Data from: Wild bees as winners and losers: relative impacts of landscape composition, quality, and climate

Wild bees, like many other taxa, are threatened by land use and climate
change, which in turn jeopardizes pollination of crops and wild plants.
Understanding how land-use and climate factors interact is critical to
predicting and managing pollinator populations and ensuring adequate
pollination services, but most studies have evaluated either land-use or
climate effects, not both. Further, bee species are incredibly variable,
spanning an array of behavioral, physiological and life history traits
that can increase or decrease resilience to land use or climate change.
Thus, there are likely bee species that benefit, while others suffer, from
changing climate and land use, but few studies have documented
taxon-specific trends. To address these critical knowledge gaps, we
analyzed a long-term dataset of wild bee occurrences from Maryland,
Delaware, and Washington DC, USA, examining how different bee genera and
functional groups respond to landscape composition, quality, and climate
factors. Despite a large body of literature documenting land-use effects
on wild bees, in this study, climate factors emerged as the main drivers
of wild-bee abundance and richness. For wild-bee communities in spring and
summer/fall, temperature and precipitation were more important predictors
than landscape composition, landscape quality, or topography. However,
relationships varied substantially between wild-bee genera and functional
groups. In the Northeast USA, past trends and future predictions show a
changing climate with warmer winters, more intense precipitation in winter
and spring, and longer growing seasons with higher maximum temperatures.
In almost all of our analyses, these conditions were associated with lower
abundance of wild bees. Wild-bee richness results were more mixed,
including neutral and positive relationships with predicted temperature
and precipitation patterns. Thus, in this region and undoubtedly more
broadly, changing climate poses a significant threat to wild-bee
communities.