近30年鄱阳湖滨岸缓冲带土地利用变化及生态系统服务价值

滨岸缓冲带作为湖泊生态系统的重要组成部分，研究其土地利用变化及生态系统服务价值（ESV）对维持湖泊水安全和生物多样性具有重要意义。基于1988-2018年间7期Landsat遥感卫星影像数据，采用土地利用相关分析、ESV当量因子估算等方法，深入分析了鄱阳湖滨岸缓冲带近30年土地利用时空演变特征及ESV变化。结果表明：（1）近30年鄱阳湖滨岸缓冲带土地利用类型逐渐形成了以耕地为主导，林地、草地、水域、建设用地等主要地类占比相对均衡的格局。耕地面积明显增加，增幅为21.48%；建设用地和林地面积增幅分别为542.90%和326.23%，耕地、水域、草地是二者面积增加的主要来源；草地面积出现明显减少，幅度达66.79%，主要转变为林地、耕地和水域；水域和未利用地面积出现小幅减少。研究区内，南昌县综合土地利用动态度以1.81%高于其他11个区（县），土地利用较其他区（县）出现更大的变化。（2）近30年鄱阳湖滨岸缓冲带生态系统服务价值总体呈现先上升后下降的趋势，总损失25.54亿元，降幅为24.18%；各类ESV的变化趋势与各土地利用类型面积变化的趋势相似，其中水文调节为研究区内最主要的生态服务功能，占总ESV的66.03%。（3）水域和草地对ESV变化的贡献率最大，是鄱阳湖滨岸缓冲带ESV变化的主要影响因素；水域面积减少是导致滨岸缓冲带ESV下降的主要原因。总体而言，修复和保护滨岸缓冲带内的水域和草地对维持鄱阳湖生态系统生物多样性和服务功能具有重要作用，对周边乃至长江中下游地区的生态环境保护亦具有重要意义。

Land use changes and ecosystem service value in the buffer zone of Poyang Lake in recent 30 years

The buffer zone is an indispensable part of the lake ecosystem. Study on land use changes and ecosystem service value (ESV) in the buffer zone is important to maintain the water security and biodiversity of the lake. Based on seven Landsat remote sensing satellite images from 1988 to 2018, this study adopts Land use correlation analysis method and ESV equivalent factor estimate method to deeply analyze spatiotemporal changes of land use and ESV changes in the buffer zone of Poyang Lake in last 30 years. The results show that:(1) the land use type of the buffer zone of Poyang Lake has gradually formed a pattern in which the cultivated land was dominant and the proportion of major land types such as forestland, grass land, water area and construction land were relatively balanced. During this period, the cultivated land area increased significantly, with an increase of 21.48%. The area of construction land and forestland increased by 542.90% and 326.23%, respectively; the cultivated land, water area and grassland were the main sources of their area increase. Grass land area showed a significant decrease of 66.79%, which was mainly transformed into forestland, cultivated land and water area. Water area and unused land decreased slightly. In the study area, the dynamic degree of comprehensive land use in Nanchang County was 1.81%, which was higher than that in other 11 districts and counties, showing that Nanchang County witnessed a bigger change in land use. (2) In recent 30 years, the ecosystem service value in the buffer zone of Poyang Lake generally showed a trend of increase first and then decrease, with a total loss of 2.554 billion yuan and a total decrease of 24.18%. At the same time, changes in different types of ESV were similar to that of land use. Hydrological regulation, which plays a vital role in ecological service function in study area, occupied 66.03% of the total ESV. (3) Water area and grass land contributed the most to ESV changes and were the main influencing factors of ESV changes in the buffer zone of Poyang Lake. The decrease of water area mainly explains the decline of ESV in the buffer zone. In general, restoration and protection of water area and grass land in the buffer zone of Poyang Lake is of great significance in maintaining the biodiversity and service function of its own ecosystem, and is also crucial for protecting the ecological environment of the surrounding area and even the middle and lower reaches of the Yangtze River.