Liu Hong-lai, Zhang Wei-hua, Wang Kun, Zhao Na
College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
Ying Yong Sheng Tai Xue Bao. 2009 Mar;20(3):659-64.
In the agriculture-pasturage ecotone of Northern China, a typical zone with linear boundary of cropland and grassland was chosen to investigate its soil moisture regime, and the moving split-window technique was adopted to study the edge influence of soil moisture at the boundary. The results showed that the edge influence was 10 m, from 6 m within grassland and 4 m within cropland, and was categorized as the acute change type boundary. Accordingly, the farmland-grassland landscape boundary could be divided into three functional zones, i.e., grassland zone, farmland zone, and compositional ecotone zone. Soil moisture content varied abruptly in the ecotone zone, but presented linear distribution in both grassland zone and farmland zone. The average soil moisture content in grassland was about 1 g x g(-1) higher than that in farmland, which was mainly caused by the decreased capillary moisture capacity of farmland. Owing to the different vegetation cover, farmland and grassland had different transpiration and evaporation, which led to the diverse soil moisture regime, making soil water potential changed and water movement from one ecosystem to another possible.
在中国北方农牧交错带，选取了一个具有典型农田与草地线性边界的区域来研究其土壤水分状况，并采用移动分裂窗技术研究边界处土壤水分的边缘效应。结果表明，边缘效应范围为10米，其中草地内部6米，农田内部4米，属于急剧变化型边界。据此，农田-草地景观边界可划分为三个功能区，即草地功能区、农田功能区和复合生态交错区。土壤水分含量在生态交错区内变化剧烈，但在草地功能区和农田功能区内呈线性分布。草地的平均土壤含水量比农田高约1克/克，这主要是由于农田毛管持水能力下降所致。由于植被覆盖不同，农田和草地的蒸腾与蒸发作用各异，导致土壤水分状况不同，使得土壤水势发生变化，水在不同生态系统间的移动成为可能。
