| 摘要: |
| 浮游植物是湖泊生态系统的主要初级生产者，对环境变化极为敏感，但长期以来青藏高原湖泊缺乏有效的观测数据，导致了对青藏高原湖泊生态系统现状和变化趋势认识的不足。本研究通过2019年7月-2021年9月三年对青藏高原72个湖泊敞水区浮游植物进行调查，刻画了该区域湖泊浮游植物群落结构特征和主要驱动因素。本研究共鉴定出8门91属，各湖泊浮游植物生物量变化范围为1.01 μg/L至8742.24 μg/L，大部分湖泊浮游植物生物量处于100-1000 μg/L 水平。该区域湖泊浮游植物主要为硅藻门与绿藻门，硅藻门藻类在35个湖泊中占比超过50%、绿藻门藻类在18个湖泊中占比超过50%。青藏高原湖泊浮游植物优势属为小球藻属（Chlorella）、卵囊藻属（Oocystis）、舟形藻属（Navicula）、小环藻属（Cyclotella）。在属水平，浮游植物丰富度指数（richness）变化范围为1-25属，平均值为8.6属；均匀度指数(evenness)的变化范围为0.08-0.93，平均值为0.55；辛普森指数的变化范围为0-0.87，平均值为0.53；香农指数范围为0-2.39，平均值为1.16。通过Mantel test与RDA分析进行驱动因素分析，发现盐度和电导率是青藏高原地区浮游植物群落结构差异的主要驱动因子，温度（气温）和pH是浮游植物生物量差异的主要驱动因子。本研究结果填补了青藏高原湖泊浮游植物认识上的空白，可为认识青藏高原湖泊生态系统对气候变化和人类活动的响应提供参考。 |
| 关键词: 青藏高原 浮游植物 群落结构 生物量 驱动因子 |
| DOI： |
| 分类号: |
| 基金项目:青藏高原二次科考项目（2019QZKK0202） 国家自然科学基金项目（32171546） |
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| Characteristics and driving factors of phytoplankton community Structure in Lakes on the Tibetan Plateau |
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Meng Yangyang, Wang Liya, Zhou Yongqiang, Zhang Enlou, Zhang Min
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State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences
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| Abstract: |
| Phytoplankton serves as the primary producer in lake ecosystems and exhibits a high sensitivity to environmental changes. Nonetheless, the prolonged absence of reliable observational data in Tibetan Plateau lakes has resulted in an inadequate understanding of the current status and evolving trends within the Tibetan Plateau"s lake ecosystem. From July 2019 to September 2021, we conducted an extensive study involving the collection, identification, and quantification of phytoplankton samples from 72 open water areas across lakes in the Qinghai-Tibet Plateau. Our analysis revealed a total of 10 phyla and 93 genera of phytoplankton. The phytoplankton density in the lakes varied significantly, ranging from 1.01 μg/L to 8742.24 μg/L, with the majority of lakes exhibiting a density within the 0.1-1 mg/L range. The predominant phytoplankton lake types in the region were Bacillariophyta and Chlorophyta, with Bacillariophyta organisms constituting over 50% in 35 lakes, and Chlorophyta organisms exceeding 50% in 18 lakes. Noteworthy The predominant phytoplankton species in the lakes of the Qinghai-Tibet Plateau included Chlorella, Oocystis, Navicula, and Cyclotella. The richness indices of lake phytoplankton in the region were characterized by species, ranging from 1 genus to 25 genera, with an average value of 8.6 genera. The evenness index exhibited a range of 0.08 to 0.93, with a mean of 0.533. Similarly, the Simpson Index varied from 0 to 0.87, averaging at 0.533. The Shannon index displayed a range of 0 to 2.38, with an average of 1.16. Through the Mantel test and RDA analysis, it was determined that salinity and phosphate were the primary drivers of differences in phytoplankton community structure, while salinity and temperature were the main factors influencing variations in phytoplankton biomass in the Tibetan Plateau. The findings of this study bridge the knowledge gap regarding lake phytoplankton in the Qinghai-Tibet Plateau, offering valuable insights into how lake ecosystems in the region respond to climate change and human activities. |
| Key words: Tibet Plateau phytoplankton community structure biomass driving factor |
