The Vegetation/Ecosystem Modeling and Analysis Program (VEMAP) was a multi- institutional, international effort that addressed the response of biogeography and biochemistry to environmental variability in climate and other drivers in both space and time domains.

The objectives of VEMAP were to:

• study the intercomparison of biogeochemistry models and vegetation type distribution (biogeography) models
• determine model sensitivity to changing climate, elevated atmospheric carbon dioxide concentrations, and other sources of altered forcing

The VEMAP project was conducted in two phases.

VEMAP Phase 1 was structured as a sensitivity analysis with combinations of climate (current and projected under doubled CO₂); atmospheric CO₂; and mapped and model-generated vegetation distributions. The highly structured nature of the intercomparison allowed rigorous analysis of results while constraining the range of questions explored. The data used as model input in VEMAP Phase 1 were published on CD-ROM as:

• Kittel, T. G. F., N. A. Rosenbloom, T. H. Painter, D. S. Schimel, H. H. Fisher, A. Grimsdell, VEMAP Participants, C. Daly, and E. R. Hunt, Jr. 2000. The VEMAP Phase 1 Database: An Integrated Input Dataset for Ecosystem and Vegetation Modeling for the Conterminous United States. CD-ROM. National Center for Atmospheric Research and University Corporation for Atmospheric Research, Boulder, Colorado, U.S.A.

The objective of VEMAP Phase 2 was to compare time-dependent ecological responses of biogeochemical and coupled biogeochemical-biogeographical models to historical and projected transient forcings across the conterminous U.S. These model experiments were driven by historical time series and projected transient scenarios of climate and atmospheric CO₂.

• VEMAP Phase 1 User's Guide (PDF)
• VEMAP Phase 2 User's Guide (PDF)