北京市景观格局演变及其对多种生态系统服务的影响

景观格局是人与自然共同作用的结果，深刻影响着区域的生态系统服务及可持续发展。以高度城市化地区——北京市为案例，选取了粮食生产、水质净化、空气净化、气体调节、生境质量以及休闲娱乐6项重要生态系统服务，采用InVEST （Integrated Valuation of Ecosystem Services and Tradeoffs）、ROS （Recreation Opportunity Spectrum）等模型定量评估了1980-2018年生态系统服务时空分布。通过对北京市景观组成与景观配置指数进行定量分析，进一步探索了景观格局演变对生态系统服务的影响。结果表明：（1）北京市1980-2018年建设用地扩张了120%，建设用地扩张是耕地面积减少的主要原因。景观格局总体上趋于破碎化，斑块形状复杂化，斑块异质性增加；（2）时间上，北京市1980-2018年粮食生产、水质净化、气体调节、生境质量、休闲娱乐5项生态系统服务均呈现下降趋势；空间上，粮食生产呈现东南部较高，西北部较低的分布特征，其余生态系统服务均呈现西北部较高，东南部较低，市中心最低的分布特征；（3）景观水平上，林地、建设用地等景观组成变化对生态系统服务影响最为显著。破碎化指数、多样性指数等景观配置指数对生态系统服务影响最为显著；类型水平上，平均斑块面积、斑块聚集度对生态系统服务影响相对最为显著。总体来讲，通过分析景观格局演变如何影响生态系统服务，为如何通过设计和优化景观格局来提升生态系统服务提供了定量依据，从而为促进区域的景观可持续规划提供理论依据和案例参考。

Changes of landscape pattern and its impacts on multiple ecosystem services in Beijing

Landscape pattern is the result of the interaction between human and nature. During the urbanization process, the landscape pattern had changed significantly, which affected the ecological process and thus threatened ecosystem services. The assessment of the impacts of landscape pattern on ecosystem services is crucial for regional sustainable development. Taking Beijing as a case study, we quantified the spatiotemporal changes of six selected ecosystem services, including food production, water purification, air quality regulation, carbon storage, habitat quality, and recreation opportunity from 1980 to 2018 by using the InVEST and Recreation Opportunity Spectrum (ROS) models. In addition, we analyzed changes of landscape patterns in Beijing, and explored the impacts of landscape patterns on ecosystem services. The results showed that:1) the landscape pattern in Beijing experienced dramatically changes from 1980 to 2018. The build-up land expanded by 120%, which mainly resulted in the reduction of cropland. The overall landscape pattern tended to be fragmented, the patch shape index became more complicated and the heterogeneity of the patches also increased. 2) Food production, water purification, carbon storage, habitat quality, and recreation opportunity showed a decreasing trend from 1980 to 2018. Spatially, food production was higher in the southeast and lower in the northwest. For the other ecosystem services, they were higher in the northwest, lower in the southeast, and the lowest in the central downtown area. During the past 38 years, the food production decreased the most in the central region of Beijing, while the air quality regulation, carbon storage, habitat quality, and recreational opportunity decreased the most in the eastern and southern regions. 3) At the landscape level, changes in land-use types, such as woodland, grassland, and build-up land had the most significant impacts on ecosystem services. Landscape metrics, such as the fragmentation index and diversity index influenced ecosystem services more obviously. At the class level, the mean patch area and the patch aggregation index had the most significant impacts on ecosystem services. Among them, the mean patch area and aggregation index of woodland showed positive effects on air quality and carbon storage. However, the aggregation index of built-up land showed a negative effect on habitat quality. In general, this study focused on analyzing the impacts of landscape pattern changes on ecosystem services, which can help decision makers to improve the ecosystem services by optimizing landscape patterns. The results of this study also can provide theoretical and practical basis for promoting regional landscape sustainable planning.