7.0 Summary of Methods and Standards

7.1 Summary

The Terrestrial Ecosystem Mapping methodology integrates the climatic, vegetative, and physical attributes of British Columbia's diverse ecosystems into one map product. The methodology emphasizes the relationship between topographic, terrain and soil features of the landscape, and the vegetation and vegetation development stages of each ecosystem unit. Recommended for ecosystem mapping at scales of 1:5000 to 1:50 000, the methodology describes standards for ecosystem unit development, symbology, sample types, mapping procedures, required data attributes, legends, and summaries of potential interpretive products.

In order to achieve consistency in the products of TEM mapping, this methodology has been prepared for and approved by the Resources Inventory Committee for use in British Columbia. The goal is to ensure the delivery of high quality, consistent map products through standards, correlation and quality assurance.

A three-level classification hierarchy of ecological units is embedded within the methodology. At the broadest level, both ecoregion and biogeoclimatic classifications are utilized. Site units and vegetation developmental units depict terrestrial ecosystems at a more detailed level. At these detailed levels, individually mapped polygons are described by ecosystem units, which are composed of site series, site modifiers and structural stage. Each polygon may contain up to three ecosystem units; the proportions of the units are indicated by deciles preceding each site series (see Figure 3.8).

Mapping terrestrial ecosystems is an integrative process where specialists from each of the major disciplines combine their expertise to capture the spatial representation of ecosystems in a project area. The approach to mapping begins with consideration of the existing classifications for the area (ecoregion, biogeoclimatic, and site), and their relationships to topography, terrain, and developmental patterns on the landscape. All related land information data and maps are collected and analyzed for their usefulness with the mapping. Once appropriate imagery is obtained, ecosystem map polygons are delineated.

Ecosystems are pre-typed on the photos, and subsequently checked in the field. Field sampling provides the information required to confirm biogeoclimatic unit boundaries, describe the site series as they occur within the study area, classify new ecosystems, and describe structural and vegetation characteristics of younger structural stages. To maximize the efficiency of the field crews, the methodology recommends developing a detailed sampling plan to guide field work. Field data are of three types: 1) full plots; 2) ground inspections; and 3) visual checks. For most terrestrial ecosystem projects these sampling types should follow the ratios outlined for survey intensity level 4 (see Table 6.3). However, in some cases and for special purposes, other survey intensity levels and sampling ratios may be used.

Ecosystem mapping provides spatial data for a multitude of ecological interpretations. Since the final map is digital, in a geographic information system, the attribute files can be accessed and models developed to display or summarize interpretive information. In addition, the polygon-based data can be integrated with other resource inventories to develop even more interpretations. As the TEM provincial database is developed, it will facilitate many aspects of natural resource management.

Ecosystem mapping in British Columbia has evolved from several similar but disparate methods to what is now called Terrestrial Ecosystem Mapping. TEM itself has undergone a rapid evolution in the past few years, but the intent now is to stabilize the methodology for several years. There will always be new ideas on various aspects of mapping ecosystems. The intent of this standard is not to stop development, but to control it so that a provincial database of ecosystem mapping can be developed and used for management interpretations wherever required in BC.

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