Native Bee Habitats Key to Farming, Conservation, Nutrition
Honeybees are getting too much credit, it seems. Wild bee species pollinate more than a third of California's crops ? to the tune of $889 million to $2.2 billion* per year, according to a study published in the June 2011 issue of Rangelands. And many of those crop-pollinating wild bees live in rangelands—chiefly ranches that graze cattle.
"This means that preserving rangelands has significant economic value, not only to the ranchers who graze their cattle there, but also to farmers who need the pollinators," said Claire Kremen Berkeley associate professor of environmental science, policy, and management (ESPM), and senior author of the study.
Kremen said that if California is to sustain its agricultural output of pollinator-dependent crops, worth an estimated $11.7 billion per year to the state's economy, diversifying sources of pollination is critical—like diversifying a stock portfolio. "This will become even more important with climate change, as some species will thrive in changed conditions and others won't," she said.
And while it's common sense that healthy crops result in a healthy food supply, a separate study led by Kremen, published the same month in the international online journal PLoS ONE, put a number on the human health benefits of animal pollination. The researchers estimated that up to 40 percent of some essential vitamins, minerals, and dietary lipids provided by fruits and vegetables could be lost if there were no pollinators around to do the job.
The study notes that cancer-fighting vitamins in bright red, yellow, and orange fruits and vegetables come from animal pollinator-dependent crops, as do other important antioxidants. "The yield increase attributable to animal-dependent pollination of these crops is significant and could have a potentially drastic effect on human nutrition if jeopardized," Kremen said.
Kremen says one solution to preserving wild bee habitats is for farmers to pay ranchers to maintain rangelands, just as they pay beekeepers to bring honeybee colonies to their farms. On a larger scale, a sea change that includes decreased use of pesticides and monoculture agriculture, together with thoughtful, integrated land use policies would help increase native bee populations and diversify pollination sources. (See "How to Feed the World: Start Small")
*These numbers reflect a minor adjustment from those published in the original study. An erratum will be published in an upcoming issue of Rangelands.
CROWD-SOURCING BEE DATA: ESPM professor Gordon Frankie led the first annual Sonoma Bee Count in July 2011, launching an endeavor that is expected to continue for at least 10 years. The Sonoma Ecology Center invited Frankie?s group to spearhead the citizen-initiated, citizenconducted count, one of the first quantitative bee counts by citizens in the United States.