太湖流域耕地变化及其对生态服务功能影响研究

人类活动驱动下的土地利用变化对生态系统服务功能影响是当前生态学研究的前沿和热点,中国东部沿海经济发达地区耕地变化对生态系统服务功能影响尚不清楚。论文以中国经济快速发展和典型商品粮基地--太湖流域为研究区,利用多期遥感解译数据、统计资料和历史文献,分析太湖流域25 a 来耕地变化情况,并选取农产品生产、碳蓄积、水源涵养三个关键指标探讨耕地变化对生态系统服务功能的影响。结果表明:① 25 a 来太湖流域耕地减少显著,以城市建设用地占用为主,1985-2000 年流域耕地仅减少1 346.82 km²,主要集中在上海市和江苏省,态势并不严峻;2000-2010 年是流域耕地减少的主要时期,减少面积达4 317.46 km²,县级市耕地减少明显加剧。② 25 a 间太湖流域耕地变化造成生态服务功能退化明显,供给服务功能中仅小麦产量有所提高,稻谷和油料产量分别下降39.60%、56.56%,调节服务功能中土壤碳储量降低显著,但对水源涵养能力影响较小。建议加强耕地保护力度,协调耕地保护、经济发展和生态服务之间的平衡,有助于减缓流域耕地减少对生态服务功能退化的压力。

Impacts of Cropland Change on Ecosystem Services in the Taihu Lake Basin

Land use change has been one of the most important drivers to significantly influence the provision of ecosystem services. Impacts of land use change on ecosystem services have been one focus of ecology research and attracted more and more attentions from domestic and international. However,impacts of cropland change on ecosystem services in eastern coastal developed regions of China are still not clear, which limits comprehensive understanding of the mechanism between land use change and ecosystem services. In this paper, the Taihu Lake Basin was chosen as the study area due to its representativeness of rapid economic development and commodity grain base in this area. Based on remote sensing data and the statistics, spatial and temporal change of cropland and its impacts on ecosystem services were carried out in the Taihu Lake Basin. Three key ecosystem services—gain production, carbon sequestration and water conservation were selected to examine what extent and how cropland change on eco-logical services. The results showed that: 1) The area of cropland decreased significantly over the past 25 years in the Taihu Lake Basin, mainly transforming into urban and built-up areas. A small reduction of cropland with 1346.84 km² in 1985-2000, mainly concentrated in Shanghai Municipality and Jiangsu Province. While cropland area decreased by 4317.46 km² in 2000- 2010, which presented an obvious degraded trend at the county-level. 2) Ecosystem services in the Taihu Lake Basin in 1985-2010 presented an obvious degraded trend. Rice and oil production decreased by 39.6% and 56.6%, respectively, only wheat production presented a very small increment. Regulating function decreased significantly, of which soil carbon storage obviously decreased, but little effect on water conservation capacity. We propose to strengthen the protection of cropland to coordinate the balance between cropland protection, economic development and ecological services in the Taihu Lake Basin, which is beneficial for reducing pressure on degradation of ecosystem services for cropland decrease.