高密度城区居住用地附属绿地对生态连通性影响——以深圳市福田区为例

Impact of Residential Green Space on Ecological Connectivity in High-Density Built-up Areas:A Case Study of Futian District of Shenzhen City

文章通过识别生态源地、提取居住用地附属绿地,基于最小阻力模型,分析居住用地附属绿地支持与阻隔生物流通情景下的生态网络,探讨居住用地附属绿地对高密度城区生态连通性的影响,提出保护建议。结果表明:1)福田区中部莲花山公园、东部荔枝公园、南部皇岗公园生态连通性受其周围居住用地内连片或连续分布的带状附属绿地影响较大。2)居住用地附属绿地对生态连通性的影响体现在减小廊道阻力,其中对中阻力廊道的影响最大(单位成本距离下降29.2%);使具有重要生态保护价值的区域连片;能缓解在高密度建成区中的狭窄低阻力通道处形成夹点的情况。3)不同居住用地附属绿地连通情景下、不同阻力阈值下生态网络中重复出现的生态夹点被定为是最具有保护价值的一级夹点。根据不同情景下重复出现的生态夹点位置的重要性等级分类,针对性提出支持城市生态连通性的保护措施。建议加强新洲路福民路交汇处等一级夹点4处,优先保护靠近源地且位于源地间拓扑连接上的、规模超过平均规模5920.22 m^(2)的居住用地附属绿地。

High-intensity land use and fragmented habitats are becoming more prevalent with urbanization,thereby accelerating the demand for maintaining and improving the ecological connectivity of habitat patches in high-density built-up areas.Previous studies have shown that small dispersed patches are crucial for enhancing connectivity across an entire landscape.However,as an important component of urban green space,residential green space in high-density built-up areas is often overlooked in ecological connectivity analysis.Taking Futian district,Shenzhen,as a case study,we explored the ecological connectivity in high-density built-up areas considering not only habitat patches but also green areas in residential quarters.We identified ecological patches and green areas in the residential areas of the study area.This was followed by a functional connectivity analysis under different scenarios.Several protection suggestions for improving ecological connectivity have been proposed based on functional connectivity analyses under different scenarios.The results show:1)The area of residential green space in Futian district is 3.86 km^(2),covering 26.9%of the total green space in the study area,with the western part being sparser than other regions.The total area of the ecological patches was 14.34 km^(2),and the importance of the patches was not consistent with their size.The ecological connectivity of Lianhuashan Park in the central region,Lichi Park in the eastern region,and Huanggang Park in the southern region is greatly affected by the contiguous or continuously distributed strips of residential green space around them.2)Residential green spaces affect eco-connectivity primarily by lowering corridor resistance,creating connectors for regions that require protection,and supporting biological flow.In particular,it had the largest effect on middle-resistance corridors(the unit cost distance was reduced by 29.2%)and alleviated the situation of pinch points formed in narrow low-resistance channels in high-density built-up areas.3)The ecological pinch points that recurred in the ecological network under different scenarios of connecting residential green spaces and different resistance thresholds were identified as the most valuable primary pinch points for protection.It is recommended to strengthen the intersection of Xinzhou Road and Fumin Road and prioritize the protection of residential green spaces located near the ecological patches and on the topological connection between the ecological patches,with a scale exceeding the average size of 5,920.22 m^(2).Through the analysis of pinch points in various scenarios,it was found that 21 pinch points,including those close to Lianhuashan Park,could be used as substitute green spaces for urban renewal projects when nearby residential green spaces are destroyed or occupied.This supports the preservation of functional connectivity in urban renewal projects.It is increasingly difficult to construct significant habitat patches in high-density built-up areas to compensate for habitat fractures.The results identified the significant location and proportion of residential green spaces as critical bio-flow carriers in Futian District.These findings could encourage more comprehensive urban conservation plans that incorporate both sizable habitat patches and residential green spaces.These findings can be used to create more effective sustainable development plans that encourage biodiversity in urban renewal planning.