PARENT SESSION
Poster Session 2: Forest Ecology
Monday, August 8, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

Effects of spatial configuration of habitat patches on the abundance of cavity nesting birds in boreal forest of Quebec, Canada.

Gagné, Caroline^{1, 2}, Drapeau, Pierre^{1, 2}, Imbeau, Louis^{1, 2}, ¹ Groupe de recherche en écologie forestière interuniversitaire, Montréal, Québec, Canada² Chaire industrielle CRSNG UQAT-UQAM en aménagement forestier durable, Rouyn-Noranda, Québec, Canada

ABSTRACT- Aggregated and dispersed clear-cuts are two management strategies that create an artificially fragmented landscape and a temporary loss of habitat for late-successional species; those who are dependent on dead wood for nesting and foraging are particularly vulnerable. The objectives of our study are to (1) determine whether the occurrence and abundance of eight cavity nesting bird species are influenced by the spatial configuration of habitat patches (leave strips from aggregated clear-cuts vs residual blocks from dispersed clear-cuts) and (2) determine what habitat variables, at local and landscape scales, influence the occurrence and abundance of these species. We sampled bird species using point count and playback methods. A total of 160 sites were located in both residual forest types. Some of our results show that large woodpeckers (Northern Flicker, Colaptes auratus) are significantly more abundant in leave strips of aggregated clear-cuts than in residual blocks of dispersed clear-cuts. For large secondary hole users, these results show that in landscapes with high level of fragmentation, nesting sites excavated by woodpeckers may not decline in proportion to habitat loss because large excavators are more preponderant in leave strips of aggregated clear-cuts. On the other hand, we expect that the occurrence and abundance of birds shall vary according to the basal area and the deterioration state of dead trees and to the extent of mature forest around each sampling point. Finally, our study suggests that leave strips of aggregated clear-cuts should be permanently preserved from logging because they are used by many late-successional species and they represent the last fragments of mature forest in intensively managed landscapes.

Key words: cavity nesting birds, aggregated clear-cuts, dispersed clear-cuts, spatial configuration of habitat patches