Declines in forage availability for bumblebees at a national scale

Author
Carvell Claire
Roy D. B.
Smart Simon M.
Pywell Richard F.
Preston Christopher D.
Goulson Dave
Keywords
Abstract

<p>We assessed national scale changes in the forage plants of bumblebees in Britain, as a means of providing quantitative evidence for the likely principal cause of declines in bumblebee species. We quantified the relative value of native and long-established plant species as forage (nectar and pollen) resources for bumblebees by collating visitation data from 14 field sites across Britain. Twentieth Century changes in range and frequency of these forage plants were assessed using data from the New Atlas of the British and Irish Flora (1930–1969 to 1987–1999) and the Countryside Surveys of Britain (1978–1998). Forage plants declined in both large-scale range and local-scale frequency between the two survey periods. These changes were of greater magnitude than changes in other native plant species, reflecting serious reductions in quality of foraging habitats for bees as well as a general decline in insect-pollinated plants. Seventy-six percent of forage plants declined in frequency within 1-km squares, including those (e.g. Trifolium pratense) of particular value for threatened bumblebee species. We consider how our findings relate to other recorded changes in the British flora, how they may help to explain declines in bumblebees and how they could contribute to a conservation strategy.</p>

Year of Publication
2006
Journal
Biological Conservation
Volume
132
Issue
4
Number of Pages
481-489
Date Published
October 2006
ISBN Number
0006-3207
DOI
10.1016/j.biocon.2006.05.008
Short Title
Biological Conservation
Scheme