Climatic warming and overgrazing induced the high concentration of organic matter in Lake Hulun, a large shallow eutrophic steppe lake in northern China

► About 90% of the OM in Lake Hulun is of terrigenous origin. ► Climatic change and over grazing induced the high concentration of OM in Lake Hulun. ► The inputs of soil-derived OM to the lakes in northern China need more attention.