滇石林石漠化与次生林的土壤含水率时空变化比较研究

土壤水分是植被发育和生态恢复的关键。降雨、植被等影响着土壤含水率的时空异质性等的变化，这种作用在西南喀斯特地区尤为显著。以云南石林为例，选取典型石漠化样地及次生林样地，利用PR2(PR2-UM-2.0)传感器于每月月末对两类样地中0~1 000 mm土层的土壤含水率进行测定。结果表明：（1）石漠化样地各土层的土壤含水率在1年测定时间范围内均显著高于次生林样地，这与非喀斯特区域植被-土壤含水率关系不同；（2）两类样地的1年内各月土壤含水率之间差异显著，雨季各层土壤含水率高且波动较旱季小；（3）土壤含水率随土层深度增加而增加，400~600 mm范围增幅最大，600 mm以下的土壤含水率增幅会逐渐减小。

Comparison of spatio temporal variations of soil moisture in rock desertification and secondary forest areas of Shilin, Yunnan

Soil moisture is key to vegetation development and ecological restoration. The temporal and spatial variations of soil moisture are mainly affected by rainfall and vegetation, which is particularly significant in karst areas. The PR2 sensor was used to measure the Soil Moisture Content (SMC) of two typical soils at the depth of 0-1，000 mm on a monthly basis, with the case in the Rock Desertification Ecosystem (RDE) and Secondary Forest Ecosystem (SFE) in Shinlin,Yunan Province, China. The results show that the SMC of the RDE is significantly higher than that of the SFE during the study period, which is completely different from non-karst regions. The SMCs of both monitoring sites show considerably monthly difference, which fluctuates along with monthly weather and rainfall. Furthermore, the SMC increases with the depth at a soil profile; and it increases the most at the depth from 400 to 600 mm. Below 600 mm deep, the SMC gradually declines.