Effects of river damming on ground-dwelling arthropods along riparian-upland habitats: Effects of river damming on ground-dwelling arthropods

River damming is one of the most serious anthropogenic disturbances impacting river ecosystems. Little is known about the consequences of river damming on ground-dwelling arthropods, although they represent a functionally important component of riverine ecosystems because they provide an essential link between aquatic and terrestrial ecosystems. We investigated the effects of river damming on the composition and structure of arthropod communities in the Baijia Stream located in the centre of the Three Gorges Reservoir. Our results revealed that (a) river damming modified the community composition of riparian arthropods, as 24 taxa disappeared and 11 taxa colonized the new habitat after damming; (b) river damming altered the community structure of arthropods because higher richness and abundance of arthropods were recorded in the regulated section, especially for predators, detritivores, and herbivores; and (c) river damming altered the lateral distribution along riparian-upland gradients and the temporal dynamics of arthropod communities. Interestingly, upland habitats of streams supported more species than the riparian habitat in the regulated section, suggesting that uplands may become an important habitat for riparian species after river damming. Although higher total abundance and richness and higher abundance of some feeding guilds of arthropods were observed in the regulated section, the negative effects of river damming on biodiversity are addressed in this paper. Thus, ground-dwelling arthropods appear to be sensitive indicators of the ecological effects of river damming. Assessment of the consequences of river damming and dam management plans should consider ground-dwelling arthropod communities in associated riparian and upland habitats.