Validité de la carte forestière pour décrire les habitats fauniques à l'échelle locale : une étude de cas en Abitibi-Témiscamingue

Abstract

Wildlife habitats may be described at low cost using forest maps. Because the main objective of forest maps is to estimate the wood volume over large areas whereas wildlife applications often require accurate data at the stand level, their accuracy may not be acceptable. During a study of marten (Martes americana) habitat, we ground-checked 1:20 000 forest maps in two areas (70 and 123 km2) in the Abitibi-Témiscamingue region. Surveys involved 72 stands : 44 black spruce (Picea mariana), 18 jackpine (Pinus banksiana), 5 mixed deciduous, and 5 deciduous stands. The dominant tree species group was accurate in most black spruce (43 over 44) and jackpine stands (16 over 18). For mixed and deciduous stands, gross errors were noted in the cover type and the dominant tree species group. The cover density on the map was poorly related to the crown closure measured on the ground. There was a closer agreement between height classes on the map and actual height. In black spruce stands, the age class enabled discriminating between young (30- and 50-years classes) and old stands (90- and 120-years). We conclude that caution is needed when using forest maps to describe wildlife habitats, and that the accuracy of the mapped attributes should be checked before using such data at local scales. Key words: forest maps, forest survey, GIS, ground check, wildlife habitat