祁连山区亚高山灌丛土壤含水量的空间分布与月份变化规律

为了探究祁连山区不同灌丛类型的土壤水分时空变异规律,论文以祁连山排露沟小流域的箭叶锦鸡儿（Caragana jubata）、吉拉柳（Salix gilashanica）、金露梅（Potentilla fruticosa）、鲜黄小檗（Berberis diaphana）、甘青锦鸡儿（Caragana tangutica）5种灌丛为对象,建立固定样地,进行了一个生长季的分层（0~10、10~20、20~30、30~40、40~60 cm）土壤含水量监测。结果表明：1）在各灌丛类型样地之间,土壤含水量差异很大,由大到小依次为：箭叶锦鸡儿>吉拉柳>金露梅>鲜黄小檗>甘青锦鸡儿。2）在小流域内空间尺度上,地形（海拔、坡向）、气象（降水、温度）、植被、土壤等作为主要因素共同影响着土壤含水量的差异,导致土壤含水量的空间分布具有随海拔（降水）升高而增大、随地形遮荫作用增强而增大（阴坡高于阳坡）的变化规律。3）不同灌丛类型样地土壤含水量在生长季内各月的变异程度均为弱变异或中等变异,相同土层含水量变异系数大小顺序基本为：鲜黄小檗>箭叶锦鸡儿>吉拉柳>金露梅>甘青锦鸡儿。

The Spatial Distribution and Monthly Variation of Soil Moisture of Sub-alpine Shrubs in Qilian Mountains

In order to explore the spatial distribution and monthly variation of soil moisture of the main shrub types in the Qilian Mountains, permanent sample plots were set up for five shrub types in the small watershed of Pailugou of Qilian Mountains, including Caragana jubata, Salix gilashanica, Dasiphora fruticosa, Berberis diaphana and Caragana tangutica. The soil moisture at the depth layer of 0-10, 10-20, 20-30, 30-40, 40-60 cm was measured in a growing season. The results showed that: 1) Among the five shrub plots, the soil moisture differed obviously, according to the following decreasing order: Caragana jubata, Salix gilashanica, Potentilla fruticosa, Berberis diaphana and Caragana tangutica. 2) At the spatial scale of the studied small watershed of Pailugou, the soil moisture was jointly influenced by several factors, such as the elevation (precipitation), slope aspect, vegetation, and soil. This leads to the increase of soil moisture with increasing elevation (higher soil moisture at higher plot) and terrain shading effect (higher soil moisture on shaded slops than on sunny slope). 3) The degree of variation of soil moisture in the growing season can be basically classified into the low or middle intensity for all the five shrub types. The variation coefficients of soil moisture in the same soil layer basically following the decreasing order of Berberis diaphana > Caragana jubata > Salix gilashanica > Potentilla fruticosa > Caragana tangutica.