Grantee Research Project Results
2000 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, 2000 through December 31, 2001
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 the 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 and 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:
During the second year of the project, we continued to assemble the necessary data layers with the help of our collaborators at the Adirondack Park Agency. A principal task was to complete the delineation of the watersheds for the Oswegatchie-Black River drainage (i.e., western section) of the Adirondack Park and to add new data for over 100 lakes and watersheds that became available in the Upper Hudson section of the Adirondack Park. We completed these tasks.
With all the data compiled, we then developed a mass balance model to explain variation in DOC concentration among 577 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 in protected wilderness areas, but many of the watersheds contain active forestry and lakeshore development. The model assumes that mid-summer lake DOC concentrations are at steady state, and reflect the balance of inputs in the form of (1) in-lake production, (2) loading from wetland and upland land 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 both 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 also 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 m 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 ~ 50 percent of the variation in DOC for the whole sample of 577 lakes. 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 vs. 40-60 kg/ha/yr for upland forest types). However, on average, wetlands make up only 10 percent of watershed area, so our analyses indicate that upland forests were the major source of DOC to the lakes. For most of the major wetland and forest cover types, DOC loading did not decline significantly with distance from the lake, indicating that these watersheds were very well linked hydrologically.
We also conducted a resurvey of 100 lakes in the Adirondacks. Field work and initial chemical analyses were completed in 2000.
Future Activities:
We plan two major activities for the coming year. The first activity is to complete the modeling analysis. This involves considering a few additional factors in the model such as in-lake properties, accounting for some likely interannual variations in climate that affect the 1984-1987 data, and further synthesizing results. We will write a manuscript summarizing the modeling results for publication. The second activity is to fully analyze the resurvey of lakes conducted in the summer of 2000, to synthesize the data, and to produce manuscripts from this portion of the study.
Journal Articles:
No journal articles submitted with this report: View all 16 publications for this projectSupplemental Keywords:
ecological effects, aquatic, terrestrial, land water interactions, limnology, dissolved organic carbon, likelihood analysis, landscape, Adirondacks, DOC, GIS., RFA, Scientific Discipline, Water, Geographic Area, Ecosystem Protection/Environmental Exposure & Risk, Water & Watershed, Hydrology, State, Regional/Scaling, Ecology and Ecosystems, Ecological Risk Assessment, Watersheds, aquatic, carbon allocation, landscape scale determinations, model ecosystem effects, regional analysis, ecosystem assessment, modeling, temporal scale, ecological variation, dissolved organic carbon, regional scale impacts, aquatic ecosystems, water quality, GIS, water management options, Adirondack Lake, integrated ecological assessment, remote sensing imagery, wetland, land useRelevant Websites:
http://www.ecostudies.org
http://www.northeastnet.org/adirondackparkagency/gis/index.html
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.