Cuthbert Ross N, Dickey James W E, McMorrow Clare, Laverty Ciaran, Dick Jaimie T A
Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK.
R Soc Open Sci. 2018 Aug 1;5(8):180339. doi: 10.1098/rsos.180339. eCollection 2018 Aug.
Invasive species continue to severely impact biodiversity, yet predicting the success or failure of introduced species has remained elusive. In particular, the relationship between community invasibility and native species diversity remains obscure. Here, we apply two traditional ecological concepts that inform prey population stability and hence invasibility. We first show that the native predatory crustacean exhibited similar type II (destabilizing) functional responses (FRs) towards native mayfly prey and invasive amphipod prey, when these prey species were presented separately. However, when the two prey species were presented simultaneously, the predator did not exhibit prey switching, instead consuming disproportionately more native prey than expected from the relative abundance of native and invasive species. These consumptive propensities foster reductions of native prey, while simultaneously limiting biotic resistance against the invasive species by the native predator. Since our theoretical considerations and laboratory results match known field invasion patterns, we advocate the increased consideration of FR and prey switching studies to understand and predict the success of invasive species.
入侵物种继续对生物多样性造成严重影响，但预测引进物种的成败仍然困难重重。特别是，群落可入侵性与本地物种多样性之间的关系仍不明确。在此，我们应用两个传统的生态学概念，这些概念有助于解释猎物种群的稳定性，进而说明可入侵性。我们首先表明，当本地捕食性甲壳动物分别面对本地蜉蝣猎物和入侵性双足虾猎物时，它对这两种猎物表现出相似的II型（使种群不稳定的）功能反应。然而，当同时呈现这两种猎物时，捕食者并未表现出猎物转换行为，相反，其消耗的本地猎物数量比根据本地和入侵物种的相对丰度所预期的要多得多。这些消费倾向促使本地猎物数量减少，同时限制了本地捕食者对入侵物种的生物抗性。由于我们的理论思考和实验室结果与已知的野外入侵模式相符，我们主张更多地考虑功能反应和猎物转换研究，以理解和预测入侵物种的成功。
