Air Pollution May Hinder Pollination

June 11, 2008 -- Scientists at the University of Virginia recently reported that air pollution may be preventing bees from finding flowers to pollinate. It's a problem that could have long-lasting effects on plant reproduction and diversity, and might help explain why populations of bees and other pollinators are declining.

Using a computer model, the scientists studied how far the scent of flowers travels with the wind. They found that when no air pollution was present, a flower's scent trail, or the path over which its scent drifts, extended beyond a kilometer. But when any of the components of air pollution were added, both the concentration of scent compounds and the distance of the scent trail decreased. When substantial air pollution was present, half of a flower's scent trail could be lost within 200 meters of the plant.

Recent attention on pollinators has focused on the mysterious disappearance of a large number of honeybees from colonies in the U.S., a phenomenon known as Colony Collapse Disorder. While not directly related to the colony collapses, diminishing scent trails could be a reason for declining bee populations as well, the study suggests.

Playing a critical role in moving pollen from one flower to another so that plant fertilization can occur, pollinators are necessary for the production of most fruits and vegetables we eat and many crops on which livestock rely. National Pollinator Week, from June 22 to 28, recognizes the importance of pollinators to ecosystem health and agriculture and encourages efforts to increase awareness and support for protecting and sustaining pollinators. During this week, events will take place in our nation's capitol and throughout the country.

The National Research Council reported on the decline of some pollinator populations in a recent report, Status of Pollinators in North America. It recommends increased efforts to monitor their status and more research on the sustainable management of these important species. May Berenbaum, the chair of the committee that wrote the report, testified about the issue before Congress.

• Status of Pollinators in North America (2006)
• Congressional Testimony by May Berenbaum on Colony Collapse Disorder and Pollinator Decline (2007)
• The National Academies resources on pollinators

• The Pollinator Partnership
• Atmospheric Environment Journal