Tree responses to CO(2) enrichment: CO(2) and temperature interactions, biomass allocation and stand-scale modeling.

In this review, I focus on modeling studies of tree responses to CO(2) enrichment. First, I examine leaf-scale models of assimilation with respect to the interaction between low temperature and CO(2) enrichment. Second, because changes in allocation within a tree may be significant in determining the growth response of trees to CO(2) enrichment and low temperatures, I review models of the control of allocation in plants. Finally, models of stand-scale processes are discussed with respect to their ability to make reliable estimates of likely vegetation responses to predicted climate change. I conclude that our ability to make reliable predictions is hindered by our lack of understanding of several processes, namely: the interaction between increased atmospheric CO(2) concentration and low temperatures; the control of allocation in plants; and the modeling of stand-scale processes.