晋西北黄土丘陵区4种植被类型土壤水分含量的变化特征研究

不同植被类型对于陆地生态系统的水分循环具有重要的调节作用。以晋西北黄土丘陵区偏关县境内的小叶杨林地、柠条林地、草地和撂荒地4种植被类型为研究对象，采用土钻法分别测定0～600cm不同土层的土壤水分含量，分析了晋西北不同植被类型的土壤水分含量的垂直分布特征及4种植被含水量的差异比较。结果表明：（1）在0—600cm土层中，平均土壤水分含量因植被类型不同表现显著差异（P〈0．05），依次表现为小叶杨〉草地〉撂荒地〉柠条；（2）在0—600cm土层中，土壤水分含量随着土层深度的增加呈现先逐渐降低后趋于稳定的趋势，且同一植被类型不同土层深度间土壤水分含量差异显著（P〈0．05），同一土层不同植被类型间的土壤水分含量也有显著差异（P〈0．05）；（3）研究区土壤剖面可分为易变层（0～100cm）、活跃层（100～200cm）、次活跃层（200—300em）和相对稳定层（300—600em）。在晋西北黄土丘陵区植被恢复中，应根据本区域土壤水分变化特点，选择适宜的植物种类，采取乔一草或乔一灌一草相结合的植被配置模式，以减少该区域土壤水分的过度消耗，这对于改善当地植被的生态效益具有重要意义。

Soil Moisture Characteristics of Different Vegetations in Hilly Region of Loess Plateau in Northwest Shanxi

Various vegetations play important roles in regulating hydrological cycles of terrestrial ecosystems. Four types of vegetation namely Populus simonii forest, Caragana korshinskii forest, grass land and abandoned land in Pianguan county of Shanxi province were chosen as the study sites to measure the soil moisture content in 0 ~ 600cm soil layer respectively, with the objectives to understand the soil moisture content conditions, vertical distributions and variations of different vegetation types in northwest Shanxi. The results were as follows ： （ 1 ） In the 0 - 600 cm soil layer, the average content of soil moisture of the four vegetations is significantly different （p 〈 0.05 ） , showed the results of Populus simonii forest 〉 grass land 〉 abandoned land 〉 Caragana korshinskii forest ; （2） In the 0 600 cm soil layer, the soil moisture content decreases gradually and then goes stable as the soil depth increases . Significant differences of soil moisture content are shown in both the same vegetation type in different depths of soil and different vegetation types in the same depth of soil; （3） Soil profiles can be divided into four parts based on the actual situation of research plots： variable layers （0 - 100 era）, active layers （100 -200 cm）, sub-active layers （200 -300 era）, and relatively stable layers （300 -600 era）. Therefore, selection of appropriate plant species and adoption of vegetation configuration modes which combine tree-grass modes and tree-shrub-grass modes according to the characteristics of changes of soil moisture in this region are of great significance to guide vegetation construction in this region.