我国干旱半干旱地区脆弱生态系统及其退化成因

The Fragile Ecosystem Types in Arid and Semi-Arid Region of China and Their Degradation Causes

当今世界生态与环境的诸多问题中,生态系统脆弱性是焦点问题之一。依据我国干旱半干旱地区草场退化、土地沙漠化及盐碱化等三种主要问题的剖析结果,分析了退化草原生态系统、绿洲生态系统、荒漠生态系统、湿地生态系统、农牧交错生态系统等五类主要脆弱生态系统的成因和生态性状。最后得出结论:气候异常和人类非理性活动是造成脆弱生态系统长时期处于恶性循环的主要原因,前者表现在气候变化和气候变异两方面,后者则以超载放牧、无序垦荒、无度利用有限水资源、乱樵滥采资源等四类为主。这些研究结论为我国干旱半干旱地区防止脆弱生态系统进一步退化和生态综合整治提供了理论基础。

In ecological and environmental problems of present world, ecological vulnerability is one of the focus issues. Based on analysis on three main courses in arid and semi-arid region of China, it is analyzed on the formation and traits of main type fragile ecological systems. In this study area, main courses includes grassland degradation, desertification and salinization while main fragile ecological systems refer to degraded grassland ecosystem, irrigated oasis ecosystem, desert ecosystem, wetland ecosystem and farming-pastoral ecosystem. In conclusion, both climate anomalies and human irrational activities are main reasons, which resulted in fragile ecosystem being in a vicious circle for a long time. The former refers to both climate change and climate variability while the latter includes over-grazing, disorder-reclaiming, excessive- utilizing of water resources, misuse and gouging natural resources, et al. These conclusions will provide theoretical basis so as to prevent further deterioration of ecosystem and comprehensive harnessing in arid and semi-arid region of China.