View Mobile Site
 
Posted: April 18, 2010 12:01 a.m.

The yellow menace

 The loblolly pine pollen coating your home, car and pets this week is the trees’ attempt to spread their genes far and wide. Really far and really wide. The yellow dust has been found to travel up to 1,800 miles from its source.

 Despite its exposure to moisture, cold and UV radiation from sunlight during its long travels, more than half of the pollen can still do its job — making pine tree seeds, says forest biologist Claire Williams, who studies airborne pollen at the National Evolutionary Synthesis Center in Durham, N.C.

 Williams and her colleagues used a hand-held device called a spore sampler to capture and analyze pollen found miles out to sea off the Outer Banks of North Carolina during the spring from 2006 to 2009. Sampling by helicopter and by ferry, they found viable pine pollen as far as 2,000 feet in the air and 25 miles offshore.

 More than 50 percent of loblolly pine pollen still germinates after drifting those distances, they discovered.

 Loblolly pollen’s incredible staying power could have profound implications if and when the USDA approves genetically engineered trees.

 "Long-distance dispersal of transgenic pine pollen is a potential problem if that pollen is viable," says Williams, who also works with the Forest History Society. Her research was funded by the USDA.

 If a single tree can send its DNA dozens of miles, it would be difficult to prevent traits developed in genetically modified trees — such as drought tolerance and disease- and pest-resistance — from spreading to their wild counterparts, Williams says.

 The loblolly pine, Pinus taeda, grows on nearly 60 million acres in the southern U.S. and provides more than 15 percent of the world’s timber. "Roughly one billion loblolly pines are planted in the American South each year," Williams says. "But right now none are genetically modified."

 Although transgenic trees have not yet been approved for commercial use, they are planted as field trials.

 On the other hand, potency of far-flung pollen could be good news for forests facing climate change, Williams adds. "Under human-induced climate change we expect higher wind speeds and more frequent storms will move pollen and seeds even farther from the source," she says.

 The findings were published online March 26, 2010 in the American Journal of Botany.

Commenting is not available.

Commenting not available.

Please wait ...