TY - JOUR
T1 - Early-season mass-flowering crop cover dilutes wild bee abundance and species richness in temperate regions
T2 - A quantitative synthesis
AU - Riggi, L.G.A.
AU - Raderschall, C.A.
AU - Fijen, T.P.M.
AU - Scheper, J.
AU - Smith, H.G.
AU - Kleijn, D.
AU - Holzschuh, A.
AU - Aguilera, G.
AU - Badenhausser, I.
AU - Bänsch, S.
AU - Beyer, N.
AU - Blitzer, E.J.
AU - Bommarco, R.
AU - Danforth, B.
AU - González-Varo, J.P.
AU - Grab, H.
AU - Le Provost, G.
AU - Poveda, K.
AU - Potts, S.G.
AU - Rundlöf, M.
AU - Steffan-Dewenter, I.
AU - Tscharntke, T.
AU - Vilà, M.
AU - Westphal, C.
AU - Berggren,
AU - Lundin, O.
PY - 2024/3
Y1 - 2024/3
N2 - Pollinators benefit from increasing floral resources in agricultural landscapes, which could be an underexplored co-benefit of mass-flowering crop cultivation. However, the impacts of mass-flowering crops on pollinator communities are complex and appear to be context-dependent, mediated by factors such as crop flowering time and the availability of other flower resources in the landscape. A synthesis of research is needed to develop management recommendations for effective pollinator conservation in agroecosystems. By combining 22 datasets from 13 publications conducted in nine temperate countries (20 European, 2 North American), we investigated if mass-flowering crop flowering time (early or late season), bloom state (during or after crop flowering) and extent of non-crop habitat cover in the landscape moderated the effect of mass-flowering crop cover on wild pollinator abundance and species richness in mass-flowering crop and non-crop habitats. During bloom, wild bee abundance and richness are negatively related to mass-flowering crop cover. Dilution effects were predominant in crop habitats and early in the season, except for bumblebees, which declined with mass-flowering crop cover irrespective of habitat or season. Late in the season and in non-crop habitats, several of these negative relationships were either absent or reversed. Late-season mass-flowering crop cover is positively related to honeybee abundance in crop habitats and to other bee abundance in non-crop habitats. These results indicate that crop-adapted species, like honeybees, move to forage and concentrate on late-season mass-flowering crops at a time when flower availability in the landscape is limited, potentially alleviating competition for flower resources in non-crop habitats. We found no evidence of pollinators moving from mass-flowering crop to non-crop habitats after crop bloom. Synthesis and applications: Our results confirm that increasing early-season mass-flowering crop cover dilutes wild pollinators in crop habitats during bloom. We find that dilution effects were absent late in the season. While mass-flowering crop cultivation alone is unlikely to be sufficient for maintaining pollinators, as part of carefully designed diverse crop rotations or mixtures combined with the preservation of permanent non-crop habitats, it might provide valuable supplementary food resources for pollinators in temperate agroecosystems, particularly later in the season when alternative flower resources are scarce.
AB - Pollinators benefit from increasing floral resources in agricultural landscapes, which could be an underexplored co-benefit of mass-flowering crop cultivation. However, the impacts of mass-flowering crops on pollinator communities are complex and appear to be context-dependent, mediated by factors such as crop flowering time and the availability of other flower resources in the landscape. A synthesis of research is needed to develop management recommendations for effective pollinator conservation in agroecosystems. By combining 22 datasets from 13 publications conducted in nine temperate countries (20 European, 2 North American), we investigated if mass-flowering crop flowering time (early or late season), bloom state (during or after crop flowering) and extent of non-crop habitat cover in the landscape moderated the effect of mass-flowering crop cover on wild pollinator abundance and species richness in mass-flowering crop and non-crop habitats. During bloom, wild bee abundance and richness are negatively related to mass-flowering crop cover. Dilution effects were predominant in crop habitats and early in the season, except for bumblebees, which declined with mass-flowering crop cover irrespective of habitat or season. Late in the season and in non-crop habitats, several of these negative relationships were either absent or reversed. Late-season mass-flowering crop cover is positively related to honeybee abundance in crop habitats and to other bee abundance in non-crop habitats. These results indicate that crop-adapted species, like honeybees, move to forage and concentrate on late-season mass-flowering crops at a time when flower availability in the landscape is limited, potentially alleviating competition for flower resources in non-crop habitats. We found no evidence of pollinators moving from mass-flowering crop to non-crop habitats after crop bloom. Synthesis and applications: Our results confirm that increasing early-season mass-flowering crop cover dilutes wild pollinators in crop habitats during bloom. We find that dilution effects were absent late in the season. While mass-flowering crop cultivation alone is unlikely to be sufficient for maintaining pollinators, as part of carefully designed diverse crop rotations or mixtures combined with the preservation of permanent non-crop habitats, it might provide valuable supplementary food resources for pollinators in temperate agroecosystems, particularly later in the season when alternative flower resources are scarce.
KW - dilution effects
KW - floral resource
KW - landscape composition
KW - mass-flowering crops
KW - pollinator abundance
KW - pollinator richness
KW - seasonal effects
U2 - 10.1111/1365-2664.14566
DO - 10.1111/1365-2664.14566
M3 - Article
AN - SCOPUS:85180226973
SN - 0021-8901
VL - 61
SP - 452
EP - 464
JO - Journal of Applied Ecology
JF - Journal of Applied Ecology
IS - 3
ER -