Loblolly pine pollen is everywhere
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. “The odd thing is that pollen germination did not decline as distance increased,” she says. “You would expect germination to gradually drop off as pollen floats further away, but that’s not the case.”
This could be more than just an annoyance, Williams says. 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.
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.” 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. That means that genes needed to adapt to warmer temperatures will have a better chance of mixing with populations that don’t have them, she explained.
The findings were published online March 26 in the American Journal of Botany.