Features of the heat and water regime of Taiga - Alas landscapes
Alexei R. Desyatkin (1), Tatyana N. Semenova (1), Maiya Ch. Nikolaeva (1)
(1) Institute of Biological Problem of Cryolithozone SB RAS
In the period of 1988-2000 temperature and water regime of taiga- alas ecosystems soils was studied on the base of a model alas. Multi year investigation determined:
1. The permafrost landscape soils of Taiga - Alas ecosystems are characterized by high annual heat cycle, which mainly associated by high heat expenses for their thawing (72-95 % from annual heat cycle amount). High cryogenesis potential in soils provides poor productive heat cycle.
2. The heat content of soils increasing by 2 times during stubbing and plowing, and thawing depth increase by more than 2 times. Positive effect of forest stubbing - is the only factor in improvement of heat resources. In 15 years upon stubbing, the soils under tillage permanently suffer water deficit during 9-10 years (soil moisture decreased at the time of vegetation marcescence level or capillary breaking). Therefore, the forest stubbing and plowing are factors of secondary spatial contrast making, equal with natural at the scale.
3. Forest soils of inter alas during the all years of investigation characterized by adequate moistening. Therefore the hydrological role of permafrost forest evaluated as a moistening of surrounding landscapes. It is need to take into account this factor with agriculture reclamation of permafrost forests. No need to build vast stub-out areas without necessity.
4. Most dry soils are located under the steppe meadow on the highest places of alas. The soils of forest edge, the real and the wet meadows in the all years of investigation are occasionally differed by superabundant moistening. Over permafrost top water sometimes takes main part of forest edge, the real and the wet meadows water balance.
5. Evapotranspiration predominate in expenses part of water balance of permafrost alas soils. At the same time, main part of water circle proceeded in upper 0-20 „ƒm and 0-50 „ƒm soil layer.
6. In the wet years in the middle and low belts of alas repeated drench of soils up to permafrost level and accumulation of thick top water observed. Upward water movement predominates in the dry years in all soil types, i.„u. accumulated soil water stock returns to the active water circle zone.
7. Accumulation ability and subsequent returning of moisture is important distinction of permafrost alas soils water regime and favorable factor for plants moisture supply in cryolithozone.
Submittal Information
Name :
Date :
Mr. Alexei R. Desyatkin
29-May-01-16:45:18
Organization :
Theme :
Institute of Biological Problems of Cryolithozone SB RAS
