Macroinvertebrate community in relation to water quality and riparian land use in a substropical mountain stream, China.

Exploring how water quality and land use shape the benthic macroinvertebrate community composition is of widespread interest in biodiversity conservation and environmental management. In this study, we investigated the structures of benthic macroinvertebrate assemblages and their environmental controls in terms of water quality and riparian land use in the Jinshui River, China. We carried out three campaigns including wet season (August 2009), dry season (November 2009), and normal season (April 2010) based on the hydrological regime in Jinshui basin. The result showed that macroinvertebrate assemblage variations were better explained by water quality factors than land use based on variance partitioning procedure. The land use of 2 km upstream from the sampling sites had explained more variation than that of the whole riparian zone in upstream catchment on macroinvertebrate community, and land use of 2 km upstream also had more interactions with water quality. Canonical correspondence analysis (CCA) indicated that the elements or nutrient of magnesium (Mn), selenium (Se), strontium (Sr), silicon (Si), dissolved inorganic nitrogen (DN), sulfur (S), total organic carbon (TOC), and total nitrogen (TN) in water exhibited a strong relationship with macroinvertebrate assemblages. However, the variance in water quality explained by land use was lower than that explained by water quality in rivers using redundancy analysis. Our study suggested that proximate factors (i.e., water quality) were more important to interpret the macroinvertebrate community compared to ultimate factors (i.e., land use) for macroinvertebrate assemblages in river system.