长江上游弥陀漫滩水体鱼类食物网动态的季节性变化  

Seasonal variation in the consumption of food by fish in the Mituo floodplain waters of the upper Yangtze River and implications for food web dynamics

作　　者：李斌[1,3] 郑宇辰 徐丹丹 陶敏[1,3] 李红 LI Bin;ZHENG Yuchen;XU Dandan;TAO Min;LI Hong(School of Life Sciences,Neijiang Normal University,Neijiang 641100,China;Scientific Observing and Experimental Station of Fishery Resources and Environment in the Lower Reaches of the Changjiang River,Ministry of Agriculture and Rural Affairs,Freshwater Fisheries Research Center,Chinese Academy of Fishery Sciences,Wuxi 214081,China;Key Laboratory of Sichuan Province for Fishes Conservation and Utilization in the Upper Reaches of the Yangtze River,Neijiang 641100,China)

机构地区：[1]内江师范学院,生命科学学院,内江641100 [2]农业农村部长江下游渔业资源环境科学观测实验站,中国水产科学研究院淡水渔业研究中心,无锡214081 [3]长江上游鱼类资源保护与利用四川省重点实验室,内江641100

出　　处：《生态学报》2023年第4期1664-1675,共12页Acta Ecologica Sinica

基　　金：四川省科技厅项目(2019YJ0397);农业农村部长江下游渔业资源环境科学观测实验站开放课题;内江师范学院创新创业项目(X2021057,X2021100)。

摘　　要：长江上游是我国鱼类生物多样性最为丰富的地区之一,漫滩作为河流生态系统的重要组成部分对维持区域鱼类生物多样性具有重要作用。于2019年丰水期(8月份)和枯水期间(11月份)应用碳、氮稳定同位素技术并结合Bayesian混合模型和SIBER分析方法,对长江上游弥陀漫滩水体鱼类食物网结构动态的季节性变化特征进行了研究。结果显示:丰水期基础碳源的δ^(13)C、δ^(15)N平均值分别为-23.02‰和2.58‰,范围分别为-31.01‰—-11.2‰(δ^(13)C)和-0.51‰—6.84‰(δ^(15)N);枯水期其δ^(13)C、δ^(15)N平均值分别为-21.93‰、7.22‰,范围分别为-26.31‰—-15.36‰(δ^(13)C)和4.89‰—8.81‰(δ^(15)N)。丰水期鱼类食物网能量主要依赖于外源性营养物质,食物链长度达到3.6级;枯水期内源性营养物质是食物网能量的主要贡献者,食物链长度为2.6级。相对于枯水期,丰水期间鱼类群落拥有更大的生态位空间面积,反映了其食物来源的多样化或利用了不同的生境类型。研究结果表明水文连通性的季节性变化不仅能改变消费者与食物资源之间的耦合模式,也是决定研究区域生物多样性高低和鱼类食物网结构稳定性的重要因素。研究结果可为长江上游漫滩水体水生生物多样性保护提供理论依据。The upper reach of the Yangtze River is one of the regions with the richest fish biodiversity in China, and its floodplain waters, as an important part of the river ecosystem, play an important role in maintaining regional fish biodiversity. Based on the Bayesian mixture model and the SIBER method, the carbon and nitrogen stable isotope techniques were applied in the wet season(August) and the dry season(November) in 2019 to determine the seasonal variation in the consumption of food by fish in the Mituo floodplain waters and implications for food web dynamics. The results showed that in the wet season, the average value of δ^(13)C of the basic carbon source was-23.02‰(with a range from-31.01‰ to-11.2‰), and the average value of δ^(15)N was 2.58‰(with a range of-0.51‰—6.84‰). Moreover, the average values of δ^(13)C and δ^(15)N in the dry season were-21.93‰ and 7.22‰, respectively, and their ranges were from-26.31‰ to-15.36‰(δ^(13)C) and from 4.89‰ to 8.81‰(δ^(15)N). The allochthonous nutrients were identified as the main energy sources of the food web during the wet season with a trophic level length of 3.6, while the autochthonous nutrients were identified as the main contributors to energy sources in the food web during the dry season with a trophic level length of 2.6. Compared with those in dry season, fish communities in wet season had larger ecological niche space, indicating the diversification of their food sources and the utilization of different habitat types. Furthermore, the increase of basal carbon sources(CR) and habitat diversification during the wet season were found to enlarge the niche space(TA, SEAB and SEAC) for fish communities, and the niche redundancy further enhanced the ecosystem structure stability. Conversely, the decrease in the external nutrient inputs and the retreat of water level during the dry season reduced the freshwater fish diversity and niche space area. The results also showed that seasonal changes in hydrological connectivity profoundly affec

关 键 词：漫滩水体 碳、氮稳定同位素 食物网动态 Bayesian混合模型 长江上游 

分 类 号：S931.1[农业科学—渔业资源]