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Compendium on methods and tools to evaluate impacts of, and vulnerability and adaptation to, climate change

IBIS (Integrated BIosphere Simulator)

IBIS performs integrated assessments of water balance, carbon balance, and vegetation structure on both global and regional scales based on an integrated modeling approach that explicitly represents competition between plant functional types (competition for light and water) and characterizes their responses to global change drivers (land use changes, climate variability and change, atmospheric CO2).

IBIS is designed around a hierarchical conceptual framework, and includes several submodels (or “modules”) that are organized with respect to their characteristic temporal scale: land surface processes (energy, water, carbon and momentum balance); soil biogoechemistry (carbon and nitrogen cycling from plant through soil); vegetation dynamics (plant competition for light, water, and eventually nutrients); vegetation phenology (based on a growing degree day approach); and atmospheric coupling (IBIS is now directly coupled to GENESIS and CCM3 GCMs).

Appropriate Use IBIS represents a wide range of ecosystem and land surface processes in a single, physically consistent framework. In this way, IBIS can simulate the dynamic behavior of land surface and ecosystem processes, and their consequences for vegetation composition and structure.
Scope Global; spatial: 0.5°, 1.0°, 2.0° and 4.0°; temporal: hourly.
Key Output GPP, above and belowground NPP, NEP, fine root and heterotrophic respiration, nitrogen mineralization, latent, sensible heat, aet, evaporation, transpiration, snow temperature, extension and depth. Carbon and nitrogen: (a) vegetation: fine roots, leaves, and wood for upper canopy (trees) and fine roots and leaves for lower canopy (shrubs and grasses); (b) litter: above and belowground (fine root) separated in 3 distinct pools (decomposable, structural and resistant); (c) soil organic matter: microbial biomass, protected and unprotected “slow” C pools, and passive C pool.
Key Input Climatic, site, vegetation, soils and resolution (e.g., daily, monthly).
Ease of Use Expert ecosystem vegetation scientist
Training Required Yes
Training Available No formal training offered
Computer Requirements High performance cluster

Applications Global climate impacts and


Global climate impacts

Contacts for Framework, Documentation, Technical Assistance

Jonathan Andrew Foley

Center for Sustainability and the Global Environment (SAGE), Institute for Environmental Studies, University of Wisconsin, 1225 West Dayton Street, Madison, Wisconsin 53706 USA; Tel: 608.265.9119; Fax: 608.265.4113; e-mail:

Cost Not provided

Foley, J.A., I.C. Prentice, N. Ramunkutty, S. Levis, D. Pollard, S. Sitch, and A. Haxeltine. 1996. An integrated biosphere model of land surface processes, terrestrial carbon balance and vegetation dynamics. Global Biogeochemical Cycles 10:603-628.

Delire, C. and J.A. Foley. 1999. Evaluating the performance of a land surface/ecosystem model with biophysical measurements from contrasting environments. Journal of Geophysical Research (Atmospheres) 104(D14):16:895-16,909.

Kucharik, C.J., J.A. Foley, C. Delire, V.A. Fisher, M.T. Coe, J. Lenters, C. Young-Molling, N. Ramankutty, J.M. Norman, and S.T. Gower. 2000. Testing the performance of a dynamic global ecosystem model: Water balance, carbon balance and vegetation structure. Global Biogeochemical Cycles 14(3):795-825.

Wang, G., E.A.B. Eltahir, J.A. Foley, D. Pollard and S. Levis. 2004. Decadal variability of rainfall in the Sahel: results from the coupled GENESIS-IBIS atmosphere-biosphere model. Climate Dynamics 22(6-7):625-637.