汶川县生态系统服务对景观格局及其变化的响应

景观格局及其变化是影响生态系统服务供应与维持的主要原因之一,也是生态系统服务管理与景观空间配置优化的基础。基于30 m分辨率土地利用数据,统计汶川县2000—2015年多种景观格局指数和碳固定、水源涵养、土壤保持3种生态系统服务的变化,划分等级探究生态系统服务对景观格局及其变化的响应。研究结果表明:1)汶川县整体景观趋于破碎化、斑块形状复杂化,斑块异质性增加,且主要是在林地、草地和耕地之间转换;2)对于生态系统服务,碳固定在全域内有所减少,而大部分区域水源涵养和土壤保持呈增长趋势;3)不同生态系统服务对景观格局的响应存在差异,不仅表现在指标上,也体现在程度上,如碳固定对斑块形状指数(Landscape Shape Index,LSI)响应较为明显,而对蔓延度指数(Contagion Index,CONTAG)敏感性较差;4)并非所有景观格局变化均会引起生态系统服务变化,尺度也会对结果造成影响。本研究通过生态系统服务对景观格局的响应分析,可为区域景观管理的相关评估提供借鉴。

Response of ecosystem services to landscape pattern and its changes in Wenchuan County, Sichuan Province

Landscape patterns and their changes are one of main reasons that affect the supply and maintenance of ecosystem services. It is revealed that the relationship between landscape patterns and ecosystem services is the basis of ecosystem service management and landscape space allocation optimization. Based on 30 m resolution land use data, this article counted the various landscape metrics and three kinds of ecosystem services including carbon fixation, water conservation, and soil conservation in Wenchuan County from 2000 to 2015. We also defined the response range of ecosystem service to landscape pattern according to data rating. The results showed that: 1) The overall landscape tended to be more fragmented, the shape of the patches was more complicated and the heterogeneity were more increased, which mainly took place among forest land, grassland and cultivated land in Wenchuan County. 2) In terms of ecosystem services, the carbon fixed services have decreased, while water conservation and soil conservation have shown the increasing trend in most areas. 3) Different ecosystem services to the landscape patterns were not only reflected in the indicators, but also in the extent. For example, the carbon fixation was more responsive to Landscape Shape Index (LSI) and less sensitive to Contagion Index (CONTAG). 4) Not all changes in landscape patterns could cause changes in ecosystem services and the scale factor must be taken into consideration. This study provides a reference for regional landscape management through the response analysis of ecosystem services to landscape patterns.