Evans Tracie M, Cavers Stephen, Ennos Richard, Vanbergen Adam J, Heard Matthew S
NERC Centre for Ecology and Hydrology Wallingford UK.
Institute of Evolutionary Biology University of Edinburgh Edinburgh UK.
Ecol Evol. 2017 Jul 11;7(16):6507-6518. doi: 10.1002/ece3.3186. eCollection 2017 Aug.
Landscape heterogeneity in floral communities has the potential to modify pollinator behavior. Pollinator foraging varies with the diversity, abundance, and spatial configuration of floral resources. However, the implications of this variation for pollen transfer and ultimately the reproductive success of insect pollinated plants remains unclear, especially for species which are rare or isolated in the landscape. We used a landscape-scale experiment, coupled with microsatellite genotyping, to explore how the floral richness of habitats affected pollinator behavior and pollination effectiveness. Small arrays of the partially self-compatible plant Californian poppy ( were introduced across a landscape gradient to simulate rare, spatially isolated populations. The effects on pollinator activity, outcrossing, and plant reproduction were measured. In florally rich habitats, we found reduced pollen movement between plants, leading to fewer long-distance pollination events, lower plant outcrossing, and a higher incidence of pollen limitation. This pattern indicates a potential reduction in per capita pollinator visitation, as suggested by the lower activity densities and richness of pollinators observed within florally rich habitats. In addition, seed production reduced by a factor of 1.8 in plants within florally rich habitats and progeny germination reduced by a factor of 1.2. We show this to be a consequence of self-fertilization within the partially self-compatible plant, . These findings indicate that locally rare plants are at a competitive disadvantage within florally rich habitats because neighboring plant species disrupt conspecific mating by co-opting pollinators. Ultimately, this Allee effect may play an important role in determining the long-term persistence of rarer plants in the landscape, both in terms of seed production and viability. Community context therefore requires consideration when designing and implementing conservation management for plants which are comparatively rare in the landscape.
花卉群落中的景观异质性有可能改变传粉者的行为。传粉者的觅食行为会随着花卉资源的多样性、丰富度和空间配置而变化。然而，这种变化对花粉传播以及最终对虫媒植物繁殖成功的影响仍不明确，尤其是对于在景观中稀有或孤立的物种。我们进行了一项景观尺度的实验，并结合微卫星基因分型，以探究栖息地的花卉丰富度如何影响传粉者行为和授粉效果。在整个景观梯度上引入了部分自交亲和的植物加州罂粟的小型阵列，以模拟稀有、空间隔离的种群。测量了对传粉者活动、异交和植物繁殖的影响。在花卉丰富的栖息地，我们发现植物之间的花粉移动减少，导致远距离授粉事件减少、植物异交率降低以及花粉限制发生率更高。这种模式表明人均传粉者访花次数可能减少，正如在花卉丰富的栖息地中观察到的传粉者活动密度和丰富度较低所表明的那样。此外，花卉丰富栖息地中的植物种子产量降低了1.8倍，后代发芽率降低了1.2倍。我们表明这是部分自交亲和植物自身受精的结果。这些发现表明，当地稀有的植物在花卉丰富的栖息地中处于竞争劣势，因为邻近植物物种通过争夺传粉者干扰了同种交配。最终，这种阿利效应可能在决定景观中较稀有植物在种子产量和活力方面的长期存续方面发挥重要作用。因此，在为景观中相对稀有的植物设计和实施保护管理时，需要考虑群落背景。
