Recent environmental changes in the Yunnan–Guizhou Plateau inferred from organic geochemical records from the sediments of Fuxian Lake

During the past century, many lacustrine environments have changed substantially at ecosystem level as a result of anthropogenic activities. In this study, distributions n-alkane homologues, carbon isotopes (δ13Corg), organic carbon, and C/N atomic ratio in two sediment cores from Fuxian Lake (Yunnan, southwest China) are used to elucidate impacts on deep, oligotrophic, freshwater lake. The preference index (CPI) long-chain components, average chain length (ACL), proportion aquatic macrophytes (Paq), terrigenous/aquatic ratios (TAR) show different temporal patterns that reflect variations biological production. Notably, homologues shown be more sensitive environmental changes than δ13Corg ratio. Prior 1950s, minor sedimentary geochemical record were likely caused by climate changes, they represent natural stage lake evolution. onset cultural eutrophication occurred when proxies collectively exhibited high-amplitude fluctuations but overall decreasing trends coincided with population growth related increases land-use pressure. 21st has become even eutrophic response human activities, indicated sharp ratio, Paq, δ13Corg, ACL, CPI, TAR. Our findings provide robust molecular evidence confirming evolution lakes Yunnan–Guizhou Plateau over century was closely associated enhanced