How fish traits and functional diversity respond to environmental changes and species invasion in the largest river in Southeastern China

PeerJ

article

Li Lin¹  Weide Deng²  Xiaoxia Huang⁴  Yang Liu¹  Liangliang Huang⁵  Bin Kang⁶ 

[1] College of Fisheries, Ocean University of China;Henry Fok College of Biology and Agriculture, Shaoguan University;Department of Oceanography, National Sun Yat-Sen University;Key Laboratory of Atmospheric Environment and Processes in the Boundary Layer Over the Low-Latitude Plateau Region, School of Earth Science, Yunnan University;College of Environmental Science and Engineering, Guilin University of Technology;Key Laboratory of Mariculture ,(Ocean University of China), Ministry of Education

关键词: The Min River;    Fish fauna;    Functional diversity;    Turnover;    Environmental filtering;    Species interaction;   

DOI  :  10.7717/peerj.11824

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

BackgroundFreshwater fish populations are facing multiple stressors, including climate change, species invasion, and anthropogenic interference. Temporal studies of fish functional diversity and community assembly rules based on trait-environment relationships provide insights into fish community structure in riverine ecosystems.MethodsFish samples were collected in 2015 in the Min River, the largest freshwater riverine system in Southeastern China. Fish functional diversity was compared with the background investigation in 1979. Changes in functional richness, functional evenness, functional divergence, and functional beta diversity were analyzed. Relationships between functional diversity and environmental factors were modeled by random forest regression. Correlations between fish functional traits and environmental factors were detected by fourth-corner combined with RLQ analysis.ResultsFunctional richness was significantly reduced in 2015 compared with 1979. Functional beta diversity in 2015 was significantly higher than that in 1979, with functional nestedness being the driving component. Reduction of functional richness and domination of functional nestedness is associated with species loss. Trait convergence was the dominant mechanism driving the temporal changes of functional diversity. Precipitation, temperature, species invasion, and human population were the most significant factors driving fish functional diversity. Higher precipitation, higher temperature, and presence of invasive species were significantly associated with higher swimming factor and higher relative eye diameter, while the opposite environmental conditions were significantly associated with higher pectoral fin length and eurytopic water flow preference.ConclusionsEnvironmental filtering is the dominant temporal assembly mechanism shaping fish community structure. This work contributes to the understanding of temporal freshwater fish community assembly and the associations between fish functional structure and local environmental conditions, which will be informative for future freshwater fish conservation.

【 授权许可】

CC BY