Ostracod assemblages and their relationship with water depth in surface sediments of Nam Co, Tibetan Plateau

作者：T. Xu, Yang Zhang, Manping Xie, Junbo Wang, Huaxiu Hu, Dasheng Ge · 发表于：Palaeogeography Palaeoclimatology Palaeoecology · 年份：2026 · DOI：10.1016/j.palaeo.2026.113584 · 被引用次数：1 · 研究领域：Geology and Paleoclimatology Research、Tree-ring climate responses、Cryospheric studies and observations

Quantitative reconstruction of lake-level changes at Nam Co is essential for the understanding long-term environmental evolution and climate dynamics of the Tibetan Plateau. Ostracod-based transfer functions for water depth serve as valuable tools for quantitative lake-level reconstructions. However, their reliability at Nam Co has been constrained by limited spatial and depth coverage, insufficient robustness testing, and weak cross-validation with independent regional proxies. To address these limitations, we integrated ostracod assemblages from multiple regions and applied comparative modeling to construct a more robust transfer function for Nam Co. This function was then used to reconstruct lake-level changes since the mid–late Holocene. Our results indicate that ostracod samples collected in different years exhibit no significant compositional differences, allowing their consolidation into a comprehensive lake-wide calibration dataset and improving model representativeness. Reconstructions generated through various statistical approaches revealed broadly consistent lake-level trends, supporting the robustness of the findings. By applying a random forest transfer function based on the integrated dataset, we quantitatively reconstructed the lake-level fluctuations at Nam Co since the mid–late Holocene. The reconstruction reveals a sequence of humid–arid phases followed by a return to humid conditions, closely aligned with other regional paleoclimatic records. These results...