Grantee Research Project Results
2009 Progress Report: Nonlinear and Threshold Responses to Environmental Stressors in Land-river Networks at Regional to Continental Scales
EPA Grant Number: R833261Title: Nonlinear and Threshold Responses to Environmental Stressors in Land-river Networks at Regional to Continental Scales
Investigators: Melillo, Jerry , Peterson, Bruce J. , Vörösmarty, Charles J. , Felzer, Benjamin S. , Kicklighter, David Wesley , McClelland, James , Wollheim, Wil
Institution: Marine Biological Laboratory , University of New Hampshire , City University of New York , Lehigh University
Current Institution: Marine Biological Laboratory , University of New Hampshire
EPA Project Officer: Packard, Benjamin H
Project Period: September 1, 2007 through August 31, 2010 (Extended to August 31, 2011)
Project Period Covered by this Report: November 1, 2008 through October 31,2009
Project Amount: $899,191
RFA: Nonlinear Responses to Global Change in Linked Aquatic and Terrestrial Ecosystems and Effects of Multiple Factors on Terrestrial Ecosystems: A Joint Research Solicitation- EPA, DOE (2005) RFA Text | Recipients Lists
Research Category: Climate Change , Aquatic Ecosystems
Objective:
Our objective in this research is to explore the relationships among environmental stresses, the nonlinear and threshold behaviors they cause within freshwater ecosystems of large drainage basins, and the ecosystem services provided by the streams and rivers of the basins. To do this we are refining our process-based aquatic model, the Aquatic Ecosystem Model (AEM) and testing its ability to simulate documented nonlinear and threshold responses to environmental stresses at a variety of spatial scales, from the river reach to the entire river network within a drainage basin. We are also coupling the AEM with our improved terrestrial biogeochemistry model, the Terrestrial Ecosystem Model (TEM), thereby creating a new version of our Drainage Basin Model, which we will use for regional analyses of nonlinear and threshold behaviors in freshwater systems at large scales. A cartoon conceptualization of these couplings appears in Figure 1.
Figure 1. Conceptualization of the Drainage Basin Model. Nonpoint loading of solutes and particulates to river and stream ecosystems will first be predicted by TEM. The AEM will then use these simulated nonpoint loadings along with estimates of point sources as inputs into both local (within grid) and ultimately macro-scale (between grid) river networks. AEMg will simulate biological processing of organic matter and nutrients in low order streams within a grid cell computing the net export of constituents to higher order macro-level streams. AEMrc will then simulate additional biological processing of organic matter and nutrients in major river corridors to estimate the export of materials on their movement downstream to the river mouth. Water will be moved between stream reaches with the Water Transport Model (WTM). Potential 8 km networks are shown. The heavy black line on the map represents the Missouri and lower Mississippi Rivers.
Progress Summary:
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References:
Journal Articles on this Report : 4 Displayed | Download in RIS Format
Other project views: | All 28 publications | 13 publications in selected types | All 13 journal articles |
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Alexander RB, Bohlke JK, Boyer EW, David MB, Harvey JW, Mulholland PJ, Seitzinger SP, Tobias CR, Tonitto C, Wollheim WM. Dynamic modeling of nitrogen losses in river networks unravels the coupled effects of hydrological and biogeochemical processes. Biogeochemistry 2009;93(1-2):91-116. |
R833261 (2008) R833261 (2009) R833261 (2010) R833261 (Final) R834187 (2010) R834187 (2011) R834187 (2012) R834187 (2013) R834187 (Final) |
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Felzer BS, Cronin TW, Melillo JM, Kicklighter DW, Schlosser CA. Importance of carbon-nitrogen interactions and ozone on ecosystem hydrology during the 21st century. Journal of Geophysical Research-Biogeosciences 2009;114(G1):G01020 (10 pp.). |
R833261 (2008) R833261 (2009) R833261 (2010) R833261 (Final) |
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Green MB, Wollheim WM, Basu NB, Gettel G, Rao PS, Morse N, Stewart R. Effective denitrification scales predictably with water residence time across diverse systems. Nature Precedings 2009;3520.1. |
R833261 (2009) R833261 (2010) R833261 (Final) R834187 (2010) R834187 (2011) R834187 (2012) R834187 (2013) R834187 (Final) |
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Harrison JA, Maranger RJ, Alexander RB, Giblin AE, Jacinthe P-A, Mayorga E, Seitzinger SP, Sobota DJ, Wollheim WM. The regional and global significance of nitrogen removal in lakes and reservoirs. Biogeochemistry 2009;93(1-2):143-157. |
R833261 (2008) R833261 (2009) R833261 (2010) R833261 (Final) R834187 (2010) R834187 (2011) R834187 (2012) R834187 (2013) R834187 (Final) |
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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.