Evidence for global warming over the past 200 years is overwhelming (Hulme et al. 1999), based on both direct weather observation and indirect physical and biological indicators such as retreating glaciers and snow/ice cover, increasing sea level, and longer growing seasons (IPCC 2001). Recent GCM projections of the Hadley Centre (Gordon et al. 2000) for Siberia show an increase in temperature of 4º C to 6º C and an increase in precipitation of as much as 25% by 2100. These changes, moreover, could occur at a rate of 0.1º C to 0.4º C per decade (Watson et al., 1996).The rapid rate of change coupled with the large absolute amount of change is expected to have profound effects on plants of the boreal forests at all hierarchial levels: from forest zones (Monserud et al., 1993), to ecosystems (Guisan et al. 1996), to species (Iverson and Prasad 1998, Box et al. 1999), to populations within species (Rehfeldt et al. 1999b, 2002).
Our goals are to estimate effects of a warming climate on Siberian vegetation, first, at the highest level of organization, and, second, the lowest. The first considers the effects of global warming as zonal vegetation shifts across the plains and plateaus of central Siberia, and the second considers intraspecific effects within the mountains of southern Siberia. For the second objective, we invoke Turesson's concept of climatypes, the climatic ecotypes that comprise species, and illustrate intraspecific effects for Pinus sylvestris and Larix sibirica.