受控的沉积物冲洗操作(CSFO)可以恢复水库的储存损失,同时重新平衡被大坝中断的沉积物通量,但是,同时,可能造成不可接受的生态影响。在这项研究中,我们调查了高地溪流的食物网对CSFO的反应,重点关注在三个不同的中生境中检测到的细沉积物沉积的影响,即,一个游泳池,一个片段,和一个台阶池。野外运动持续了两年,包括对精细沉积物的重复测量,和附生植物的取样,底栖大型无脊椎动物和鱼类。由于CSFO对食物网的较低营养水平具有短期和中期的生态影响,因此发生了中度和斑片状的沉积。这可能会影响整个生态系统的功能。对所调查河流中所有可用的中生境的监测可以检测对CSFO的生态响应的变化,对影响进行更充分的评估。不出所料,池中的沉积较大,但是,与我们的假设相反,对于居住在浅滩中的底栖生物,影响较小,恢复时间较长。在鱼类的情况下,短期内没有观察到褐鳟鱼和牛头鱼的致死性影响,但不能排除长期持续影响的发生.迄今为止,这是为数不多的研究之一,涉及详细综合评估水库沉积物管理对河流生态系统非生物和生物成分的下游影响。
Controlled sediment flushing operations (CSFOs) allow to recover reservoirs storage loss while rebalancing the sediment flux interrupted by dams but, at the same time, may cause unacceptable ecological impact. In this study, we investigated the responses of the food web of an upland stream to a CSFO, focusing on the effects of fine sediment deposition detected in three different mesohabitats, i.e., a pool, a riffle, and a step-pool. The field campaign lasted two years and included repeated measurements of fine sediment deposits, and sampling of periphyton, benthic macroinvertebrates and fishes. A moderate and patchy deposition occurred due to the CSFO with short and medium-term ecological impact on the lower trophic levels of the food web, which may affect the whole ecosystem functioning. The monitoring of all available mesohabitats in the investigated stream allowed to detect variations in the ecological response to CSFO, providing a more adequate assessment of the impact. As expected, sedimentation was larger in the pool but, in contrast to our hypotheses, the impact was lower and the recovery was longer for the benthic organisms inhabiting the riffle. In the case of fishes, no lethal impact of both brown trout and bullhead was recorded in the short term but the occurrence of longer lasting effects could not be excluded. To date, this is one of the few studies dealing with a detailed integrative assessment of the downstream impact of sediment management from reservoir on both abiotic and biotic components of stream ecosystem.