Stanley Amber, Martel Carlos, Arceo-Gómez Gerardo
Department of Biological Sciences, East Tennessee State University, Johnson City, TN 37614, USA.
Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.
AoB Plants. 2021 Oct 22;13(6):plab069. doi: 10.1093/aobpla/plab069. eCollection 2021 Dec.
Pollinator-mediated competition and facilitation are two important mechanisms mediating co-flowering community assembly. Experimental studies, however, have mostly focused on evaluating outcomes for a single interacting partner at a single location. Studies that evaluate spatial variation in the bidirectional effects between co-flowering species are necessary if we aim to advance our understanding of the processes that mediate species coexistence in diverse co-flowering communities. Here, we examine geographic variation (i.e. at landscape level) in bidirectional pollinator-mediated effects between co-flowering and We evaluated effects on pollen transfer dynamics (conspecific and heterospecific pollen deposition) and plant reproductive success. We found evidence of asymmetrical effects (one species is disrupted and the other one is facilitated) but the effects were highly dependent on geographical location. Furthermore, effects on pollen transfer dynamics did not always translate to effects on overall plant reproductive success (i.e. pollen tube growth) highlighting the importance of evaluating effects at multiple stages of the pollination process. Overall, our results provide evidence of a spatial mosaic of pollinator-mediated interactions between co-flowering species and suggest that community assembly processes could result from competition and facilitation acting simultaneously. Our study highlights the importance of experimental studies that evaluate the prevalence of competitive and facilitative interactions in the field, and that expand across a wide geographical context, in order to more fully understand the mechanisms that shape plant communities in nature.
传粉者介导的竞争和促进作用是介导同时开花群落组装的两个重要机制。然而，实验研究大多集中在评估单一地点单个相互作用伙伴的结果。如果我们旨在深化对介导不同同时开花群落中物种共存过程的理解，那么评估同时开花物种间双向效应的空间变异的研究是必要的。在这里，我们研究了同时开花植物之间双向传粉者介导效应的地理变异（即在景观水平上）。我们评估了对花粉传播动态（同种和异种花粉沉积）和植物繁殖成功率的影响。我们发现了不对称效应（一个物种受到干扰而另一个物种得到促进）的证据，但这些效应高度依赖于地理位置。此外，对花粉传播动态的影响并不总是转化为对植物整体繁殖成功率（即花粉管生长）的影响，这突出了在授粉过程的多个阶段评估影响的重要性。总体而言，我们的结果提供了同时开花物种间传粉者介导相互作用的空间镶嵌证据，并表明群落组装过程可能是竞争和促进作用同时发挥的结果。我们的研究强调了实验研究的重要性，这些研究评估田间竞争和促进相互作用的普遍性，并在广泛的地理背景下展开，以便更全面地理解塑造自然植物群落的机制。
