A generalized, lumped-parameter model of carbon (C) ,water and nitrogen (N) in interactions in forest ecosystems (PnET-CN) is presented. The model operates in a monthly time step and at the stand-to-watershed scale, and is validated against data on annual net primary productivity, monthly carbon and water balances, annual net N mineralization, ... nitrification, foliar N concentration and annual and monthly N leaching losses for two sites, Hubbard Brook (West Thornton, NH) and Harvard Forest (Petersham, MA). It is then used to predict transient responses in function resulting from changes in land use and N deposition, as well as the maximum rate of N cycling which can be sustained for any given combination of site, climate and species. Model predictions suggest a very long legacy effect of land use history on N cycling. Even with only one 'active' soil organic matter pool, complete recovery from three modest harvests at Hubbard Brook is predicted to require more than two centuries at current N deposition rates. Complete recovery is predicted to take even longer at the Harvard Forest where biomass removals have been more intense. PnET-CN is used to predict maximum sustainable rates of N cycling for 14 sites throughout the northeastern USA. Predicted maximum values were higher, as expected, than measured N mineralization rates for all but one site. The measured fraction of N mineralization nitrified at these 14 sites showed a general relationship with the ratio of measured net N mineralization. This latter ratio is discussed as a potentially useful indicator of the degree of nitrogen saturation in forest ecosystems. A regional map of predicted maximum N cycling rates is presented based on regressions between model predictions and summary climatic variables.
Related URL
Link:
VIEW PROJECT HOME PAGE
Description:
Pnet model journal articles, PnET source code, PnET executable.
Geographic Coverage
Spatial coordinates
N: 48.0
S: 38.0
E: -66.0
W: -77.0
Data Set Citation
Dataset Creator:
John D. Aber, Scott V. Ollinger, Charles T. Driscoll
Dataset Title:
Modeling nitrogen saturation in forest ecosystems in response to land use and atmospheric deposition
Dataset Series Name:
Ecological Modelling, 101: 61-78, 1997
Dataset Release Date:
1997
Dataset Publisher:
CSRC, University of New Hampshire
Data Presentation Form:
ASCII and image
Online Resource:
http://eos-webster.sr.unh.edu
Name:
DENISE
BLAHA Phone:
1-603-862-3785
Fax:
603-862-0188
Email:
support at cooa.sr.unh.edu
Contact Address:
Complex Systems Research Center
Institute for the Study of Earth, Oceans, and Space
Morse Hall
University of New Hampshire City:
Durham
Province or State:
New Hampshire
Postal Code:
03824
Country:
USA
Distribution
Distribution Media:
CD-ROM, Online Internet (HTTP)
Distribution Format:
ASCII, GIF images
Fees:
None
Personnel
JOHN
D.
ABER Role:
INVESTIGATOR
Phone:
603-862-3045
Email:
John.Aber at unh.edu
Contact Address:
University of New Hampshire
Complex Systems Research Center City:
Durham
Province or State:
NH
Postal Code:
03824
Country:
USA
RITA
FREUDER Role:
TECHNICAL CONTACT
Role:
DIF AUTHOR
Phone:
603-862-1792
Fax:
603-862-0188
Email:
Rita.Freuder at unh.edu
Contact Address:
Complex Systems Research Center
Institute for the Study of Earth, Oceans, and Space
Morse Hall
University of New Hampshire City:
Durham
Province or State:
New Hampshire
Postal Code:
03824
Country:
USA
SCOTT
V.
OLLINGER Role:
INVESTIGATOR
Phone:
603-868-2926
Email:
Scott.Ollinger at unh.edu
Contact Address:
University of New Hampshire
CSRC/ Morse Hall City:
Durham
Province or State:
NH
Postal Code:
03824
Country:
USA
Links
