LeCroy Kathryn A, Arceo-Gómez Gerardo, Koski Matthew H, Morehouse Nathan I, Ashman Tia-Lynn
Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, United States.
Department of Environmental Sciences, University of Virginia, Charlottesville, VA, United States.
Front Plant Sci. 2021 Jan 8;11:602951. doi: 10.3389/fpls.2020.602951. eCollection 2020.
Functional traits, particularly those that impact fitness, can shape the ecological and evolutionary relationships among coexisting species of the same trophic level. Thus, examining these traits and properties of their distributions (underdispersion, overdispersion) within communities can provide insights into key ecological interactions (e.g., competition, facilitation) involved in community assembly. For instance, the distribution of floral colors in a community may reflect pollinator-mediated interactions between sympatric plant species, and the phylogenetic distribution of color can inform how evolutionary contingencies can continue to shape extant community assemblages. Additionally, the abundance and species richness of the local habitat may influence the type or strength of ecological interactions among co-occurring species. To evaluate the impact of community size and species richness on mechanisms shaping the distribution of ecologically relevant traits, we examined how floral color (defined by pollinator color vision models) is distributed within co-flowering assemblages. We modeled floral reflectance spectra of 55 co-flowering species using honeybee () and syrphid fly () visual systems to assess the distributions of flower color across 14 serpentine seep communities in California. We found that phylogenetic relatedness had little impact on the observed color assemblages. However, smaller seep communities with lower species richness were more overdispersed for flower color than larger, more species-rich communities. Results support that competitive exclusion could be a dominant process shaping the species richness of flower color in smaller-sized communities with lower species richness, but this is less detectable or overwhelmed by other processes at larger, more speciose communities.
功能性状，尤其是那些影响适合度的性状，能够塑造同一营养级中共存物种之间的生态和进化关系。因此，研究这些性状及其在群落内分布的特性（均匀度不足、过度分散），可以深入了解群落组装过程中涉及的关键生态相互作用（如竞争、促进作用）。例如，群落中花色的分布可能反映了同域分布植物物种之间传粉者介导的相互作用，而花色的系统发育分布可以说明进化偶然性如何继续塑造现存的群落组合。此外，当地栖息地的丰度和物种丰富度可能会影响同时出现的物种之间生态相互作用的类型或强度。为了评估群落大小和物种丰富度对塑造生态相关性状分布机制的影响，我们研究了花色（由传粉者颜色视觉模型定义）在同期开花组合中的分布情况。我们使用蜜蜂（ ）和食蚜蝇（ ）的视觉系统对55种同期开花物种的花反射光谱进行建模，以评估加利福尼亚州14个蛇纹石渗流群落中花色的分布。我们发现系统发育相关性对观察到的颜色组合影响很小。然而，物种丰富度较低的较小渗流群落的花色比物种丰富度较高的较大群落更加过度分散。结果支持竞争排斥可能是塑造物种丰富度较低的较小群落中花色物种丰富度的主导过程，但在物种更丰富的较大群落中，这一过程较难检测到或被其他过程掩盖。
