Shortage of Pollinators Is Not Affecting Crops, at Least for Now

Henry Fountain, New York Times 20 Oct 08;

In recent years, the worldwide decline in pollinators has been big news in agriculture. The collapse of honeybee populations, which is still poorly understood, has gotten the most press, but more broadly there is evidence of declines among other pollinators.

Since many fruits, seeds and vegetables depend to varying extents upon pollination by insects or birds, agricultural experts have become concerned that a decline in pollinators may lead to a decrease in crop yields.

For those experts, there’s good news and bad news in a study by Marcelo A. Aizen of the National University of Comahue in Argentina and colleagues.

On a global scale, the researchers report in Current Biology, pollinator shortages are not affecting crop yields. But there could be problems in the future because, the researchers say, the amount of acreage being devoted to pollinator-dependent crops is increasing.

The researchers analyzed 45 years of Food and Agricultural Organization data for pollinator-dependent crops like fruits, nuts and seeds and nondependent crops like many grains and root vegetables. Over all since 1961, yields have increased consistently by about 1.5 percent a year, and in looking at trends over time, the researchers found little difference between pollinator-dependent and nondependent crops in either the developed or developing worlds.

They did find that the proportion of pollinator-dependent crops increased greatly over the decades — to 23 percent of total agricultural production in 2006 from 14 percent in 1961. So if pollinators keep declining, the shortage may eventually have an impact.