Science & Technology
; Life Sciences & Biomedicine
Environmental Sciences & Ecology
The relationship between diversity and stability is a fundamental property of ecosystems. A growing body of empirical evidence suggests that the temporal stability of communities is typically controlled by diversity. Dams have been recognized as one of the primary means by which humans alter fluvial ecosystems and cause significant influences on stream ecosystems. Here, we investigated a small dam on Xiangxi River, the largest tributary of Three Gorges Reservoir in Hubei Province, Central China, to evaluate the impact of the dam on macroinvertebrate temporal stability. We established four sites, two unregulated sites located upstream of the dam and two downstream. We calculated the inverse of coefficient of variation (ICV) and temporal stability index (TSI) to represent temporal stability of community. We found that the mean values of species richness and Shannon-Wiener index in unregulated sites located upstream the dam were higher than in regulated sites downstream the dam, and these differences were significant especially in winter and autumn (P<0.05). The mean value of evenness was significant only in winter (P<0.05). The temporal stabilities of species richness, Shannon-Wiener index, and evenness were higher in unregulated sites than those in regulated sites. Regression analysis showed that the relationships between diversity and stability were significant linear (P<0.05) both in unregulated and regulated sites, but the dam reduced the strength of these relationships. Our results suggest that maintaining higher diversity can enhance the temporal stability and the diversity stability relationships. Removing dams and regulating flow are effective approaches to recover and maintain stream macroinvertebrates diversity and achieve the aim of maintaining stream ecosystem stability.