PnET is a suite of three
nested computer models which provide a modular approach to simulating
the carbon, water and nitrogen dynamics of forest ecosystems. Though
primarily a temperate forest canopy model, work is currently underway
to generalize PnET and produce a simple, alternative model applicable
to all terrestrial ecosystem types.
PnET-Day is the instantaneous canopy flux module, PnET-II adds nutrient allocation, a water balance and soil respiration to produce a monthly time-step carbon and water model which is driven by nitrogen availability. PnET-CN further extends the soil dynamics component and closes the N cycle by tracking nitrogen, along with carbon, throughout all compartments and fluxes.
The best source of information about PnET are the journal publications available for online viewing on the Publications page. The model itself is released as open source and users are encouraged to extend and enhance it for their own purposes.
PnET is available as both MATLAB and Visual Basic source. The distribution package contains example files which will allow the user to run each version of the model using data acquired at the Harvard Forest and Hubbard Brook experimental forests and a subset of the VEMAP continental U.S. data.
PnET was developed at the Complex Systems Research Center (a division of the Institute for the Study of Earth, Oceans and Space at the University of New Hampshire). Read more about the history of PnET at the CSRC. PnET development and application is supported through grants from the following agencies:
PnET C++ daily version is released. It is based on CN version.
PnET C++ version PnET_C1 is released. It is based on M2.2 version.
MATLAB codes (PnET_M2.2) were updated as some bugs are corected (e.g, NetCBal, O3Effect, out.foln, et al.). A function of PnET-II and PnET-Day based on PnET-CN was created.
A PnET application database was uploaded for users and developpers.
PnET User Group Google group was set up for users
PnET Release 2 is available for download
A longstanding error in the RootTurnover equation has been corrected in both the VB and MATLAB codes. Since turnover is constrained, this is not expected to have a significant impact on existing modeling results.