Effects of riparian land use on water quality and fish communities in the headwater stream of the Taizi River in China

Riparian land use remains one of the most significant impacts on stream ecosystems. This study focuses on the relationship between stream ecosystems and riparian land use in headwater regions. Four riparian land types including forest, grassland, farmland, and residential land were examined to reveal the correlation between stream water and fish communities in headwater streams of the Taizi River in north-eastern China. Four land types along riparian of 3 km in length were evaluated at 25, 50, 100, 200 and 500 m widths, respectively. Generally, the results found a significant relationship between riparian land uses and stream water quality. Grassland was positively correlated with water quality parameters (conductivity and total dissolved solids) at scales from 100 to 500 m riparian width. Farmland and residential land was negatively correlated with water quality parameters at scales from 25 to 500 m and from 50 to 200 m riparian widths, respectively. Although the riparian forest is important for maintaining habitat diversity and fish communities, the results found that only fish communities were significantly correlated with the proportion of riparian farmland. Farmland had a positive correlation with individual fish abundance within a riparian corridor of 25 to 50 m, but a negative correlation with fish diversity metrics from 25 to 100 m. This study indicates that effective riparian management can improve water quality and fish communities in headwater streams.