| 摘要: |
| 在长江大保护的背景下，长江中下游洪泛湖泊经历了从集约化的围网养殖渔业向禁渔和多样性保护转型。长江中下游洪泛湖泊不仅支撑了较高的鱼类多样性，同时也是我国重要的渔业生产基地，统筹和协调生物多样性保护和渔业可持续发展需要厘清鱼类多样性和群落稳定性的关系。本研究以升金湖为例，分别在围网拆除前（2017年）和围网拆除后（2019年）的丰水期和枯水期对鱼类群落进行系统的调查采集。本研究采用3种物种多样性指数（Shannon-Wiener多样性指数、Simpson优势度指数和Pielou均匀度指数）、3种功能多样性指数（FRic功能丰富度指数、FDis功能分散指数和FEve功能均匀度指数）和6种功能性状（最大体长、生长速率、寿命、初次性成熟时间、初次性成熟体长、营养级），从物种和功能两个维度探讨围网拆除前后鱼类群落稳定性水平和稳定性驱动因子的差异。结果表明：1）升金湖围网拆除前以鲢（Hypophthalmichthys molitrix）、鳙（Aristichthys nobilis）等物种作为主要优势种，围网拆除后优势种变为黄尾鲴（Xenocypris davidi）、翘嘴鲌（Culter alburnus）等物种。2）单因素方差分析结果显示围网拆除后鱼类群落多样性水平显著高于围网拆除前，群落稳定性显著低于围网拆除前。3)多元线性逐步回归结果显示围网拆除前的群落稳定性和初次性成熟时间呈正相关，与生长速率呈负相关，这可能与围网拆除前占据优势地位的周期策略鱼类的功能性状有关；围网拆除后的群落稳定性与生长速率呈正相关，与寿命和初次性成熟时间呈负相关，这可能与围网拆除后作为优势种的机会策略鱼类的功能性状有关。此外，围网拆除前和围网拆除后的群落稳定性均与均匀度指数（Pielou）呈正相关，均匀度较高的群落可能通过物种间的保险效应去支撑群落整体的稳定。本研究通过分析和比较围网拆除前和围网拆除后鱼类群落稳定和多样性的差异和作用关系，可为升金湖和其他洪泛湖泊鱼类资源的保护和利用提供理论基础与数据支撑。 |
| 关键词: 围网养殖 鱼类 群落稳定性 功能性状 升金湖 |
| DOI： |
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| 基金项目:国家自然科学基金面上项目（32373139），安徽省自然科学基金面上项目（2108085MC86），流域水安全保障湖北省重点实验室开放研究基金项目（CX2023K17），安徽省高等学校自然科学研究项目重点项目（KJ2020A0045） |
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| Relationships between community stability and diversity for fish assemblages in Lake Shengjin before and after pen-culture ban |
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SHI chenxi, LIANG yangyang, XIE chang, JIANG zhongguan
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School of Resources and Environmental Engineering, Anhui University
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| Abstract: |
| In the context of the Yangtze River protection, the lakes in the middle and lower reaches of the Yangtze River floodplain have experienced a transition from intensive pen-culture fisheries to fishing ban and diversity conservation. The lakes in the middle and lower reaches of the Yangtze River floodplain not only support high fish diversity, but also serve as important fishery production bases in China. Integrating and coordinating biodiversity conservation and sustainable fishery development requires clarifying the relationship between fish diversity and community stability. In this study, a systematic survey was conducted to collect the fish community in Lake Shengjin during the high water season and low water season before (2017) and after (2019) pen-culture ban, respectively. We used three species diversity index (Shannon-Wiener diversity index, Simpson dominance index and Pielou evenness index), three functional diversity index(FRic functional richness index, FDis functional dispersion index, and FEve functional evenness index), and six functional traits (maximal length, growth rate, life span, first sexual maturity time, first sexual maturity length, trophic level) to explore the differences in the level of stability and drivers of stability of fish communities before and after pen-culture ban in terms of both species and function. The results showed that: (1) Hypophthalmichthys molitrix and Aristichthys nobilis were the main dominant species before pen-culture ban in Lake Shengjin. But the dominant species changed to Xenocypris davidi and Culter alburnus after pen-culture ban. (2) One-way PERMANOVA results showed that community stability (TSI and ASY index) was significantly higher before pen-culture ban than after pen-culture ban. (3) The results of multiple linear stepwise regression (MLR) showed a positive correlation between community stability and time to first sexual maturity time and a negative correlation with growth rate before pen-culture ban. It may be related to the functional traits of the dominant periodic strategy fish before pen-culture ban. Community stability was positively correlated with growth rate and negatively correlated with life span and first sexual maturity time after pen-culture ban. It may be related to the functional traits of the dominant opportunistic strategy fish after pen-culture ban. In addition, community stability was positively correlated with the evenness index (Pielou) before and after pen-culture ban, and communities with higher evenness may support community stability through the insurance effect between species. By analyzing and comparing the differences and relationships of fish community stability and diversity before and after pen-culture ban, this study can provide theoretical basis and data support for the conservation and utilization of fish resources in Lak Shengjin e and other floodplain lakes. |
| Key words: pen culture fish community stability functional trait Lake Shengjin |
