TEM

The Terrestrial Ecosystem Model



Model Description:

The Terrestrial Ecosystem Model (TEM) is a process-based ecosystem model that describes carbon and nitrogen dynamics of plants and soils for terrestrial ecosystems of the globe. The TEM uses spatially referenced information on climate, elevation, soils, vegetation and water availability as well as soil- and vegetation-specific parameters to make monthly estimates of important carbon and nitrogen fluxes and pool sizes of terrestrial ecosystems. The TEM operates on a monthly time step and at a 0.5 degrees latitude/longitude spatial resolution.

Improvements in computer resources have allowed us to examine ecosystem processes across the globe in more detail over time so that several versions of TEM have been developed over the past decade. At first, TEM only conducted equilibrium analyses of terrestrial carbon and nitrogen dynamics with hydrological inputs determined by an independent water balance model (WBM, Vörösmarty et al., 1989). This WBM used the same climatic data and soil-specific parameters as TEM. In version 4.0, the algorithms of the WBM were incorporated directly into TEM so that terrestrial carbon, nitrogen and water variables were determined concurrently. Then, we were then able to develop TEM 4.1 using relatively minor modifications of TEM 4.0 so that the model could conduct either equilibrium or transient analyses of terrestrial carbon and nitrogen dynamics.

Version Type of Analysis Major Modifications Applications References
1.0 Equilibrium Original Examined spatial patterns of long-term mean net primary production (NPP) in South America Raich et al. 1991
2.0 Equilibrium New feedback algorithm between C and N uptake by vegetation Examined spatial patterns of long-term mean NPP across North America McGuire et al., 1992
3.0 Equilibrium Split vegetation N pool (NV) into structural (NVS) labile (NVL) pools to inplement recycling of N within vegetation Examined the responses of NPP and carbon storage to changes in climate and atmospheric CO2 concentration at the global and continental scales McGuire et al., 1993, 1995, 1996; Melillo et al., 1993, 1995; Melillo 1994; Joyce et al., 1995; McGuire and Joyce, 1995,; Perez-Garcia et al., 1997
4.0 Equilibrium Redefined CS pool to represent storage of reactive soil organic carbon instead of total soil organic carbon. Parameters for plant production, decomposition and N immobilization are now dependent on soil texture. Examined the responses of NPP and carbon storage to changes in climate and atmospheric CO2 concentration at the global and continental scales VEMAP Members, 1995; Pan et al.,1996, 1998; McGuire and Hobbie, 1997; McGuire et al., 1997; Xiao et al., 1997, 1998a Schimel et al., 1997; Heimann et al., 1998; Cramer et al., 1999; Kicklighter et al., 1999a; Jenkins et al., 1999, 2000; Nungessor et al., 1999; Schloss et al., 1999
4.1 Transient Incorporated water balance and leaf phenology algorithms. Allow study of transient dynamic of terrestrial carbon, nitrogen and water. Examined interannual variations of NPP and net ecosystem production (NEP) in response to:
  1. historical CO2 for the globe
  2. historical climate and CO2 for the Amazon Basin
  3. historical climate and CO2 for the conterminuous United States
  4. historical and future climate and CO2 for arctic ecosystems
  5. future projections of climate and CO2 change across the globe
  1. Melillo et al., 1996; Kicklighter et al., 1999b
  2. Tian et al., 1998, 2000
  3. Tian et al., 1999; Schimel et al. 2000
  4. McGuire et al., 2000a, 2000b; Clein et al., 2000
  5. Xiao et al., 1998b; Prinn et al., 1999; Reilly et al., 1999; Webster et al., 2003
4.2 Transient Inplemented algorithms describing the effects of land-use change on terrestrial carbon dynamics. Examined the time-dependent responses of terrestrial carbon storage and the net carbon exchange with the atmosphere as influenced by historical climate CO2, and land use McGuire et al., 2001
4.3 Transient Incorporated algorithms describing the effects of ozone on plant productivity. Examined the time-dependent responses of terrestrial carbon storage and the net carbon exchange with the atmosphere as influenced by historical and future climate, CO2, land use and ozone Felzer et al., 2002, 2004, 2005, 2007; Webster et al., 2009 Sokolov et al., 2005, 2008, 2009 Reilly et al., 2007a, 2007b; Webster et al., 2009
4.4 Transient Incorporated disturbance cohort structure to describe sub-grid effects of land-use change on terrestrial biogeochemistry. Examined the time-dependent responses of terrestrial carbon storage and the net carbon exchange with the atmosphere as influenced by future climate CO2, land use and ozone pollution Melillo et al., 2009a, 2009b;
5.0 Transient Incorporated algorithms describing soil thermal regime and the effects of soil temperature on plant productivity, decomposition and nitrogen availability. Does not consider ozone effects Examined the time-dependent responses of terrestrial carbon storage and the net carbon exchange with the atmosphere as influenced by historical and future climate, CO2, land use and soil thermal regime Zhuang et al., 2001, 2002, 2003, 2006, 2007; Lu et al., 2009; Xiao et al., 2009;
5.1 Transient Updated algorithms describing the effects of soil temperature on plant productivity and added algorithms to describe effects of wildfire. Does not consider ozone effects. Examined the time-dependent responses of terrestrial carbon storage and the net carbon exchange with the atmosphere as influenced by historical and future climate, CO2, wildfires, and soil thermal regime. Euskirchen et al., 2006; Balshi et al., 2007, 2009
TEM-Hydro Transient Updated algorithms describing plant physiology from TEM 5.0, but does not include soil thermal dynamics or their effects on terrestrial biogeochemistry. Examined the time-dependent linked responses of terrestrial water, carbon and nitrogen dynamics as influenced by future climate, CO2 fertilization, nitrogen limitation and ozone pollution. Felzer et al., 2009


