Modeling needs for predicting responses to CO2 enrichment: plants, communities and ecosystems

Abstract

Abstract Carbon dioxide enhancement of plant growth is an important direct effect of rising atmospheric CO 2 . New or modified modeling approaches are needed to understand and predict responses of native species and ecosystems to CO 2 enrichment. As atmospheric CO 2 doubles within the next 100 years, validated models will be important tools for predicting responses such as changed productivity, altered composition of plant communities, and changes in amounts of sequestered carbon. Needs for modeling plant and ecosystem responses are discussed as part of a comprehensive plan for research of direct effects of CO 2 on vegetation. Primary needs are: (a) a level of model complexity commensurate with general ecological knowledge, one which treats principal CO 2 response functions; (b) the development of models for predicting plant, community and ecosystem responses to CO 2 , (c) an evaluation of sensitivity and uncertainty of CO 2 -dependent model parameters; and (d) validation of model predictions. A secondary need is to establish a framework for evaluating data requirements for models.