Thesis
STREAM-ASSOCIATED AMPHIBIAN DETECTION AND FINE-SCALE DISTRIBUTION: INFERENCES FROM ENVIRONMENTAL DNA
Washington State University
Master of Science (MS), Washington State University
01/2021
DOI:
https://doi.org/10.7273/000001876
Handle:
https://hdl.handle.net/2376/120681
Abstract
The coastal redwood region in California has seen warming temperatures and declines in frequency of coastal fog upon which the ecosystem depends and faces an uncertain future in the face of changing climate. The region is home to a diversity of amphibian species, for which conservation and management decisions must be informed by knowledge of factors shaping their habitat selection. Surveying for stream amphibians is labor-intensive, often requiring disturbance of species’ habitat and leads to variable detection rates. The collection of environmental DNA from water is an effective tool for determining presence of stream amphibian species in water without negatively impacting study species. However, there are still uncertainties in how eDNA results can be interpreted in stream systems due to complexities of downstream transport dynamics.
We used eDNA to model occupancy of coastal tailed frog at the southern extent of its range on the northern California coast in relation to stream habitat, temperature, and forest management covariates and explored the use of eDNA quantification as a tool to support occupancy models based on eDNA presence/absence by informing scale of downstream eDNA transport. We found that median eDNA transport distances are likely short (less than 100 meters) in our system and that coastal tailed frog occupancy was best explained by level of summertime fog and correlated low air temperature. Additionally, we used eDNA and visual encounter surveys to add to our knowledge of an understudied amphibian species, the red-bellied newt, with a range limited almost exclusively to the coastal redwood forest region of California. We found red-bellied newts select breeding sites in large 4th to 6th Strahler low-gradient streams with cobble substrate and that breeding males overwhelmingly occupied pools. Through the results of this study, we demonstrate the utility of eDNA to model occupancy of stream-associated amphibian species of conservation concern and add to our knowledge of the transport dynamics of eDNA in watersheds.
Metrics
24 File views/ downloads
64 Record Views
Details
- Title
- STREAM-ASSOCIATED AMPHIBIAN DETECTION AND FINE-SCALE DISTRIBUTION: INFERENCES FROM ENVIRONMENTAL DNA
- Creators
- Kelsey Marshall
- Contributors
- Caren S Goldberg (Advisor)Jonah Piovia-Scott (Committee Member)Dan Thornton (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Environment, School of the (CAHNRS)
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University
- Number of pages
- 82
- Identifiers
- 99900606651001842
- Language
- English
- Resource Type
- Thesis