Elevated Temperature and Land Use Flood Frequency Alteration Effects on Rates of Invasive and Native Species Interactions in Freshwater Floodplain WetlandsEPA Grant Number: R833837
Title: Elevated Temperature and Land Use Flood Frequency Alteration Effects on Rates of Invasive and Native Species Interactions in Freshwater Floodplain Wetlands
Investigators: Richardson, Curtis J. , Qian, Song S. , Flanagan, Neal
Current Investigators: Richardson, Curtis J. , Ho, Mengchi , Flanagan, Neal
Institution: Duke University , Nicholas School of the Environment and Earth Sciences
EPA Project Officer: Packard, Benjamin H
Project Period: April 1, 2008 through March 31, 2011 (Extended to March 31, 2012)
Project Amount: $598,107
RFA: Ecological Impacts from the Interactions of Climate Change, Land Use Change and Invasive Species: A Joint Research Solicitation - EPA, USDA (2007) RFA Text | Recipients Lists
Research Category: Ecological Indicators/Assessment/Restoration , Aquatic Ecosystems , Climate Change
The primary objective is to assess how predicted climate and land use driven changes in hydrologic flux and temperature regimes of floodplain ecosystems affect plant communities in terms of their vulnerability to the establishment and spread of invasive species and, in turn, ecosystem functions and services. Future climate scenarios for the southeastern U.S. predict that surface water temperatures will warm (in concert with air temperature) and that stream flows will likely decrease, with a greater proportion of annual watershed hydrologic yield occurring during major storm events. Land use changes (urban vs. forested etc.) have been shown to also raise water temperature and increased pulsed water releases during storms. We focus on the relationships among native species composition, diversity, productivity, and invasibility of floodplain ecosystems affected by alterations of water temperature and annual hydrographs driven by climate change and land use change. We will use a combination of varying scale experimental studies and one novel large-scale regional study to verify our experimental and threshold modeling results.
There are 4 study levels. (1) A field-based warming experiment will allow us to directly evaluate and model treatment-effects of temperature and hydrology on species invasions, community composition, and ecosystem services of an experimental (restored) floodplain ecosystem. (2) Ninety-nine diversity plots on a floodplain will be used to test how species richness affects species invasions. (3) We will use 102 permanent vegetation plots distributed over 3 hydrogeomorphic zones in the floodplain (stream bank, low terrace and high terrace) to assess species invasions effected by pulsed waters. (4) Regional studies on wetlands downstream of surface and bottom-releasing dams will be used to assess pulsed water and temperature effects on invasive species as compared to control rivers. At each experimental level we will assess how feedbacks from invasive species alter ecosystems services such as flood control, sediment retention and maintenance of water quality. A unified Bayesian hierarchical model will be developed as a decision support tool to predict temperature and hydrology thresholds for invasive species response to alterations in floodplain ecosystems.
Experimental results will be used to estimate consequences of predicted temperature increases and increased storm flow events on the ability of existing floodplain communities to resist invasive species. Proposed Bayesian modeling methods can address nonlinear responses and provide a risk assessment probability analysis to predict ecosystem threshold shifts.