Data from: Contemporary human-altered landscapes and oceanic barriers limit bumble bee gene flow

Much of the world's terrestrial landscape is being altered by humans
in the form of agriculture, urbanization, and pastoral systems, with major
implications for biodiversity. Bumble bees are one of the most effective
pollinators in both natural and cultivated landscapes, but are often the
first to be extirpated in human-altered habitats. Yet, little is known
about the role of natural and human-altered habitats in promoting or
limiting bumble bee gene flow. In this study, I closely examine the
genetic structure of the yellow-faced bumble bee, Bombus vosnesenskii,
across the south-western US coast and find strong evidence that natural
oceanic barriers, as well as contemporary human-altered habitats, limit
bee gene flow. Heterozygosity and allelic richness were lower in island
populations, while private allelic richness was higher in island
populations compared to mainland populations. Genetic differentiation,
measured for three indices across the 1000km study region, was
significantly greater than the null expectation (FST =0.041, F’ST=0.044,
Dest=0.155) and correlated with geographic distance. Furthermore, genetic
differentiation patterns were most strongly correlated with contemporary
(2011) not past (2006, 2001) resistance maps calibrated for high dispersal
limitation over oceans, impervious habitat, and croplands. Despite the
incorporation of dramatic elevation gradients, the analyses reveal that
oceans and contemporary human land use, not mountains, are the primary
dispersal barriers for B. vosnesenskii gene flow. These findings reinforce
the importance of maintaining corridors of suitable habitat across the
distribution range of native pollinators to promote their persistence and
safeguard their ability to provide essential pollination services.