湘西生态系统服务价值对城乡建设用地扩张的响应机理

Response Mechanism of Ecosystem Service Value to Urban and Rural Construction Land Expansion in Xiangxi

为了实现提升区域生态环境质量,为土地合理利用提供参考、保障生态安全的目的。以湘西州为例,基于1990~2018年湘西州土地利用/覆盖变化数据,通过修正当量因子的方法突出其时空特征,并构建模型评估其生态系统服务价值进一步探究建设用地扩张对生态系统服务功能的响应机理。结果显示:(1)1990~2018年,湘西州土地利用以林地、耕地和建设用地三者之间的相互转化为主,建设用地侵占耕地和林地现象突出;(2)28年间湘西州地区ESV整体下降趋势明显,由1990年的688.88亿元下降至2018年的453.38亿元,ESV在空间上呈现出显著的地区空间差异;(3)建设用地扩张对气候调节的破坏程度最大,对水文调节的破坏程度次之,对食物生产和气体调节的影响相对较低。研究发现,减少对林地及耕地的不合理占用是提高生态系统服务价值的有效策略,湘西州在未来的城乡建设活动应谨慎评估其对生态系统服务价值变化的影响,严格管控生态红线内的建设占用,避免增加生态风险。

In order to achieve the purpose of improving the quality of regional ecological environment,providing reference for rational land use and ensuring ecological security,taking Xiangxi Prefecture as an example,based on land use/cover change data from 1990 to 2018,this paper highlighted its spatial and temporal characteristics by correcting the equivalent factors,and established a model to evaluate its ecosystem service value to further explore the response mechanism of construction land expansion to ecosystem service function.The results showed that:From 1990 to 2018,the main land use in Xiangxi Prefecture was the conversion of forest land,cultivated land and construction land,and the encroachment of construction land on cultivated land and forest land was prominent.;@Over the past 28 years,the overall trend of ESV in Xiangxi Prefecture showed a significant downward trend,from 68.888 billion yuan in 1990 to 45.338 billion yuan in 2018,and ESV showed significant regional spatial differences;③theexpansion of construction land had thegreatest impact on climateregulation,followed by hydrological regulation,and had relatively low impact on food production and gas regulation.It was found that reducing the unreasonable occupation of forest land and cultivated land is an effective strategy to improve the ecosystem service value.In future urban and rural construction activities in Xiangxi Prefecture,the impact on the change of ecosystem services value should be carefully evaluated,and construction occupation within the ecological red line should be strictly controlled to avoid increasing ecological risk.