贵州人工草地-农田界面土壤水热耦合影响域动态变化研究

通过对贵州人工草地-农田界面表层土壤(0~20cm)的调查采样和室内分析,明确界面土壤水分和温度的空间变化特征,利用水分和温度双因素耦合来判定界面影响域,探讨其季节性动态变化过程。结果表明:人工草地土壤水分四季分别为60.7%±0.31,23.6%±0.20,19.7%±0.20和70.4%±0.19,均高于农田的34.5%±0.52,11.8%±0.23,10.0%±0.19和64.1%±0.13;土壤温度空间变化表现为夏秋季节草地低于农田,冬春季节草地高于农田;贵州农田-人工草地界面四季土壤水热耦合影响域处于一个动态变化的过程,呈现为"窄-宽-窄"的规律;四季界面影响域宽度分别为25,28,34和29m。利用双因素耦合判定界面影响域能够在一定程度上避免单因素判定造成的"偏向性"结果。

Dynamic Variation of the Magnitude of Edge Influence of the Coupling of Soil Temperature and Moisture on Cultivated Grassland-cropland Boundary in Guizhou Province

This study aimed to quantify the spatial variation characteristics of soil temperature and moisture,and to determine the dynamic variation of the magnitude of edge influence of the coupling of soil tempera ture and moisture on cultivated grassland-cropland boundary in Guizhou province.Results showed that the soil moisture of grassland in four seasons was 60.7％±0.31,23.6％±0.20,19.7％±0.20 and 70.4± 0.19,respectively,which was higher than that in cropland area;Soil temperature in grassland was lower than in cropland in summer and autumn,but it was completely opposite in winter and spring;Magnitude of seasonal edge boundary of cultivated grassland-cropland were 25 m,28 m,34 m and 29 m,respectively,and the changes showed a "narrow-wide-narrow" trend.The one-sided results caused by the single factor may be avoided by using the coupling of these two factors to determine the edge influence of boundary.