珠三角城市群景观生态格局评价与优化

Evaluation and optimization of ecological landscape pattern for urban agglomeration in the Pearl River Delta, China

景观生态格局评价与优化对珠三角城市群森林质量精准提升与城市高质量发展具有重要的理论指导意义。本研究基于2021年森林资源管理“一张图”数据和数字高程模型数据,采用形态空间格局分析与最小累计阻力模型方法,对珠三角城市群景观生态格局进行评价与优化。结果表明:珠三角城市群可作为生态源地的斑块共435861块,面积为7346.60 km^(2),占珠三角面积的13.4%,通过面积与斑块重要性指数选取30个斑块作为研究区的生态源地,面积为2792.59 km^(2),占珠三角面积的5.1%。珠三角城市群整体自然环境优秀,生态阻力等级较小,外围生态阻力低,核心生态阻力高,林分类型与景观格局仍有较大调整空间,需通过调整林分树种组成与空间分布的方式进行优化。以30个生态源地、103个重点生态廊道和95个生态节点优化珠三角城市群生态网络,优化后的可能连接度指数和整体连接度指数提升率分别为297.5%和695.1%。优化结果能有效连接各生态源地,扩散生态源地的生态服务功能。

The evaluation and optimization of landscape ecological pattern has important implications for the accurate improvement of forest quality and high-quality urban development in the Pearl River Delta urban agglomeration.Based on the"one map"data and digital elevation model data of forest resource management in 2021,we evaluated and optimized landscape ecological pattern of the Pearl River Delta urban agglomeration by morphological spatial pattern analysis and minimum cumulative resistance model.The results showed that there were 435861 patches in the Pearl River Delta urban agglomeration that could be used as ecological source area,covering an area of 7346.60 km^(2)and accounting for 13.4%of the Pearl River Delta area.Thirty patches were selected as the ecological source area of the study area by using the area and patch importance index,covering an area of 2792.59 km^(2)and accounting for 5.1%of the Pearl River Delta area.The overall natural environment of the Pearl River Delta urban agglomeration was excellent.The ecological resistance level was small.The peripheral ecological resistance was low.The core ecological resistance was high.There was still a large room for adjustment of stand types and landscape patterns,which should be optimized by adjusting the composition and spatial distribution of tree species.The ecological network of the Pearl River Delta urban agglomeration was optimized with 30 ecological sources,103 key ecological corridors,and 95 ecological nodes.The improvement rates of the optimized probability of connectivity index and integral index of connectivity index were 297.5%and 695.1%,respectively.The optimization results could effectively connect the ecological sources and spread the ecological service functions of ecological sources.