Newby J.R.,University of Montana |
Scott Mills L.,University of Montana |
Ruth T.K.,Wildlife Conservation Society |
Pletscher D.H.,University of Montana |
And 4 more authors.
Biological Conservation | Year: 2013
An understanding of how stressors affect dispersal attributes and the contribution of local populations to multi-population dynamics are of immediate value to basic and applied ecology. Puma (Puma concolor) populations are expected to be influenced by inter-population movements and susceptible to human-induced source-sink dynamics. Using long-term datasets we quantified the contribution of two puma populations to operationally define them as sources or sinks. The puma population in the Northern Greater Yellowstone Ecosystem (NGYE) was largely insulated from human-induced mortality by Yellowstone National Park. Pumas in the western Montana Garnet Mountain system were exposed to greater human-induced mortality, which changed over the study due to the closure of a 915km2 area to hunting. The NGYE's population growth depended on inter-population movements, as did its ability to act as a source to the larger region. The heavily hunted Garnet area was a sink with a declining population until the hunting closure, after which it became a source with positive intrinsic growth and a 16× increase in emigration. We also examined the spatial and temporal characteristics of individual dispersal attributes (emigration, dispersal distance, establishment success) of subadult pumas (N=126). Human-caused mortality was found to negatively impact all three dispersal components. Our results demonstrate the influence of human-induced mortality on not only within population vital rates, but also inter-population vital rates, affecting the magnitude and mechanisms of local population's contribution to the larger metapopulation. © 2012 Elsevier Ltd.
Scott J.H.,Bridger Teton National Forest |
Helmbrecht D.J.,Bridger Teton National Forest |
Thompson M.P.,Bridger Teton National Forest
USDA Forest Service - Research Note RMRS-RN | Year: 2014
Characterizing wildfire risk to a fire-adapted ecosystem presents particular challenges due to its broad spatial extent, inherent complexity, and the difficulty in defining wildfire-induced losses and benefits. Our approach couples stochastic wildfire simulation with a vegetation condition assessment framework to estimate the conditional and expected response of vegetation condition to wildfire. We illustrate application of this framework for the Bridger-Teton National Forest (BTNF) in western Wyoming, USA. Results illustrate generally positive net effects of wildfire on vegetation condition across the major forested biophysical settings on the Forest, supporting the notion that wildfire can play a role in restoring or enhancing the ecological integrity of landscapes affected by fire exclusion. These results carry significant implications for future management of wildfire on the BTNF, and highlight temporal relationships between short-term incident response and long-term ecological integrity. © 2014, USDA Forest Service. All rights reserved.