Hydroecology of Intermittent and Ephemeral Streams: Will Landscape Connectivity Sustain Aquatic Organisms in a Changing Climate?
RC-1724
Objective
Global environmental change attributable to human activities is expected to have significant ecological consequences during this century. Climate change and increasing urban water use are likely to affect hydrologic processes, nutrient cycles, and disturbance regimes, all of which have the potential to greatly alter the structure and functioning of intermittent and ephemeral streams and the sensitivity of these ecosystems to other anthropogenic stressors in the southwestern United States. Preparing for this uncertain future represents a pressing challenge for ecosystem-based management and monitoring on Department of Defense (DoD) lands.
The objective of this project is to improve understanding of how intermittent and ephemeral streams provide critical habitat and population connectivity for obligatory aquatic species (insects, amphibians, and crayfish) and address whether these ecological functions will be maintained in a changing climate. Researchers will examine how hydrology, hydrologic connectivity, and other riverine characteristics influence the demography (e.g., distribution, abundance) and population genetics (e.g., gene flow, structure, diversity) of aquatic species across a gradient of flow permanence. These functional relationships will then be integrated into quantitative models that forecast the ecological and genetic consequences of altered hydrologic connectivity as a result of climate change or other anthropogenic activities.
Technical Approach
This project has four core elements that collectively link hydrologic modeling with ecological and molecular investigations to quantify the sensitivity of intermittent and ephemeral ecosystems to future climate change. First, spatially explicit watershed- and reach-scale models of flow permanence and hydrologic connectivity will be developed by combining a semiarid rain-runoff model with field-based deployment of electrical resistance sensors. Second, the current distribution of obligatory aquatic species will be surveyed and their niche requirements modeled in relation to hydrology, riparian vegetation, and geomorphology. Third, molecular tools will be used to evaluate patterns of gene flow and dispersal abilities of species with contrasting life histories across a gradient of flow intermittence. Fourth, a hydrological model will be used to forecast future patterns of flow permanence and landscape connectivity under various climate change scenarios and to forecast the ecological implications for aquatic species distributions and population structure.
Results will include: (1) a georeferenced database containing information on the distribution and abundance of aquatic invertebrates and amphibians in multiple seasons over a 3-year period, including at-risk native species and non-native bullfrogs and crayfish; (2) habitat suitability maps for aquatic species at the reach- and watershed-scale; (3) comprehensive genetic characterization of the landscape that quantifies patterns of gene flow, population metapopulation dynamics, and genetic discontinuities that reflect possible barriers to migration; (4) a quantitative model linking hydrologic connectivity and projected climate change to species distributions and patterns of gene flow (i.e., individual movements); and (5) predicted species and locations on the landscape most at risk to shifts from perennial to intermittent-ephemeral flow and temporal changes in hydrological connectivity. In addition, a workshop will be conducted to educate DoD personnel on the hydroecology of intermittent and ephemeral streams on military lands, specifically with respect to aquatic insects, herpetofauna, and future effects of climate change.
Benefits
By identifying how present day and future dynamics of hydrologic connectivity reduce or enhance gene flow, population structure, and species distributions, this research will help DoD resource managers in accounting for the effects of projected climate change and other human activities that influence river hydrology. Model predictions will help identify aquatic taxa whose persistence is particularly jeopardized on military lands by future climate change (alone, or in combination with different management plans) and that, as a result, may require active management efforts such as corridor connections, translocations, or water management for their long-term conservation. (Anticipated Project Completion - 2014)
Symposium & Workshop
FY 2013 New Start Project Selections
Points of Contact
Principal Investigator
Dr. Julian Olden
University of Washington
Phone: 206-616-3112
Program Manager
Resource Conservation and Climate Change
SERDP and ESTCP
Document Types
- Fact Sheet - Brief project summary with links to related documents and points of contact.
- Final Report - Comprehensive report for every completed SERDP and ESTCP project that contains all technical results.
- Cost & Performance Report - Overview of ESTCP demonstration activities, results, and conclusions, standardized to facilitate implementation decisions.
- Technical Report - Additional interim reports, laboratory reports, demonstration reports, and technology survey reports.
- Guidance - Instructional information on technical topics such as protocols and user’s guides.
- Workshop Report - Summary of workshop discussion and findings.
- Multimedia - On demand videos, animations, and webcasts highlighting featured initiatives or technologies.
- Model/Software - Computer programs and applications available for download.
- Database - Digitally organized collection of data available to search and access.