生物多样性 ›› 2020, Vol. 28 ›› Issue (12): 0-0.DOI: 10.17520/biods.2019390

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西藏横断山区溪流细菌beta多样性组分对气候和水体环境的响应

李明家1,2  吴凯媛1,3  孟凡凡1,2  沈  吉1,2  刘勇勤2,4  肖能文5,*  王建军1,2,*   

  1. 1 (湖泊与环境国家重点实验室, 中国科学院南京地理与湖泊研究所, 南京 210008)

    2 (中国科学院大学, 北京 100049)

    3 (江南大学环境与土木工程学院, 江苏无锡 214122)

    4 (中国科学院青藏高原研究所, 北京 100101)

    5 (中国环境科学研究院, 北京 100021)

  • 收稿日期:2019-12-07 修回日期:2020-03-31 出版日期:2020-12-20 发布日期:2020-05-25
  • 通讯作者: 王建军

Beta diversity components of stream bacteria in Hengduan Mountains: The effects of climate and environmental variables

Mingjia Li1,2, Kaiyuan Wu1,3, Fanfan Meng1,2, Ji Shen1,2, Yongqin Liu2,4, Nengwen Xiao5,*, Jianjun Wang1,2,*   

  1. 1 State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008

    2 University of Chinese Academy of Science, Beijing 100049

    3 School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122

    4 Institute of Tibetan Plateau Research Chinese Academy of Science, Beijing 100101 5 Chinese Research Academy of Environmental Sciences, Beijing 100021

  • Received:2019-12-07 Revised:2020-03-31 Online:2020-12-20 Published:2020-05-25
  • Contact: JianJun WANG

摘要: 理解沿环境或空间梯度的群落组成变化(即beta多样性)一直是生态学和保护生物学的中心问题,且beta多样性的形成机制及其对环境的响应已成为当前生物多样性研究的热点问题。本文以西藏横断山区怒江和澜沧两个流域入江溪流中的细菌为研究对象,使用Baselga的beta多样性分解方法,基于S?rensen相异性指数将细菌的beta多样性分解为周转(turnover)和嵌套(nestedness)两个组分,探究了细菌beta多样性及其分解组分随海拔变化的演替模式,并且衡量了环境、气候和空间因子对于其的相对重要性。结果表明,两个流域中细菌的群落结构显著不同。两个流域的细菌总beta多样性和周转组分随海拔高度的增加而增加,周转组分占总beta多样性的成分较大。气候和环境因子是两个流域中细菌总beta多样性及周转过程的重要预测因子,并且所有的显著因子均为正相关,其中环境因子中相关性最高的为海拔(R2=0.408,P < 0.001),而气候因子中相关性最高的为年平均温度(R2=0.417,P < 0.001)。细菌的总beta多样性和周转组分主要受环境过滤的影响,而嵌套组分主要受扩散限制的影响。此外,较为恶劣的环境条件会增加细菌的总beta多样性和周转率,并且会形成更强的环境筛选作用去影响细菌群落的物种组成。我们的研究首次评估了横断山脉溪流中周转和嵌套两种过程对细菌总beta多样性的作用,以及从beta多样性分解和造成其变化的主要因素入手,深入研究了海拔梯度造成群落物种组成差异的生态机制,为生物多样性保护提供了科学的理论依据。

关键词: beta多样性, 周转, 嵌套, 海拔梯度, 气候, 环境筛选

Abstract: Understanding community composition variation (beta-diversity) along environmental and spatial gradients is a central interest in ecology and conservation biology. Although bacterial elevational patterns are somewhat established, their underlying processes were understudied. To better understand the patterns behind beta diversity, we investigated aquatic bacterial community composition in individual streams in Nujiang and Lancang Rivers located in the Hengduan Mountains of the Tibetan Plateau. Using Baselga’s approach of beta diversity partitioning based on the Sørensen dissimilarity index, we explored the elevational patterns of turnover and nestedness through linear models and measured the relative importance of environmental, climatic, and spatial factors on bacterial beta diversity with multiple regression on distance matrices and variation partitioning analyses. Our results show bacterial community composition differed between the Lancang and Nujiang rivers. Total beta diversity and turnover component increased with increasing elevational distance, and total beta diversity was driven by turnover component. Climatic and environmental factors were important predictors of total beta diversity and turnover component in the two catchments, and all the significant correlations were positive. The highest correlation factors were elevation (R2=0.408, P < 0.001) and mean annual temperature (R2=0.417, P < 0.001). The variation partitioning results suggest nestedness component was heavily affected by dispersal limitation while total beta diversity and turnover were mainly affected by environmental filtering. Moreover, harsher climate conditions will increase total beta diversity and turnover, and form stronger environmental filtering processes that impact the bacterial species composition. Our research shows that the conservation of bacterial diversity in the stream of Hengduan Mountains in Tibet needs to target the whole multiple sites, rather than a few richest sites of biodiversity.

Key words: beta diversity, turnover, nestedness, elevation gradient, climate, environmental filtering