Host–enemy interactions provide limited biotic resistance for a range‐expanding species via reduced apparent competition
Host–enemy interactions provide limited biotic resistance for a range‐expanding species via reduced apparent competition
复制标题
宿主与敌人的相互作用通过减少明显的竞争为范围不断扩大的物种提供有限的生物抗性
DOI：
10.1111/ddi.13763
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发表时间：
2023
影响因子：
4.6
通讯作者：
Powell, Thomas H. Q.
中科院分区：
文献类型：
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作者：
Prior, Kirsten M.;Jones, Dylan G.;Meadley‐Dunphy, Shannon A.;Lee, Susan;Milks, Alyson K.;Daughton, Sage;Forbes, Andrew A.;Powell, Thomas H. Q.
作为对人为变化的响应，物种的范围向两极移动，如果它们进入多样性较少的群落，不能有效地与新的种群或物种相互作用，或者如果祖先相互作用的种群或物种不能同步转移，它们可能会失去拮抗作用。我们利用易驯化的昆虫宿主-敌人群落中向极地范围的扩展来揭示改变本地和接受群落之间的拮抗作用有助于为范围扩大的昆虫带来高生态位机会(有限的生物抵抗力)的机制。位置北美，太平洋西北部。方法我们通过在本地和扩大范围扩大范围的五倍子蜂物种的本地和扩展范围内的一种优势橡树树种的400棵树上取样，建立了定量的昆虫宿主-敌人相互作用网络。我们比较了不同地区的主敌网络结构。我们测量了寄生蜂和相互作用的寄生蜂的性状(物候、形态)，预测在扩大范围内会有更大的性状差异。我们测量了与寄主控制相关的功能，并探索了相互作用和特征改变是否导致功能降低或生物抗性。结果相互作用网络在扩大范围内种类较少，寄主物种间寄生蜂组合的互补性较低。虽然网络更具广泛性，但与范围扩大的物种的相互作用在扩大的范围内更加专业化。专业敌人有效地跟踪了射程扩大的宿主，并且共同的多面手敌人减少了与共生宿主的明显竞争。在范围扩大的范围内，与范围扩大和共生的寄主相互作用的敌人群落的物候差异较大，这可能是造成明显竞争较弱的原因。在扩大范围内，生物抗性较低，从扩大范围寄主的虫卵中出现的寄生蜂较少。主要结论与多面手敌人相互作用的变化创造了高生态位机会，但生物抗性有限，表明弱的表观竞争可能是嵌入多面手敌人网络中的扩展范围昆虫的一种释放机制。
AimAs species' ranges shift poleward in response to anthropogenic change, they may lose antagonistic interactions if they move into less diverse communities, fail to interact with novel populations or species effectively, or if ancestral interacting populations or species fail to shift synchronously. We leveraged a poleward range expansion in a tractable insect host–enemy community to uncover mechanisms by which altered antagonistic interactions between native and recipient communities contributed to ‘high niche opportunities’ (limited biotic resistance) for a range‐expanding insect.LocationNorth America, Pacific Northwest.MethodsWe created quantitative insect host–enemy interaction networks by sampling oak gall wasps on 400 trees of a dominant oak species in the native and expanded range of a range‐expanding gall wasp species. We compared host–enemy network structure between regions. We measured traits (phenology, morphology) of galls and interacting parasitoids, predicting greater trait divergence in the expanded range. We measured function relating to host control and explored if altered interactions and traits contributed to reduced function, or biotic resistance.ResultsInteraction networks had fewer species in the expanded range and lower complementarity of parasitoid assemblages among host species. While networks were more generalized, interactions with the range‐expanding species were more specialized in the expanded range. Specialist enemies effectively tracked the range‐expanding host, and there was reduced apparent competition with co‐occurring hosts by shared generalist enemies. Phenological divergence of enemy assemblages interacting with the range‐expanding and co‐occurring hosts was greater in the expanded range, potentially contributing to weak apparent competition. Biotic resistance was lower in the expanded range, where fewer parasitoids emerged from galls of the range‐expanding host.Main ConclusionsChanges in interactions with generalist enemies created high niche opportunities, and limited biotic resistance, suggesting weak apparent competition may be a mechanism of enemy release for range‐expanding insects embedded within generalist enemy networks.