Surface Cover and Soil Hydrological Characteristics of Alpine Timberline Ecotone in the Upper Reaches of Bailongjiang River
The surface cover and soil hydrological characteristics of alpine timberline ecotone in the upper reaches of Bailongjiang River were studied with the survey of community plots and laboratory analysis methods in the report.The result showed that:(1) the total volume of surface cover varied from 37.33 t/hm2 to 127.28 t/hm2 in the different areas in the upper reaches of Bailongjiang River,it reached the minimum above the timberline,it reached the maximum under the timberline;the timberline area was no different from the below timberline;the volume of the litter decomposition layer in the surface cover was the largest,it accounted for more than half of total volume;the maximum water holding capacity and specific retention of the surface cover under the timberline were the maximal,instead,they reached the minimum above the timberline;(2) soil bulk density increased significantly with the depth of the soil layer;the change of soil bulk density above the timberline was the maximal;the soil bulk density in 0 10 cm soil layer was 0.56 g/cm3,which reached the minimum,and it was 1.12 g/cm3 in 20-40 cm of soil layer,which reached the maximal;however,the change of non-capillary porosity appeared the diametric trend,non-capillary porosity decreased significantly with the depth of the soil layer;non-capillary porosity of surface soil under the timberline was 8.07％,which reached the maximal;and it was 6.27％ above the timberline,which reached the minimum;(3) initial infiltration rate and average infiltration rate were all the largest in 0-10 cm soil layer in the timberline,it reached the minimum above the timberline;the change of initial infiltration rate,final infiltration rate and average infiltration rate were all basically consistent with the changes of the soil layer depths.The result showed that the relation between the specific retention of the surface cover and the immersing time followed the power function.It was expressed as the equation:Y=atk.
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万方数据
维普
