Community-level response of birds to burned and salvage-logged forests (Alberta).

摘要

Wildfire is the largest natural disturbance agent within the boreal forest. Understanding how wildlife respond to natural disturbances is important for conservation and to forest companies committed to sustainable forest management. This study monitored the forest bird community the first 3-years (1999–2001) following a wildfire, near Chip Lake, in west-central Alberta. The design included study sites within burned/unharvested (Leaves), burned/salvage-logged (Salvages), and unburned (Controls), deciduous-dominated mixedwood forest. By the second and third year post-fire, measures of songbird abundance and species richness were significantly higher within Leave treatments. Measures of relative reproductive activity indicated no difference or significantly higher indices for several species within burned forests. Similarity indices identified moderate overlap in bird communities between Leave and Control treatments, and suggested increased similarity over time; whereas divergence in similarity was indicated for bird communities in Salvage and Control sites. Many cavity-nesting species used natural cavities created by the fire, however the condition of the forest before disturbance may be very important, as many individuals used broken-top snags and/or snags in an advanced state of decay. This study suggests older-aged, burned forests provide a unique and valuable habitat for many breeding bird species, the quality of which is significantly diminished through salvage-logging. Forest management should recognize the importance of early post-fire habitat by maintaining unsalvaged areas throughout the landscape, as part of a coarse-filter approach to biodiversity conservation.