生态系统退化的过程及其特点

The Degraded Processes and Features of Ecosystem.

随着人口迅速增长和社会经济的加速发展，人们对环境资源的过度使用和破坏，使生态系统的退化已成为普遍现象。据初步统计，我国处于退化状态的生态系统面积已占国土面积的４５％以上，目前仍继续处于恶化状态［１］。加强对生态系统退化的研究已成为当前我国面临的重大问...

Intensifying the researches on degraded ecosystem has been faced as pressing problem in China.In this paper,the factors of ecosystem degradation were analyzed,degraded processes and characteristics of ecosystem were expounded, and some problems about restoration and rehabilitation also were discussed. Disturbance induced by human has been the main force of degradation. According to the disturbance regimes and behaves of degradation, processes of ecosystem degradation have several models, namely, sudden degradation course, leap degradation course, gradual degradation course, continual degradation course and compex of several courses. For example, according to degraded extent the gradual degradation course could be divided into four steps with different degradation characteristics including biodiversity loss and declining, structural simplification, disintegration of food web,open of substance recycles , productivity decline,abnormality and some troubles of energy flow, losing or weakening abilities of environmental protection, and lowering of system stability . Based on differences of degradation processes and extent,the restoration and rehabilitation on different degraded ecosystem should have verious countermeasures. The restoration of biodiversity and system structure is the key and pathways of rehabilitation and restoration of the degradaed ecosystem.