Распределение запасов фитомассы кустарниковых тундр Алтае-Саянской горной области в связи с экспозицией склонов

Abstract

Shrub tundra is an integral component of the high mountains of the Altai-Sayan mountain region (ASMR). Phyto-mass reserves were identified in 42 shrub communities located in 24 mountain systems and 3 bioclimatic sectors of the ASMR. Accounting of AGP communities was carried out by the method of mowing in 10-fold repetition, UGP - by the monoliths method in 5-fold repetition on sites with an area 0.25 m2. In the studied tundra, the AGP reserves vary from 874 to 6815 g/m2 on the slopes and from 1419 to 2352 g/m2 on the tops of the ranges. A region of aboveground mass high index is traced on the Southern slopes in the humid and semiarid sectors (2768-6815 g/m2) and it becomes dis-placed to the Northern slopes in the arid sector (2338 g/m2). In the structure of the AGP, the live mass of communities on the slopes is at the level of 197-1727 g/m2, and in the aligned areas - 358-1037 g/m2. It has been established that on the Northern slopes the shrubs prevail in the live weight of the communities (421-899 g/m2, 53-77 %). During the transition to the Southern slopes in the botanical composition of the communities, the mass of shrubs remains high in the humid highland communities (660 g/m2), while in the semiarid and arid highlands they are replaced by lichens (367-461 g/m2) and sedges, respectively (33-53 g/m2). UGP of shrub tundra on different elements of the mesorelief is within the range of 2181-10 829 g/m2. On the slopes and aligned areas of mountain systems of ASMR various biocli-matic sectors, significant relationships were found between the aboveground and underground phytomass reserves (r = -0.93-0.97; n = 6).