Year: 1998
Abstract:
In managed forests, riparian buffer strips are maintained primarily to protect water quality. They are also thought to safeguard diverse plant and animal communities. The value of buffer strips to area-dependent and edge-sensitive forest songbirds, however, is largely unknown. Numbers of one such species, the Ovenbird (Seiurus aurocapillus), have declined in narrow buffers following upland timber harvest I assessed the conservation potential of riparian buffer strips for Ovenbirds in Alberta's boreal mixed-wood forest. I measured abundance, territory characteristics, and pairing success in 20m, 100m, and 200m buffers, one year before and one year after upland clearcutting. Following timber harvest, Ovenbirds were absent from 20m buffer strips. Harvesting did not influence abundance, territory size, or pairing success in 100m or 200m buffers. Territories narrowed in both 100m and 200m buffers, though the response was significant only in the latter. Post-harvest territory position did not change in 200m buffers, but territories in 100m strips shifted lakeward, including more habitat adjacent to the riparian edge than before harvest. This positional adjustment may have resulted in changes to the structure of Ovenbird habitat. Further research is necessary to determine whether short-term results reflect long-term effects.