NOTE: When TEM is run in "equilibrium" mode, all carbon and nitrogen fluxes within terrestrial ecosystems are assumed to be balanced and annual carbon and nitrogen inputs to the ecosystem are equal to annual losses. When TEM is run in "transient" mode, annual net ecosystem production (NEP) can increase or decrease in response to transient climate and atmospheric CO2 concentration. In the absence of disturbances, annual NEP represents the net annual CO2 flux between the atmosphere and the terrestrial biosphere. Terrestrial ecosystems act as a sink of atmospheric CO2 when NEP is positive and act as a source of CO2 when NEP is negative.


Collaborations:

Institution Program Collaborators Topics
Auburn University Ecosystem Dynamics and Global Ecology Laboratory Hanqin Tian, Shufen Pan, Guangsheng Chen, Mingliang Liu, Chaoqun Lu, Wei Ren, Xiaofeng Xu, Chi Zhang land use-ecosystem-climate Interactions in Monsoon Asia
The City College of New York, City University of New York Environmental Crossroads Initiative Charlie Vörösmarty, Balázs Fekete, Pamela Green nonlinear and threshold responses of rinverine carbon and nitrogen export to environmental stresses in U.S. rivers
Lehigh University Department of Earth and Environmental Sciences Benjamin S. Felzer carbon-nitrogen-water interactions in terrestrial ecosystems, air pollution impacts, land-use change (including biofuels) impacts
Massachusetts Institute of Technology Joint Program on the Science and Policy of Global Change Ronald Prinn, Henry Jacoby, John Reilly, Mick Follows, Andrei Sokolov, Adam Schlosser, Chien Wang, Eunjee Lee, Tim Cronin earth system modeling, air pollution impacts, land-use change (including biofuels) impacts, climate impacts of abrupt changes in methane emissions from high-latitude ecosystems, uncertainty analyses
Pennsylvania State University Department of Meteorology Chris E. Forest earth system modeling, climate impacts of abrupt changes in methane emissions from high latitude ecosystems, uncertainty analyses
Purdue University Ecosystems and Biogeochemical Dynamics Laboratory Qianlai Zhuang interactions of climate, fire, land cover and land use with carbon storage and greenhouse gas emissions in Northern Eurasia
University of Alaska-Fairbanks Spatial Ecology Laboratory A. David McGuire, Joy Clein, Eugenie Euskirchen, Dan Hayes, Todd Burnside interactions of climate, fire, land use with terrestrial carbon storage, river carbon export and greenhouse gas emissions in the Pan-Arctic
Water and Environmental Research Center Katey Walter climate impacts of abrupt changes in methane emissions from high-latitude ecosystems
Universdade de São Paulo, Brazil Centro de Energia Nuclear na Agricultura Carlos C. Cerri land-use change effects on carbon storage and greenhouse gas emissions in Brazil
Escola Superior de Agricultura "Luiz de Queiroz" Carlos E. P. Cerri

Projects:

