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6.6 Interpretive Mapping

The polygon attribute files should contain a complete set of core attributes (Table 4.1) plus any project-specific attributes. The full capability of the ecosystem maps is realized when all the data is compiled in GIS. Users can produce maps colour-themed for any number of purposes, as well as outputting summary statistics.

Interpretive maps can be in many forms (see Table 4.2). They may simply be maps combining specific attributes to display broader management units, or they may be the result of an algorithm combining many attributes in the database. Examples of interpretive products include maps with any of the following themes: Two example algorithms are presented, one for the site productivity of the Dog Creek project area (Table 6.7); and one for habitat suitability for Mountain Goats (Table 6.8). The resulting maps are presented in Figure 6.5 and Figure 6.6.

The information in Table 6.7 is used with the attribute database to determine an area-weighted site index average for each polygon that results from an overlay of the ecosystem map with the forest cover map. The site index value for the dominant tree species in each resulting ecosystem/forest cover polygon is determined from the ratings table. Polygons with the same site index class are then grouped together for the final map.

Table 6.7Ratings table for site productivity of Dog Creek TEM project
IDF dk3
Site Series
Tree Species
Code
Name

FdPlSx
LPFdPl - Pinegrass - Feathermoss 1518
DKFd - Juniper - Kinnikinnick 1212
DJFd - Juniper - Peltigera 1215
DWFd - Bluebunch wheatgrass - Needlegrass 12
DMFd - Feathermoss - Step moss 1515
DPFd - Pinegrass - Aster 1515
SRSxwFd - Prickly rose - Sedge 181818
SSSxwFd - Prickly rose - Sarsaparilla 181818
SHSxw - Horsetail - Glow moss 1815
Notes: Values for tree species in table are site index @ age 50 (breast height age).Assumptions for site productivity interpretation: SIBEC table results (BC Ministry of Forests, 1997) apply to study areasite productivity for a polygon is determined by site series and leading tree species combination site index classes will adequately represent the variability

In developing most interpretations, the mapper has two requirements: a "ratings" table, where the values for selected attributes (e.g., site series) are tabulated; and a set of assumptions. For the "site productivity for forestry" interpretation, Table 6.7 is the ratings table. The assumptions for the analysis are appended to the table.

Figure 6.5Site productivity interpretive map for portion of Dog Creek TEM project


The "Mountain Goat suitability" interpretive map is shown in Figure 6.6 The ratings table and assumptions are presented in Table 6.8.
Table 6.8Ratings table for Mountain Goat suitability
Notes: Habitat suitability in Figure 6.6 was determined by calculating a weighted average of food and security within each polygon.
Security habitat was weighted 4:1 over feeding habitat.
Subsequently, all polygons with security ratings less than moderately high were assigned a suitability rating of nil.
Figure6.6Habitat suitability interpretive map for Mountain Goat

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