DOI: 10.5061/dryad.qv9s4mwcs
title: Pollen transfer networks reveal alien species as main heterospecific pollen donors with fitness consequences for natives

description: The ecological dynamics of co-flowering communities are largely mediated
 by pollinators. However, current understanding of pollinator-mediated
 interactions primarily relies on how co-flowering plants influence
 attraction of shared pollinators, and much less is known about plan-plant
 interactions that occur via heterospecific pollen (HP) transfer. Invaded
 communities in particular can be highly affected by the transfer of alien
 pollen, but the strength, drivers, and fitness consequences of these
 interactions at a community scale are not well understood. Here we analyze
 HP transfer networks in nine coastal communities in the Yucatan Mexico
 that vary in the relative abundance of invasive flowers to evaluate how HP
 donation and receipt varies between native and alien plants. We further
 evaluate whether HP donation and receipt are mediated by floral traits
 (e.g. display, flower size) or pollinator visitation rate. Finally, we
 evaluated whether post-pollination success (proportion of pollen tubes
 produced) was affected by alien HP receipt and whether the effect varied
 between native and alien recipients. HP transfer networks exhibit
 relatively high connectance (ca. 15%), suggesting high HP transfer within
 the studied communities. Significant network nestedness further suggests
 the existence of species that predominantly act as HP donors or recipients
 in the community. Species-level analyses showed that natives receive 80%
 more HP compared to alien species, and that alien plants donate 40% more
 HP than natives. HP receipt and donation were mediated by different floral
 traits and such effects were independent of plant origin (native or
 alien). The proportion of alien HP received significantly affected
 conspecific pollen tube success in natives, but not that of alien species.
 Synthesis. Our results suggest that HP transfer in invaded communities is
 widespread, and that native and alien species play different roles within
 HP transfer networks, which are mediated by a different suite of floral
 traits. Alien species, in particular, play a central role as HP donors and
 are more tolerant to HP receipt than natives—a finding that points to two
 overlooked mechanisms facilitating alien plant invasion and success within
 native co-flowering communities.
description: In nine coastal communities, 3-4 styles per plant for all plants
 present within 10 plots were collected  (average per species 48.5 ± 68.95,
 ± SD). A total of 4500 styles were collected (average per site 498.22 ±
 348.32, ± SD) corresponding to 1273 individual plants. Styles were
 collected from senesced flowers in the afternoon (» 1500 hrs), after
 pollinator activity had ceased, and were stored in formalin-acetic alcohol
 (FAA). For each style collected, the number of conspecific pollen (CP) and
 heterospecific pollen (HP) grains on stigmas, and the number of pollen
 tubes at the base of the style were scored with a fluorescence microscope
 (Nikon e2010). To identify CP and HP pollen grains from
 plot-collected styles/stigmas, a pollen library was first created from
 mature floral buds (3-5) collected from each species present in the
 community. Pollen grains were photographed with an optical microscope
 equipped with a digital camera that allowed for the morphological
 characterization of pollen grains (Motic BA310). This pollen library was
 then used as a reference to identify pollen loads on stigmas and to record
 CP and HP abundance on each stigma.
description: This data base contains:     Sheet name   Information Plant species codes   Scientific name (identity) and codes of each plant species recorded in the coastal dunes of the Yucatan Peninsula, Mexico.       HP Transfer network   Data by site (community) of HP transfer.  Species code of the specie's  Target (pollen receiver) and species code of the specie's      source (pollen donor). HP= # of hetrospecific pollen        ReproductiveSuccess data   The site (community), species code, origen (native or alien), Recipient (# HP receiver), Donor (# HP donated)      Authority and Hub values.       Flower traits: color= Saturation and Tonality, Herkogany (mm), flower size (PC1), floral display size     Insect visitation rate (log)       Pollen data   Name of the community sampled, species code, #Conspecific pollen, proportion of hetrospeciefic pollen received      heterospecific pollen richness, # pollen tubes, proportion of alien pollen received, proportion of pollen tubes