长江大型通江湖泊中克氏原鳌虾(Procambarus clarkii)种群数量的影响因子

Factors Determining the Abundance of Red Swamp Crayfish(Procambarus clarkii) in a Large Lake Connected to the Yangzte River

入侵物种和栖息地退化都是导致淡水生物多样性丧失的主要原因。但是关于栖息地退化和入侵物种种群数量的研究很少。克氏原鳌虾(Procambarus clarkii)是淡水生态系统中最具破坏性的入侵物种之一。本研究采用主成分分析法(Principal Component Analysis,PCA)、广义线性模型(Generalized Linear Model,GLM)和贝叶斯模型(Bayesian model),分析了2017-2019年西洞庭湖天然湿地和改造湿地中的克氏原鳌虾的单位捕捞努力量渔获量(CPUE)与环境因子的关系。研究结果表明,克氏原鳌虾CPUE与总氮、总磷、水温、pH、水深、水透明度呈正相关,与溶解氧和氧化还原电位呈负相关。克氏原鳌虾CPUE在天然湿地和改造湿地中的差异不显著。克氏原鳌虾CPUE呈逐年下降趋势,且2018年与2019年的克氏原鳌虾CPUE均显著低于2017年。水文情势的年际变化对克氏原鳌虾种群数量的影响起重要作用。保证夏季水位和流速对控制克氏原鳌虾种群数量具有重要意义。

Invasive species and habitat degradation are the main reasons for freshwater biodiversity loss. Reports on the habitat degradation and invasion ecology of Red Swamp crayfish(Procambarus clarkii) are few, although it is one of the most devastating invasive species in freshwater ecosystems. Based on a three-year investigation during 2017-2019 in West Dongting Lake, this study used Principal Component Analysis(PCA), Generalized Linear Model(GLM) and Bayesian model to analyze the relationships of P. clarkii stocks and environment factors in natural and modified wetlands. The results showed that the abundance of P. clarkii was positively correlated with total nitrogen, total phosphorus, water temperature, pH, water depth, and water transparency;while it was negatively correlated with dissolved oxygen and redox potential. The difference between P. clarkii stocks in natural and modified wetlands was nonsignificant. The P. clarkii stock decreased yearly, as levels in both 2018 and 2019 were significantly lower than in 2017. We concluded that inter-annual variation of the hydrological regime plays an important role in P. clarkii dynamics, and thus it is of great importance to ensure that the water level and flow velocity in summer to control the invasive P. clarkii.