Assessing lake ecosystem health from disturbed anthropogenic landscapes: Spatial patterns and driving mechanisms

Freshwater lake ecosystems face unprecedented challenges with escalating anthropogenic pressure worldwide. An improved understanding of how environmental and socioeconomic factors impact lake health is crucial for strategic conservation and management. Here, we compiled data from 85 lakes from China's most densely populated regions and proposed an integrated index to examine spatial patterns of lake ecosystem health. We further evaluated how 16 socioeconomic drivers and environmental conditions drive these changes by using the Bayesian hierarchical model and Gradient boosting decision tree models. Our results suggest the integrated index can provide a comprehensive picture of lake ecosystem quality from a systems perspective combining water bodies and lakeshore zones. We find that lake degradation shows clear spatial heterogeneity patterns given the common forcings associated with climate factors and land-use practices within this region. We further reveal the non-linear relationships between the social and economic factors (distance, population, food production, gross domestic product [GDP], etc.) and lake ecology, and find that distance of the lake from the city center was the predominant factor that influenced the lake system health among these multiple drivers. This study contributes to the understanding of the differences and driving mechanisms of lake ecological degradation in areas of high human activity as a basis for further identifying environmental conflicts and recommendations to improve the state of lake ecosystems.