Climate and lake ecosystem evolution over the last millennium on the north-eastern Tibetan Plateau: Insights from stable isotope records of gastropod shells in Xing Co

• Published in: Palaeogeography, palaeoclimatology, palaeoecology Vol. 667; p. 112896
• Main Authors: Li, Yunqing, Zhang, Wanyi, Liu, Siyao, Zhang, Yanrong, Cao, Xianyong, Tian, Fang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2025
• Subjects: aquatic plants; biomass; China; climate change; ecosystems; evolution; Gastropoda; Gyraulus cf. eugyne; humans; humid zones; Lake productivity; lakes; land use; Little Ice Age; Medieval Warm Period; oxygen; Palaeoclimate reconstruction; palaeogeography; paleoclimatology; paleoecology; photosynthesis; plant growth; sedimentation rate; soil erosion; stable isotopes; total nitrogen; total organic carbon; δ13Cshell and δ18Oshell; China; Gyraulus cf. eugyne; Palaeoclimate reconstruction; Lake productivity; δ13Cshell and δ18Oshell; Little Ice Age; Medieval Warm Period
• ISSN: 0031-0182
• DOI: 10.1016/j.palaeo.2025.112896

The evolution of alpine lake ecosystems on the north-eastern Tibetan Plateau (NETP) over the last millennium has been affected by climate change and human activity. This study reconstructs the palaeoclimate and lake productivity of Xing Co using carbon and oxygen isotopes from aquatic gastropod shells (δ13Cshell and δ18Oshell), grain-size, total organic carbon (TOC), total nitrogen (TN), and the TOC/TN (C/N) ratio. The highest lake productivity – during the Medieval Warm Period (MWP) – is likely linked to enhanced photosynthesis of aquatic plants and increased biomass within the lake. This increase was driven by warm, humid climate conditions, indicated by higher δ13Cshell values, lower δ18Oshell values, and increased coarse-grain content. In contrast, the significant decline in lake productivity during the Little Ice Age (LIA) resulted from deterioration of trophic status and restricted aquatic plant growth under colder, drier climate conditions. However, the decrease in lake productivity since 1950 CE, amid global warming, may be linked to increased soil erosion and sedimentation rate from intensified human activity and land-use changes. The combined effects of climatic shifts and human disturbances highlight the need for ongoing monitoring of lake ecosystems to understand their resilience and response to future environmental changes. •Paleoclimate and lake productivity changes in NETP were reconstructed over the last millennium.•Highest lake productivity occurred during the warm and humid Medieval Warm Period.•Lake productivity significantly decreased during the cold and dry Little Ice Age.•Decreased lake productivity since 1950 CE is linked to enhanced human impacts.