Organic carbon burial in Chinese lakes over the past 150 years

Organic carbon (OC) accumulation and storage in lake sediments is considered to be an important component of global C cycling. However, the storage of OC in Chinese lakes is not well constrained, and its role in future global change processes has rarely been considered. Here, we analyzed the OC burial and its correlation with lake catchment properties in Chinese lakes that have experienced heavy anthropogenic influence over the last ∼150 years. We compiled OC data from sixty-four lakes from the literature. The results showed that organic carbon accumulation rates (OCARs) in Chinese lakes ranged between 1.4 and 259.5 g m−2 yr−1, with a mean of 22 g m-2 yr−1 over the past ∼150 years, consistent with the global estimate of the carbon burial rate in lake sediments (11-26 g m−2 yr−1). Extrapolated to the whole country, a total of 269.5 Tg OC (ranging from 138.9 to 690.4 Tg C) was stored in Chinese lakes over the past 150 years. Spearman analysis revealed that OCARs strongly depended on lake and catchment size, precipitation, temperature, longitude, altitude and anthropogenic activities. Moreover, OCARs showed an increasing trend, especially after the 1950s, coinciding with land use changes and lake nutrient level shifts.