IPI Crops: Research: Recent Publications

Recent Publications

C. Polce, M.P.D. Garratt, M. Termansen, J. Ramireez-Villegas, A.J. Challinor, M.G. Lappage, N.D. Boatman, A. Crowe, A.M. Endalew, S.G. Potts, K.E. Somerwill and J.C. Biesmeijer (2014) Climate-driven spatial mismatches between British orchards and their pollinators: increased risks of pollination deficits. Global Change Biology, doi: 10.1111/gcb.12577

Abstract: Understanding how climate change can affect crop-pollinator systems helps predict potential geographical mismatches between a crop and its pollinators, and therefore identify areas vulnerable to loss of pollination services. We examined the distribution of orchard species (apples, pears, plums and other top fruits) and their pollinators in Great Britain, for present and future climatic conditions projected for 2050 under the SRES A1B Emissions Scenario. We used a relative index of pollinator availability as a proxy for pollination service. At present, there is a large spatial overlap between orchards and their pollinators, but predictions for 2050 revealed that the most suitable areas for orchards corresponded to low pollinator availability. However, we found that pollinator availability may persist in areas currently used for fruit production, which are predicted to provide suboptimal environmental suitability for orchard species in the future. Our results may be used to identify mitigation options to safeguard orchard production against the risk of pollination failure in Great Britain over the next 50 years; for instance, choosing fruit tree varieties that are adapted to future climatic conditions, or boosting wild pollinators through improving landscape resources. Our approach can be readily applied to other regions and crop systems, and expanded to include different climatic scenarios.
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Potts, S., Garratt, M., Senapathi, D. and Breeze, T. (November 2014) Policy and Practice Notes 13: The benefits of managing pollinators for crop production: As demands on food production increase how can land managers, growers and policy makers help to conserve and manage insect pollinators? Swindon: Living With Environmental Change

Abstract: Insect pollinators are essential for food production, improving the yield and quality of three quarters of UK crops. Multiple pressures threaten pollinator populations and the pollination services they provide, including changing land use, disease, climate change and agrochemicals. This has resulted in declining abundance and species richness in both managed and wild pollinator populations andthreatens the stability of crop pollination services. It is therefore essential to conserve and manage insect pollinators as demands on food production increase.

M.P.D. Garratt, T.D. Breeze, N. Jenner, C. Polce, J.C. Biesmeijer, S.G. Potts (2014) Avoiding a bad apple: Insect pollination enhances fruit quality and economic value. Agriculture, Ecosystems & Environment 184: 34-40

Abstract: Insect pollination is important for food production globally and apples are one of the major fruit crops which are reliant on this ecosystem service. It is fundamentally important that the full range of benefits of insect pollination to crop production are understood, if the costs of interventions aiming to enhance pollination are to be compared against the costs of the interventions themselves. Most previous studies have simply assessed the benefits of pollination to crop yield and ignored quality benefits and how these translate through to economic values. In the present study we examine the influence of insect pollination services on farmgate output of two important UK apple varieties; Gala and Cox. Using field experiments, we quantify the influence of insect pollination on yield and importantly quality and whether either may be limited by sub-optimal insect pollination. Using an expanded bioeconomic model we value insect pollination to UK apple production and establish the potential for improvement through pollination service management. We show that insects are essential in the production of both varieties of apple in the UK and contribute a total of £36.7 million per annum, over £6 million more than the value calculated using more conventional dependence ratio methods. Insect pollination not only affects the quantity of production but can also have marked impacts on the quality of apples, influencing size, shape and effecting their classification for market. These effects are variety specific however. Due to the influence of pollination on both yield and quality in Gala, there is potential for insect pollination services to improve UK output by up to £5.7 million per annum. Our research shows that continued pollinator decline could have serious financial implications for the apple industry but there is considerable scope through management of wild pollinators or using managed pollinator augmentation, to improve the quality of production. Furthermore, we show that it is critically important to consider all production parameters including quality, varietal differences and management costs when valuing the pollination service of any crop so investment in pollinator management can be proportional to its contribution.
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T.D. Breeze, B.E. Vaissière, R. Bommarco, T. Petanidou, N. Seraphides, L. Kozák, J. Scheper, J.C. Biesmeijer, D. Kleijn, S. Gyldenkærne, M. Moretti, A. Holzschuh, I. Steffan-Dewenter, J.C. Stout, M. Pärtel, M. Zobel and S.G. Potts (2014) Agricultural Policies Exacerbate Honeybee Pollination Service Supply-Demand Mismatches Across Europe. PLoS ONE 9(1): e82996.

