Spatial differentiation of ecological security and differentiated management of ecological conservation in the Pearl River Delta, China

The ecological security (ES) pattern in China is gaining considerable attention worldwide due to intensifying urban development and human activities that threaten ecosystem structures and ecological processes. The Pearl River Delta (PRD) has experienced intense economic development for nearly 40 years; however, the ES pattern in the PRD is poorly understood. In this paper, we used a multisource data approach to assess ES, performed downscaling to a 1 x 1 km(2) grid size, and applied spatial statistics to analyze the ES pattern in the PRD. We found three natural "ecological buffers," namely, nature reserves and forest patches covering several municipalities in the delta, thus guaranteeing the socio-economic development of this highly urbanized area. The spatial autocorrelation results indicated that the ES pattern is significantly spatially correlative (p = 0.001), with a Moran's I of 0.7766. We identified several hot and cold spots for the ES spatial distribution that occupied 58.49% of the PRD's total area. Moreover, a semivariance analysis showed that structural factors are dominant in the ES spatial distribution. Based on the ES area proportions, the 9 municipalities of the PRD can be grouped into three categories: optimized development zones, comprehensive development zones, and ecological conservation development areas. Zhaoqing, Huizhou and Jiangmen are key areas for improving ES conservation in the PRD. In this study, we explore an ES assessment model coupled with a spatial heterogeneity analysis to provide insights into ecological conservation efforts in urban agglomerations.