Grantee Research Project Results
2001 Progress Report: Regional Analysis of Variation in Adirondack Lake Ecosystems: Landscape Scale Determinations of Dissolved Organic Carbon
EPA Grant Number: R826762Title: Regional Analysis of Variation in Adirondack Lake Ecosystems: Landscape Scale Determinations of Dissolved Organic Carbon
Investigators: Pace, Michael L. , Canham, Charles D.
Institution: Cary Institute of Ecosystem Studies
EPA Project Officer: Packard, Benjamin H
Project Period: January 1, 1999 through December 31, 2001 (Extended to December 31, 2002)
Project Period Covered by this Report: January 1, 2001 through December 31, 2002
Project Amount: $453,775
RFA: Regional Scale Analysis and Assessment (1998) RFA Text | Recipients Lists
Research Category: Aquatic Ecosystems , Ecological Indicators/Assessment/Restoration
Objective:
The objectives of this research project are to: (1) develop a regional scale modeling approach to predict variation in lake ecosystem properties as a function of landscape characteristics; (2) analyze landscape within lake processes that determine variation in lake dissolved organic carbon (DOC); and (3) analyze temporal trends in lake DOC related to landscape and lake processes.Progress Summary:
In Project Year 3, we largely completed the analysis of our mass balance model to explain variation in DOC concentrations among lakes in the Adirondack Mountains of New York. The lakes vary dramatically in morphometry and chemistry, and in the makeup of wetlands and forests within their watersheds. The bulk of the lakes are located in protected wilderness areas, but many of the watersheds contain active forestry and lakeshore development. The model assumes that midsummer lake DOC concentrations are at a steady state and reflect the balance of inputs in the form of: (1) in-lake production; (2) loading from wetland and upland cover types within the immediate watershed; and (3) inputs via stream flow from upstream lakes, and outputs in the form of stream discharge from the lake and within-lake loss (from physical and biological processes). Loading of DOC from within the watershed is assumed to vary as a function of vegetation cover type and distance (along flow paths) from the lake. Lake DOC data were compiled from a survey of lake chemistry by the Adirondack Lake Survey Corporation between 1984-1987. Wetland cover types were mapped by the Adirondack Park Agency, using aerial photography taken during the same period. Forest cover types were classified by the Park Agency using Landsat Thematic Mapper imagery from the same time period. A 10 m resolution digital elevation model was used to delineate the watersheds of the 577 lakes (approximately 240,000 ha) and to determine flow paths. Each watershed was gridded at a 10 x 10 m resolution, and the cover type and distance to lake was recorded for each cell. We used maximum likelihood methods with simulated annealing to estimate the parameters of the model, including the predicted loadings of DOC (in kg/ha/yr) from different wetland and upland cover types as a function of distance from the lake.
The analysis explains 55 percent of the variation in DOC for the 355 headwater lakes, and 48 percent of the variation in DOC for the entire lake set. The predicted rates of DOC loading from the major wetland types were much greater on a per unit area basis than from the forest types (150-250 kg/ha/yr for different wetland cover types versus 40-60 kg/ha/yr for upland forest types). However, on average, wetlands make up only 10 percent of watershed area, so our analysis indicated that upland forests are a major source of DOC to the lakes. For most of the major wetland and forest cover types, DOC loading did not significantly decline with distance from the lake. Within lake DOC processing was related to lake depth, the acid neutralizing capacity of the water, and the percent of DOC loading from wetlands. The figure below illustrates the fit of the model in terms of predicted versus observed values for headwater lakes.
Future Activities:
In the no-cost extension phase of the project, we will conclude our analytical work and prepare manuscripts from the study.Journal Articles on this Report : 1 Displayed | Download in RIS Format
| Other project views: | All 16 publications | 1 publications in selected types | All 1 journal articles |
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Canham CD, Pace ML, Papaik MJ, Primack AGB, Roy KM, Maranger RJ, Curran RP, Spada DM. A spatially explicit watershed-scale analysis of dissolved organic carbon in Adirondack lakes. Ecological Applications 2004;14(3):839-854. |
R826762 (2001) R826762 (Final) |
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Supplemental Keywords:
ecological effects, aquatic, terrestrial, land water interactions, limnology, dissolved organic carbon, DOC, likelihood analysis, landscape., RFA, Ecosystem Protection/Environmental Exposure & Risk, Scientific Discipline, Geographic Area, Water, Ecological Risk Assessment, State, Watersheds, Regional/Scaling, Hydrology, Water & Watershed, Ecology and Ecosystems, model ecosystem effects, ecological variation, wetland, regional analysis, ecosystem assessment, water management options, water quality, carbon allocation, temporal scale, Adirondack Lake, aquatic, integrated ecological assessment, remote sensing imagery, New York (NY), land use, GIS, landscape scale determinations, modeling, aquatic ecosystems, dissolved organic carbonRelevant Websites:
http://www.ecostudies.org Exit
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.