In this chapter, ecosystem and economic models are integrated to estimate the impact of climate change on the US timber industry. Beginning with alternative General Circulation Model (GCM) climate scenarios, the steady-state response of ecosystems in the United States to climate change is predicted. We then develop dynamic scenarios of ecosystem change from these steady-state predictions. Using a dynamic economic model, harvests and endogenous prices are calculated over time, which adjust to these gradual changes in forest distribution and productivity. Model results vary depending on the combination of models used. For example, combining a dynamic ecological scenario with a dynamic economic one results in net benefits because this allows for salvage and other human management and adaptation.
Changes in temperature and precipitation can affect the natural ecosystems by altering the growing season, available soil moisture, or nutrient balances. The combined impact of these changes may affect the growth rates of plants or alter the competitive balance among species (Solomon and West, 1985). Ultimately, this will lead to a change in species composition on the land, and/or a change in land productivity (Neilson and Marks, 1994; Melillo et al., 1993; McGuire et al., 1993; Neilson et al., 1992; Prentice et al., 1992; IPCC, 1996b).
Although substantial work has been done on agricultural impacts, there are few studies of the impact of climate change on timber (Binkley and Van Kooten, 1994).