Loss of bees causes shortage of key food crops,
study finds
Apple and cherry production hampered by lack of wild
bees
Bees affected by loss of habitat, pesticides and
climate crisis
Oliver
Milman
@olliemilman
Wed 29 Jul
2020 05.01 BSTLast modified on Wed 29 Jul 2020 08.25 BST
A lack of
bees in agricultural areas is limiting the supply of some food crops, a new
US-based study has found, suggesting that declines in the pollinators may have
serious ramifications for global food security.
Species of
wild bees, such as bumblebees, are suffering from a loss of flowering habitat,
the use of toxic pesticides and, increasingly, the climate crisis. Managed honeybees,
meanwhile, are tended to by beekeepers, but have still been assailed by
disease, leading to concerns that the three-quarters of the world’s food crops
dependent upon pollinators could falter due to a lack of bees.
The new
research appears to confirm some of these fears.
Of seven
studied crops grown in 13 states across America, five showed evidence that a
lack of bees is hampering the amount of food that can be grown, including
apples, blueberries and cherries. A total of 131 crop fields were surveyed for
bee activity and crop abundance by a coalition of scientists from the US,
Canada and Sweden.
“The crops
that got more bees got significantly more crop production,” said Rachael
Winfree, an ecologist and pollination expert at Rutgers University who was a
senior author of the paper, published by the Royal Society. “I was surprised, I
didn’t expect they would be limited to this extent.”
The
researchers found that wild native bees contributed a surprisingly large
portion of the pollination despite operating in intensively farmed areas
largely denuded of the vegetation that supports them. Wild bees are often more
effective pollinators than honeybees but research has shown several species are
in sharp decline. The rusty patched bumblebee, for example, was the first bee
to be placed on the US endangered species list in 2017 after suffering an 87%
slump in the previous two decades.
Swaths of
American agriculture is propped up by honeybees, frantically replicated and
shifted around the country in hives in order to meet a growing need for crop
pollination.
Almonds,
one of the two crops not shown to be suffering from a lack of bees in the
study, are mostly grown in California, where most of the beehives in the US are
trucked to each year for a massive almond pollination event.
The US is
at the forefront of divergent trends that are being replicated elsewhere in the
world – as farming becomes more intensive to churn out greater volumes to feed
a growing global population, tactics such as flattening wildflower meadows,
spraying large amounts of insecticide and planting monocultural fields of
single crops are damaging the bee populations crucial for crop pollination.
Honeybee
colonies are weaker than they used to be and wild bees are declining, probably
by a lot
Rachael Winfree
According
to the UN’s Food and Agriculture Organization, the amount of crop production
dependent upon insect and other pollinators has increased 300% over the past 50
years. Pollination shortfalls could cause certain fruit and vegetables to
become rarer and more expensive, triggering nutritional deficits in diets.
Staple foods such as rice, wheat and corn won’t be affected, however, as they
are pollinated via the wind.
“Honeybee
colonies are weaker than they used to be and wild bees are declining, probably
by a lot,” said Winfree. “The agriculture is getting more intensive and there
are fewer bees, so at some point the pollination will become limited. Even if
honeybees were healthy, it’s risky to rely so much on a single bee species.
It’s predictable that parasites will target the one species we have in these
monocultural crop fields.”
The paper
recommends that farmers gain a better understanding of the optimal amount of
pollination needed to boost crop yields, as well as review whether the level of
pesticide and fertilizer put on to fields is appropriate.
“The trends
we are seeing now are setting us up for food security problems,” Winfree said.
“We aren’t yet in a complete crisis now but the trends aren’t going in the
right direction. Our study shows this isn’t a problem for 10 or 20 years from
now – it’s happening right now.”
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