Sustainable Management of Orchard Pollination Services

Insect pollinators provide a vital ecosystem service supporting crop pollination and reproduction in wild plants. Reported declines in pollinators threaten this service and could have serious implications for food security. A key crop dependent on insect pollination is apples, and the contribution of wild pollinators to UK apple production is worth an estimated £95M p.a. However, "pollination gaps" of more £6000/ha have been identified in some varieties, where desired yields and quality are not being achieved due to inadequate pollination. This presents a major opportunity for growers for increased production and profit through better pollination. The documented decline of pollinating insects also poses a significant risk to fruit production by negatively impacting on crop production. In response, top fruit growers have articulated the need to effectively manage pollination services by wild insects in a way that is cost effective in order to maintain production and quality in the face of continued environmental change.

Our project will develop high quality science to address this need by designing and testing three pollinator management strategies in field scale trials in commercial apple orchards. These include establishing flower rich strips to provide food and shelter for pollinators, providing nesting habitat for ground nesting bees, and adapting the number and placement of 'polleniser' trees in orchards to increase levels of pollination.

Apple trees are predominantly self-incompatible and require pollen from 'polleniser' trees to set fruit, so although they don't produce saleable fruit, pollenisers are planted in orchards. Currently the number of pollinisers planted is based on a rule of thumb of 1 polleniser for every 12 apples trees. As a first step in this project we will trial different numbers and arrangements of polliniser tree in study orchards and measure how this effects pollination and apple production in order to establish an optimum arrangement and ratio.

Flower strips are known to benefit pollinators. In this project, for the first time, we will design bespoke flower strips specifically aimed at supporting known apple pollinators. We will design our flower strips to contain plants that are particularly good for ground nesting bees and bumblebees which have been identified as top pollinators in apple orchards. Furthermore, we will top our margins (i.e. use a high level cut to remove just the flowers) during apple flowering to push pollinators off the flower strips and onto the apple blossom thus maximising the benefit strips provide. The impact of these targeted flower strips on pollinators and apple production will be measured in field scale trials in commercial orchards.

While the provision of floral resources for pollinators is a well-established approach for increasing pollinator numbers, provision of nesting sites has been widely overlooked and little is known about the effect this can have on pollination service. In this project we will create novel ground nesting bee nest sites in our study orchards and measure the impact these have on bee populations and their contribution to the pollination of apples.

Findings from our field trials will be brought together, and the cost of interventions and the economic return in terms of long-term improvements in quality and production will be established. Our overarching aim is to understand the mechanistic basis of how these three interventions, individually and in combination, effect the value of pollination service contributions to production and profit, so that we can "engineer" the most effective in-orchard interventions. The costs and benefits of these approaches will be assessed to allow specific management recommendations to be made to growers that are practical to implement and provide proven economic returns to growers by supporting long-term stable pollination of apple orchards.

Insect pollination is essential for apple production, improving yield, fruit quality and market value. Pollination deficits in excess of £6,000/ha in UK dessert apple orchards have been identified, so significant economic returns by improving pollination services could be made. Research shows that the majority of apple pollination services are provided by a few species of wild bees. The aim of this project is to design and test three interventions to enhance the effectiveness of wild pollinators of orchards.

Pollinisers are trees grown in orchards providing a viable pollen source for the commercial trees, but do not contribute to production. Currently the numbers and locations of pollinisers in orchards uses a 'rule of thumb'. The optimum number and spatial distribution of polliniser trees in orchards will be tested in field trial manipulations.

Floral strips benefit pollinators and enhancing wild bee nesting habitat can locally enhance bee numbers. We will "engineer" the optimal floral composition of flower strips, based on morphology and flowering time, to develop and test flower margins specifically targeted at apple pollinators. In tandem, ground nesting bee habitat will be created to test effects on pollinators and pollination service. Impact of these interventions, individually and in combination, on pollinators and pollination services will be tested in a large scale field trial.

Bio-economic analysis of these interventions will be undertaken utilising a production function method linking management and habitat quality parameters to pollination services as well a portfolio analyses developing spatially explicit management portfolios for growers. Findings will be disseminated through our industrial partners and then to the wider grower community and more broadly through policy benefitting top-fruit production across the UK by promoting cost effective wild pollinator management strategies increasing production quality and stable yields.

The impact of this research will be far reaching and findings from the project will directly benefit growers and inform policy decision making with resulting benefits for the consumer and the general public.

GROWERS:
The value of insect pollination to UK agriculture is estimated to be £691M p.a. (2011) with the value to apples alone at least £95M. The direct involvement and financial support of Avalon Produce, Worldwide Fruit and Syngenta in this IPA project reflects their interest in the outcomes and they have been involved through the proposal development process. Production loss of more than £6,000/ha due to sub-optimal pollination have been identified in some apple orchards. Addressing this pollination gap, based on finding from this proposal will have real financial implication for the 100's of apple growers in the UK. Furthermore, effective management to improve crop pollination services will increase the resilience of production to environmental change and particularly climate change. Stable fruit yield and quality year to year is a key requirement for apple producers and addressing this issue will have a real positive impact on UK apple growers. Factoring ecosystem services such as crop pollination into farmer portfolio risk analysis presents a real step forward in the way growers think about managing such ecosystem based services. Increasing grower understanding and appreciation of managing wider biodiversity on farmland using techniques developed by this proposal will benefit crop production and wider ecosystem health.

POLICY MAKERS:
Findings from this project will provide evidence to help shape UK policy, particularly in areas of sustainable food production and CAP Countryside Stewardship schemes. Effective pollinator management strategies and an improved understanding of how creating optimised forage and nesting habitat benefit pollinator communities in agricultural landscapes, integrated into countryside policy will improve the effectiveness of Stewardship Schemes. This will increase the positive impacts these schemes can provide by boosting crop pollination services but also supporting wild pollinator communities of conservation concern, both key objectives of Defra's National Pollinator Strategy.

GENERAL PUBLIC:
Pollinators provide essential services underpinning production of high value, nutritious, locally produced products. Evidence from this project will help support sustainable management of pollination services in the UK, ensuring a more stable supply of quality produce which will feedback through the supply chain and benefit consumers. Furthermore, the public has an increasing awareness of the links between pollinators and food production and our outreach and extension work will look to further the public's understanding of the importance of wild pollinators. Our project will enable grower to produce crops in a more sustainable way by supporting wild pollinators while simultaneously reducing their dependence on other agricultural inputs. Our industrial partners directly supply all major UK food retailers including Waitrose, M&S, Tesco, Asda, Co-Op, Aldi, Lidl, Morrisons and Sainsbury's, so a huge number of consumers buying these products can be sure of better sustainability and providence of UK top fruit supply.