May 8, 2009

Domesticated Bee Numbers Rising Fast

Despite shrinking numbers of wild honey bees in the U.S. and Europe, several species of domesticated bees are on the rise, said a study released on Thursday.

"The honey bee decline observed in the USA and in other European countries including Great Britain, which has been attributed in part to parasitic mites and more recently to colony collapse disorder, could be misguiding us to think that this is a global phenomenon," according to Marcelo Aizen of Universidad Nacional del Comahue in Argentina.  At least in his country, however, this is not the case.

Aizen is co-author of a study published in the June edition of Current Biology that used data on the number of domesticated honeybee hives reported by the Food and Agriculture Organization to study whether the world is heading towards a pollination crisis.

The study found that although the number of domesticated bee hives used commercially for supplying honey have increased by 45 percent in the last 50 years, they are not necessarily being used for pollination purposes.

Though most large agricultural operations for grains like corn, wheat and rice don't require pollination, popular "luxury" crops like cherries, plums and a variety of berries and nuts do depend on bees and other insects to fertilize their blossoms.  As demand for these goods has more than tripled in the last half century and continues to rise, researchers have doubts as to whether there will be a sufficient number of insects available in the future to carry out the task of pollination.

"We were particularly astonished when we found that the fraction of agricultural production that depends on pollinators, which includes all of these luxury agriculture items, started growing at a faster pace since the fall of communism in the former USSR and Eastern Europe," added Aizen.

"Although the primary cause of the accelerating increase of pollinator-dependent crops seems to be economic and political, not biological, their rapid expansion has the potential to trigger future pollination problems for both these crops and native species in neighboring areas."

Researchers concerns are two-fold: as demand rises for these crops rises, there may not be enough bees to carry-out the job of pollination, while at the same time overall increases in demand for all agricultural products is rapidly shrinking the number of habitats that support thousands of species of wild pollinators.

"Most importantly, decreasing yield by these pollinator-dependent crops surely would imply rising market prices, which undoubtedly would constitute a further incentive for their cultivation," explained Aizen. 

"This situation would create a positive feedback circuit that could promote more habitat destruction and further deterioration of pollination services.  The good news is that less-intensively managed agro-ecosystems that preserve patches of natural and semi-natural habitats and uncultivated field edges can sustain abundant and diverse communities of wild pollinators."


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