人地作用关系中生态陷阱现象解析

选择我国北方农牧交错带作为案例对象,分析了该区人地作用关系中生态脆弱的本质与恶性循环链式反应的机理,并用生态陷阱来类比描述人地作用关系中的这一现象过程.指出生态陷阱是特定生态系统属性与相应的人类活动干扰耦合导致人地作用自驱动机制形成,最终导致人地关系不断衰减恶化的现象和过程,本质上是人地作用过程中产生了路径依赖,进入了一种低水平的轨道锁定状态.生态陷阱概念或者研究视角的提出将为生态系统管理、生态建设与恢复提供更加清晰的思路,结合农牧交错带的问题提出了该区生态建设的方向性建议.

Exploration of ecological pitfalls embeded in the human-land interaction

The concepts of ecological vulnerability and vicious circle were often used to describe the characteristic of ecosystem and human-land interaction respectively in past research works.The essence of ecological vulnerability and vicious circle of human-land relationship is still undefined in light of their ecological attribute and dynamic interaction process with regarding to human interference.In this paper,agro-pastoral interweaving belt in north China was adopted as a case object to analyze the transition between cultivation and grazing activity and associated land degradation.The result shows that the invasion of cultivation,positive feedback mechanism between cultivation and grazing and soaring population resulting from marginal agriculture should be responsible for the formation of vicious circle.The new concept of ecological pitfall was suggested to compare and analyze the interaction process between human exploitation and ecosystem.Ecological pitfall is primarily defined as phenomenon and process that specific ecological attributes resonate with corresponding interference and in turn results in self-driving mechanism of human-land dynamics,leading to continuous degradation and attenuation of ecosystem.The concept of ecological pitfall implicates as follows(1) ecological vulnerability is a relative concept,i.e.relative to interference from human's exploitation of natural resources.It is meaningless without considering outside interference.(2) the process of ecological pitfall mostly start from human's exploitation of nature sources and then result in continuous degradation of ecosystem due to its self-driving mechanism.(3) chain reaction is main characteristic of ecological pitfall and self-driving mechanism is the function of resonance and coupling action of inertia of land use manner,irreversibility of human population in short period and long time demand for ecological rehabilitation.(4) the ecological pitfall is a scale-related concept,and interference of small scale sometime comprise normal structural component of large scaleThe essence of ecological pitfall is a path-dependence of human exploiting nature resources and a low level lock-in state of human-land relationship.The new concept would contribute to management of ecosystem,ecological building and rehabilitation.From the point of this view,it is prerequisite to break down the ecological pitfall before we take action to combat desertification.In order to break down ecological pitfall,external impetus is necessary to pull out from pitfall while regulating its internal structure,involving capital investment from outside,export of population pressure,technology assistance and policy privilege.Here,with respect to the agro-pastoral interweaving belt,some suggestions were put forward on ecological rebuilding in agro-pastoral interweaving belt of north China.