The coming global climate changes associated with the increase of atmospheric greenhouse effect, may disturb the natural carbon cycle in the biosphere and may lead to large-scale ecological consequences. The cognition of the mechanisms of environmental sustainability in changing climate is connected with studying the biotic regulation of the carbon cycle. Boreal forests play an important role in the global carbon cycle. This book expounds the regional-local prognostic conception as a scientific basis of monitoring forest ecosystems under global climatic changes. Predictive landscape-ecological scenarios of the nearest future of temperate forests and their paleogeographical analogs as a single system of global changes have been considered for the first time by the example of a large region—the Volga River basin.