THE VEMAP INTEGRATED DATABASE FOR MODELING UNITED-STATES ECOSYSTEM VEGETATION SENSITIVITY TO CLIMATE-CHANGE/

For the Vegetation/Ecosystem Modelling and Analysis Project (VEMAP), w e developed a model database of climate, soils and vegetation that was compatible with the requirements of three ecosystem physiology models and three vegetation life-form distribution models. A key constraint was temporal, spatial and physical consistency among data layers to pr ovide these daily or monthly time step models with suitable common inp uts for the purpose of model inter-comparison. The database is on a 0. 5 degrees latitude/longitude grid for the conterminous United States. The set has both daily and monthly representations of the same long-te rm climate. Daily temperature and precipitation were stochastically si mulated with WGEN and daily solar radiation and humidity empirically e stimated with CLLMSIM. We used orographically adjusted precipitation, surface temperature and surface windspeed monthly means to maintain co nsistency among these fields and with vegetation distribution. Vegetat ion classes were based on physiognomic and physiological properties th at influence biogeochemical dynamics. Soils data include characteristi cs of the 1-4 dominant soils per cell to account for subgrid variabili ty.