| 摘要: |
| 了解生物群落中物种共存机制是群落生态学研究的重要组成部分.鉴于河口鱼类群落结构与温盐等理化因子密切相关，同时多数鱼类产卵、育幼在时间上具有同步性（主要在春夏季发生），因此环境过滤机制可能是促使河口鱼类时间上共存的主要机制.为证实该假设，本研究以长江口鱼类群落为例，利用广义可加非线性模型（GAMs）分析其时间生态位及鱼类与环境因子的关系，同时基于零模型（null models）从生态位利用的角度阐述河口鱼类群落时间上的共存机制.结果表明：鱼类物种间实测生态位大于预期值，揭示出环境过滤机制是促使鱼类时间上共存的主要机制；多数鱼类物种与非生物环境因子关系拟合较好，说明未知因素（如物种间的竞争作用等机制）对其分布影响权重较小.上述结果支持环境过滤学说是长江口鱼类物种时间共存格局的主导机制. |
| 关键词: 海洋生物学 环境过滤 鱼类群落 时间共存 零模型 GAMs 长江口 |
| DOI：10.3969/J.ISSN.2095-4972.2018.04.008 |
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| 基金项目:中国水产科学研究院东海水产研究所基本科研业务费资助项目(2014T11)；国家973重点基础研究发展计划资助项目（2010CB429005） |
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| Environmental filtering mechanism controlling the species temporal coexistence pattern for fish communities in Changjiang Estuary |
| SHI Yun-rong,CHAO Min,SHEN Xin-qiang |
| (East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China) |
| Abstract: |
| Understanding mechanisms structuring coexistence of species within biological communities is a central issue of community ecology. It is widely recognized that structure of fish community is mainly regulated by abiotic factors (e.g., salinity, temperature), as well as most of fish species co-occurred temporally in estuaries, e.g., spawning and nursing mainly during spring and summer. Thus, we hypothesize that environmental filtering is an important force promoting the coexistence of fish species in those environments. Aiming to examine such hypothesis, we analyzed the temporal niche overlaps among fish species within assemblages using null models, and relationships based on GAMs between fish species and abiotic factors of Changjiang Estuary. Results of null models and GAMs are as follows. Firstly, observed values of niche overlaps are more than expected ones. Secondly, fish assemblages were expressed well by abiotic variables, which together suggesting that environmental filtering mechanism plays a critical role but other unmeasured influences (e.g., inter-specific competitions) may also promote temporal distribution of fish species. Thus, the present study supports the theory of environmental filtering. |
| Key words: marine biology environmental filtering fish assemblages temporal coexistence null models GAMs Changjiang Estuary |
