Spatial and temporal patterns of a pulsed resource dynamically drive the distribution of specialist herbivores
Spatial and temporal patterns of a pulsed resource dynamically drive the distribution of specialist herbivores
复制标题
DOI：
10.1038/s41598-019-54297-6
复制
发表时间：
2019-11-28
影响因子：
4.6
通讯作者：
Boivin, Thomas
中科院分区：
文献类型：
--
作者：
Doublet, Violette;Gidoin, Cindy;Boivin, Thomas
食草动物的时空分布模式和驱动因素是其对植物种群生态和进化影响的关键因素。草食动物的空间分布可能会受到增加（RCH：资源集中假说）或减少（RDH：资源稀释假说）资源密度的影响，但这种分布的资源密度的时间变化的影响仍然很少记录。我们使用了一个桅杆树种和种子捕食者在法国东南部的调查，以解决主机的脉冲资源的时空分布的高度专业化的昆虫食草动物的种子喂养的效果。在资源和种子捕食者密度的变化进行了评估，估计种子生产和种子虫害率在重点树木在连续10年。我们发现增加种子侵染率与降低宿主树密度在低种子产量的年份，表明RDH模式的种子捕食者。然而，这种模式是不持久的，在多年的高种子生产期间，种子侵染率不依赖于宿主树密度。我们发现，在资源密度的时间变化可能会导致种子捕食者的空间分布的瞬态。这项研究强调了如何在自然生态系统中的植物-草食动物相互作用的预测可能依赖于时间成分的RCH和RDH假设。
Patterns and drivers of the spatio-temporal distribution of herbivores are key elements of their ecological and evolutionary impacts on plant populations. Herbivore spatial distributions may be influenced by increased (RCH: resource concentration hypothesis) or decreased (RDH: resource dilution hypothesis) resource densities, but the effect of temporal variations in resource densities on such distributions remains poorly documented. We used a survey of a masting tree species and its seed predators in Southeastern France to address the effect of a host's pulsed resource on the spatio-temporal distributions of highly specialized insect herbivores feeding on seeds. Variations in both resource and seed predator densities were assessed by estimating seed production and seed infestation rates in focus trees during 10 consecutive years. We found increasing seed infestation rates with decreasing host tree densities in years of low seed production, indicating a RDH pattern of seed predators. However, such pattern was not persistent in years of high seed production during which seed infestation rates did not depend on host tree densities. We showed that temporal variations in resource density can lead to transience of seed predator spatial distribution. This study highlights how predictions of plant-herbivore interactions in natural ecosystems may rely on temporal components underlying RCH and RDH hypotheses.