ИСТИНА

Changes in the boundaries of high-altitude mountain belts can be treated as a proof of climate change. These changes were caused by the termination of human activities. The paper presents the role of climatic factors in changes of the boundaries and state of sub-alpine landscapes in the North Caucasus, where the transformation of land use system was observed. Weakening and even termination of the economical activity, population outflow and abandonment of the mountain grasslands make marginality a many-sided problem of the mountain regions. These processes are occurring at the background of the climate change. The estimate of changes in heat and humidity was made for the mountains of Central Caucasus using vegetation index (NDVI), the index of vegetation conditions (VCI), the sum of active temperatures (air temperature above + 10 °C) and precipitation. Methods of remote sensing and mapping of vegetation indexes (NDVI, VCI) prove that there is a trend to increase of humidity from the beginning of XXI century in the studied mountain grassland areas. In the middle mountains of the North Caucasus regeneration of natural boundaries of altitude zones is observed: the expansion of mountain-forest belt and restoration of pine forests on the southern slopes; restoration of mountain meadow steppe and steppe sub-alpine meadows on former agricultural terraces; northern slopes overgrown with crooked birch. Thus, climate change and weakening economic activity on the territory lead to restoration of vegetation in the area of middle mountains. The climate change with positive consequences for the mountain landscapes can be one of the opportunities to overcome some aspects of marginality of the territory.