Modeling the status, trends, and impacts of wild bee abundance in the United States


TitleModeling the status, trends, and impacts of wild bee abundance in the United States
Publication TypeJournal Article
Year of Publication2015
AuthorsKoh, I, Lonsdorf, EV, Williams, NM, Brittain, C, Isaacs, R, Gibbs, J, Ricketts, TH
JournalProceedings of the National Academy of Sciences
Pagination201517685
Date Published2015/12
ISSN0027-8424
Keywordscrop pollination, ecosystem services, habitat suitability, land-use change, uncertainty
Abstract

Wild bees are highly valuable pollinators. Along with managed honey bees, they provide a critical ecosystem service by ensuring stable pollination to agriculture and wild plant communities. Increasing concern about the welfare of both wild and managed pollinators, however, has prompted recent calls for national evaluation and action. Here, for the first time to our knowledge, we assess the status and trends of wild bees and their potential impacts on pollination services across the coterminous United States. We use a spatial habitat model, national land-cover data, and carefully quantified expert knowledge to estimate wild bee abundance and associated uncertainty. Between 2008 and 2013, modeled bee abundance declined across 23% of US land area. This decline was generally associated with conversion of natural habitats to row crops. We identify 139 counties where low bee abundances correspond to large areas of pollinator-dependent crops. These areas of mismatch between supply (wild bee abundance) and demand (cultivated area) for pollination comprise 39% of the pollinator-dependent crop area in the United States. Further, we find that the crops most highly dependent on pollinators tend to experience more severe mismatches between declining supply and increasing demand. These trends, should they continue, may increase costs for US farmers and may even destabilize crop production over time. National assessments such as this can help focus both scientific and political efforts to understand and sustain wild bees. As new information becomes available, repeated assessments can update findings, revise priorities, and track progress toward sustainable management of our nation’s pollinators.

URLhttp://www.pnas.org/lookup/doi/10.1073/pnas.1517685113
DOI10.1073/pnas.1517685113
Short TitleProc Natl Acad Sci USA
Refereed DesignationRefereed
Status: 
Published
Attributable Grant: 
RACC
Grant Year: 
Year5
Acknowledged VT EPSCoR: 
Ack-No