生物多样性 ›› 2023, Vol. 31 ›› Issue (10): 23095.  DOI: 10.17520/biods.2023095

• 研究报告: 动物多样性 • 上一篇    下一篇

长江干流鱼类功能群空间分异

王安伦1,2,3, 何萍1,2,3,*(), 龙心远1,2,3   

  1. 1.中国环境科学研究院, 北京 100012
    2.国家环境保护区域生态过程与功能评估重点实验室, 北京 100012
    3.环境基准与风险评估国家重点实验室, 北京 100012
  • 收稿日期:2023-03-31 接受日期:2023-06-29 出版日期:2023-10-20 发布日期:2023-07-22
  • 通讯作者: *E-mail: heping@craes.org.cn
  • 基金资助:
    生态环境部生物多样性调查评估项目(2019HJ2096001006)

Spatial differentiation of fish functional groups in the Yangtze River

Anlun Wang1,2,3, Ping He1,2,3,*(), Xinyuan Long1,2,3   

  1. 1. Chinese Research Academy of Environmental Sciences, Beijing 100012
    2. State Environmental Protection Key Laboratory of Regional Ecological Processes and Functions Assessment, Beijing 100012
    3. State Key Laboratory of Environmental Criteria and Risk Assessment, Beijing 100012
  • Received:2023-03-31 Accepted:2023-06-29 Online:2023-10-20 Published:2023-07-22
  • Contact: *E-mail: heping@craes.org.cn

摘要:

河流是一个连续而整体的系统, 大型河流中的鱼类物种组成沿河流纵向随环境梯度的分异而变化。本研究采用从长江上游金沙江起点直门达至下游入海口的168种淡水鱼类分布数据, 根据鱼类的体型、形状、食性和生活史策略划分功能群, 利用层次聚类分析和排序分析方法研究了长江干流鱼类功能群分布格局及其对不同尺度的环境因子的适应性。结果显示, 长江干流鱼类功能群的分布存在一级和二级的空间分异: 一级分异以龙开口为分界点; 而二级分异以石鼓、龙开口和白鹤滩坝下为分界点。自上游到下游, 鱼类功能群的变化规律是: 体型从小型过渡到中型和大型, 形状从仅有纺锤形和圆柱形过渡到出现侧扁形, 食性从杂食性过渡到更多样性的食性, 生活史策略从机会策略过渡到周期策略和均衡策略。鱼类功能群的分布格局是适应不同尺度环境因子空间分异的结果: 在大尺度的整条长江干流中, 与气候特征相关的海拔和气温是主导影响因素; 而随着研究的空间尺度缩小, 与地形特征相关的河段坡降的影响显现, 在中尺度的I-1段中作为主导。本研究对认识长江干流的鱼类空间分布规律以及环境适应性特征具有参考意义。

关键词: 河流连续体, 长江, 鱼类功能群, 空间分异

Abstract

Aim: The composition of fish in large rivers exhibits longitudinal variation along the river influenced by environmental gradients. The River Continuum Concept revolutionized the understanding of river ecosystems by linking changes in river macro-invertebrate trophic functional groups to the differentiation of nutrient sources between upstream and downstream areas. The concept offers a novel framework for studying the distribution patterns of river biomes at large scale, from upstream to downstream. In this study, a dataset encompassing 168 species of fish were used, covering the entire range from Zhimenda, the starting point of the Jinsha River, to the estuary. Functional groups were first classified based on criteria such as body sizes, shapes, feeding habits, and life-history strategies. Subsequently, their distribution patterns as well as their adaptability to environmental factors were investigated across different scales.

Methods: A total of 14 functional groups and 59 combined function groups were classified, and 5 environmental factors were selected: elevation, mean temperature, mean annual temperature range, river width and river slope gradient. The distribution pattern of fish functional groups was analyzed using hierarchical clustering, while ordination analysis was applied to analyze the relationship between environmental factors and fish functional groups at different scales.

Results: The results revealed a primary and secondary differentiation in the distribution of fish functional groups within the Yangtze River: the primary differentiation occurs at Longkaikou, acting as the dividing point, while the secondary differentiation is observed at Shigu, Longkaikou and Downstream of Baihetan Dam. Moving from the upstream to the downstream, fish body sizes transition from small to medium and large, body shapes shift from predominantly fusiform and cylindrical to include compressform appearances. Feeding habits evolve from primarily omnivorous to encompass a more diverse range of feeding functional groups, and life-history strategies transform from opportunistic to periodic and equilibrium strategies. The distribution pattern of fish functional groups is a result of adaptation to spatial differentiation of environmental factors at different scales. Across the larger scale of the entire Yangze River, elevation and temperature, which are associated with climatic features, serve as dominant factors; whereas, as the spatial scale of the study shrinks, the influence of river slope drop associated with topographic features, becomes more prominent and plays the most important role in the I-1 river section at medium scale.

Conclusion: The distribution pattern of fish functional groups is direct outcome of the fish adaptation to environmental differentiation. Furthermore, the specific environment factors that determine the distribution of fish functional groups vary at different scales, consequently affecting the corresponding functional traits of the fish. This study contributes to our understanding of the river continuum theory, the spatial distribution pattern of fish in the Yangtze River, and the environmental adaptation characteristics of fishes.

Key words: the river continuum, the Yangtze River, fish functional groups, spatial differentiation