全球气候变化和非气候性人为扰动如何影响生物群落中动植物数量、群落结构以及生态系统机能已成为生态学研究的一大挑战。为此，科学家通过对河流中鱼群的研究从侧面对该问题进行了探讨。
法国一研究小组收集了法国主要河流上7个不同研究区域内15至25年间的历年数据，通过定义鱼种丰度、均匀度指数等生物学变量，运用整合分析和线性回归等方法对构建的多采样点、多鱼种数据库进行分析。研究结果表明，鱼类繁殖期内上游的水温逐年上升。繁殖期内的水温同总丰度和暖水鱼类所占比例成正比，同均匀度成反比关系；水电和核电建设项目对气候变化的影响没有明显抑制或推动作用，说明气候变化对生物群落的影响超过了非气候性人为扰动的作用。因此，研究长期生态模式时，甚至在已受到非气候性人为扰动的区域内，有必要将全球气候变化系统地加以考虑。
相关论文发表在《全球变化生物学》（Global Change Biology）上。（科学新闻杂志 王冰/编译）
生物谷推荐原始出处：
（Global Change Biology），Volume 13 Issue 12 Page 2467-2478，MARTIN DAUFRESNE，PHILIPPE BO?T
Climate change impacts on structure and diversity of fish communities in rivers
MARTIN DAUFRESNE and PHILIPPE BOËT
It is widely accepted that climate change constrains biota. Yet, because of the lack of consistent multisite and multitaxon surveys, few studies have addressed general rules about how climate change impacts on structure and diversity of animal communities. Especially, the relative influence of nonclimatic anthropogenic disturbances on this impact is fairly unknown. Here, we present for the first time a meta-analysis assessing the effect of global warming on stream organisms. Fish communities of large rivers in France undergoing various anthropogenic pressures showed significant increase in proportions of warm-water species and of specific richness during the last 15–25 years. Conversely, the equitability decreased, indicating a gradual decrease of the number of dominant species. Finally, the total abundance increased, coupled with rejuvenation and changes in size-structure of the communities. Interestingly, most of these effects were not depressed by the strength of nonclimatic anthropogenic disturbances. Conversely, geographical location of communities and especially closeness of natural barriers to migration could influence their response to climate change. Indeed, increase in the proportion of southern species seemed hindered at sites located close to the southern limit of the European species' geographical ranges. This work provides new evidence that climate change have deep impacts on communities which, by overtaking the effects of nonclimatic anthropogenic disturbances, could be more substantial than previously thought. Overall, our results stress the importance of considering climate change impacts in studies addressing community dynamics, even in disturbed sites.
