Response of unmanaged forests to CO/sub 2/-induced climate change: available information, initial tests, and data requirements

Abstract

The scientific literature is reviewed to determine how tree recruitment, growth, and mortality are related to climate directly and indirectly through climate's modulation of plant competition, succession, and migration. The resulting potential responses of forest communities to climate changes expected under increased atmospheric CO/sub 2/ concentrations are described. Empirical data sets, containing measurements of climate variables and tree densities in the eastern United States, are evaluated for their potential use in statistical projections of forest responses to climate change. Also evaluated for projection purposes is a forest-stand simulation model based on many of the processes which determine forest dynamics. The ability of the model to reproduce extant forests at 21 sites in eastern North America was first verified. Then, a model experiment simulated responses of forests at those 21 locations to a scenario in which climate responds to doubling and quadrupling of CO/sub 2/. The implications of the forest simulations are discussed in terms of internal forest dynamics and requirements for specified information from climate projections, as well as for additional model developments that could address remaining ecological uncertainties. 236 references, 35 figures, 4 tables.