Pollination, Food and Environment
Pollinators are not only vital to our food supply, they are a key part of biodiversity that all forms of life depend on. Most plants would become extinct without their pollinators and pollinators would become extinct without plants. It is through pollination that plants are fertilised and able to produce the next generation of plants, including the fruit and vegetables and crops that we eat to survive.
Of all the different animals and insects that serve as pollinators, the most important are wild bees and honeybees. Worldwide, we have over 20,000 species of bees, and almost the same number of butterfly and moth species. In the UK we have around 270 species of bees, just under 250 of which are solitary or 'wild' bees, and we also have 59 species of butterflies and 2,500 species of moths. All these species, and flies, moths, wasps, beetles, birds, bats and other small animals contribute to pollination.
Pollination results in the proliferation of 87% of the world’s flowering plant species plants that provide around 77% of our global food supply.
Around 1.4 billion jobs worldwide depend on pollinating insects such as bees, beetles and butterflies. Three quarters of the world’s crops, worth $500 billion, rely on nature’s pollinators, say the experts.
Declines in pollinating species have alarmed scientists, environmentalists and policymakers, since many crops depend on native wild bees.
A recent PLOS ONE study warns that declines in wild and managed bees threaten pollination services to flowering plants globally, potentially exacting costs for more than 85% of flowering plants, 75% of agricultural crops and human health. The agricultural losses alone are estimated at over $200 billion per year globally, and costs from diminished pollination services in wild ecosystems likely exceed this. Causes of pollinator declines are complex and include diminishing flower resources, habitat loss, climate change, increased disease incidence and exposure to pesticides.
Until the last few decades we relied on wild bees to pollinate our vegetables, fruits, nuts and crops but as the 2016 IPBES Report explains, a growing number of pollinator species worldwide are being driven toward extinction by diverse pressures, many of them human-made, threatening millions of livelihoods and hundreds of billions of dollars worth of food supplies.
The authors of the review ‘Safeguarding pollinators and their values to human well-being’ conclude that “wild and managed pollinators provide a wide range of benefits to society in terms of contributions to food security, farmer and beekeeper livelihoods, social and cultural values, as well as the maintenance of wider biodiversity and ecosystem stability. Pollinators face numerous threats, including changes in land-use and management intensity, climate change, pesticides and genetically modified crops, pollinator management and pathogens, and invasive alien species. There are well-documented declines in some wild and managed pollinators in several regions of the world. However, many effective policy and management responses can be implemented to safeguard pollinators and sustain pollination services”.
The lead author of the review, professor Simon Potts explains that bees face two major threats as a result of climate change: habitats moving, and the changing seasonal behaviour of different species of bees. Under climate change, habitats that bees and pollinators use will shift but the bees may or may not be able to move, and there may be no connection between the habitat bees have now and the new habitats they may have. As a result of climate change, bees are “emerging earlier and earlier” in the year and in the UK flowers are blossoming earlier by 4 or 5 days each decade whereas the bees are becoming earlier by 7-10 days per decade. The worry is that if bees become active before flowering plants are available there is an increased risk of local extinctions.