典型红壤区自然生态修复的适用性  

Research on the application of natural ecological restoration in a typical region of China with red soils

作　　者：马华 钟炳林 岳辉 曹世雄[3] 

机构地区：[1]广西壮族自治区水利科学研究院,南宁530023 [2]福建省长汀县水土保持监测站,龙岩366300 [3]北京林业大学经济管理学院,北京100083

出　　处：《生态学报》2015年第18期6148-6156,共9页Acta Ecologica Sinica

基　　金：国家自然基金重点项目(91025002)

摘　　要：自然修复主要通过封山育林、禁止农作、禁牧禁伐措施,减少人类对环境的扰动,利用自然生态环境的自我演替能力,恢复生态环境,实现生态平衡。自然修复作为一种成本低、无污染的生态修复手段很早就受到人们重视,但关于自然修复适用范围的研究较少。为了正确认识自然修复的适用性,选择了我国南方红壤地区长期遭受严重土壤侵蚀危害的福建省长汀县为研究对象,通过对长期自然修复样地的监测资料分析,发现在坡度条件为20%—30%下,当植被覆盖度低于20%的退化阈值时,严重的土壤侵蚀引发的土壤肥力损失将导致生态系统自我退化,自然修复不仅无法改善当地的生态系统,反而会引起生态系统的进一步恶化。由此可见,自然修复并不适合所有的生态系统,当生态系统退化到一定程度时,退化生态系统必须通过人工干预来修复。因此,必须探索适合当地的生态修复模式,在生态系统退化突破阈值时,红壤丘陵区应通过恢复土壤肥力、促进自然植被覆盖度增加、综合提高生态系统健康水平。Natural restoration is mainly accomplished by allowing natural reforestation to occur, combined with prohibiting agriculture and grazing to reduce human disturbance of the environment. Taking advantage of the succession that occurs in natural ecosystems is a common ecological restoration measure that can restore ecosystems and keep them in balance. However, conservation and restoration biologists have increasingly recognized that ecological communities are likely to exhibit threshold changes in structure that may prevent succession from occurring. Because long-term monitoring data are generally lacking, little is known about the consequences of such ecological thresholds for the processes of ecosystem degradation and recovery. To identify whether a degradation threshold exists that defines the boundary between the possibility of natural recovery and the need for artificial restoration of an ecosystem and to use this knowledge to support the development of a suitable strategy for environmental restoration, we have performed long-term monitoring of vegetation recovery in China＇ s ＂irreversible loss of Changting County since 1986. We found a severe problem in this area, which we refer to as the soil services＂： when vegetation cover decreases below an ecological degradation threshold, leading to sustained degeneration of the vegetation community, erosion of the surface soil and declining soil fertility occur. These changes represent a severe and long-term disturbance of the vegetation, the soil, and the landscape. We identified a degradation threshold at about 20% vegetation cover, which suggests that for some sites with a vegetation cover of between 20 and 30%, vegetation cover can serve as a simple proxy for more sophisticated approaches to identifying thresholds ; when vegetation cover declines to this level, restoration must start with the restoration of soil fertility and continue by facilitating vegetation development. Our results support the concept of ecological thresholds （ specifically, for soil

关 键 词：生态阈值 生态修复 植被覆盖度 物种多度 土壤肥力 生态系统 

分 类 号：X171.4[环境科学与工程—环境科学] S158.5[农业科学—土壤学]