东部发达区生态安全格局构建——以苏南地区为例

随着城市化进程的加快,东部发达区面临水土流失、生态廊道阻断、栖息地破碎化等生态问题。识别重要生态用地,构建生态安全格局,对区域生态保护和可持续发展具有重要意义。选取苏南地区为研究区,分别基于生物多样性保护价值、水资源安全和土壤保持3项指标进行生态用地识别,结合GIS技术进行生态用地评价,以高等级生态用地作为源地;利用最小累积阻力模型,识别缓冲区和生态廊道,构建区域生态安全格局。取得以下研究结果:(1)生态安全格局由源地、廊道和缓冲区共同构成。研究区内高等级(非常重要)生态用地面积比例为22.97%;将面积大于10 km~2的高等级生态用地提取为源地,生态源地的面积比例为19.17%。(2)基于最小累积阻力模型,确定了生态缓冲区和生态廊道,其中生态缓冲区占研究区总面积的30.52%,潜在生态廊道的主要景观构成为耕地、林地和水域,分别占廊道总面积的31.82%、19.06%和17.27%。(3)通过叠加城市建设用地与生态源地、生态缓冲区图层,识别城市建设用地与生态用地的冲突区域,总面积为603.84 km~2,占源地与缓冲区面积总和的4.38%,空间上主要集中在长江沿线和太湖周边。

Establishment of an ecological security pattern in the eastern developed regions: A case study of the Sunan District

Humans and nature are in an organic and dynamic equilibrium, and human beings must respect, conform to, and protect nature. However, along with continuous economic growth and urbanization, our country faces huge pressures for resources, and the environment and ecological systems are under serious threat. How to protect ecological security has become a focus for our country''s sustainable development. Urban expansion is an important driving force of land use and cover change, and high-intensity human activities have greatly altered the structure of natural ecosystems, decreased ecosystem service functions, and seriously threatened regional ecological security. In recent years, a series of environmental problems have arisen, including habitat fragmentation, biodiversity reduction, and water pollution. Therefore, it is of great importance to identify ecological land and establish an ecological security pattern for regional ecological protection and sustainable development. Although there are a lot of studies about ecological security patterns in China, in most cases, the research scale is at the municipal or county level, and there are few studies at the regional scale, especially those aimed at the eastern developed areas. The study area of this research was the Sunan District, which is in the south Jiangsu Province of eastern China. It is one of the most developed and modernized regions of China with a GDP close to the level of other developed countries, and the proportion of its urban population was 75.9% in 2016.In such a fast-growing region, it is essential to establish a landscape security pattern for the coordinated development of economy and ecology. Based on the ecological background characteristics of the Sunan District, this study quantified and mapped three ecosystem services, namely biodiversity conservation, water resource security, and soil conservation, and classified ecological land into five levels (very important, important, relatively important, general, and not important) using a GIS spatial analysis method. In order to reflect differences in the impact of different land use patterns and intensities on ecological resistance under the same land use coverage type, we used nighttime light data to modify the basic ecological resistance surface which was obtained by the expert scoring method based on land-use type assignments. The minimum cumulative resistance model was used to identify ecological corridors and buffers. The ecological sources, buffers, and corridors, collectively, made up the ecological security pattern for the study area. The results showed that the area of very important ecological land was 6365.92 km² and accounted for 22.97% of the total area. When very important ecological land above 10 km² was selected as a source, the total area was 5313.31 km² and accounted for 19.17% of the total area. The ecological buffer area was 8458.79 km² and accounted for 30.52% of the total area. As for the ecological corridors, about 31.82% was farmland, 19.06% was forested areas, and 17.27% was a water body. We believe that building a comprehensive security pattern of critical ecological lands, with the advantages of spatial linkages, is an efficient spatial approach for species conservation and landscape optimization. Therefore, our results could provide a scientific reference for regional ecological and spatial layout planning for future sustainability.