景观生态恢复与重建是区域生态安全格局构建的关键途径

生态恢复与重建是跨尺度、多等级的问题，其主要表现层次应是生态系统（生物群落）、景观，甚至区域，而不能仅仅局限于生态系统。景观的恢复与重建是针对景观退化而言，景观退化从表现形式上可分为景观结构退化与景观功能退化。景观结构退化即景观破碎化，是指景观中各生态系统之间的各种功能联系断裂或连接度(connectivity)减少的现象；而鲜受重视的景观聚集（aggregation）在很多情况下同样具有造成景观退化的负面效应。景观功能退化是指与前一状态相比，由于景观异质性的改变导致景观的稳定性与服务功能等的衰退现象。景观恢复是指恢复原生生态系统间被人类活动终止或破坏的相互联系；景观生态建设应以景观单元空间结构的调整和重新构建为基本手段，包括调整原有的景观格局，引进新的景观组分等，以改善受胁或受损生态系统的功能，提高其基本生产力和稳定性，将人类活动对于景观演化的影响导入良性循环。二者的综合，统称为景观生态恢复与重建，是构建安全的区域生态格局的关键途径。其目标是建立一种由结构合理、功能高效、关系协调的模式生态系统（model ecosystem）组成的模式景观（model landscape），以实现生态系统健康、生态格局安全和景观服务功能持续，以3S(RS，GPS，GIS)技术为支撑的GAP(ageographic approach to protect biological diversity)分析将为大尺度景观恢复的诊断、评价、规划提供重要的手段。景观中某些关键性点、位置或关系的破坏对整个生态安全具有毁灭性的后果，研究景观层次上的生态恢复模式及恢复技术、选择恢复的关键位置、构筑生态安全格局已成为景观生态学家关注的焦点。

A vital method for constructing regional ecological security pattern:landscape ecological restoration and rehabilitation

Ecological restoration and rehabilitation should be a multiple-scale project rather than be limited in a single ecosystem, and should include ecosystem or biota, landscape and even region. Landscape restoration and rehabilitation have become important due to widespread landscape degradation, including structure and function degradation. Landscape structure degradation, that is landscape fragmentation, is defined as the phenomenon that functional diversity relationships are ruptured or connectivity is reduced among ecosystems within the landscape. In addition, landscape aggregation, which has long been neglected, has negative effects on the landscape as well. Degradation of function is a loss or the degradation of stability and service functions due to a change in heterogeneity relative to a former state.Landscape reintegration means to restore contiguous relationships among ecosystems, which have been ruptured or fragmented by human activities. This ecological landscape reconstruction will improve functions of threatened or impacted ecosystems by adjusting and reconstructing landscape units' spatial structures; hence, primary productivity and stability are promoted, and landscape evolution influenced by human activities involves in virtuous circle, such as adjusting original landscape pattern, introducing new landscape elements. These two works are called landscape ecological restoration and rehabilitation, which is a vital method to construct a regional ecological security pattern. Its aim is to rebuild a model landscape consisting of several model ecosystems with reasonable structures, effective functions and harmonized relationships, so as to get healthy ecosystems, secure ecological pattern and sustainable landscape service. The method of GAP (A Geographic Approach to Protect Biological Diversity) supported by 3S (RS, GPS, GIS) technique provides an important tool of diagnosis, assessment and program of landscape restoration at a large scale. Degradation or destruction of certain strategic portions, positions or relationships among them has destructive consequences to ecological security. In order to establish a landscape restoration model by effective techniques and to build a regional ecological security pattern by means of strategic positions, it is increasingly attractive for ecological research to focuse on landscape scale degradation in structure and function originating from human disturbance; this is an issue of great concern. However, how to construct model landscapes effectively and determine the critical position for this end remains a tough question.