Thesis
Evaluating the effects of mountain lion kills on the nitrogen cycle in the Greater Yellowstone ecosystem
Washington State University
Master of Science (MS), Washington State University
05/2020
DOI:
https://doi.org/10.7273/000004065
Handle:
https://hdl.handle.net/2376/125098
Abstract
Apex felids play a key role in ecological communities through the direct and indirect effects of predation and the temporal and spatial distribution of animal carcasses. Carcasses directly influence a wide range of ecological processes, both above and below ground. These effects include provisioning of scavenger communities, altering of microbial and decomposer communities, and changes to ecosystem dynamics. A decomposing animal carcass is a nutrient-rich resource that alters soil biochemical processes, which can have significant effects on plant communities. Apex felid predators have been shown to positively affect scavenger and invertebrate communities; however, the effects of felid-produced animal carcasses on soil and plant nitrogen (N) composition have not been examined. Here we documented the relationship between ungulate carcasses created by mountain lions (Puma concolor) on soil dynamics and plant forage quality in the Greater Yellowstone Ecosystem. Our examination of 172 carcasses revealed that carcass decomposition significantly altered soil N composition over a 3 year period, which resulted in [delta]15N enrichment of soils and nearby plants. To highlight the contribution of nutrient rich ungulate carcasses to trophic processes we used 15 years of GPS data to predict areas of high carcass deposition, and data on kill rates and density to quantify overall deposition rates. Mountain lion kills were concentrated in fairly restricted areas of the landscape with favorable conditions for kills (e.g., lower elevation, southernly aspects, steeper slopes and forested cover types). We estimated the total ungulate carcass biomass in our 2,734 km2 study area as 120,530 kg/year. Taken together, our results reveal the long lasting effects of ungulate carcasses created by mountain lions on soil and plant chemistry, and suggest that mountain lions, through their actions as top predators, create numerous 'hotspots' of nutrient inputs from carcasses that are highly concentrated in small areas of the landscape. Our research adds to the growing literature regarding carcass resources and its implications on ecosystem dynamics, and highlights contributions of mountain lions to spatio-temporal variability in ecosystem processes at a landscape-scale.
Metrics
12 File views/ downloads
45 Record Views
Details
- Title
- Evaluating the effects of mountain lion kills on the nitrogen cycle in the Greater Yellowstone ecosystem
- Creators
- Michelle Marie Peziol
- Contributors
- Daniel Thornton (Advisor) - Washington State University, School of the Environment (CAS)
- Awarding Institution
- Washington State University
- Academic Unit
- School of the Environment (CAS)
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University
- Identifiers
- 99900890791101842
- Language
- English
- Resource Type
- Thesis