青海省刚察县吉尔孟地区不同厚度土壤水分研究

通过土壤含水量测定,对青海湖西部天然草地不同厚度土壤含水量等问题进行了研究.结果表明,吉尔孟厚土层和薄土层土壤含水量均呈现随深度增加而逐渐降低的趋势.在相同土壤厚度条件下,低草地土壤含水量比高草地含水量高.在植被相同条件下,厚土层含水量比薄土层的含水量高.草地厚土层在80 cm深度出现土壤干层,指示当地的土壤下部水分不足.30 cm厚度的薄土层高草地和30 cm厚度的薄土层低草地分别在21和24 cm出现了含水量低于11％的干化现象.厚土层上部30 cm含水量比30 cm厚度的薄土层含水量高12.4％.吉尔孟土壤水分的突出特点是上部含水量高,说明该区土壤水分具有在上部聚集的特点,这是该区土壤冻结期较长和蒸发及蒸腾较少造成的,土壤水分在上部聚集对草原植被生长是有利的.由于该区土壤下部水分不足,该区应该发展耐旱牧草和其他耗水较少的草原植被,不适于发展深根系耗水较多的植被.

Soil Moisture of Different Thicknesses in Jiermeng Area of Gangcha County,Qinghai Province

The variation of soil moisture content of different thicknesses in the western Qinghai Lake was investigated based on the measurements of soil moisture content.Results showed that the soil moisture contents of thick and thin soil layers in Jiermeng area gradually decreased with the increased depth.In the same soil thickness,the soil moisture content in short grass land was higher than that in tall grass land.Under the same vegetation conditions,the soil moisture content of thick soil layer was higher than that of thin soil layer.A soil dry layer appeared at 80cm depth in thick soil layer,indicating the local moisture deficiency in the lower part of the soil layer.The soil moisture content of thin soil layer(30cm thickness)presented a drying phenomenon,with less than 11% of the moisture content at the 21cm depth in tall grass land and 24cm depth in short grass land,respectively.Soil moisture in Jiermeng area was outstandingly characterized by the higher moisture content in the upper part of soil layer,implying that there was a gather characteristic in the upper part.The outstanding characteristic was mainly caused by longer freezing period and less transpiration and evaporation,and it was beneficial to develop grassland vegetation.Because of the local moisture deficiency in the lower part of soil layer,the region is suitable for the development of drought-resistant and low water consumption vegetation and is not suitable for the development of vegetation with deep root and high water consumption.