Grantee Research Project Results
2001 Progress Report: Land Use and Geomorphic Indicators of Biotic Integrity in Piedmont Streams
EPA Grant Number: R826597Title: Land Use and Geomorphic Indicators of Biotic Integrity in Piedmont Streams
Investigators: Leigh, D. S. , Kramer, E. A. , Freeman, Mary C. , Rosemond, A. D. , Freeman, Byron J. , Pringle, Catherine M.
Institution: University of Georgia
EPA Project Officer: Packard, Benjamin H
Project Period: January 1, 1999 through December 31, 2001
Project Period Covered by this Report: January 1, 2001 through December 31, 2002
Project Amount: $780,834
RFA: Ecological Indicators (1998) RFA Text | Recipients Lists
Research Category: Ecological Indicators/Assessment/Restoration , Aquatic Ecosystems
Objective:
The main objective of this research project is to define the predictive capabilities of scale-variable attributes of land cover (GIS-based) and geomorphology as risk assessment indicators of the biotic integrity of stream ecosystems. The study area is the Etowah River basin north of Atlanta, GA, which is one of the Nation's fastest growing urban areas. Various types of land cover and land cover changes influence water and sediment inputs (stressors) that shape stream geomorphology, which is the physical template for stream ecosystems. Landscape alteration influences these physical stressors and occurs over large areas within which stream networks are nested. Given various aspects of landscape change, our research is investigating the following three questions. First, do physical stressors and the corresponding ecological response vary as a function of land use? Second, is this relationship consistent within watersheds of different size? Third, does antecedent land use (> 50 years ago) influence the physical stressor and ecological response relationship? To answer these questions, our research is split into two main phases of data collection. The first phase is a comprehensive survey of geomorphic conditions and biological integrity in 32 streams (11 to 126 km2 and 5 to 60 percent urban land cover), and development of general predictive models ("indicators") from those physical and biotic data sets. The second phase is a detailed analysis of site-specific geomorphic conditions, stream habitat dynamics, and biotic integrity at a subset of selected sites, which represent large versus small deviations from the general models produced in the first phase of our analysis.Progress Summary:
During 2001, a great deal of our work was devoted to compiling and writing results of the phase 1 analysis concerned with developing predictive models (indicators) of stream biota from geomorphic, water chemistry, and land cover variables. These efforts are reflected in the completion of three masters theses, publication of five proceedings papers, and submission of three journal articles during the 2001 research period. A concise summary of these findings can be obtained on our Web site (http://etowahepa.ecology.uga.edu/) in the overview proceedings paper by Leigh, et al. (2001), and the other papers. In general, our findings indicate that multivariate models using two or three geomorphic and land cover variables can explain 60 to 90 percent of the overall variance found in multimetric scores of biotic integrity for fishes and macroinvertebrates. More specifically, we have found that measures of geomorphic conditions within the stream-reach tend to provide the most predictive data, and that land cover and water quality data tend to explain remaining variance. Measures of stream slope and bed texture commonly are the best overall predictors. In many cases, slope and texture can be viewed as background conditions of the physical template for biota, upon which other drivers have their effects. We find that our models tend to explain more variance than others presented in the literature, and we think that it is because we are restricting the analysis to "wadeable" streams, and we have a very comprehensive set of geomorphic variables to build the best models.Field work during the 2001 grant period was focused on completing the phase 2 analysis of site-specific geomorphic conditions, stream habitat, and biotic integrity within a subset of four sites (sites 13, 15, 22, and 30). Remaining field tasks consisted of topographic survey, habitat survey, and discharge measurements at those sites, and all of those tasks were completed in 2001. Sites 13 and 22 plotted as "average" sites according to our preliminary models predicting biotic integrity, whereas sites 15 and 30 plotted as positive residuals. Thus, a great deal of our research is aimed at determining why sites 15 and 30 are positive residuals, or better-than-expected sites. Preliminary results indicate that daily stream discharge may be a very important factor, because other measures of physical conditions are less explanatory. At site 30, we found that baseflow discharge is almost twice that of site 22, despite the fact that site 22 has a slightly larger basin than site 30. The baseflow discharge has been severely stressed by drought conditions in Georgia, and this has been somewhat fortuitous because it has allowed us to examine these sites under naturally stressed conditions. In addition, we have found that sites 13 and 15 may not be as different as our original models had suggested. Because we have developed more varieties of multivariate models to predict biota from geomorphic and land cover data, we have found that site 15 is not consistently a positive residual. This result has been significant in helping us to define the reliability of the basin-wide models of biotic integrity.
Another area of data collection that we completed during this period was that of antecedent land cover conditions. We have quantified land cover conditions for all of our sites from Landsat imagery from 1973 and 1987, and these are being incorporated into our analyses. In addition, land cover classes of forest, urban, and agricultural land were quantified for 1983 from aerial photographs. In addition, county-wide population and agricultural census data have been compiled to help analyze the importance of past conditions and rates of change. All of these data are being used to evaluate the importance of antecedent conditions as an element of modern biotic conditions in streams.
In summary, we have finished our data collection and are fully immersed in analyzing and writing the results of our research. Publications are now emerging from this research, and we anticipate that several more journal articles will result in a timely fashion.
Future Activities:
We have completed all of our field data collection and are in the process of compiling and writing the results of our research. In addition to the three journal articles that currently are in review, we have planned submission of several more journal articles in the 2002. In addition, most of our investigators will be presenting results of this research at forthcoming professional conferences. We plan to submit the final technical report to the U.S. Environmental Protection Agency in September 2002.Journal Articles on this Report : 3 Displayed | Download in RIS Format
Other project views: | All 55 publications | 4 publications in selected types | All 4 journal articles |
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Type | Citation | ||
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Roy AH, Rosemond AD, Paul MJ, Leigh DS, Wallace JB. Stream macroinvertebrate response to catchment urbanisation (Georgia, U.S.A.). Freshwater Biology 2003;48(2):329-346. |
R826597 (2001) |
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Roy AH, Rosemond AD, Leigh DS, Paul MJ, Wallace JB. Habitat-specific responses of stream insects to land cover disturbance: biological consequences and monitoring implications. Journal of the North American Benthological Society 2003;22(2):292-307. |
R826597 (2001) R826597 (Final) |
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Walters DM, Leigh DS, Freeman MC, Freeman BJ, Pringle CM. Geomorphology and fish assemblages in a Piedmont river basin, U.S.A. Freshwater Biology 2003;48(11):1950-1970. |
R826597 (2001) R826597 (Final) |
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Supplemental Keywords:
ecology, geography, fluvial geomorphology, watersheds, ecological effects, ecosystem, indicators, aquatic, habitat, landsat, remote sensing, southeast, EPA Region 4, Appalachia., RFA, Scientific Discipline, Water, Geographic Area, Ecosystem Protection/Environmental Exposure & Risk, Water & Watershed, Ecology, Ecosystem/Assessment/Indicators, Ecosystem Protection, exploratory research environmental biology, Chemical Mixtures - Environmental Exposure & Risk, Environmental Chemistry, Ecological Effects - Environmental Exposure & Risk, Monitoring/Modeling, Ecological Effects - Human Health, Ecological Risk Assessment, Biology, Geology, Watersheds, Ecological Indicators, EPA Region, risk assessment, aquatic biota , landscape indicator, biodiversity, land use effects, stream ecosystems, ecosystem indicators, geomorphic indicators, soil, aquatic ecosystems, water quality, GIS, land useRelevant Websites:
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.