
07	MP	YcHm - Hellebore	very moist/medium to rich sites with open canopy forests
08	MP	HmYc - Sphagnum	wet/poor sparsely forested bog
09	MP	YcHm - Skunk cabbage	wet/medium to rich sites on poorly drained soils with open canopy forests
21	DR	Yc – Rhacomitrium bluffs	scrubby bluff sites
ATc and MHmmp2 units
60	RO	Penstemon - Juniper	Dry lithic: steep lithic sites with talus and rock
61	AK	Bl -Phyllodoce	Dry lithic: krummholz
62	PK	Bl – Black huckleberry	Tree islands: closed forest stands, generally on steep, snow-shedding slopes
63	AH	Cassiope - Phyllodoce	Heath: alpine heather-dominated heath
64	AH	Hm - Cassiope	Heath: upper MH heath with dwarf Hm, Bl
65	PK	Parkland - heath	Parkland: complex of tree islands with heath matrix
66	PK	Parkland – dry herbaceous	Parkland: complex of tree islands with dry herbaceous matrix (Phlox, Pedicularis, Valeriana, etc.)
67	PK	Parkland – lush herbaceous	Parkland: complex of tree islands with lush herbaceous matrix (Valeriana, Heracleum, Veratrum, Lupin, etc.)
68	AM	Caltha - Leptarrhena	Very moist to wet, moisture collecting: on seepage and moisture collecting sites (encompasses Philonotis order)
69	AM	Valeriana meadows	Moist to very moist slopes: lush moist herbaceous meadows
70	WE	Carex - Eriophorum	Wetlands: includes the group of sedge/bryophyte communities that occupy water collecting subalpine/alpine basins (Eriophorum order)
71	AM	Carex nigricans	Snow basins: encompasses all snow basins; Marsupella included in this complex as it occurs as small depressions in more extensive C. nigricans community.
72	AM	Carex spectabilis	Moist fragmental: fresh to moist stony sites
73	AM	Dry herbaceous	Carex dominated alpine meadows

Non/Sparsely Forested Units
Wetlands
30	WE	Ledum-Sphagnum	Bog¹: Ledum groenlandicum.-Sphagnum (Klinka et al 1997)
31	WE	Myrica-Sphagnum	Bog: similar to Carex-Myrica gale (Klinka et al 1997) but more bog-like
32	WE	Carex fen	Fen: not specifically in (Klinka et al 1997) but fits in Spirea Order
33	WE	Spirea fen	Fen: Spirea douglasii.- Carex sit. (Klinka et al 1997)
34	WE	Juncus-Typha	Marsh: close to Juncus ens.-Typha lat. (Klinka et al 1997)
35	WE	Typha	Marsh: Typha lat. (Klinka et al 1997)
36	WE	Equisteum	Shallow water: very limited; lakeshore fringe
37	WE	Menyanthes	Shallow water: similar to Menyanthes-Dulichium (Klinka et al 1997)
38	WE	Nuphar	Shallow water: Nuphar poly. (Klinka et al 1997)
39	WE	DrWi-Skunk cabbage	Swamp: Lysichitum-Salix (Klinka et al (1997); inundated alluvial site
40	WE	Shrub carr	Swamp: not specifically in (Klinka et al 1997) but fits in Spirea Order
Avalanche tracks
51	AV	Sitka alder – Salmonberry avalanche	shrub dominated avalanche tracks
52	AV	Valerian – Hellebore avalanche	herb dominated avalanche tracks
54	AV	Ba – Copperbush avalanche	young conifer dominated avalanche tracks
55	AV	Brushy talus	talus slopes dominated by shrub species
Non Vegetated
BU	UR	Buildings, parking, etc.
CB	SO	Cutbank
ES	SO	Exposed soil	areas of recent disturbance, such as mud slides, debris torrents, and unspecified human-made disturbances
GB	SO	Gravel Bar
GC	GC	Golf course
GL	IC	Glacier, permanent snow
GP	SO	Gravel pit
LA	WA	Lake
MN	RO	Moraine	Recently deglaciated glacial moraine
OW	WA	Shallow Open Water	A wetland composed of permanent shallow open water less than 2 m deep and lacking extensive emergent plant cover (may occasionally dry up)
PD	WA	Pond	A small body of water greater than 2 m deep, but not large enough to be classified as a lake
PL	UT	Powerline
PN	IC	Permanent snow
RE	WA	Reservoir
RI	WA	River
RN	UT	Railway Surface
RO	RO	Bedrock
RV	RO	Bedrock – vegetated	Lichen and bryophyte dominated bedrock in the alpine (e.g. Rhizocarpon geographicum, Umbilicaria proboscidea)
RU	RO	Rubble	Common in alpine areas, on ridgetops, gentle slopes and flat areas due to the effects of frost heaving
RZ	UT