Data about the aquatic insects drift in Xingu River

The drift movement consists of the displacement of the organisms inside the water which allows its locomotion. This movement will result in a variation of the communities of organisms along the river, generating patterns. Based on this, we tested the hypotheses a) the movement of organisms along an upstream-downstream gradient will result in a pattern of nesteness distribution of organisms in aquatic insect communities; b) there will be an increase in the number of individuals and genera as we approach the most downstream point. The present study was carried out in seven sampling points distributed along the Xingu River. The sampling occurred at night in the central area of the river. The distribution of genera along the river remained constant. A nesteness distribution of the communities in the upstream-downstream gradient was not observed. Based on the results it is possible to visualize that the dispersion movement generates a nestedness of the genera downstream of the river, occurring a confluence for the last sampling point. The organisms are carried by the flow of the water stream and are influenced by the characteristics of the water body adapting to the type of environment in which they are located.

漂流运动指水生生物在水体中的位移过程，借此完成自身的移动。该运动将引发河流沿线生物群落组成的变化，并形成相应的分布格局。基于上述背景，我们对两项假说进行了检验：a) 沿上下游梯度的生物移动，会使水生昆虫群落的生物呈现嵌套分布（nestedness）格局；b) 越靠近下游最末端采样点，个体数量与属的数量均会随之增加。本研究在兴古河（Xingu River）沿线布设的7个采样点开展，采样工作于夜间在河道中心区域进行。各生物属在河流沿线的分布整体保持稳定，上下游梯度上的群落嵌套分布格局并未被观测到。结合研究结果可见，生物的扩散运动使得河流下游的生物属类形成嵌套分布，且在最后一个采样点处出现物种汇聚现象。生物个体随水流输送，并受水体特性影响，进而适应其所处的环境类型。