Relationships between macroinvertebrate communities and land use types within different riparian widths in three headwater streams of Taizi River, China

Abstract

The effects of riparian land uses on water quality and macroinvertebrate communities were examined in three headwater streams of the Taizi River in northeastern China. Land uses of forest, grassland, farmland, and villages were evaluated within different widths of riparian corridors (length = 3 km upstream; width = 25, 50, 100, 200, and 500 m). Overall, the results revealed a significant trend for each stream linking a relatively low proportion of farmland in the riparian corridor with better water quality and healthier macroinvertebrate community. Cluster analysis confirmed significant variation in the macroinvertebrate communities found among the three streams. Correlation analysis identified significant positive correlations between the proportion of farmland and metrics of water quality (conductivity, dissolved solids, and total nitrogen) at small (25–50 m) to medium (100–200 m) widths of riparian corridors. The sensitive taxa of stoneflies and functional feeding groups of scrapers and predators were good predictors of anthropogenic disturbance associated with the proportional extent of farmland and village land use across most of all riparian widths. In contrast, correlations between biodiversity indices and proportion of villages and between bioassessment indices and proportion of farmland were only significant at relatively small widths (25–50 m) of riparian corridors. The canonical correspondence analysis revealed that the proportions of forest (25 m), farmland (200 m), grassland (200 m), and village (100 m) showed independent effects on the spatial distribution of macroinvertebrates in the Taizi River. The first two axes contributed 34.6% of the cumulative percent variance of species–environment relations. This research indicates that management of riparian corridor land uses at relatively small to medium widths (25–200 m) could be effective in restoring water quality and macroinvertebrate communities in headwater stream regions.