基于时空分析的生态保护与修复试点工程实施效果评估——以赣州市为例

以“山水林田湖草生命共同体”为中心思想，从生态系统的格局和质量两个方面，对赣州市山水林田湖生态保护与修复试点工程实施效果进行了综合评估。结果如下：（1）从生态系统格局来看，2015到2018年，赣州市森林、农田和城镇生态系统面积明显增加，超过40%的草地生态系统转变为森林生态系统，且近45%的城镇生态系统面积增量由草地生态系统贡献。此外，多数自然生态系统的斑块破碎化加剧，森林生态系统破碎化现象最为明显，最大斑块指数从54.36降低到37.41，而半自然生态系统最大斑块指数增大。（2）从生态系统质量来看，赣州市归一化植被指数稳定在0.7以上并呈增长趋势，水土流失综合治理面积从16543.8 km²增长到18550.4 km²，重点流域水质基本稳定在Ⅱ、Ⅲ级，城镇生态系统受土壤重金属污染的风险较小，但部分县区农田生态系统受一种或多种土壤重金属污染的风险较大。整体而言，赣州市山水林田湖生态保护与修复试点工程取得了显著成效，较好的完成了实施方案中的规划目标。在进一步的生态保护与修复工作中，应重视赣州市自然生态系统斑块破碎化严重地区、水质出现波动较大的河流断面以及农田生态系统受土壤重金属污染威胁较大的县区。

Evaluation on the implementation effect of the pilot project for ecological protection and restoration of multi ecological elements based on spatio-temporal analysis: A case study of Ganzhou

From the perspective of the ecosystem pattern and quality, the effectiveness of the pilot project for ecological protection and restoration of multi ecological elements in Ganzhou was comprehensively evaluated based on the central idea of mountains-rivers-forests-farmlands-lakes-grasslands system as a community of life. The results are as follows:(1) For ecosystem pattern, the area of forest, farm and urban ecosystems in Ganzhou increased significantly. More than 40% of grassland ecosystems were converted to forest ecosystems, and nearly 45% of urban ecosystem area increment were contributed by grassland ecosystems. In addition, landscape fragmentation in most natural ecosystems was intensified, and the largest patch index (LPI) of forest ecosystems were decreased from 54.36 to 37.41, while the LPI in semi-natural ecosystems were increased. (2) Regarding ecosystem quality, the normalized difference vegetation index (NDVI) of Ganzhou was stable above 0.7 and showed an increasing trend. The comprehensive control area of soil erosion increased from 16543.8 km² to 18550.4 km², and the water quality in key river basins was basically stable at Grade II and III. For the quality of soil environment, urban ecosystems were less threatened by the risk of soil heavy metal pollution. But the soil of farm ecosystems in some areas were at higher risk of being contaminated by one or more heavy metals. Overall, the ecological protection and restoration project in Ganzhou has achieved remarkable effectiveness, and the planning objectives in the implementation plan have been well completed. In the further ecological restoration work, there are three problems should be taken seriously, including the natural ecosystems with severe landscape fragmentation, the rivers with large fluctuations in water quality, and the farm ecosystems with high risk of heavy metal pollution.