Providing evidence to improve practice

Individual study: Nest-searching and foraging queen bumblebees Bombus spp. are attracted to agri-environment scheme options on lowland arable farms in East and Central Scotland

Published source details

Lye G., Park K., Osborne J., Holland J. & Goulson D. (2009) Assessing the value of Rural Stewardship schemes for providing forage resources and nesting habitat for bumblebee queens (Hymenoptera: Apidae). Biological Conservation, 142, 2023-2032

Background

Many bumblebee species Bombus spp. have suffered severe declines in the UK, widely thought to be due to agricultural intensification. The bumblebee population is most vulnerable in Spring, when individual queens found colonies. This study examined the attractiveness of three Rural Stewardship Scheme (RSS) options to nest-searching and foraging Spring queen bumblebees on lowland arable farms in Scotland.

Action

Five farms that signed RSS management plans in 2004 were chosen in East and Central Scotland. Each had at least one example of the following options:

- grass margins on arable fields, 1.5 - 6 m, unsprayed, uncut
- species-rich grassland (existing or restored), uncut between March and August
- hedgerows only cut every three years in winter, gaps filled and vegetation below unmown, unsprayed.
These farms were paired with five comparison farms, less than 5 km away in each case, with similar land use but no agri-environment scheme participation.
Nest-searching and foraging queen bumblebees were recorded on six 100 x 6 m transects on each farm, once a week from 14 April to 16 May 2009, on dry days with temperatures of 5-25°C. Each farm had two arable field margin transects, two grassland (non-boundary) transects, and two hawthorn- or blackthorn-dominated hedgerow transects. On farms with RSS, one of each transect type was under the agri-environment scheme.

Consequences

On RSS farms, agri-environment scheme transects attracted significantly more nest-searching and foraging queen bumblebees than conventionally managed transects. RSS field margins attracted nest-searching and foraging queens at the highest densities - about nine nest-searching queens and over three foraging queens/100 m, compared to around five nest-searchers and less than one forager/100 m for conventional field margins.

Hedgerows were least attractive to spring queens. There was no significant difference in numbers of foraging or nesting queens between RSS and conventional hedgerows.

Unmanaged areas of grassland contained more flowers in spring, and attracted more foraging queen bumblebees than RSS species-rich grassland. Across all farms, non-RSS grassland attracted the highest abundance of foraging queen bumblebees (>4 queens/100m transect on conventional farms).
On conventionally managed transects, there was no significant difference between farms with and without agri-environment schemes in numbers of nest-searching queens, but conventionally managed farms had more foraging queens.

 

Note: If using or referring to this published study, please read and quote the original paper, this can be viewed at: www.sciencedirect.com/science/journal/00063207.