Resource potential of the Volga River basin forests in mitigation of Global Warming (towards the Paris Agreement on Climate Change)

The known conceptual provisions on the ecological resources of the forest cover as its ability to additionally absorb greenhouse gases using mechanisms of regulation of the carbon cycle under climate change are empirically substantiated. Using the example of the Volga basin, a regional experiment was carried out on the numerical solution of a dual problem set by the Paris (2015) Agreement on Climate Change: to calculate the absorption of CO2 from the atmosphere by forest communities under current global warming, taking into account their adaptation to climate change, and thereby assess the regulation of the carbon cycle by forests, which should contribute to the mitigation of warming. The materials of largescale landscape surveys previously conducted by the author in the Middle and Upper Volga region were used. The index of elasticplastic stability of forest ecosystems is proposed as an adaptation indicator. Multiple regression methods are used to reveal spatial variability of forest carbon balance in connection with changes in their adaptive potential and with the climate predicted for 2100 according to the global HadCM3 model, which is adequate to the current unprecedentedly high growth of global warming. The adsorption potential of native and derivative boreal and nemoral forests is established, their ability to mitigate climate change, including reducing anthropogenic warming, is assessed. A picture of a significant increase in the adsorption capacity of boreal and nemoral forests with an increase in their elasticplastic stability is obtained. A quantitative assessment of the loss of environmental resources by forests of the Volga river basin since the beginning of intensive forest and land use is carried out. Contrasting changes in the environmental resources of boreal and nemoral forests in the process of global warming are revealed. The expected structural changes in boreal and nemoral forests in this process should not significantly change their adsorption potential. For the initial period of global warming (1990–2009), the verification of predictive models of the carbon balance of the Volga basin for boreal forests of Central Canada was carried out. Numerical assessment of the influence of elastic stability of forest formations and predicted climatic conditions on the carbon balance of forests was carried out using multiple regression methods.