Species and Phylogenetic Heterogeneity in Visitation Affects Reproductive Success in an Island System

Abstract

Editor: Susan J. MazerPlant-pollinator mutualisms can be disrupted in fragmented and isolated populations. Isolated populations attract fewer and less diverse pollinators, but it is not generally known whether this is due to reductions in the abundance and/or diversity of flowers at a site or to the biogeography of pollinators (or both). Islands represent one system potentially suitable to analyze the effects of spatial isolation. Here, we examine the contribution that differences in visitor composition make to increased selfing and seed production by examining the major visitors to Plectritis congesta in populations on the Gulf Islands and Vancouver Island. We find that (1) connectivity is more strongly associated with visitor assemblages and seed production than components of the floral community and (2) taking phylogeny into account suggests that increased visitation by solitary bees as opposed to other functional groups increases female fitness in P. congesta.

Forecasting pollination declines through DNA barcoding: the potential contributions of macroecological and macroevolutionary scales of inquiry

“…Models that have incorporated spatial heterogeneity find that specialists should evolve when their habitat or mutualists become common (Whitlock, ; Débarre & Gandon, ). There have been few empirical tests of these models using host‐plant use because they require community‐level sampling over vast areas (Bridle et al ., ; Vamosi et al ., 2014a; Adderley & Vamosi, ). By assessing the pollen on pollinators through DNA barcoding across a species’ range, we can determine to what degree this heterogeneity in ecological options throughout the geographic range of a species determines our measurement of pollinator specialization (Table ).…”

Increasing land use drives changes in plant phylogenetic diversity and prevalence of specialists

“…In other words, like observed in Allan et al (2014) and Allan et al (2015) , some specialist species thrive in disturbed environments. However, the potential consequence of these changes in composition is that, for these two particular types of plant communities, the reduction to a community of specialists at the plant trophic level, is that the combination of functional traits (i.e., functional redundancy) are likely reduced, which may cascade into a lower phylogenetic diversity of pollinators supported ( Adderley & Vamosi, 2015 ).…”

On the capacity for rapid adaptation and plastic responses to herbivory and intraspecific competition in insular populations of Plectritis congesta

“…congesta is an iconic winter annual of threatened oak–savanna habitat in western North America, a key resource for native pollinators (e.g. Adderley & Vamosi, 2015; Kelly & Elle, 2020; Schultz et al, 2010), and ideal for our purposes. P .…”