关于生态屏障若干问题的探讨

Discussion on Some Issues of Ecological Barrier

生态屏障是生态文明建设中构建国家生态安全战略格局的重要组成部分,生态安全是生态屏障建设的目标,生态屏障则是生态安全的保障。许多学者从不同角度对生态屏障理论与方法进行了深入的探讨,进而形成生态屏障是处于特定的区域,具有保护功能的生态安全系统的理念,但由于生态屏障具有复杂性与特殊性,目前其概念、类型及特点等尚处于发展中。文章在总结前人研究基础上,基于生态系统服务理论,梳理了生态屏障的概念及内涵,认为生态屏障多处于过渡地带,是经过人工改良的具有明确保护与防御对象的复合生态系统,具有一定的空间跨度,在空间上呈封闭或半封闭分布,能提升生态系统服务,促进区域或国家生态安全。它具有如下特点:(1)防护性,即对反生态系统服务的防御或者对正生态系统服务的保护;(2)梯度性,即根据保护的区域重要性或者反生态系统服务的严重程度而建立的不同等级的生态屏障;(3)指向性,即生态屏障具有明显的方向性;(4)动态性。本文根据屏障对象性质将生态屏障划分为正向服务保护型、反向服务防护型和退化服务恢复型,其中"两屏三带"防护体系中的东北森林带为正向服务保护型,北方防沙带、川滇-黄土高原生态屏障和南方丘陵山地带为反向服务防护型,青藏高原生态屏障则为退化服务恢复型。该研究可为生态保护和恢复提供科学基础。

Ecological barrier is an important part of national ecological security strategy in the construction of ecological civilization.Ecological security is the goal of ecological barrier construction,and ecological barrier is the protection of ecological security.Many scholars have discussed the ecological barrier theory and method from different aspects valuably,and they all think ecological barrier is located in specific places and it is an ecological security system that has a protective function.But because of the complexity and particularity of the ecological barrier,the concept,type and characteristics of the ecological barrier remain in development in recent years.On the basis of summarizing previous research,from the horizon of the ecosystem service theory,the ecological barrier is considered to be a multiple ecological system with clear protection and defense object,which are improved artificially.It usually distributes in closed or semi-closed form in the transitional areas.There is a definite spatial span in it.Ecosystem services can be improved by it,and it promotes the ecological security of areas or country.It has the following characteristics：（1）Protection：defending negative ecosystem services or protecting positive ecosystem services;（2）Gradient：ecological barriers of different grade is established according to the importance of protected areas or the severity of the negative ecosystem services;（3）Directivity：there is obvious direction in ecological barrier;And（4）dynamics.It also can be classified as positive service protection type,negative service protection type and degraded service restoration type according to the barrier object.In the two ecological barriers and three shelters of China,North-eastern forest belongs to the first type,and the northern desert prevention,Chuan-Dian—the Loess Plateau ecological barrier and hilly terrain of southern China belong to the second type.Qinghai-Tibetan Plateau ecological barrier belongs to the third type.The research can provide a scientific basis for the ecological protection and restoration.