By Carol Clark
A growing number of species key to the world’s food supply, including 40 percent of invertebrate pollinators, are headed towards extinction, warns a new United Nations report – the first global assessment of pollinators.
“If pollinator declines continue at this rate it will have serious implications not just for human food security and economics but also for biodiversity and the health of ecosystems in general,” says Berry Brosi, an assistant professor in Emory’s Department of Environmental Sciences and one of the lead authors of the report.
Brosi, a biologist and ecologist whose research focuses on both managed honeybees and wild bees, was among 77 international experts who worked on the pollinator assessment for the U.N.’s Intergovernmental Panel for Biodiversity Ecosystem Services (IPBES). They spent two years evaluating information from more than 3,000 scientific papers, as well as indigenous and local knowledge from more than 60 locations around the world. The summary of the report will be posted online February 29.
Seventy-five percent of the world’s food crops depend on pollination by at least one of the 20,000 species of pollinators, including bees, butterflies, moths, wasps, beetles, birds, bats and other vertebrates. And yet, the report warns, more than 40 percent of invertebrate pollinator species, particularly bees and butterflies, face extinction. And 16 percent of vertebrate pollinators are under threat.
“When we lose even one pollinator species from an ecosystem, it can degrade the functioning of the system overall,” Brosi says. “Studies have shown this relationship between biodiversity of pollinators and both agricultural productivity and plant reproduction in wild ecosystems.”
The report cites diverse pressures on pollinators, many of them human-made, including habitat loss; use of pesticides such as neonicotinoid insecticides; parasites and pathogens; and global warming.
“Pollinators are important to many of the foods that are key sources of the vitamins and minerals in our diets, such as fruits, vegetables, nuts and seeds,” Brosi says. “Nutritionally, the pollinator declines will likely have the biggest impact on the poorest people of the world.”
Many crops also represent an important source of income in developing countries, such as coffee and cocoa.
The report found that the annual total value of global crops directly affected by pollinators is between $235 billion and $577 billion.
“Pollinator decline is a multi-faceted issue with many drivers contributing to it,” Brosi says. “We can’t just fix one thing and have the problem go away.”
The report provides a portfolio of ways to reduce the risk to pollinators, including the promotion of sustainable agriculture, reducing pesticide use and maintaining patches of natural habitat amid agricultural fields.
“I hope this report will raise the visibility of this issue globally and help spur more efforts to reverse the trend of pollinator declines,” Brosi says. “We need a global-scale effort and coordination among different countries and regions.”
The global assessment follows several calls for action at a national level, including the National Strategy to Promote the Health of Honeybees and Other Pollinators launched last year by President Obama.
Some additional findings by the global assessment:
The volume of agricultural production dependent on animal pollination has increased by 300 percent during the past 50 years.
Nearly 90 percent of all wild flowering plants depend at least to some extent on animal pollination.
In addition to food crops, pollinators contribute to crops that provide biofuels (canola and palm oils), fibers (cotton), medicines, forage for livestock and construction materials.
Pollinators, especially bees, have also played a role throughout history as inspirations for art, music, religion and technology. Sacred passages about bees occur in all major world religions.
Related:
Biologist Berry Brosi on Obama's 'plan bee'
Bees 'betray' their flowers when pollinator species decline
No comments:
Post a Comment