​Forest structure and composition at young fire and cut edges in black spruce boreal forest​

Abstract: We compared structure and composition at forest edges created by wildfire and clear-cutting in black spruce (Picea mariana(Mill.) BSP) dominated boreal forest in northwestern Quebec. Forest structure and plant species composition were sampled along transects perpendicular to eight 3- to 4-year-old fire edges and eight 2- to 5-year-old cutedges. Significance of edge influence was assessed by comparing mean values at different distances from the edge tothe range of variation in interior forest. The influence of clearcut edges was minimal, generally extending only 5m from the edge, and included greater log density and different species composition, compared with interior forest. At fire edges, prominent responses to edge creation included increased snag density and lower moss cover, compared with interior forest, extending up to 40 m into the forest. This initial structural change was likely due to partial burning ex-tending into the forest. Overall, fire edges had more snags and a different species composition than cut edges. Our hypothesis that edge influence is more extensive at fire edges than at cut edges was supported for overstory andunderstory structure, but not for species composition. We suggest that there is a need for management to consider the cumulative effect of the loss of fire edges on the landscape.

Authors: Karen A. Harper, Daniel Lesieur, Yves Bergeron, and Pierre Drapeau

Published on the NRC Research Press Web site at http://cjfr.nrc.caon13 February 2003

DOI: 10.1139/X