摘要
A case study is made of the Mendeleev volcano (Kunashir Island, Southern Kuril Chain) to carry out a quantitative assessment of the influence of magmatic energy of an active volcano on the thermal regime of the soil and the ground-level air level as well as on the water balance and forest formation processes in the insular volcanic landscape. It is established that the influent channels of steam-hydrotherms cause an anomalous rise in soil temperature thereby having a substantial influence on the structure and functioning of forest ecosystems. Using a specially developed method, we calculated the geotherm-caused temperature anomalies in the soil. Calculations showed that the forest communities of the Mendeleev volcanic landscape evolved into existence and persist under the same heat and energy conditions as their zonal marginalmainland counterparts. The active volcano compensates for a deficiency in the climatic resource and ensures a stable functioning and a structural configuration of these “climatically unjustified” (extrazonal) island-arc ecosystems. We have empirically substantiated the proposition that geothermal energy of passive volcanoes serves as the factor for acceleration evolution of the insular phytobiota. This constitutes the phenomenon of biogeocenological organization of the volcanogenic landscape in the continent-to-ocean transition zone. It is shown that the magmatic geotherms of the Mendeleev volcano promoted the transgression of species and whole communities from southern areas to this boreal-forest region. We examine the rearrangement of the forest cover toward an increase in its floro- and phytocenotic diversity, the formation of relatively stable boreal-subboreal forest ecosystem with subtropical relicts as well as rudimentary buffer forest communities. It is demonstrated that a geothermal heating of the soil on the slopes and at the foot of the volcanoes of the Kuril Ridge is a large-scale (rather than an exceptional) phenomenon in the hydrothermal regime of forest ecosystems of island-arc ecoregions.