Human-induced ecological shifts in biological communities of lakes in China within the past two centuries

Limited large-scale studies that integrate multi-community dynamics, long-term ecological trends, and the drivers of ecological shifts constrain our ability to manage freshwater ecosystems affected by climate change and human activities. In this study, we compile and synthesize biotic community data (cladocerans and diatoms) from lakes across China to reveal ecological shifts over the past two centuries. Our results indicate an overarching ecological transition occurring in the 1960s, although the timing of these shifts varies among different lake districts. Following this transition, zooplankton (cladoceran) taxa generally showed increased relative abundances in planktonic taxa and overall concentrations, accompanied by declines in diversity across most plain/basin lakes. In contrast, temporal changes in diatom assemblages displayed stronger regional variability. Human-induced warming and enhanced nutrient inputs are likely the primary drivers underlying these changes in biotic community structure. Additionally, lake morphology, hydrological alterations, and catchment characteristics significantly influence the ecological trajectories of individual lakes. Overall, these findings underscore the importance of understanding the complex interactions between environmental change and anthropogenic pressures to guide sustainable water resource management and mitigate further degradation of freshwater ecosystems.