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How rising CO2 levels may contribute to die-off of bees 

Lisa Palmer, YALE ENVIRONMENT 360
Specimens of goldenrod sewn into archival paper folders are stacked floor to ceiling inside metal cabinets at the Smithsonian National Museum of Natural History. The collection, housed in the herbarium, dates back to 1842 and is among five million historical records of plants from around the world cataloged there. Researchers turned to this collection of goldenrod — a widely distributed perennial plant that blooms across North America from summer to late fall — to study concentrations of protein in goldenrod pollen because it is a key late-season food source for bees.
The newer samples look much like the older generations. But scientists testing the pollen content from goldenrod collected between 1842 and 2014, when atmospheric concentrations of carbon dioxide rose from about 280 parts per million to 398 ppm, found the most recent pollen samples contained 30 percent less protein. The greatest drop in protein occurred from 1960 to 2014, when the amount of carbon dioxide in the atmosphere rose dramatically. A field experiment in the same study that exposed goldenrod to CO2 levels ranging from 280 to 500 ppm showed similar protein decreases.
More than 100 previous studies have shown that elevated levels of atmospheric carbon dioxide decrease the nutritional value of plants, such as wheat and rice. But the goldenrod study, published last month, was the first to examine the effects of rising CO2 on the diet of bees, and its conclusions were unsettling: The adverse impact of rising CO2 concentrations on the protein levels in pollen may be playing a role in the global die-off of bee populations by undermining bee nutrition and reproductive success.
“Pollen is becoming junk food for bees,” says Lewis Ziska, a plant physiologist at the U.S. Department of Agriculture’s (USDA) Research Service in Maryland and lead author of the study. The study itself concluded that the decline of plant proteins in the face of soaring carbon dioxide concentrations provides an “urgent and compelling case” for CO2 sensitivity in pollen and other plant components.
Elevated CO2 levels affect plant physiology by enabling the plant’s starchier parts to grow faster and bigger, since atmospheric carbon dioxide is a building block for plant sugars. For goldenrod, this growth essentially dilutes the plant’s total protein, From 2006 to 2011, losses from managed honeybee colonies averaged 33 percent per year in the U.S. rather than concentrating it in the grain, which makes a starchier pollen.
“I knew there was work done on insects about how rising CO2 would reduce the protein content of leaves, and so insects will need to eat more leaves to get the same amount of protein,” says Ziska. “But until now, we didn’t know about how CO2 affects protein content in pollen.” The study is a synthesis of the knowledge about what is happening to bees and how CO2 impacts the quality of plants, and it brings those two disparate ideas together.
A number of new and accumulating pressures are threatening bee populations. From 2006 to 2011, annual losses from managed honeybee colonies averaged 33 percent per year in the United States, according to the USDA. Beekeepers have had to replace 50 percent of their colonies in recent years. Factors such as mite outbreaks and the use of neonicotinoid pesticides have been implicated in so-called “colony collapse disorder.”
Read more at: How Rising CO2 Levels May Contribute to Die-Off of Bees by Lisa Palmer: Yale Environment 360

Posted on Categories Agriculture/Food SystemTags , , , ,

How to keep honeybees

Rene Ebersole, MODERN FARMER

For information on bee-friendly gardening, visit thehoneybeeconservancy.org.

You can hardly say “honeybee” anymore without hearing the reverb “colony collapse disorder.” Back in 2006, American beekeepers began reporting staggering losses, ranging from 30 to 90 percent of their hives. Since then, the alarming phenomenon—in which adult bees disappear, leaving the brood behind to die—has afflicted Europe as well. And honey’s far from the only reason to care. In America alone, the pollinators enable the production of roughly 90 commercial crops, according to the United States Department of Agriculture. Without honeybees, some of the foods we eat, like almonds, could become extinct; the cost of others, such as cherries and avocados, would likely skyrocket. A decade after the disorder first surfaced, scientists have yet to identify a definitive culprit.
Meanwhile, U.S. citizens have taken up the cause, establishing hives in backyards, atop roofs, at restaurants, even on the White House lawn. Bee Culture magazine, already a publication with a narrow focus, recently launched a spin-off targeted even more specifically at beginners. Williams-Sonoma, ostensibly a kitchenware retailer, started selling beekeeping equipment in 2012. Even Costco carries hives these days.
Longtime beekeeper Rob Keller of Napa, California, should not be counted among the recent converts. He does, however, have the current apiary craze to thank for his success. Since launching the Napa Valley Bee Company in 2008, the 52-year-old has helped more than 100 clients—individuals and businesses, including Alice Waters’ legendary Chez Panisse—start and maintain honeybee colonies. “I can’t just sell my bees and walk away. I know that queen’s mother and her mother’s mother. I’d rather guide someone through all four seasons,” Keller explains. “It’s weird, man. It’s like I’m turning into, not a crazy cat lady, but a crazy bee guy. I have the utmost respect for this six-legged insect.”
Read more at: How to Keep Honeybees – Modern Farmer