Abstract: Declines in insect pollinators across Europe have raised concerns about the supply of pollination services to agriculture. Simultaneously, EU agricultural and biofuel policies have encouraged substantial growth in the cultivated area of insect pollinated crops across the continent. Using data from 41 European countries, this study demonstrates that the recommended number of honeybees required to provide crop pollination across Europe has risen 4.9 times as fast as honeybee stocks between 2005 and 2010. Consequently, honeybee stocks were insufficient to supply >90% of demands in 22 countries studied. These findings raise concerns about the capacity of many countries to cope with major losses of wild pollinators and highlight numerous critical gaps in current understanding of pollination service supplies and demands, pointing to a pressing need for further research into this issue.
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Garratt M.P.D., Coston D.J., Truslove C.L., Lappage M.G., Polce C., Dean R., Biesmeijer J.C. and Potts S.G. (2014) The identity of crop pollinators helps target conservation for improved ecosystem services. Biological Conservation 169: 128-125

Abstract: Insect pollinated mass flowering crops are becoming more widespread and there is a need to understand which insects are primarily responsible for the pollination of these crops so conservation measures can be appropriately targeted in the face of pollinator declines. This study used field surveys in conjunction with cage manipulations to identify the relative contributions of different pollinator taxa to the pollination of two widespread flowering crops, field beans and oilseed rape. Flower visiting pollinator communities observed in the field were distinct for each crop; while field beans were visited primarily by a few bumblebee species, multiple pollinator taxa visited oilseed, and the composition of this pollinator community was highly variable spatially and temporally. Neither pollinator community, however, appears to be meeting the demands of crops in our study regions. Cage manipulations showed that multiple taxa can effectively pollinate both oilseed and field beans, but bumblebees are particularly effective bean pollinators. Combining field observations and cage manipulations demonstrated that the pollination demands of these two mass flowering crops are highly contrasting, one would benefit from management to increase the abundance of some key taxa, whilst for the other, boosting overall pollinator abundance and diversity would be more appropriate. Our findings highlight the need for crop specific mitigation strategies that are targeted at conserving specific pollinator taxa (or group of taxa) that are both active and capable of crop pollination in order to reduce pollination deficits and meet the demands of future crop production.
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Polce C., Termansen M., Aguirre-Gutierrez J., Boatman N.D., Budge G.E., Crowe A., Garratt M.P., Pietravalle S., Potts S.G., Ramirez J.A., Somerwill K.E. and Biesmeijer J.C. (2013) Species distribution models for crop pollination: A modelling framework applied to Great Britain. PLoS ONE 8 (10): e76308

Abstract: Insect pollination benefits over three quarters of the world's major crops. There is growing concern that observed declines in pollinators may impact on production and revenues from animal pollinated crops. Knowing the distribution of pollinators is therefore crucial for estimating their availability to pollinate crops; however, in general, we have an incomplete knowledge of where these pollinators occur. We propose a method to predict geographical patterns of pollination service to crops, novel in two elements: the use of pollinator records rather than expert knowledge to predict pollinator occurrence, and the inclusion of the managed pollinator supply. We integrated a maximum entropy species distribution model (SDM) with an existing pollination service model (PSM) to derive the availability of pollinators for crop pollination. We used nation-wide records of wild and managed pollinators (honey bees) as well as agricultural data from Great Britain. We first calibrated the SDM on a representative sample of bee and hoverfly crop pollinator species, evaluating the effects of different settings on model performance and on its capacity to identify the most important predictors. The importance of the different predictors was better resolved by SDM derived from simpler functions, with consistent results for bees and hoverflies. We then used the species distributions from the calibrated model to predict pollination service of wild and managed pollinators, using field beans as a test case. The PSM allowed us to spatially characterize the contribution of wild and managed pollinators and also identify areas potentially vulnerable to low pollination service provision, which can help direct local scale interventions. This approach can be extended to investigate geographical mismatches between crop pollination demand and the availability of pollinators, resulting from environmental change or policy scenarios.
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Garratt M.P.D., Truslove C.L., Coston D.J., Evans R.L., Moss E.D., Dodson C., Jenner N., Biesmeijer J.C. and Potts S.G. (2013) Pollination deficits in UK apple orchards. Journal of Pollination Ecology 11

Abstract: Apple production in the UK is worth over £100 million per annum and this production is heavily dependent on insect pollination. Despite its importance, it is not clear which insect pollinators carry out the majority of this pollination. Furthermore, it is unknown whether current UK apple production, in terms of both yield and quality, suffers pollination deficits and whether production value could be increased through effective management of pollination services. The present study set out to address some of these unknowns and showed that solitary bee activity is high in orchards and that they could be making a valuable contribution to pollination. Furthermore, fruit set and apple seed number were found to be suffering potential pollination deficits although these were not reflected in apple quality. Deficits could be addressed through orchard management practices to improve the abundance and diversity of wild pollinators. Such practices include provision of additional floral resources and nesting habitats as well as preservation of semi-natural areas. The cost effectiveness of such strategies would need to be understood taking into account the potential gains to the apple industry.
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Garratt M. (2013) Sustainable Pollination Services for UK Crops. Antenna 37 (1): 39-41

Abstract: As well as being essential to the functioning of wild ecosystems, insect pollinators contribute to the pollination of our crops, increasing fruit & seed production, improving quality, speeding up ripening and improving taste. However, we do not know the true contribution made by insects to the yield and quality of many crops. The Sustainable Pollination Services for UK Crops project aims to address these unknowns, and this paper shows initial results from a series of experiments conducted during 2011.