Food production and biodiversity are at risk if pollinators are unable to recognise odours due to air pollution
Air pollution is preventing pollinators finding flowers, according to a research team comprising the UK Centre for Ecology & Hydrology (UKCEH) and the Universities of Birmingham, Reading, Surrey and Southern Queensland, Australia.
The researchers found that ozone substantially changes the size and scent of floral ‘odour plumes’ given off by flowers, and that it reduced honeybees' ability to recognise odours by up to 90% from just a few metres away.
Ground-level ozone typically forms when nitrogen oxide emissions from vehicles and industrial processes react with organic compounds emitted from vegetation in the presence of sunlight and ‘degrades’ the scent given off by flowers.
Dr Ben Langford, Atmospheric Scientist at UKCEH, who led the study, said: "Some 75% of our food crops depend, to some extent, upon animal pollination, particularly by insects. Therefore, understanding what adversely affects pollination, and how, is essential to helping us preserve the critical services that we rely upon for production of food, textiles, biofuels and medicines."
Professor Christian Pfrang from the University of Birmingham, who collaborated on the research, said the study “provides robust evidence” that pollinators are struggling to carry out their crucial role.
He said: “This should act as a wake-up call to take action on air pollution and help safeguard food production and biodiversity for the future."
Dr Elizabeth Boakes, Centre for Biodiversity and Environment Research, University College London said that food security is already a “grave concern” due to the combined pressures of climate change and biodiversity loss.
A House of Lords briefing paper last year (Impact of climate change and biodiversity loss on food security) concluded that ‘climate change and biodiversity loss were among the biggest medium to long term risks to UK domestic food production’. In addition, the Intergovernmental Panel on Climate Change has identified climate change and biodiversity loss as ‘major contributing factors’ to food insecurity around the world.
“Tropical crops are particularly reliant on pollinators, so it is essential that the UK acts to safeguard its environment and support environmental regulations overseas…”
Dr Boakes said: “Biodiversity underpins the global agricultural system with more than 50% of internationally traded crops relying on pollination. Loss of pollinators world-wide means that crop yields are already down by a global average of 5% and as much as 30% in some countries.
“It is therefore extremely alarming that air pollution has been found to further impede pollinators from carrying out their vital role in food production.”
She said the study’s findings “demonstrate the urgency” of schemes to reduce air pollution, for example, low-emission zones.
She added: “Tropical crops are particularly reliant on pollinators, so it is essential that the UK acts not only to safeguard its own environment but also to support environmental regulations overseas, for example via sustainability chapters in trade agreements.”
Barnaby Coupe, Land Use Policy Manager at The Wildlife Trusts said: “We have lost more than 50% of our insects since 1970, largely caused by toxic pesticides and loss of habitat. Now, this evidence suggests ground-level ozone pollution is putting our vital insects in even greater jeopardy.
“We need insects and if we don’t act now, and act decisively, then we risk undermining the natural systems which underpin our ability to feed ourselves.
“The good news is it is not too late – insect populations can recover quickly given the right conditions, but we urgently need to reduce the factors currently threatening our insects."
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