Influence of stand size on pattern of live trees in mixedwood landscapes following wildfire

Abstract

Burned areas and patches of residual live trees were mapped from post-fire aerial photographs of 168 mixedwood stands (a total of 9367 ha), in eight large wildfires in the boreal forest of northern Alberta. The stands were stratified into three size classes: small (<10 ha), medium (10–60 ha), and large (>60 ha).We described the area occupied by single live residual trees, unburned patches of live trees and partially burned patches of live trees within these mixedwood stands. Although results from individual stands were highly variable, there was proportionally more area covered by live residual trees in large fire-killed stands compared to medium stands, which in turn had proportionally more than small stands. For most sizes and types of live tree patches, larger fire-killed stands had a greater proportion of live tree area compared to smaller stands. Results of this study are compared to similar studies and current harvest guidelines. We outline the amount and distribution of live tree patches that would be needed to create harvest areas similar to that found after wildfire. Key words: natural disturbance, wildfire, live residual trees, ecosystem management, forest harvest pattern, boreal mixedwood