夏季若尔盖高寒湿地水生生物群落食物网结构特征

THE CHARACTERISTIC OF THE FOOD WEB STRUCTURE AT AQUATIC ORGANISMS COMMUNITY IN SUMMER OVER ZOIGE APLINE WETLAND

  • 摘要: 为了解若尔盖高寒湿地夏季水生生物群落食物网结构及营养关系特征,应用稳定同位素技术分析了若尔盖湿地 3个不同区域(ZS1、ZS2和ZS3)水生生物群落碳、氮稳定同位素比值,并计算了13C-15N同位素生态位中的6个营养结构量化指标。结果显示:外源性营养源陆生植物13C、15N值分别为-28.23- -26.07,-1.20-5.98; 内源性营养源颗粒有机物 (POM:主要成分为藻类)和水生植物13C、15N值分别为-26.39- -21.17、-25.37- -24.15,3.68-6.61、3.50-4.01; 其中POM样品13C、15N组成存在明显的区域性差异(P0.05,P0.001)。食物网营养结构分析显示若尔盖湿地外源性碳源输入(优势陆生植物)对于维持该水域生态系统结构稳定有着十分重要的作用。若尔盖湿地水域食物网营养级介于2-3,暗示了其生态系统结构的相对脆弱性。同位素量化指标标记发现若尔盖湿地水生动物群落生态结构存在明显的空间异质性,可能与若尔盖湿地发达的畜牧产业相关。

     

    Abstract: Zoige Apline wetland is the largest plateau in the world and plays important roles in the biodiversity conservation, regional and global carbon circulation balance and social sustainable development. In order to understand the relationship of food web structure and the trophic characteristics of aquatic organisms community in Zoige Apline wetland, stable isotopes techniques were used to analyze the carbon and nitrogen stable isotope ratios of different aquatic organisms community at 3 sampling areas in Zoige Apline wetland and calculate 6 trophic structure measurable index in 13C-15N isotopic niche. The result showed that the 13C and 15N values of exogenous nutrition source (land plant) were -28.23- -26.07 and -1.20-5.98 respectively. The 13C and 15N values of endogenous nutrition source POM (POM is short for particulate organic matter and it mainly consisted of algae) were -26.39- -21.17 and -25.37- -24.15 respectively. The 13C and 15N values of aquatic plants were 3.68-6.61 and 3.50-4.01 respectively. The 13C and 15N values of POM had a spatial dependent pattern (P0.05, P0.001). The result of food web structure analysis revealed that the carbon (advantaged land plant around Zoige Apline wetland) played a key role in the foundation of the food web structure for the aquatic ecosystem. The food web trophic level between 2 and 3 implied the instability of the ecosystem structure. The result of isotope measurable indexes demonstrated significant spatial differences among the animal community ecosystem structure of the different sampling areas, which might associated with the developed graziery of Zoige Apline wetland.

     

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