川东南小型水库营养结构特征的稳定C、N同位素分析

CHARACTERIZING THE TROPHIC STRUCTURE OF A SMALL RESERVOIR IN SOUTHEAST OF SICHUAN PROVINCE USING STABLE CARBON AND NITROGEN ISOTOPE ANALYSIS

  • 摘要: 为了解我国水库生态系统营养结构特征, 研究应用稳定同位素技术分析了四川省东南部的典型小型水库松林水库中不同水生生物碳、氮稳定性同位素比值。基于Bayesian混合模型(SIAR)分析了不同消费者基础碳来源, 并计算了δ13C–δ15N同位素生态位中6个营养结构量化指标。结果表明: 调查期间松林水库处于富营养化状态; 初级生产者POM(主要成分为浮游藻类)、固着藻类、喜旱莲子草Alternanthera philoxeroides和水蓼Polygonum hydropiperδ13C值范围为–29.20‰—18.81‰, δ15N值范围为4.01‰—12.73‰; 其中POM和固着藻类是多数消费者的主要碳源; 松林水库食物网营养级长度为3级, 以杂食性鱼类为优势类群并存在营养冗余现象, 暗示了该生态系统鱼类群落结构的相对稳定性; 入侵物种福寿螺Pomacea lineata、罗非鱼Oreochromis spp.与土著物种铜锈环棱螺Bellamya aeruginosa、鲫Carassius auratus等之间存在明显的同位素生态位重叠现象。建议加强水生生物资源管理, 减少外来物种入侵对当地土著物种的保护具有重要意义。

     

    Abstract: Reservoir plays important roles in realizing the sustainable development of economy and society. It can provide water resource to human beings for living, industrial and agricultural usage, and for flood control, power generation and regional ecological service as well. The sustainable utilization of the reservoir water resource is the prerequisite for fishery industry development. However, following with the impacts of increasing human activities, pollutant input and water eutrophication, the ecological environment gets deteriorated overtime, which was revealed by water balance disorders, such as sharp decrease of biodiversity and others. In order to better understand the trophic structure characteristics of reservoir ecosystem in China, Songlin, a typical small reservoir in Southeast Sichuan province, was selected for the stable isotope analysis. The basic carbon sources of different consumers were analysed based on the Bayesian mix-model (SIAR), and six nutrition structure quantitative indicators in δ13C—δ15N isotopic niches were calculated as well. Results showed a eutrophication state of this small reservoir, and the δ13C and δ15N values of primary producers such as POM (mainly the planktonic algae), periphyton, Alternanthera philoxeroides and Polygonum hydropiper were within the scopes of –29.20‰—18.81‰ and 4.01‰—12.73‰, respectively. POM and periphyton were found as the main carbon sources for most consumers. The food web trophic level length of Songlin reservoir was calculated at Level 3, with omnivorous fishes as superior group and existed the nutrition redundancy phenomenon, which suggested a relatively stable fish community structure in Songlin reservoir. Additionally, niche overlaps and competitions were found between invasive species (such as Pomacea lineata and Oreochromis sp) and native species (such as Bellamya aeruginosa and Carassius auratus, etc). Taking together, we suggested to enhance the management of aquatic organism resources, and powerful strategies must be taken to prevent and control the invasive alien pest for better protection on the biodiversity of Sonlin reservoir.

     

/

返回文章
返回