土地利用影响溪流底栖动物群落特征的空间尺度效应研究

It has become clear that the influence of land uses on stream ecosystem is scale-dependent. Therefore, understanding how the land use changes, impacted steam macroinvertebrates at multiple spatial scales is essential to explore the mechanism of degradation and recovery of stream macroinvertebrate communities, and thus it is helpful in biodiversity protection and impaired stream ecological recovery. Stream macroinvertebrates are influenced independently or interactively, directly or indirectly by factors at regional, watershed, riparian and local scales. However, researches related to terrestrial characteristics at different scales yielded mixed results. Moreover, present reports were mainly concentrated on watershed, riparian and local spatial scales, rare in regional scale. Li River, Qiantang River and Weihe watersheds in China are possess of distinct climate and geography character, different intensity of land uses and rich in macroinvertebrate diversity as well. In this proposal, we will investigate data of streams system, sub-watersheds, land use at different scales, stream habitats, water quality and macroinvertebrate in 1-3 order streams in above three watersheds. Furthermore, we will analyze relationships among environmental factors of different spatial scales, and factors with macroinvertebrate community by proper statistic methods. We aim to explore relative importance of multiscale environmental factors or stressors potentially to stream macroinvertebrate communities composition and structure, with the emphasis on the role of regional factors in shaping undisturbed and disturbed stream macroinvertebrate communities character among three watersheds. Our specific objects were 1) to describe differences in macroinvertebrate community composition and structure of non or little disturbed streams among regions, and to examine whether there were differences in the effect of factors on macroinvertebrate in a watershed; 2) to quantify the distinctive effects of stressors related to or resulted from watershed land use changes in shaping community structure among regions；3) to construct the response pattern models of macroinvertebrate community to land use changes at broad scales. It is hoped that our objects could provide a tool for proper evaluation of the influence of land use changes on stream ecosystems, stream ecological monitoring, impaired stream ecological recovery design, and evaluation of the effect of ecological recovery practice.

土地利用对溪流生态系统的影响与空间尺度有关。解析土地利用影响溪流底栖动物的空间尺度效应，有助于更科学地揭示底栖动物群落的退化和恢复机制。区域、流域、沿岸带和局部尺度环境因子综合作用于底栖动物，但现有研究集中在流域、沿岸带和局部尺度。项目拟以漓江、钱塘江中游、渭河水系西安地区河流所在流域的溪流为研究对象，应用GIS技术与方法提取水系和划分子流域，解译遥感影像来获得和计算不同空间尺度下的土地利用，结合水质、生境和底栖动物的野外调查、室内分析和鉴定数据，采有多元统计方法，探讨在受农田及城镇用地干扰情况下，区域尺度环境因子对流域间底栖动物群落特征变化的作用；探寻适合不同流域的，能高效反映农田城镇用地对底栖动物群落影响的最佳空间尺度，建立基于不同空间尺度环境因子的底栖动物群落对农田或城镇用地的响应模式。研究结果将对科学评价土地利用变化的生态效应、生态健康评价及受损溪流的生态恢复实践有积极作用。