基于Ecopath模型的厦门湾生态系统结构与功能变化分析

Analysis of Ecosystem Structure and Function Changes in Xiamen Bay in the Past 10 Years Based on Ecopath Model

厦门湾的生态资源十分丰富,但由于自然因素与人为因素的综合影响,厦门湾生态系统承受着十分巨大的压力。对生态系统的动态模拟,可以为分析生物种类的生物量变动、能量流动变化及生态系统的稳定性提供科学依据。根据2019—2020年厦门湾渔业资源调查数据,应用EwE软件构建厦门湾生态系统模型,并与根据2010年资料建立的生态系统模型进行比较。模型包括哺乳动物、斑竹鲨、鳐科、鳀鲱科、鯻科、虾类、蟹类、头足类、浮游动物、浮游植物、底栖生物、碎屑等26个功能群,基本涵盖了厦门湾生态系统中的能量流动途径。结果表明,厦门湾的大型捕食者相对缺乏,使得厦门湾生态系统的捕食压力较低,因而处于较低营养级的生物,如小型鱼类等种类在该生态系统中占据优势地位,导致厦门湾生态系统的食物网结构较为简单,同时模型表明该系统目前的稳定性较低。与2010年相比,2020年厦门湾的生物类群有所变化,能量流动也发生相应变化,2020年生态系统较低营养级的生物量、流向碎屑量及总流量小于2010年,而较高营养级功能群的上述参数要高于2010年。总体而言,2020年厦门湾生态系统的能流规模要小于2010年。该研究可以为厦门湾生态系统的保护和管理提供科学依据。

Xiamen Bay is rich in ecological resources and has diversified service functions. However, due to the comprehensive action of natural, human activities and other factors, Xiamen Bay ecosystem is under great pressure. Dynamic simulation of ecosystem can provide scientific basis for the analysis of biomass variation, energy flow variation and ecosystem stability. An EwE model was developed based on the fishery resources survey data of Xiamen Bay in 2019-2020, and was compared with the model used in 2010. Totally 26 functional groups were included in this model, such as marine animals, bamboo shark, fanray, anchovy, terapon, shrimps, crabs, cephalopods, zooplankton, phytoplankton, benthos, detritus, et al, which have basically covered the whole energy flow pathway in the ecosystem of Xiamen Bay. Results show that the large predators in Xiamen Bay was relative few, leading to the low pressure on Xiamen Bay ecosystem predation, and the dominant position of low trophic level creatures like small fishes occupied in the ecosystem. The ecosystem structure of food web in Xiamen Bay was relatively simple, and the stability of the ecosystem is currently low. Compared with the results of the model used in 2010, the functional groups and energy flow in Xiamen Bay had changed in 2020. The biomass, detritus flow and total throughput in the lower trophic levels of the ecosystem in 2020 were less than that in 2010, while those in the higher trophic levels were higher than that in 2010. In general, total system throughput of Xiamen Bay ecosystem in 2020 was smaller than that in 2010. This study can provide scientific basis for the protection and management of Xiamen Bay ecosystem.