부산대학교 도서관

• Stream conditions are critical filters to stream macroinvertebrate assemblages. • Spate has more drastic effect on macroinvertebrates than flow reduction. • Streams with stable refugee contribute to mitigate ecological disturbances. • Conservation of stream habitats is plausible to buffer hydrological disturbances. Knowledge on the effects of habitat and flow alterations is basis for sustainable stream habitat conservation. This study explores the effects of hydrological and stream habitat alterations on the macroinvertebrates in Dinki watershed headwater streams, central highlands of Ethiopia. A total of 86 macroinvertebrate and water composite samples were collected over 25 sampling reaches in four-round sampling effort. A multivariate analysis of variance (MANOVA) was computed to assess variations in mean values of the three dependent variables (taxa abundance, richness, and diversity) across the independent variables, study sites (Dens, Gedamoch, Hagere-Selam, and Dinki). The mean differences in macroinvertebrate and environmental variables between sampling sites were computed using a one-way analysis of variance (ANOVA). Likewise, a principal component analysis (PCA) was computed to ordinate sampling sites in relation to macroinvertebrates. Furthermore, the resistance and resilience scores were calculated to quantify the invertebrates' persistence and rate of recovery to habitat and hydrological alterations. The MANOVA indicated a significant spatial variation in taxa abundance. Both the reduced flow and spates had declined assemblage structures in all sampling sites. The PCA also showed that the stream habitat condition influenced the distribution of macroinvertebrates. In general, macroinvertebrate assemblages in both the pre-and-post disturbance events were higher in the forested Gedamoch sites, indicating the role of stream habitat conservation to buffer hydrological disturbances. As a result, management priorities aiming to protect and restore stream condition is a sound mitigation tool to maintain stream condition and its resilience to ecological disturbances. [ABSTRACT FROM AUTHOR]