Aquatic Coleoptera response to environmental factors of freshwater ecosystems in Changbai Mountain, northeast China

Aquatic Coleoptera (beetles) play a key role in freshwater ecosystems and are considered as a suitable bioindicator. Despite being widely distributed in China, there are few aquatic Coleoptera-based methods to assess ecological quality and environmental conditions. Changbai Mountain, with its distinct temperate and boreal forest ecosystems, provides an excellent opportunity to explore the influence of environmental features on aquatic beetles along altitude gradients. The objectives of the study were to investigate community structure and to determine the dominant factors controlling aquatic beetles in the montane environment. Study results showed that there were 8 families, 40 genera, and 72 aquatic beetle species on Changbai Mountain, and that Dytiscidae, Hydrophilidae and Haliplidae were the dominant families. Seven sensitive species of aquatic beetles could be considered as the candidate of indicator for environmental monitoring. Canonical correspondence analysis showed that water pH, concentrations of total organic matter and total phosphorus in sediment, water conductivity and water temperature had a significant impact on the community structure of aquatic beetles, and that water pH was the most important factor. Our results suggested that water quality played a key role in species richness of aquatic beetles, and that therefore they could be considered as an indicator organism of freshwater ecosystem health.