Moose browsing, understorey structure and plantspecies composition across spruce budworm-inducedforest edges
Abstract:
Investigating the impact of forest edges created by insect outbreaks on moose browsing severity, understorey structure, and species composition, this study sheds light on their intricate relationships. Conducted in the balsam fir-dominated boreal forest of Cape Breton Highlands National Park, Nova Scotia, Canada, the research employed meticulous methods. Sampling understorey vegetation involved contiguous 1-square-meter quadrats along forested edges of insect outbreak areas, encompassing variables like moose browsing damage, sapling density, plant composition, and diversity. Utilizing generalized additive mixed models, the study discerned patterns across the disturbed area-forest gradient. Randomization tests and wavelet analyses were applied to unveil the extent of edge/forest influence and the location of abrupt changes along the edge-to-interior gradient. Notably, the results highlighted a stark difference in sapling characteristics between the disturbed area and adjacent intact forest, influencing forest regeneration dynamics. The study unraveled how the combined effects of a small insect defoliator and a large ungulate can substantially alter landscape dynamics. The implications of severe moose browsing preventing forest regeneration underscore the persistence of forest edges that would normally recede after an insect outbreak collapse. Moreover, the study uncovered nuanced distinctions in understorey vegetation responses, revealing that abrupt changes occurred even in areas where plant communities did not significantly differ from reference forest and disturbed zones. This research offers vital insights into the intricate interplay of forest edges, disturbance, and herbivore interactions.
Authors: Caroline M.A. Franklin & Karen A. Harper
Published on Journal of Vegetation Science on 30 November 2015
Doi: 10.1111/jvs.12385
Investigating the impact of forest edges created by insect outbreaks on moose browsing severity, understorey structure, and species composition, this study sheds light on their intricate relationships. Conducted in the balsam fir-dominated boreal forest of Cape Breton Highlands National Park, Nova Scotia, Canada, the research employed meticulous methods. Sampling understorey vegetation involved contiguous 1-square-meter quadrats along forested edges of insect outbreak areas, encompassing variables like moose browsing damage, sapling density, plant composition, and diversity. Utilizing generalized additive mixed models, the study discerned patterns across the disturbed area-forest gradient. Randomization tests and wavelet analyses were applied to unveil the extent of edge/forest influence and the location of abrupt changes along the edge-to-interior gradient. Notably, the results highlighted a stark difference in sapling characteristics between the disturbed area and adjacent intact forest, influencing forest regeneration dynamics. The study unraveled how the combined effects of a small insect defoliator and a large ungulate can substantially alter landscape dynamics. The implications of severe moose browsing preventing forest regeneration underscore the persistence of forest edges that would normally recede after an insect outbreak collapse. Moreover, the study uncovered nuanced distinctions in understorey vegetation responses, revealing that abrupt changes occurred even in areas where plant communities did not significantly differ from reference forest and disturbed zones. This research offers vital insights into the intricate interplay of forest edges, disturbance, and herbivore interactions.
Authors: Caroline M.A. Franklin & Karen A. Harper
Published on Journal of Vegetation Science on 30 November 2015
Doi: 10.1111/jvs.12385