REU: Debris Dams as Mitigating Patches for Stream Fauna During Floods

在面临严重干扰时仍坚持的社区可能会这样做，因为通过斑块配置和扩散，干扰的影响得到了缓解。这项建议研究了热带无脊椎动物的这一问题，这些无脊椎动物已知能迅速从洪水中恢复，但恢复机制尚不清楚。PI将检验这样一个普遍假设，即缓解斑块，即泥石坝，减轻洪水对河流小型动物的不利影响，减少洪水期间的动物迁移，并促进洪水过后，动物被转移到河底。对特定假设的实验测试概述了这些缓解斑块对动物的影响的大小和潜在的影响机制。实验将涉及：(1)实地量化动物的空间格局如何受到拟议的缓解斑块和洪水的影响；(2)斑块被操纵的野外实验以及与未被操纵的地点相比动物的恢复；以及(3)实地和水槽研究，考察动物对缓解斑块的反应机制。研究结果将提供有关自然干扰如何影响均衡条件的信息。

Communities which persist in the face of severe disturbances may do so because the impact of the disturbance is mitigated by patch configuration coupled with dispersal. This proposal examines this issue for lotic invertebrates which are known to rapidly recover from floods but for which the recovery mechanisms are not known. The PI will test the general hypothesis that mitigating patches, namely debris dams, lessen the detrimental effect of floods on stream meiofauna by reducing faunal displacement during floods and by facilitating return of displaced fauna to the stream bottom following flood. Experimental tests of specific hypotheses are outlined to address both the magnitude of the effect that these mitigating patches have on the fauna and the mechanisms underlying the effects. Experiments will involve: (1) field quantification of how the spatial patterns of the fauna are effected by the proposed mitigating patches and by flood; (2) field experiments in which patches are manipulated and recovery of fauna compared with unmanipulated sites; and (3) field and flume studies examining the mechanisms responsible for faunal response to mitigating patches. The results will provide information on how natural disturbances effect equilibrium conditions.