(1) Institute for biological problems of cryolithozone SB RAS
Temperature and water regime in permafrost zone have more interrelationship than somewhere. It is conditioned by the number of features: soil development in the annual thawing layer, presence of close underlay waterproof layer, low heat support and low quantity of precipitation. In this condition heat and water exchange occurs in the thin active layer. The maximum depth of seasonal thawing is integrated index of heat and mass exchange intensity of soil active layer in permafrost condition. In dependence of weather condition during observation years the active layer depth variated within 1,30 to 1,45 m in the forest; from 2,30 to 2,60 m on the arable land; from 0,80 to 1,30 m on the forest edge; from 1,00 to 1,15 m on the belt of over moistening, from 1,35 to 165 m on the belt of normal moistening and from 2,50 to 3,30 m on the belt of insufficient moistening.
Temperature regime of taiga-alas landscape soils during warm period of the year have high spatial variation and also depend on many factors: vegetation cover character, exposition, quantity of downward radiation in dependence of facies difference, condition of near the ground layer of atmosphere, heat capacity, heat conductivity and morphological constitution of soil mass etc. Complicated structure of taiga-alas ecosystem associates high spatial variation of water support and soil water regime. Highest water reserve has a soils of accumulative ecosystems, least – antropogenic disturbed autonomous and transit ecosystems, which located on the highest sites. Water regime of autonomous and transit ecosystems has a dynamic character and depend on weather condition.
In formation of soil temperature regime the moisture of active layer of landscapes plays big role. So in hydromorphous soils main mass of incoming energy expending to evaporation, and only tenth part for permafrost defrost and warming it. In the soils of insufficient moistening expenses of downward solar energy for evaporation decreases abruptly and to 50% of radiation balance expends for the defrost and warming of active layer.
Obtained results shows high diversity and high dynamic of heat and hydrological parameters of taiga-alas landscapes. Spatial and temporal abrupt variations of heat and water reserve of alas active layer says about studying of energy and moisture balance actuality in closed systems of alas landscape in condition of global change.
Submittal Information
Name :
Date :
Roman Vasilyevich Desyatkin
30-Jul-04-10:22:56
Organization :
Theme :
Institute for biological problems of cryolitholozone SB RAS