Responses by birds to group retention in coastal temperate forests on Vancouver Island, British Columbia

摘要

Group retention is a new forest harvesting technique designed to sustain biodiversity and mitigate concerns regarding clearcut logging of old-growth. It is characterized by retained forest patches that vary in number, size, spatial arrangement, and habitat attributes. I used birds to compare community composition and species abundance among clearcut, group retention, and uncut forest treatments, and evaluated speciesu27 responses to percentage retention. Group retention retained more bird species typical of uncut forests than did clearcuts. Probability of occurrence of sever al forest-dependent species was related to percentage retention, patch size, and various habitat attributes. I used an indicator value method to identify species for effectiveness monitoring. Eight forest-dependent birds were significant indicators of uncut forests, and five accounted for a large proportion of the uncut forest-bird community. My results confirm that group retention has fewer negative effects on forest-dependent birds than clearcuts do, and monitoring of indicators can be applied effectively.