[U-05] Advanced understanding of Quaternary and Anthropocene hydroclimate changes in East Asia

[U05-01] Anthropogenesis disturbances on diatom assamblages in Lingshui Pool, south China

★Invited Papers

*Liang-Chi Wang^1,2 (1.Department of Earth and Environmental Sciences, National Chung Cheng University, Taiwan、2.Environment and Disaster Monitoring Center, National Chung Cheng University, Taiwan)

キーワード：diatom, paleoecology, restoration

Human impact is a significant problem for shallow lakes in the karst region in south China. In recent years, the ecological issues relating to managing and restoring these critical aquatic ecosystems have come to the fore. The Lingshui Pool (LSP) is one of the most studied spring-fed lake ecosystems in south China, and it has well-preserved chronological profiles. Due to the rapid development and urbanization, this important freshwater ecosystem is suffered the severe issue of eutrophication and ecological degradation. To determine the environmental effects of anthropogenesis disturbances in recent years and establish conservation practice for this lake ecosystem, we analyzed diatom and weak acid leachable elements from a well-dated sediment core from LSP to reconstruct the changes in aquatic condition and diatom diversity during 1960-2013. The results reveal the shift in diatom assemblies, diversity, and geochemistry content are strongly linked to dam construction in 1964 and rapid eutrophication after 1990. The diatom diversity was stable and relatively high when submerged macrophytes occurred during 1964-1990. Thus, the re-introduction of endemic macrophytes can benefit the shallow lakes' ecological stability and diversity. To recover the submerged macrophytes in eutrophic water, we recommend dredging upper organic-rich sediment and managing the water depth.