6.5 Final Mapping

Before final photo typing and map labelling, all relevant information should be at hand, including pre-typed air photos, field data, and other existing maps for the area (e.g., ecosection, biogeoclimatic, forest cover, terrain, soils, bedrock geology, topographic, and satellite imagery). Typing should be corrected based on field surveys and the synthesis of field inspection data. Bioterrain and ecosystem map unit lines completed during pre-typing should be adjusted on the photos after field work is completed.

Biogeoclimatic boundaries should already have been refined to project scale from Ministry of Forests maps (1:500 000 to 1:100 000 scales) during pre-typing, assessed during field sampling, and if significant changes are anticipated, discussed with the Regional Ecologist. The boundaries may then be further refined, using sampling and observations along ground transects, as well as other sources of information such as forest cover maps. Special attention should be paid to data from zonal sites (Meidinger and Pojar, 1991), and vegetation and soil characteristics should be compared against subzone/variant descriptions in regional field guides. Distribution of other ecosystems can also be useful in refining biogeoclimatic boundaries. Overstory forest species can help guide the placement of subzone boundaries for certain subzones (e.g., ICH vs. ESSF).Where ground information is lacking, subzone/variant lines may be extrapolated from known elevational boundaries elsewhere in the study area. Because transitions from one biogeoclimatic unit to another are often gradual, adjustments to biogeoclimatic map unit boundaries to make them follow ecosystem map unit boundaries should only be made if the lines are nearly coincident. Any proposed change to existing biogeoclimatic boundaries must be approved beforehand by the appropriate Ministry of Forests, Regional Ecologist.

Adjusting ecosection boundaries to follow biogeoclimatic boundaries and ecosystem map unit boundaries can also be done during this final stage of mapping. Ecosection boundaries are not distinct, especially at medium and large scales of mapping. Such generalization of ecosection boundaries to follow biogeoclimatic and ecosystem map unit boundaries must be done to prevent the creation of polygon slivers.

Final labelling and attributing of ecosystem unit polygons is completed through the re-evaluation of polygons on the photos (including the bioterrain information) and examination of field data and other sources of information (e.g., forest cover maps may be helpful in determining structural stage). An ecosystem unit polygon may contain up to three ecosystem units and the percentage of the polygon occupied by each component is estimated. Refer to Section 3.0 for more detail on these mapping standards.

Where ecosystem mapping has been completed on adjacent mapsheets, border matching should be carried out during this final mapping stage.

During the final photo typing, the attributes for the polygon database should be assessed and entered. The recommended approach is to first transfer the photo typing to the base map, and then to assign polygon numbers and labels and create the attribute file. This approach is preferred because the topographic information on the base map allows for better integration of biogeoclimatic and ecosystem unit boundaries. Base maps also provide a broader landscape view of the study area, allowing for better delineation of biogeoclimatic boundaries than can be done on individual air photos. Attribute data is entered using ecosystem and terrain database formats available on the TEM website (see Appendix B) and should be provided digitally in ArcInfo compatible format. his database will then contain all the data required for producing the final map and any interpretive map products. The database should be reviewed to ensure it is error-free. Common problems are missing information, deciles not adding up to 10, and incorrect codes. An input program with validation routines will soon be available.

An alternate approach is to record polygon data in an attribute file before photo typing has been transferred to a base map. In this approach, the air photo number and a tentative polygon number must be assigned to each polygon. This should only be used for small project areas, occurring within one biogeoclimatic unit.

Once polygon labelling and attribute coding is completed, a thorough edit of the database and map against the original air photo polygons is essential. A digital map and attribute file should be produced as a final product. Digitizing may be done directly from air photos or from the plotted mylar map. A final edit of the digital map against the plotted map and/or air photos is also necessary.

The final map legend should be produced according to the standards described in Section 5.0. The content of an expanded legend is client-driven, but should be specified at the outset of a project to ensure the appropriate data is collected.

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