title: Contribution of insect pollinators to crop yield and quality varies with agricultural intensification.
abstract: Background. Up to 75% of crop species benefit at least to some degree from animal pollination for fruit or seed set and yield. However, basic information on the level of pollinator dependence and pollinator contribution to yield is lacking for many crops. Even less is known about how insect pollination affects crop quality. Given that habitat loss and agricultural intensification are known to decrease pollinator richness and abundance, there is a need to assess the consequences for different components of crop production. Methods. We used pollination exclusion on flowers or inflorescences on a whole plant basis to assess the contribution of insect pollination to crop yield and quality in four flowering crops (spring oilseed rape, field bean, strawberry, and buckwheat) located in four regions of Europe. For each crop, we recorded abundance and species richness of flower visiting insects in ten fields located along a gradient from simple to heterogeneous landscapes. Results. Insect pollination enhanced average crop yield between 18 and 71% depending on the crop. Yield quality was also enhanced in most crops. For instance, oilseed rape had higher oil and lower chlorophyll contents when adequately pollinated, the proportion of empty seeds decreased in buckwheat, and strawberries' commercial grade improved; however, we did not find higher nitrogen content in open pollinated field beans. Complex landscapes had a higher overall species richness of wild pollinators across crops, but visitation rates were only higher in complex landscapes for some crops. On the contrary, the overall yield was consistently enhanced by higher visitation rates, but not by higher pollinator richness. Discussion. For the four crops in this study, there is clear benefit delivered by pollinators on yield quantity and/or quality, but it is not maximized under current agricultural intensification. Honeybees, the most abundant pollinator, might partially compensate the loss of wild pollinators in some areas, but our results suggest the need of landscape-scale actions to enhance wild pollinator populations.
authors.affiliation: Department of Ecology, Swedish University of Agricultural Sciences , Uppsala , Sweden.
authors.forename: Ignasi
authors.initials: I
authors.lastname: Bartomeus
authors.affiliation: School of Agriculture, Policy and Development, University of Reading , Reading , UK.
authors.forename: Simon G
authors.initials: SG
authors.lastname: Potts
authors.affiliation: Department of Animal Ecology and Tropical Biology, Biocentre, University of Würzburg , Würzburg , Germany.
authors.forename: Ingolf
authors.initials: I
authors.lastname: Steffan-Dewenter
authors.affiliation: INRA, UR406 Abeilles & Environnement , Avignon , France.
authors.forename: Bernard E
authors.initials: BE
authors.lastname: Vaissière
authors.affiliation: Institute of Environmental Sciences, Jagiellonian University , Gronostajowa, Krakow , Poland.
authors.forename: Michal
authors.initials: M
authors.lastname: Woyciechowski
authors.affiliation: Department of Crop Science, Agroecology, Georg-August-University , Göttingen , Germany.
authors.forename: Kristin M
authors.initials: KM
authors.lastname: Krewenka
authors.affiliation: School of Agriculture, Policy and Development, University of Reading , Reading , UK ; Department of Geography, University of the Aegean , Mytilene , Greece.
authors.forename: Thomas
authors.initials: T
authors.lastname: Tscheulin
authors.affiliation: School of Agriculture, Policy and Development, University of Reading , Reading , UK.
authors.forename: Stuart P M
authors.initials: SP
authors.lastname: Roberts
authors.affiliation: Institute of Environmental Sciences, Jagiellonian University , Gronostajowa, Krakow , Poland.
authors.forename: Hajnalka
authors.initials: H
authors.lastname: Szentgyörgyi
authors.affiliation: Department of Crop Science, Agroecology, Georg-August-University , Göttingen , Germany.
authors.forename: Catrin
authors.initials: C
authors.lastname: Westphal
authors.affiliation: Department of Ecology, Swedish University of Agricultural Sciences , Uppsala , Sweden.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Bommarco
keywords: Agroecosystems; Biodiversity; Ecosystem services; Honeybees; Pollination; Wild bees
references.citation: Glob Chang Biol. 2013 Oct;19(10):3103-10
references.pmid: 23704044
references.citation: Ecol Lett. 2013 May;16(5):584-99
references.pmid: 23489285
references.citation: J Econ Entomol. 2010 Aug;103(4):1286-92
references.pmid: 20857738
references.citation: Science. 2013 Mar 29;339(6127):1608-11
references.pmid: 23449997
references.citation: Proc Natl Acad Sci U S A. 2013 May 21;110(21):8387-92
references.pmid: 23671073
references.citation: Trends Ecol Evol. 2013 Apr;28(4):230-8
references.pmid: 23153724
references.citation: Proc Biol Sci. 2008 Oct 7;275(1648):2283-91
references.pmid: 18595841
references.citation: Proc Biol Sci. 2008 Apr 22;275(1637):907-13
references.pmid: 18230596
references.citation: Proc Natl Acad Sci U S A. 2013 Apr 2;110(14):5534-9
references.pmid: 23513216
references.citation: Proc Natl Acad Sci U S A. 2013 Mar 19;110(12):4656-60
references.pmid: 23487768
references.citation: Oecologia. 2007 Sep;153(3):589-96
references.pmid: 17483965
references.citation: New Phytol. 2011 Sep;191(4):1128-1140
references.pmid: 21585389
references.citation: Ecol Lett. 2007 Nov;10(11):1105-13
references.pmid: 17877737
references.citation: Ecol Lett. 2013 Jul;16(7):903-11
references.pmid: 23692675
references.citation: Ecol Lett. 2013 Nov;16(11):1331-8
references.pmid: 23968538
references.citation: F1000Res. 2013 Jul 02;2:146
references.pmid: 24555067
references.citation: Ecol Lett. 2011 Oct;14(10):1062-72
references.pmid: 21806746
references.citation: Proc Biol Sci. 2007 Feb 7;274(1608):303-13
references.pmid: 17164193
references.citation: Ecol Lett. 2008 May;11(5):499-515
references.pmid: 18294214
references.citation: Genet Mol Res. 2009 May 12;8(2):539-45
references.pmid: 19551642
references.citation: Proc Biol Sci. 2013 Dec 04;281(1775):20132440
references.pmid: 24307669
references.citation: Proc Biol Sci. 2012 Dec 26;280(1753):20122243
references.pmid: 23269852
references.citation: Ecol Appl. 2007 Sep;17(6):1841-9
references.pmid: 17913145
references.citation: Trends Ecol Evol. 2010 Jun;25(6):345-53
references.pmid: 20188434
references.citation: Ecol Lett. 2013 Jul;16(7):870-8
references.pmid: 23692632
references.citation: Oecologia. 2012 Aug;169(4):1025-32
references.pmid: 22311256
references.citation: Agric Ecosyst Environ. 2014 Feb 1;184(100):34-40
references.pmid: 24748698
references.citation: Glob Chang Biol. 2013 Feb;19(2):540-7
references.pmid: 23504791
references.citation: PLoS One. 2012;7(2):e31599
references.pmid: 22355380
references.citation: Proc Biol Sci. 2012 Jan 22;279(1727):309-15
references.pmid: 21676979