Yang Louie H
Center for Population Biology, Section of Evolution and Ecology, University of California, One Shields Avenue, Davis, CA 95616, USA.
Science. 2004 Nov 26;306(5701):1565-7. doi: 10.1126/science.1103114.
Resource pulses are occasional events of ephemeral resource superabundance that occur in many ecosystems. Aboveground consumers in diverse communities often respond strongly to resource pulses, but few studies have investigated the belowground consequences of resource pulses in natural ecosystems. This study shows that resource pulses of 17-year periodical cicadas (Magicicada spp.) directly increase microbial biomass and nitrogen availability in forest soils, with indirect effects on growth and reproduction in forest plants. These findings suggest that pulses of periodical cicadas create "bottom-up cascades," resulting in strong and reciprocal links between the aboveground and belowground components of a North American forest ecosystem.
资源脉冲是在许多生态系统中发生的短暂资源过剩的偶发事件。不同群落中的地上消费者通常对资源脉冲有强烈反应，但很少有研究调查自然生态系统中资源脉冲对地下的影响。本研究表明，17年周期蝉（魔蝉属）的资源脉冲直接增加了森林土壤中的微生物生物量和氮有效性，对森林植物的生长和繁殖产生间接影响。这些发现表明，周期蝉的脉冲引发了“自下而上的级联效应”，导致北美森林生态系统地上和地下部分之间形成强烈的相互联系。
