State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; College of Water Sciences, Beijing Normal University, Beijing 100012, China.
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; College of Water Sciences, Beijing Normal University, Beijing 100012, China.
Sci Total Environ. 2022 Jul 10;829:154636. doi: 10.1016/j.scitotenv.2022.154636. Epub 2022 Mar 17.
Despite significant climate change on the Tibetan Plateau, the historical succession trend and underlying driving mechanism of aquatic ecosystem in alpine lake remain unclear. In this study, palaeolimnological analysis and high-throughput sequencing of sedimentary DNA were used to investigate environmental changes, primary productivity, and eukaryotic algal community succession over the past millennium in Lake Yamzhog Yumco of the southern Tibetan Plateau. Lake primary productivity significantly increased after ~1850 CE and algal community succession occurred in three stages including the Medieval Warm Periods (approximately 1000-1250 CE), the Little Ice Age (1250-1850 CE), and the Current Warm Period (1850-2020 CE). Moreover, succession was synchronous with inferred climate changes. Partial least square path modeling indicated that climate factors affected primary productivity and eukaryotic algal community structure by affecting nutrient loading. The results suggest that glacier melting and permafrost degradation caused by climate warming, combined with increased precipitation, may be the major driving factors of nutrient concentration increases, phytoplankton biomass increases, and shifts in community composition. Considering the expected trends of future climate change and continuous warming, the restoration of vegetation cover and reduction of non-point source nutrient loading in the Tibetan Plateau is urgently needed to mitigate climate change impacts on alpine lake aquatic ecosystems.
尽管青藏高原发生了重大气候变化，但高寒湖泊水生态系统的历史演替趋势及其潜在驱动机制仍不清楚。本研究采用古湖沼学分析和沉积物 DNA 高通量测序技术，对过去 1000 年来青藏高原南部的雅珠错（Yamzhog Yumco）湖泊的环境变化、初级生产力和真核藻类群落演替进行了研究。自约 1850 年以来，湖泊初级生产力显著增加，藻类群落演替经历了三个阶段，包括中世纪暖期（约 1000-1250 年）、小冰期（1250-1850 年）和当前暖期（1850-2020 年）。此外，演替与推断的气候变化同步发生。偏最小二乘路径模型表明，气候因素通过影响养分负荷来影响初级生产力和真核藻类群落结构。研究结果表明，气候变暖导致的冰川融化和多年冻土退化，加上降水增加，可能是营养物浓度增加、浮游植物生物量增加和群落组成变化的主要驱动因素。考虑到未来气候变化的预期趋势和持续变暖，青藏高原植被覆盖的恢复和非点源养分负荷的减少是缓解气候变化对高寒湖泊水生态系统影响所急需的。
