Environment Institute and School of Earth and Environmental Sciences, University of Adelaide, Adelaide, Australia.
Proc Biol Sci. 2011 Mar 7;278(1706):690-4. doi: 10.1098/rspb.2010.1512. Epub 2010 Sep 8.
Interactions between native diversity and invasive species can be more complex than is currently understood. Invasive ant species often substantially reduce diversity in the native ants diversity that act as natural control agents for pest insects. In Indonesia (on the island of Sulawesi), the third largest cacao producer worldwide, we show that a predatory endemic toad (Ingerophrynus celebensis) controls invasive ant (Anoplolepis gracilipes) abundance, and positively affects native ant diversity. We call this the invasive-naivety effect (an opposite of enemy release), whereby alien species may not harbour anti-predatory defences against a novel native predator. A positive effect of the toads on native ants may facilitate their predation on insect vectors of cacao diseases. Hence, toads may increase crop yield, but further research is needed on this aspect. Ironically, amphibians are globally the most threatened vertebrate class and are strongly impacted by the conversion of rainforest to cacao plantations in Sulawesi. It is, therefore, crucial to manage cacao plantations to maintain these endemic toads, as they may provide critical ecosystem services, such as invasion resistance and preservation of native insect diversity.
本地物种多样性与入侵物种之间的相互作用可能比目前所理解的更为复杂。入侵的蚂蚁物种通常会大量减少作为害虫自然控制剂的本地蚂蚁的多样性。在印度尼西亚（苏拉威西岛上），全球第三大可可生产地，我们发现一种掠食性特有蟾蜍（Ingerophrynus celebensis）控制了入侵蚂蚁（Anoplolepis gracilipes）的数量，并对本地蚂蚁的多样性产生了积极影响。我们将这种现象称为入侵幼稚效应（与天敌释放相反），即外来物种可能没有针对新型本地捕食者的防御性抗捕食措施。蟾蜍对本地蚂蚁的积极影响可能有助于它们捕食可可疾病的昆虫媒介。因此，蟾蜍可能会增加作物产量，但在这方面还需要进一步的研究。具有讽刺意味的是，两栖动物是全球受威胁最严重的脊椎动物类群，苏拉威西岛的热带雨林向可可种植园的转变对它们产生了强烈影响。因此，管理可可种植园以维持这些特有蟾蜍是至关重要的，因为它们可能提供关键的生态系统服务，如抵御入侵和保护本地昆虫多样性。
