## 5 Discussion
### Spatial Pattern of the ESV  
The study revealed that Grade I and II low ecosystem services value areas constituted a small proportion of the city's land area and were primarily concentrated in densely populated areas with intensive human activities, such as the Licheng and Xiuyu Districts. This finding further corroborates the earlier observation that the inefficient allocation of resources in these newly developed regions led to reduced urbanization and ecological efficiency. Grade III medium ecosystem services value areas were more prevalent, predominantly encompassing Xianyou County and Hanjiang District. These areas featured elevated forest cover, a substantial proportion of forest land, and relatively developed fruit and understory forest economic industries. Grade IV and V high ecosystem services value areas were primarily concentrated in the Xinghua Plain, situated along the lower reaches of the Mulan River. These regions, endowed with abundant water resources, served as Puiian's principal agricultural production zones for food, vegetables, and aquatic products. The superior ecological environment of these areas contributed to their higher ESV.  
The ESV evolution patterns in Puiian City revealed that Level II and III ESV remained relatively stable overall from 2000 to 2020, while Level I, IV, and V ESV areas expanded. This indicates that Puiian City actively responded to the national \"three districts and three lines\" policy, placing significant emphasis on spatial planning and national land utilization management, achieving notable outcomes. Nevertheless, it was observed that there was a slow decrease in the ESV in the majority of regions within the Licheng and Xiuyu Districts. This downturn was mainly due to the transformation of a large portion of agricultural and grassland into land for development between the years 2000 and 2020. Consequently, this resulted in an ongoing drop in the provisioning services within these districts. Additionally, local spatial autocorrelation analysis revealed a concentration of high-high ESV agglomerations in the central part of Puiian City and coastal areas of Hanjiang District, characterized by flat topography and extensive cultivated land, grassland, and water bodies. Conversely, low-low ESV agglomerations were most prevalent, primarily encompassing Xianyou County in the southwest of Puiian City, Xiuyu District in the coastal region, and Licheng District in the city center. These areas exhibited high population densities and significant urbanization levels, prioritizing rapid economic growth over ecosystem protection, resulting in low regional ESV intensity. High-low and low-high ESV agglomerations were less widespread, scattered around their high-high and low-low counterparts. These agglomerations were primarily located at the interface of forest land, cultivated land, and orchard land, with a notable presence in the Mulan River's northern mountainous region. To tackle the variances in ESV, the following suggestions are made to the Puiian Municipal Government: (a) In regions where high ESV concentrations are present, it is advised to strategically ease limitations on development for production and residential purposes, all the while preserving the ecological area. (b) In zones characterized by low ESV clusters, the focus should be on ecological rehabilitation via tree planting initiatives, converting cultivated land back to forest, and the creation of nature reserves. (c) For areas that show minimal correlation in ESV intensity, it is crucial to enhance ecological conservation efforts and broaden the scope of ecological preservation.