Dr Simon Potts, Principle Research Fellow at the Centre for Agri-Environmental Research, University of Reading, explains why it is vitally important for human health to ensure biodiversity is at the top of our agenda.
With the world population growing rapidly, the demand for food production will double in the next 40 years. This raises serious concerns about food security - how will we produce enough food to feed ourselves in the future?
Major technical advances have been made in farming through the use of new crop varieties and more effective management of water and fertilisers. But there is a limit to how far these technologies can go to increase crop productivity on their own. An additional vital ingredient underpinning our ability to grow food is biodiversity, and only by managing this properly will we be able to secure and improve our food production in years to come.
Biodiversity covers the wide variety of plants and animals we find in nature, and within this is a hard working army of insects which make sure our crops grow well and remain healthy. For instance, eight out of ten European crops depend on pollination by insects. Most of these pollinators are bees, including managed honeybees and a wide range of wild bees such bumblebees, as well as hoverflies. Without bees transferring pollen most of our crops could not produce seeds and fruits.
Our diets are full of foods which depend on bee pollination. Consider a typical breakfast: orange juice, fresh fruits, jam, marmalade, fruits in our yoghurts - these all rely on pollinators. As does coffee which is pollinated by bees in the tropics. Chocolate, which comes from cocoa, relies on a tiny midge to pollinate it. Most of our herbs and spices are also pollinator dependent and these bring flavours and variety to our meals. Even meat and dairy products partially depend on the work of pollinators, as part of the diet of many cattle relies on insect pollinated plants such as clover. Imagine then that we lose this critically important component of biodiversity. Our diets would become greatly restricted; many fruits and vegetables would be off the menu.
We would lose the diversity of foods and have less choice as consumers. This would be particularly worrying for our health as most of our 'five a day' depend on pollinators. Our food would also become bland without the spectrum of interesting flavours from herbs and spices. Chocolate Easter eggs would become a thing of the past.
Our bees and other pollinators are not about to totally disappear but they are under great threat. For instance, the UK has an amazing variety of bees with more than 250 species found. However, recent research has shown that since 1980 the diversity of bees has severely declined in more than half of our landscapes. Our one species of managed bee, the honeybee, has also declined by 54% in England since 1985. The reasons are complex, but it is almost certainly a lethal cocktail of threats including the destruction of bee habitats, intensification of farming, pests, diseases, and misuse of pesticides.
Apart from the loss of food choice there are more direct economic consequences to losing our bees. For instance, it is estimate that insects contribute more than £12 billion pounds to crop production in Europe, and more than £400 million in the UK alone. So farmer livelihoods are closely linked to bees. Further, the increasing demand for biofuels means that many oilseeds, from which we can extract fuel, could not be grown. With potential fuel poverty, as well as food poverty, on the horizon the value of bees cannot be underestimated.
So what can be done to secure the safeguard this vital service of pollination?
One strategy would be to try and replace it. So instead of bees transferring pollen we could use people to hand pollinate crops.
This is already practised in parts of China and Nepal for apples and in Madagascar for vanilla. However, to cover the cost of labour and equipment to pollinate all our crops in the UK would cost a whopping £1.5 billion a year. This is so expensive that it dwarfs the current value of the crops and would make the price of these food products so high as to be unaffordable to all but a very few.
An alternative would be to ask the British consumer to change their diets and simply forget about eating a wide variety of interesting foods and instead rely much more on non insect pollinated staples, such as bread, cereals and root vegetables. A change which would never be acceptable.
So why not just import all of our fruits and vegetables from overseas? This might be a short-term solution, as we already import a significant proportion of these products already. However, in the long-term, the countries which produce these products will have increasing local demand for food production, and the escalating cost of transport will inevitably mean the price of imported foods will increase markedly. The option of importing is not sustainable in the long-term and the UK should be able to rely on growing it's on food and thereby keeping it secure.
Thankfully there is another strategy to ensure our own food security. We can protect and conserve our bees and keep them working to pollinate our crops. British honeybees are being supported by the government's 'Healthy bee plan' though the number of colonies continues to fall. However, relying on a single bee species to do the job is somewhat risky as if a catastrophic disease hits we lose them all.
The answer lies in our diverse wild bee communities. If a disease knocks out one species then we still have many others that can replace them and keep pollinating. This acts as an insurance against unknown future threats too. We shouldn't risk putting all our 'bees' in one basket. Indeed our wild bees are of particular importance as they can pollinate some crops which honeybees cannot, such as field beans. Indeed recent research suggests that there are not enough honeybees to pollinate the existing area of crops in the UK, and so the vast majority of work is done by wild bee species.
We know that wild bees, honeybees, butterflies and many other species such as birds greatly benefit from flower rich habitats. Farmers can easily add these habitats to the landscape in the form of flowery field margins and many farmers already do this. The Environmental Stewardship scheme run by the government pays farmers for providing environmental services such as these. What is needed is a much greater uptake of these bee friendly habitats and experts estimate that if 1-2.5% of farmland was covered in this then our bees would be much better protected. This is not say that this alone is the whole solution, we still need to look after our nature reserves and other places where bees thrive, such as gardens, and we need to work to reduce the impact of diseases and pesticides. But overall with flower margins we do have solution which is known to help bees and this process of working with famers can potentially deliver large areas of flower margins across the landscape.
Insect pollination is a vital ingredient in food, providing choice, healthy diets and security. Protecting our British bees is the only logical way forward as we cannot afford to lose their services. By protecting key components of biodiversity we ensure that we can meet some of the most basic needs of society.
Source: Reading University; Photos: freefoto.com; US Forest Department