Grantee Research Project Results
An Integrated Approach to Gauge the Effects of Global Climate Change on Headwater Stream EcosystemsEPA Grant Number: FP917314
Title: An Integrated Approach to Gauge the Effects of Global Climate Change on Headwater Stream Ecosystems
Investigators: Bury, Gwendolynn W
Institution: Oregon State University
EPA Project Officer: Just, Theodore J.
Project Period: September 1, 2011 through August 31, 2014
Project Amount: $126,000
RFA: STAR Graduate Fellowships (2011)
Research Category: Academic Fellowships , Fellowship - Global Change
This work will study the effects of global climate change on headwater streams, using Rhyacotriton variegatus as an indicator of ecosystem dysfunction. Specifically, it will use a combination of physiological ecology, survey and modeling methods to look for the limiting factors in the health and survival of R. variegatus. Aim 1: Are R. variegatus disappearing from warming streams at the edge of their thermally defined range? Aim 2: What are the thermal tolerances of R. variegatus eggs? Aim 3: Are stress hormone levels of R. variegatus elevated in thermally degraded streams? Aim 4: How will global climate change affect the distribution of R. variegatus?Approach:
Aim 1: To address this aim, two methods will be used First, streams will be surveyed where R. variegatus were found historically, that are on the southern end of their thermally defined range. Second, electronic temperature loggers will be placed in a gradient of streams-streams on the edge of the range of R. variegatus, streams in the center of the range and streams just outside the range, to look for a temperature cut-off for R. variegatus presence. Aim 2: Female R. variegatus will be induced to lay eggs. Eggs will be kept in the laboratory at a range of environmentally relevant temperatures. Aim 3: In streams at the edge of R. variegatus' range, blood samples will be taken. Adult R. variegatus also will be held in the laboratory at a range of environmentally relevant temperatures and then blood samples will be taken. Samples will be analyzed for the levels of corticosteroid. Aim 4: Computer modeling and a GIS will be used to integrate the physiological limits found during the other Aims into future predictions of habitat loss for R. variegatus.Expected Results:
This study will provide a set of models that integrate climate and physiology of an indicator species. These models will allow for predictions of headwater stream dysfunction in the Pacific Northwest under a variety of possible climate scenarios. Results of this study also will provide causal data on a sensitive indicator, which is needed to accurately gauge disturbance, and is rare. Most indicator species are used in a correlation way-when they are not present, the ecosystem is not functioning. This study provides physiological causes for these correlations.
Potential to Further Environmental/ Human Health Protection
This research will provide models to estimate the locations of streams that will be most impacted by global climate change. This will encourage targeted conservation and mitigation efforts in these and connected ecosystems. The causal physiological data on R. variegatus will encourage their use as an indicator of headwater stream health and provide specific reasons for declines if they are discovered.Supplemental Keywords:
amphibians, indicator species, headwater, streams, climate change, forests, Pacific Northwest, temperature tolerance, life stages