Different types of Anthropocene signals recorded in Huguangyan Maar Lake over the past 450 years

Over the past few centuries, human activities have increasingly impacted global climate and ecological environments. The “Anthropocene” has been proposed to highlight the significant influence of human activities on the environment. However, prior research has focused on analyzing a single type of human activity in lake sediments. In this study, we examined the historical changes in water eutrophication, terrestrial vegetation, and heavy metal pollution in the sediments of Huguangyan Maar Lake over the past 450 years. By comparing different human activity records within the same regional and chronological framework, we found that the timing of significant impacts on lake sediments varied by activity type. Eutrophication, induced by population growth and agricultural fertilization, began around 1950 CE. Changes in vegetation owing to agricultural and forestry practices occurred around 1780, 1880, and 1980 CE. Significant enrichment of heavy metals from industrial production began around 1950 CE. We suggest that, in reconstructing the history of human activities or defining the onset of the “Anthropocene,” it is crucial to consider both the types of human activities and their spatial extent.