基于稳定同位素技术的新疆伊犁河流域鱼类群落营养级初步研究

The trophic levels of the fish community in the Ili River Basin of Xinjiang revealed by stable isotopes technique

为探究伊犁河流域鱼类群落营养结构动态及层级变化,本研究于2019年湿季(5-6月)和2020年干季(11月)在新疆伊犁河流域13个站位进行鱼类调查。运用稳定同位素δ^(13 )C、δ^(15) N技术分析了伊犁河鱼类的营养级,并对不同支流以及不同摄食功能群鱼类营养级进行比较分析。伊犁河流域鱼类的δ^(13) C值范围为-33.70‰~-18.51‰,δ^(15) N值范围为5.13‰~17.33‰,营养级范围在1.27~4.07之间,平均为2.54±0.55。湿季鱼类的营养级高于干季,肉食性和杂食性鱼类营养级明显高于其它类群。鱼类营养结构特征指标(氮值范围NR、碳值范围CR、总面积TA、平均离心距离CD、平均最邻近距离、最邻近距离标准差SDNND)显示,伊犁河与特克斯河的鱼类营养多样性较高,揭示种间竞争较少;喀什河营养冗余更高,表明鱼类群落抗外界干扰能力更强。本研究为后期准确全面的评估伊犁河流域鱼类群落结构与功能对人类活动干扰的响应提供了基础依据。

Ili River is the largest river in Xinjiang Autonomous Region of China,with abundant fish resources.fish surveys of two seasons were conducted in 13 stations in Ili River Basin,Xinjiang in the wet season of 2019(May-June)and the dry season of 2020(November)to explore the dynamics and levels changes of fish trophic structure in Ili River Basin,and provide basic data for the follow-up study of food web structure and energy flow of ecosystem.The trophic level of fish were analyzed by stable isotopesδ^(13) C andδ^(15) N,and the trophic level of the fish in different rivers and feeding functional groups were compared.Theδ^(13 )C values of fish ranged from-33.70‰to-18.51‰,δ15 N values ranged from 5.13‰to 17.33‰.The trophic levels ranged from 1.27 to 4.07,with an average of 2.54±0.55.The fish trophic level of in the wet season was higher than that in the dry season,and that of carnivorous and omnivorous fish was higher than that of other groups.Fish community trophic structure characteristics metrics results showed that the fish in Ili River and Tekes River had higher trophic diversity and less interspecific competition.While higher trophic redundancy were detected in Kashi River,which indicated that the fish community had stronger ability to resist external interference.The study results provided a scientific basis for the protection of fish resources and the rational development and utilization of resources in the Ili River Basin,and also provided a basis for the later accurate and comprehensive assessment of the response of fish community structure and function to human activities disturbance in the Ili River Basin.