Competition for pollinators destabilizes plant coexistence
Competition for pollinators destabilizes plant coexistence
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DOI：
10.1038/s41586-022-04973-x
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发表时间：
2022-07-20
期刊：
影响因子：
64.8
通讯作者：
Levine, Jonathan M.
中科院分区：
文献类型：
--
作者：
Johnson, Christopher A.;Dutt, Proneet;Levine, Jonathan M.
对全球传粉者数量下降的日益关注，促使人们呼吁调查它们在维持植物多样性方面的作用。理论预测，对传粉者的竞争可以通过提供生态位分化的机会来稳定植物物种之间的相互作用，同时可以驱动有利于排斥的竞争不平衡。在这里，我们通过操纵传粉者的竞争来经验性地测试这些对比效应，以预测其对植物共存的长期影响。我们对位于实验施加的邻近密度梯度上的一年生植物个体进行环境昆虫授粉或花粉补充处理，以减轻对传粉者的竞争。这些个体的生命率为预测物种共存的关键理论指标的植物种群动态模型提供了信息。对传粉者的竞争通常会破坏植物物种之间的相互作用，减少预期共存的比例。与传粉者的相互作用也影响了植物物种之间的竞争不平衡，这种影响预计将随着传粉者的减少而加强，可能会破坏植物的共存。事实上，一项模拟传粉者减少的实验结果表明，植物物种的访花次数减少得更多，种群增长率也会下降得更多。我们的研究结果表明，传粉者的竞争可能会削弱植物共存的不稳定的相互作用，并有助于竞争的不平衡，信息解释传粉者下降的影响至关重要。
Mounting concern over the global decline of pollinators has fuelled calls for investigating their role in maintaining plant diversity. Theory predicts that competition for pollinators can stabilize interactions between plant species by providing opportunities for niche differentiation, while at the same time can drive competitive imbalances that favour exclusion. Here we empirically tested these contrasting effects by manipulating competition for pollinators in a way that predicts its long-term implications for plant coexistence. We subjected annual plant individuals situated across experimentally imposed gradients in neighbour density to either ambient insect pollination or a pollen supplementation treatment alleviating competition for pollinators. The vital rates of these individuals informed plant population dynamic models predicting the key theoretical metrics of species coexistence. Competition for pollinators generally destabilized the interactions between plant species, reducing the proportion of pairs expected to coexist. Interactions with pollinators also influenced the competitive imbalances between plant species, effects that are expected to strengthen with pollinator decline, potentially disrupting plant coexistence. Indeed, results from an experiment simulating pollinator decline showed that plant species experiencing greater reductions in floral visitation also suffered greater declines in population growth rate. Our results reveal that competition for pollinators may weaken plant coexistence by destabilizing interactions and contributing to competitive imbalances, information critical for interpreting the impacts of pollinator decline.