THE REGIONAL BIOCLIMATIC SYSTEM AND ITS EVOLUTIONARY ROLE ON THE INSULAR-ARC STAGE OF CONTINENTAL BIOSPHERE FORMATION (BY THE EXAMPLE OF SOUTH-KURIL ISLAND RIDGE)

It was shown that on the island-arc stage of continental biosphere development in the North-West Pacific local geomorphological conditions created the centers of origin of diverse phytocoenological structures of the higher (zonal-regional) level at the initial stages of continental biosphere development. The causal mechanisms of the general descent of the boundaries of altitudinal climatic zones and the southward shift of natural zones on insular extratropical Neo-Pacific compared to the neighboring continents, are discussed. The phenomenal feature of bioclimatic system at the stage of insular landscape formation is the direct subordination of phytobiota to vertical hydrothermal gradients. It forms a system of altitudinal zonality already within a low-mountain landscape. An exceptionally important backbone role of forest phytobiota in the establishment and development of young volcanic landscapes was demonstrated. The optimizing strategy program for the development of plant communities, which is aimed at the maximum biomass formation on forest island-arc landscapes, is much more marked compared to their zonal analogs on the neighboring continent. At the same time, an exceptionally high percentage of green mass in the structure of production results in the acceleration of biological cycle. All the above ensures the survival of insular ecosystems of the boreal Neo-Pacific under unfavorable conditions of "cold" oceanicity.