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Climate-mediated wildfire disturbance to a mammal community within protected temperate coniferous forests

University of British Columbia

Climate disruption is anticipated to impact global biodiversity in the twenty-first century, in part by altering the frequency and intensity of natural disturbances. Wildland fires are climate-mediated disturbances that are increasing in frequency and intensity across western North American coniferous forests due to atmospheric warming and reduced summer precipitation. Coupled climate-fire models predict that climate is driving novel wildfire regimes in this system, but the landscape-level effects of increasing fire size and intensity of burns on wildlife remain unknown. The intermediate disturbance hypothesis suggests that species diversity is maximized when ecological disturbance regimes are moderate through a trade-off between colonization and competitive exclusion. If this hypothesis describes diversity-disturbance relationships in the North Cascades mountains of Canada and the United States, I expected that areas subject to fires of larger extent and greater severity than the historical norm will have reduced species diversity. To test this prediction at the landscape scale, I sampled mammal activity using passive camera traps deployed under a probabilistic sampling design, stratified across land cover type and fire history. I used these data to assess the impact of fire severity, time since fire, and fire extent on mammal species richness. I found that high mammal community diversity can persist following burns of high severity. I also found that the relationship between mammal diversity and wildfire disturbance deviates from the expected unimodal peaked pattern predicted by the intermediate disturbance hypothesis.

Text

2019-06-03

Attribution 4.0 International

http://hdl.handle.net/2429/70471

Zoology

University of British Columbia

UBCV

http://creativecommons.org/licenses/by/4.0/