Abstract:

Combining with field measurement, indoor statistics and moving-split window technology, the dynamic spatial and temporal distribution and influence of depth on the soil moisture interface of cultivated grassland-cropland boundary were studied in Guizhou Province to provide references for returning farmland to grassland and grass and crop rotation/intercropping in Southwestern mountain areas. The results showed that the topsoil moisture of cultivated grassland was higher than that of cropland in studied area, and the change trend of topsoil moisture of four seasons in a year showed as “high-low-high”, indicating that the spring, summer, autumn and winter was the storage period, consumption period and recovery period of soil moisture, respectively. Using the determination of moving split-window technology, it was concluded that the position of soil moisture interface coincided with the position of landscape interface in studied area, the total width of spring soil moisture boundary was 41 m, and the change rule was “wide-narrow-wide” in a year, the depth of edge influence variation of soil moisture boundary in cropland system was consistent with total width of boundary, while the depth of edge influence was narrower and narrower in cultivated grassland system as seasons passed. Thus, the studied area was divided into cultivated grassland functional system, cultivated grassland-cropland compound functional area system and cropland functional system. This study has reference value in the sustainable development of Southern grassland animal husbandry.

Key words: Southern ecotone, Boundary width, Moving-split window technology, Soil moisture, Seasonal variation

摘要：

采用野外测定、室内统计和移动窗口法相结合,对贵州人工草地-农田界面土壤水分的时空分布和影响宽度动态进行了研究,以期为西南山区的退耕还草和草田轮作/间作提供参考。结果表明:在空间上,研究区人工草地土壤表层(0～20 cm)的含水量高于农田;在时间上,研究区一年四季土壤表层水分的表现为“高-低-高”的变化规律,表明春季、夏季和秋季、冬季分别为土壤水分的贮存期、消耗期、恢复期。通过移动窗口法判定得出,研究区土壤水分界面位置与景观界面位置重合,春季界面总宽度为41 m,一年四季表现为“宽-窄-宽”的变化规律,土壤水分界面在农田系统的影响域变化与总界面宽度保持一致,而在人工草地系统则表现为随着季节的推移界面影响域越来越窄;由此可将研究区划分为人工草地功能区系统、人工草地-农田复合功能区系统和农田功能区系统。该研究对南方草地畜牧业的可持续发展和界面理论的丰富具有参考价值。

关键词: 南方农牧交错带, 界面宽度, 移动窗口法, 土壤水分, 季节变化