Biotic Interactions Contribute to the Geographic Range Limit of an Annual Plant: Herbivory and Phenology Mediate Fitness beyond a Range Margin
Biotic Interactions Contribute to the Geographic Range Limit of an Annual Plant: Herbivory and Phenology Mediate Fitness beyond a Range Margin
复制标题
DOI：
10.1086/703187
复制
发表时间：
2019-06-01
影响因子：
2.9
通讯作者：
Moeller, David A.
中科院分区：
文献类型：
--
作者：
Benning, John W.;Eckhart, Vincent M.;Moeller, David A.
物种的地理分布在人类世已经发生了变化。然而，我们通常不知道环境的哪些方面驱动范围动态，更不用说哪些特征介导生物体对这些环境梯度的反应。大多数研究都集中在可能的气候限制物种的分布，并忽略了生物相互作用的作用，尽管理论上支持它们在设定分布限制的重要性。我们使用现场实验和模拟，估计哺乳动物的植食性的范围边界在加利福尼亚州的一年生植物Clarkia xantiana SSP的贡献。xantiana。一个陡峭的梯度发生的概率增加的草食动物跨越边界，和先前的移植实验的重新分析显示，草食动物驾驶几倍的下降，在生命健康的边界和超越。模拟表明，在没有食草动物的情况下，种群可能会在范围边缘之外持续存在。利用一个狭同域分布的亚种，Clarkiaxantianaparviflora的数据，我们还表明，延迟物候与C。桑蒂亚纳湾xantiana的易感性草食动物和低健身超出其边界。总的来说，我们的研究结果提供了一些最全面的证据，到目前为止，如何在物种相互作用的人口，性状和空间梯度的相互作用可以产生一个地理范围限制，他们借给经验支持最近的发展范围限制理论。
Species' geographic distributions have already shifted during the Anthropocene. However, we often do not know what aspects of the environment drive range dynamics, much less which traits mediate organisms' responses to these environmental gradients. Most studies focus on possible climatic limits to species' distributions and have ignored the role of biotic interactions, despite theoretical support for their importance in setting distributional limits. We used field experiments and simulations to estimate contributions of mammalian herbivory to a range boundary in the Californian annual plant Clarkia xantiana ssp. xantiana. A steep gradient of increasing probability of herbivory occurred across the boundary, and a reanalysis of prior transplant experiments revealed that herbivory drove severalfold declines in lifetime fitness at and beyond the boundary. Simulations showed that populations could potentially persist beyond the range margin in the absence of herbivory. Using data from a narrowly sympatric subspecies, Clarkia xantiana parviflora, we also showed that delayed phenology is strongly associated with C. xantiana ssp. xantiana's susceptibility to herbivory and low fitness beyond its border. Overall, our results provide some of the most comprehensive evidence to date of how the interplay of demography, traits, and spatial gradients in species interactions can produce a geographic range limit, and they lend empirical support to recent developments in range limits theory.