The effects of novel leaf litter deposition on competitive, predator–prey and host–parasite interactions of American toad larvae

Wetland plant communities are changing rapidly due to a wide range of human activities. The deposition of leaf litter from novel plant communities can alter both the chemical and physical habitat of aquatic ecosystems. Lesser understood are the ecological consequences of novel leaf litter inputs in aquatic communities. Towards this goal, we used two plant invasion scenarios (comparing native black huckleberry to exotic autumn olive and native swamp loosestrife to exotic purple loosestrife) to simulate a shift in wetland plant communities. In this study, we investigated the effects of novel leaf litter leachates on three aquatic ecological interactions: intraspecific competition, predation, and parasitism. We examined how leaf litter leachates influence the interactions of American toad larvae (Anaxyrus americanus) with their conspecifics, a dragonfly predator (Anax spp.) and a trematode parasite (Echinostomatidae). We found that leaf litter type influenced competitive interactions only ...

湿地植物群落受各类人类活动影响正快速演替。外来植物群落的枯落物输入可改变水生生态系统的化学与物理栖息环境。目前学界对水生群落中此类新型枯落物输入所带来的生态效应仍知之甚少。为此，我们设置了两组植物入侵情景：分别以本地黑果越橘（black huckleberry）与外来秋胡颓子（autumn olive）、本地沼泽珍珠菜（swamp loosestrife）与外来千屈菜（purple loosestrife）进行对照，以此模拟湿地植物群落的转变。本研究探究了新型枯落物浸出液对三类水生生态相互作用的影响：种内竞争（intraspecific competition）、捕食作用（predation）与寄生作用（parasitism）。我们分析了枯落物浸出液如何影响美洲蟾蜍幼体（Anaxyrus americanus）与其同种个体、蜻蜓捕食者（晏蜓属Anax spp.）以及吸虫寄生虫（棘口科Echinostomatidae）之间的相互作用。研究发现，枯落物类型仅对种内竞争相互作用产生影响……