Sponsor Project Name Period PIs
DOE-SciDAC Collaborative Research: Quantifying Climate Feedbacks of the Terrestrial Biosphere under Thawing Permafrost Conditions in the Arctic September, 2011 - August, 2014 Qianlai Zhuang, Adam Schlosser, Jerry Melillo, David Kicklighter Katey Walter Anthony
NSF-Earth System Models A Regional Earth System Model of the Northeast Corridor: Analyzing 21st Century Climate and Environment May, 2011 - April, 2014 Charles J. Vörösmarty, Faye Duchin, Jorge E. Gonzalez, Jerry M. Meillo, Wilfred M. Wollheim
NSF-Cyber-Enabled Discovery and Innovation (CDI) Collaborative Research: CDI-Type II: A Paradigm Shift in Ecosystem and Environmental Modeling: An Integrated Stochastic, Deterministic, and Machine Learning Approach September, 2010 - August 2014 Qianlai Zhuang, Melba Crawford, Hao Zhang, Dongbin Xiu, Jian Zhang, Jerry M. Meillo, John Reilly
DOT-FAA Environmental Cost-Benefit Analysis of Alternative Jet Fuels (Project 28) September, 2010 - August 2011 James I. Hileman, Sergey Paltsev, Ian A. Waitz
NASA-LCLUC Changes of Land Cover and Land Use and Greenhouse Gas Emissions in Northern Eurasia: Impacts on Human Adaptation and Quality of Life at Regional and Global Scales May, 2009 - May 2012 Qianlai Zhuang, Jerry Meillo, David Kicklighter, John Reilly, Anatoly Shvidenko, Nadja Tchebakova, Elena Parfenova, Anna Peregon, Andrey Sirin, Shamil Maksyutov, Guangsheng Zhou, Jiyuan Liu
EPA Biofuel Trade-offs: Fuels, Forest, and Food March, 2009 - September, 2010 John Reilly, Jerry Melillo, Sergey Paltsev, Angelo Gurgel, David Kicklighter, Adam Schlosser
Packard Foundation Biofuels Production, Disruption of the Nitrogen Cycle and Other Ecological Effects January, 2009 - December, 2011 Jerry Melillo
DOE Impacts of Climate Change on Biofuels Production August, 2008 - August, 2011 Jerry Melillo, Ben Felzer
DOE Quantifying Climate Feedbacks from Abrupt Changes in igh-Latitude Trace-Gas Emissions August, 2008 - July, 2011 Adam Schlosser, Chris E. Forest, Ron Prinn, Jerry Melillo, David Kicklighter, Qianlai Zhuang, Katey Walter
NASA-LCLUC Land Use - Ecosystem - Climate Interactions in Monsoon Asia: Evaluating the Impacts of Current and Projected LCLUC on Climate, Water, and Carbon Cycling in the First Half of the 21st Century May, 2008 - April, 2011 Hanqin Tian, Robert Dickinson, Jerry Melillo, John Reilly, Hassan Virji
EPA Nonlinear and Threshold Responses to Environmental Stresses Inland-River Networks at Regional to Continental Scales June, 2005 - June, 2010 Jerry Melillo, Bruce Peterson, Charlie Vörösmarty, Benjamin Felzer, David Kicklighter, Wilfred Wollheim
EPA Dynamic Modeling of Emissions from Land-use Activities June, 2005 - June, 2010 John Reilly, Jerry Melillo, Benjamin Felzer, David Kicklighter, Sergey Paltsev, Qianlai Zhuang


Model Comparison and Evaluation Activities

Reference Name Products
CCMLP
  1. Phase I
  2. Phase II
Carbon Cycle Model Linkage Project
  1. Heimann et al., 1998; Kicklighter et al., 1999b; McGuire et al., 2000, 2001
GPPDI Global Primary Production Data Initiative Clark et al., 2001a, 2001b
PnET / TEM Predicting the Effects of a Changing Physical and Chemical Climate on Primary Production, Nutrient Cycling and Water Yield for Forests of the Northeastern U.S.: A Comparison of Models and Scales Jenkins et al., 1999, 2000
Potsdam 95 IGBP NPP Model Intercomparison Workshops Bondeau et al., 1999; Cramer et al., 1999; Kicklighter et al., 1999a; Schloss et al., 1999
VEMAP
  1. Phase I
  2. Phase II
Vegetation / Ecosystem Modeling and Analysis Project
  1. VEMAP Members, 1995; Pan et al.,1996, 1998; Schimel et al., 1997; Jenkins et al., 1999
  2. Schimel et al., 2000

Last Updated 22 April 2010