DOI: 10.5061/dryad.f8vs9
title: Data from: Local and landscape-level floral resources explain effects of wildflower strips on wild bees across four European countries

description: 1. Growing evidence for declines in wild bees calls for the development
 and implementation of effective mitigation measures. Enhancing floral
 resources is a widely accepted measure for promoting bees in agricultural
 landscapes, but effectiveness varies considerably between landscapes and
 regions. We hypothesize that this variation is mainly driven by a
 combination of the direct effects of measures on local floral resources
 and the availability of floral resources in the surrounding landscape. 2.
 To test this, we established wildflower strips in four European countries,
 using the same seed mixture of forage plants specifically targeted at
 bees. We used a before–after control–impact approach to analyse the
 impacts of wildflower strips on bumblebees, solitary bees and Red List
 species and examined to what extent effects were affected by local and
 landscape-wide floral resource availability, land-use intensity and
 landscape complexity. 3. Wildflower strips generally enhanced local bee
 abundance and richness, including Red-listed species. Effectiveness of the
 wildflower strips increased with the local contrast in flower richness
 created by the strips and furthermore depended on the availability of
 floral resources in the surrounding landscape, with different patterns for
 solitary bees and bumblebees. Effects on solitary bees appeared to
 decrease with increasing amount of late-season alternative floral
 resources in the landscape, whereas effects on bumblebees increased with
 increasing early-season landscape-wide floral resource availability. 4.
 Synthesis and applications. Our study shows that the effects of wildflower
 strips on bees are largely driven by the extent to which local flower
 richness is increased. The effectiveness of this measure could therefore
 be enhanced by maximizing the number of bee forage species in seed
 mixtures, and by management regimes that effectively maintain flower
 richness in the strips through the years. In addition, for bumblebees
 specifically, our study highlights the importance of a continuous supply
 of food resources throughout the season. Measures that enhance
 early-season landscape-wide floral resource availability, such as the
 cultivation of oilseed rape, can benefit bumblebees by providing the
 essential resources for colony establishment and growth in spring. Further
 research is required to determine whether, and under what conditions,
 wildflower strips result in actual population-level effects.
description: Scheper et al_J Appl
 Ecol_bee, flower & landscape dataData on bee abundance
 and richness, and flower cover and richness, in wildflower strips and
 control field boundaries. Data was collected in agricultural landscapes in
 Germany, The Netherlands, Sweden and the UK, in 2011-2013. Data on N
 input, percentage semi-natural habitat and early(May)- and
 late(July-August) floral resource availability is provided for each study
 landscape (1-km radius around wildflower strip or field
 boundary).Scheper et al_J Appl
 Ecol_red listed beesSpecies richness and
 abundance of red listed bee species in wildflower strips and control field
 boundaries in 2011 and 2012-2013 in Germany, The Netherlands, Sweden and
 the UK.