Cumulative effects of climate and landscape change drive spatial distribution of Rocky Mountain wolverine (Gulo gulo L.). Issue 21 (21st September 2017) - Heim, Nicole
Abstract: Contemporary landscapes are subject to a multitude of human‐derived stressors. Effects of such stressors are increasingly realized by population declines and large‐scale extirpation of taxa worldwide. Most notably, cumulative effects of climate and landscape change can limit species' local adaptation and dispersal capabilities, thereby reducing realized niche space and range extent. Resolving the cumulative effects of multiple stressors on species persistence is a pressing challenge in ecology, especially for declining species. For example, wolverines ( Gulo gulo L.) persist on only 40% of their historic North American range. While climate change has been shown to be a mechanism of range retractions, anthropogenic landscape disturbance has been recently implicated. We hypothesized these two interact to effect declines. We surveyed wolverine occurrence using camera trapping and genetic tagging at 104 sites at the wolverine range edge, spanning a 15, 000 km 2 gradient of climate, topographic, anthropogenic, and biotic variables. We used occupancy and generalized linear models to disentangle the factors explaining wolverine distribution. Persistent spring snow pack—expected to decrease with climate change—was a significant predictor, but so was anthropogenic landscape change. Canid mesocarnivores, which we hypothesize are competitors supported by anthropogenic landscape change, had comparatively weaker effect. Wolverine population declines and range shifts likely result from climate change and landscape change operating in tandem. We contend that similar results are likely for many species and that research that simultaneously examines climate change, landscape change, and the biotic landscape is warranted. Ecology research and species conservation plans that address these interactions are more likely to meet their objectives. Abstract : Evaluating the relative importance of the various direct and indirect effects of human disturbance is a current and pressing challenge for conservation biologists, particularly for those species with home ranges spanning a variety of ecosystem types and land management directives. We show that the cumulative effects of climate, landscape change, and shifts on biotic communities best‐explained wolverine occurrence in the heart of the Canadian Rocky Mountains. Our results emphasize the need for an integrative conceptual framework to identify and evaluate multiple stressors for effective conservation and recovery planning.