三江源地区各类生态系统土壤的性状及其形成能力

Soil property and its formation of ecosystems in three river sources,Qinghai

土壤形成是MA框架下生态系统支持功能的基本内容。运用GIS空间分析功能,测算了青海三江源区生态系统支持功能,结果表明:①源区土壤形成和生态系统支持功能呈从东南向西北降低的趋势;②源区各生态系统土壤形成的支持功能具有湿地生态系统>森林和草地生态系统>农田生态系统>荒漠和裸土地及裸岩石砾地的特点;③源区各生态系统支持功能具有从湿地生态系统、森林生态系统、草地生态系统、农田生态系统到荒漠和裸土地及裸岩石砾地依次降低的趋势;④草地生态系统退化诱导草地土壤形成功能的退化,进而驱使草地生态系统支持功能的降低;⑤强度人为干扰造成生态系统土壤各种性状向退化方向发展,土壤形成及生态系统支持功能下降。结果有助于丰富人们从土壤形成视角,对生态系统支持功能的理解和认识。

Soil formation plays an important role in ecosystem sustainable functions under MA framework. This paper, by GIS-based spatial analysis, measured the sustainable functions of ecosystems in the three river sources, through soil preservation indicators. These results suggested that, in the three river sources, the features of different ecosystems determine the basic patterns of soil formation and sustainable functions of ecosystems. These patterns present lower tendency, along the orientation from southeast to northwest. The functions of soil preservation are significantly different among different ecosystems, in the order of wetland〉forest and grassland〉farmland〉desert and bare land and bare rock. The sustainable functions of ecosystems decline in the order of wetland, forest, grassland, farmland, desert and bare land and bare rock. The patterns of grassland degradation are consistent with the distributions of soil preservation. Grassland degradation results in the reduction of ecosystem sustainable functions. Strong human disturbances cause the degradations of soil properties of each type, and induced the decline of the functions of soil formation and sustainable ecosystem. Our findings suggest that it may be useful to understand the sustainable functions of ecosystems from the aspect of soil formation.