Daurian Steppes (Daursky State Biosphere Reserve)

Description

The territory includes the whole Torey lakes, adjoining river floodplains, more than 20 small lakes and vast steppes. Climate: The climate in the area of the preserve is sharply continental, hot in summer and dry and cold in winter. The climate distinctive feature is huge amplitude of variances in temperature, daily (15-20 C) and annual (90 C), as well as non-uniform distribution of precipitation in the seasons. The climate changes are of cyclic type and they influence the hydrological regime in the territory of the reserve (in particular, a water-level in lakes), which influences in its turn ecosystem, flora and fauna condition. Relief: In the contemporary relief of the reserve's territory accumulative alluvial and lacustrine (laky) plains, rough terrain and isolated massifs of low hills are prevailing. Higher hills with relative height of 100-150 metres above sea level can only be found along the northern shore of lakes. Coastal plain consists of three lake terraces, a characteristic form of terrain here are beach ridges located in a floodplain and the first terrace of lakes above the floodplains. They were formed when the shoreline was shifted as a result of a lake level change. The number of ridges amounts to 19-20 on a slope. Their size varies from 0.5 up to 2-3 metres high and 20-30 metres wide. Hydrology: There are more than 500 lakes in the Torey hollow in the periods of high humidity. In the nominated territory there are about 40 lakes including the largest ones – the - Torey lakes. The reserve contains the Barun-Torey and Zun-Torey lakes, which have the common hydrological system. The lakes have an unsteady water regime, the periodicity of their change is mostly determined by the climate: during the last 200-320 years the lakes have dried and have filled up many times (just in the XX century - four times) with the periodicity of 25-40 years. Constant season changes of Torey level also take place. Soils: Chestnut and mountain-chestnut soils as well as a soil complex containing salines are most widely spread. In the south-western part of the reserve there are sand sediments in the form of active and non-active dunes. Along the Imalka and Uldza river basins meadow and marsh-meadow soils are formed. There are few areas of permafrost of an insular type that are mostly located around the lake hollows. According to the data available, the depth of perennially frozen rocks is about 10-15 metres and sometimes 20 metres. Flora: The list of plants in the reserve today consists of 440 species from 244 genera and 73 families. The following families are most rich with species: aster family - 56 species, gramineous family - 44 species, rose family - 38 species, fabaceous family - 36 species. The reserve has more than 20 species of rare or narrow habitat. Two of them are included in the Red Book of Russia: Chinese triborodnik (Tripogon chimensis (Franchet) Hackel) and a narrow leafed asparagus (Asparagus brachyphyllus Turcz). Mosl of the rest are included in the Red Book of Chita Region. Among the species with a special conservation status relicts and endemics of Central Asia prevail. The crossing of different habitats is typical for the reserve's flora: South-Siberian and Mongolian (64 species), Eurasian (48 species), Central-Asian (43 species), Mandjurian-Daurian (42 species), East Asian (38 species) and circumpolar (35 species) habitats. There are steppes meadow, saline, water and shrubby types of communities, with tansy steppes (a sort of meadow steppes) as endemic for Transbaikalia. Dauria's distinctive feature is a wide spread of crushed stone soils on gentle slopes, ridge tops and placoras, which makes it possible for hemypetrophic variants of steppes to develop among terrain's elements that arc unusual for them. Fauna: There are 4 fish species, 3 amphibian species, 3 reptile species 317 bird species and 48 mammalian species, more then 800 insect species in the reserve's fauna. The fauna of invertebrates is still poorly understood.