The impact of moose on forest regeneration following disturbance by spruce budworm in the Cape Breton Highlands, Nova Scotia, Canada.

摘要

I studied sites disturbed 23-33 years ago by spruce budworm ( Choristoneura fumiferana) that have been subjected to severe browsing by moose (Alces alces) in a region historically dominated by balsam fir (Abies balsamea) forest, on Cape Breton Island, Nova Scotia, Canada. Single-factor analysis of variance was used to test for differences in composition and structural characteristics among site types derived from a supervised classification. I used general linear modelling and multivariate redundancy analysis to examine the influence of moose abundance and environmental variables, on post-budworm regeneration. Results show post-budworm regeneration is varied and that severe browsing by moose has stalled secondary succession in the stand initiation stage. The data suggest the emergence of an alternate stable state as the result of the compounding effects of budworm-caused mortality and intense herbivory by moose. This study provides insight into the interaction between two prevalent natural disturbances in eastern Canadian balsam fir forests.