Breviglieri Crasso Paulo B, Oliveira Paulo S, Romero Gustavo Q
Am Nat. 2017 May;189(5):490-500. doi: 10.1086/691262. Epub 2017 Mar 9.
Predators control prey populations and influence communities and the functioning of ecosystems through a combination of consumptive and nonconsumptive effects. These effects can be locally confined to one ecosystem but can also be extended to neighboring ecosystems. In this study, we investigated the nonconsumptive effects of terrestrial avian predators on the communities of aquatic invertebrates inhabiting bromeliads and on the functioning of these natural ecosystems. Bromeliads with stuffed birds placed nearby showed a decrease in aquatic damselfly larvae abundance and biomass, and we can infer that these changes were caused by antipredator responses. These larvae, which are top predators in bromeliad ecosystems, changed the composition of the entire aquatic invertebrate community. While total species richness, mesopredator richness, and shredder abundance increased in the presence of birds, scraper biomass decreased, possibly as a consequence of the increase in mesopredator richness. High scraper biomass in the absence of birds may have accelerated detrital decomposition, making more nutrients available for bromeliads, which grew more. These results show that nonconsumptive effects triggered by terrestrial predators can cascade down to lower trophic levels and dramatically affect the functioning of aquatic ecosystems, which can in turn alter nutrient provision to terrestrial ecosystems.
捕食者通过消耗性和非消耗性影响的组合来控制猎物种群,并影响群落以及生态系统的功能。这些影响可能局部局限于一个生态系统,但也可能扩展到邻近的生态系统。在本研究中,我们调查了陆生鸟类捕食者对栖息在凤梨科植物中的水生无脊椎动物群落以及这些自然生态系统功能的非消耗性影响。附近放置了填充鸟的凤梨科植物中,水生豆娘幼虫的丰度和生物量有所下降,我们可以推断这些变化是由反捕食者反应引起的。这些幼虫是凤梨科生态系统中的顶级捕食者,它们改变了整个水生无脊椎动物群落的组成。虽然在有鸟的情况下,物种总丰富度、中等捕食者丰富度和碎食者丰度增加了,但刮食者生物量减少了,这可能是中等捕食者丰富度增加的结果。在没有鸟的情况下,高刮食者生物量可能加速了碎屑分解,使更多营养物质可供凤梨科植物利用,凤梨科植物生长得更多。这些结果表明,陆生捕食者引发的非消耗性影响可以级联到较低营养级,并显著影响水生生态系统的功能,进而改变向陆地生态系统的养分供应。