整合多重生态保护目标的广东省生态安全格局构建

Construction of ecological security pattern integrating multiple ecological protection objectives in Guangdong Province

构建生态安全格局是缓解生态保护与经济发展之间的突出矛盾,保障可持续发展的有效空间途径。但目前生态安全格局的构建过于强调综合,简单叠加多种生态系统服务的方法忽视了不同服务间的权衡与协同关系,难以直接支撑不同目标下的生态保护决策。以广东省为例,重点关注生境维持、水源涵养、水质净化、粮食生产、土壤保持、洪水调节、沿海灾害缓解七种重要的生态系统服务,面向生物多样性保育、水资源利用、粮食生产、自然灾害防范等单一生态保护目标分别构建生态安全格局。研究结果表明,面向生物多样性保育目标的生态安全格局呈“双屏障带”式分布,生态源地主要分布在粤北生态发展区;面向水资源利用目标的水安全格局呈“五江一带”式分布,重点保护区主要位于河湖水库及周边绿地;面向粮食生产目标的生态源地主要分布在广东省东西两翼;面向自然灾害防范目标的生态源地在珠三角、湛江市、汕头市少有分布,集中在粤北生态发展区。基于多种生态系统服务综合重要性判定生态源地,并整合单一生态保护目标下的多重源地,识别综合生态源地共49536.10 km^(2),主要分布在珠三角外围和粤北生态发展区。基于最小累积阻力模型和电路模型,识别了总长度2268.07 km的生态廊道;夹点共32处,主要分布在中山市、珠海市、江门市、惠州市廊道中电流值较大的12处狭窄区;障碍点共44处,主要分布在广州市、中山市、珠海市、江门市、惠州市的19处,覆盖了廊道的大部分面积。整合多重生态保护目标,广东省生态保护修复策略的制定需要高度关注粤北生态发展区的生境质量提升,河湖水库及河岸带、库滨带的水生态安全,湛江市、汕头市的耕地保护和国土综合整治,沿海地区的自然灾害防范,同时积极开展珠三角的生态夹点保护和障碍点修复,重点提升生态廊道的连通性。

Constructing ecological security pattern is an effectively spatial approach to alleviate the prominent contradiction between ecological protection and economic development to ensure sustainable development.However,the current construction of ecological security pattern emphasizes too much on synthesis.The simple method of superposition of multiple ecosystem services ignores the trade-offs and synergies among different ecosystem services,so it is difficult to directly support the ecological protection decision-making under different objectives.Taking Guangdong Province as an example,this study focused on seven important ecosystem services,including habitat maintenance,water conservation,water purification,grain production,soil conservation,flood risk mitigation,and coastal disaster mitigation.Ecological security patterns were constructed for single ecological conservation objectives,such as biodiversity conservation,water resource utilization,grain production,and natural disaster prevention.The results showed that the ecological security pattern for biodiversity conservation was distributed in a“double barrier zones”pattern,and the ecological sources were mainly distributed in the ecological development area of Northern Guangdong.The water security pattern for water resource utilization was distributed in the pattern of“five rivers-one belt”,and the key protected areas were mainly located in rivers,lakes,reservoirs and the surrounding green space.Ecological sources for grain production were mainly distributed in the east and west wings of Guangdong Province.Ecological sources for natural disaster prevention were rarely distributed in Pearl River Delta,Zhanjiang and Shantou,but mainly concentrated in the ecological development area of Northern Guangdong.The comprehensively ecological sources with total area of 49536.10 km^(2) were identified by integrating the ecological sources determined based on the comprehensive importance of multiple ecosystem services,and the multiple sources under single ecological protection objectives,which were mainly distributed in the periphery of the Pearl River Delta and the ecological development area of Northern Guangdong.Based on the minimum cumulative resistance model and circuit model,ecological corridors with total length of 2268.07 km were identified,among which were long and narrow in the Pearl River Delta.There were 32 pinch points,mainly distributed in 12 narrows with high current value in the corridors of Zhongshan,Zhuhai,and Jiangmen.There were 44 barriers,mainly distributed in Zhongshan,Zhuhai,Jiangmen and Huizhou,with 19 barriers covering most of the corridors in these cities.For the integration of multiple ecological conservation objectives,several aspects should be focused in the formulation of ecological conservation and restoration strategies in Guangdong Province,including habitat quality improvement in ecological development area of Northern Guangdong,water security of rivers,lakes,reservoirs,riparian zones and reservoir shore zone,the cultivated land protection and comprehensive land control in Zhanjiang and Shantou,natural disaster prevention in coastal area.At the same time,the protection of pinch points and the restoration of barriers should be carried out to enhance the connectivity of the ecological corridors in the Pearl River Delta.