Functional flower traits and their diversity drive pollinator visitation

Abstract

Recent studies have shown that the diversity of flowering plants can enhance pollinator richness and visitation frequency and thereby increase the resilience of pollination. It is assumed that flower traits explain these effects, but it is still unclear which flower traits are responsible, and knowing that, if pollinator richness and visitation frequency are more driven by mass-ratio effects (mean trait values) or by trait diversity.Here, we analyse a three-year data set of pollinator observations collected in a European grassland plant diversity experiment (The Jena experiment). The data entail comprehensive flower trait measurements, including reward traits (nectar and pollen amount), morphological traits (height, symmetry, area, colour spectra) and chemical traits (nectar-amino acid and nectar-sugar concentration). We test if pollinator species richness and visitation frequency of flower communities depend on overall functional diversity combining all flower traits within a community, single trait diversities (within trait variation) and community-weighted means of the single traits, using Bayesian inference.Overall functional diversity did not affect pollinator species richness, but reduced visitation frequency. When looking at individual flower traits separately, we found that single trait diversity of flower reflectance and flower morphology were important predictors of pollinator visitation frequency. Moreover, independent of total flower abundance, communityweighted means of flower height, area, reflectance, nectar-sugar concentration and nectar-amino acid concentration strongly affected both pollinator species richness and visitation frequency.Our results, challenge the idea that functional diversity always positively affects ecosystem functions. Nonetheless, we demonstrate that both single trait diversity and mass-ratio effects of flower traits play an important role for diverse and frequent flower visits, which underlines the functionality of flower traits for pollination services.

Direct and indirect effects of climate, human disturbance and plant traits on avian functional diversity

“…Here, we found that trait matching between plants and animals was the main driver of the functional trait composition of avian frugivore communities on Mount Kilimanjaro. Consistent with our results, specific traits of flowering plants affected the species richness and visitation frequency of animal pollinators in a small‐scale, experimental system (Fornoff et al, ). Hence, bottom‐up effects mediated by plant traits and biotic interactions appear to be an important mechanism influencing patterns of animal diversity across spatial scales.…”

Wildfires Influence Abundance, Diversity, and Intraspecific and Interspecific Trait Variation of Native Bees and Flowering Plants Across Burned and Unburned Landscapes

“…Measurements were collected every week, alternating between Helena and Paradise, throughout the growing season to allow for measurements during peak flowering for each species. Plant height was measured from the ground to the top of the inflorescence of a flowering individual, and can be important for plant reproduction as taller plants are more visible and often attract more pollinators (e.g., Fornoff et al, 2017). The number of flowers was counted on a randomly selected inflorescence, and is a measure of plant attractiveness to pollinators (Conner and Rush, 1996;Coux et al, 2016).…”

“…Leaf rachis and petiolules (for species with compound leaves) and petioles (for all species) were included in measurements of leaf area and dry mass. SLA is important for plant energy use and potential relative growth rate (Cornelissen et al, 2003;Vieira et al, 2013;Fornoff et al, 2017). Though SLA may not be important for pollinator attraction or rewards, we included this commonly-measured trait to gain information on the plant perspective of the potential effects of wildfire and how these effects may differ from those on plant traits important for bees.…”

Assessing the Condition of Coral Reefs and the Indicator Fish (Family: Chaetodontidae) in Coastal Waters of Jayapura City, Papua Province, Indonesia

“…The species richness and abundance of bumblebees are significantly affected by types of flower resources, indicating that there is a strong association of bumblebees with families of host plants across the study area. Many explanations have pointed out how flora characters such as morphology, color and scent are associated with the attraction of the bee communities (Stone et al, 2003, Cnaani et al, 2006Fornoff et al, 2017). Elliott (2009) resulted the relation of foraging distances, bumblebee and flower availability (Williams and Osborne, 2009) indicated that species richness of bumblebee depends on increasing flower cover and the type of host plant and their richness compared to the other factors.…”