长江口滨海湿地水鸟对底栖微藻群落的营养级联效应  

Trophic cascades of waterbirds on benthic microalgal communities in coastal wetlands in the Yangtze estuary

作　　者：刘盈麟 李春明 王昊 武长路 贺强 LIU Ying-Lin;LI Chun-Ming;WANG Hao;WU Chang-Lu;and HE Qiang(State Key Laboratory of Wetland Conservation and Restoration/Ministry of Education Key Laboratory of Biodiversity Science and Ecological Engineering/National Observation and Research Station of Wetland Ecosystems in the Yangtze Estuary,School of Life Sciences,Fudan University,Shanghai 200438,China)

机构地区：[1]复旦大学生命科学学院,湿地环境保护与生态修复全国重点实验室/生物多样性与生态工程教育部重点实验室/上海长江河口湿地生态系统国家野外科学观测研究站,上海200438

出　　处：《植物生态学报》2025年第3期367-378,共12页Chinese Journal of Plant Ecology

基　　金：国家重点研发计划(2022YFC2601100);国家自然科学基金(32271601)。

摘　　要：底栖微藻是滨海湿地的初级生产者之一,为滨海湿地食物网提供了能量和物质基础,在滨海湿地生态系统维持中发挥着重要作用。以往研究多聚焦于环境因子、维管植物和植食动物对底栖微藻的影响,忽略了捕食动物对底栖微藻的营养级联效应。该研究以长江口滨海盐沼湿地为研究系统,通过开展野外控制实验,并在一年间对底栖微藻群落的生物量和种类组成分别进行月度和季度测定,解析了水鸟对底栖微藻的营养级联效应。结果发现:(1)去除水鸟显著降低了底栖微藻的生物量。去除水鸟后,虽然水鸟直接摄食作用的缺乏有利于底栖微藻,但摄食微藻的蟹类的增多更强烈地抑制了底栖微藻。(2)去除蟹类(模拟水鸟高强度捕食)也显著降低了底栖微藻的生物量。去除蟹类后,摄食藻类的螺类大幅增多。(3)去除水鸟和去除蟹类均显著降低了优势微藻类群硅藻的多度,提高了底栖微藻群落的多样性。该研究表明滨海湿地水鸟可通过直接或间接作用对底栖微藻群落产生强烈的下行调控效应,丰富了对滨海湿地微藻群落调控机制的理论认识。Aims Benthic microalgae are one of the primary producers in coastal wetlands,providing basic energy and material to the food web of coastal wetlands and playing an important role in maintaining the stability of coastal wetland ecosystems.Previous studies have focused on the effects of environmental factors,vascular plants and herbivores on benthic microalgae,neglecting the trophic cascade effects of predators.Methods We investigated the trophic cascade effects of waterbirds on benthic microalgae in a manipulative field experiment in a coastal wetland in the Chang Jiang(Yangtze)estuary,where we measured the biomass of benthic microalgae monthly and their species composition quarterly for a year.Important findings Results showed that:(1)benthic microalgal biomass was significantly decreased in waterbird exclusion treatments.In waterbird exclusion treatments,although the lack of direct consumption by waterbirds facilitated benthic microalgae,increases in the abundance of crabs feeding on microalgae suppressed benthic microalgae more strongly.(2)Crab exclusion treatments(simulating intense predation by waterbirds)also significantly reduced benthic microalgal biomass.In crab exclusion treatments,the abundance of snail feeding on microalgae increased substantially.(3)Waterbird and crab exclusion treatments both significantly reduced the abundance of the dominant microalgal taxa,diatoms,and increased the diversity of benthic microalgal communities.This study demonstrates that waterbirds in coastal wetlands can exert strong top-down effects on benthic microalgal communities through multiple direct or indirect processes,and enriches our understanding of the mechanisms controlling microalgal communities in coastal wetlands.

关 键 词：滨海湿地 营养级联 动物消费者 底栖微藻 群落多样性 

分 类 号：Q178.1[生物学—水生生物学]