Beekeeping in a natural area affects male fitness of a native plant

Biological invasions represent one of the main threats to biodiversity. The honeybee has been deliberately introduced into a wide range of habitats worldwide. Currently, beekeeping is turning to natural areas in search of better honey quality. This practice can boost honeybee abundance, with potential ecological consequences in the local ecosystems. Although previous studies have considered how female plant fitness responds to honeybees, we know little about their potential effects on male fitness. We studied experimentally the effect of increased honeybee abundance on male fitness of a dominant shrub, Larrea divaricata, in a dryland ecosystem in Villavicencio Nature Reserve, Mendoza, Argentina. In replicated study plots near and far from managed hives we estimated pollen removal and dispersal, self-pollination and outcrossing rates, the number of mating couples, and self-pollinated flowers. Honeybees restricted pollen dispersal distance, with a potential effect on male fitness. Our findings have important implications for maintaining the reproduction and persistence of wild plants exposed to nonnative pollinators and can serve as a guide to decision making about the introduction of managed honeybee hives in nature reserves.