D3289: Landscape-scale floral resource abundance and temporal continuity underpin bumble bee occurrence and community composition

Agricultural practices and intensification over the past two centuries have dramatically altered the abundance and temporal continuity of floral resources that support pollinating insects such as bumble bees. Dichotomous, long-term trends among species in this genus in agricultural regions suggest many species have struggled to adapt to intensive agricultural conditions, while other species coped remarkably well. Several studies have explored behavioral and colony-level responses to these conditions, however whether these responses scale to the community and landscape-level is less understood. We mapped floral resource landscapes within an intensive agricultural region in the US Midwest and compared the temporal abundance and continuity of resources to bumble bee occurrence and community composition. Across the community, we found that bumble bee occurrence increases in landscapes containing more and temporally continuous floral resources. Species of conservation concern were generally more sensitive to both resource abundance and temporal continuity relative to common, increasing species. Together with existing evidence, this work suggests a renewed effort in increasing spatiotemporal resource continuity for bumble bee communities in the US Midwest. Such efforts will undoubtedly benefit other pollinator groups, ecosystem service providing taxa (e.g., natural enemies), and wildlife writ large.