Author
Berlin, Jeremy
Title
Flighty Oaks
Series
National Geographic Magazine, Vol. 216, #5, Nov. 2009, Environment Section
Publisher
National Geographic Society
City
Washington
Date
2009
Original Date
Libraries
LOW MAD
URL (full text)
Comments
Text

Flighty Oaks. In the National Arboretum's parched herbarium, where dried plants date to the 1790's, Alan Whittemore is providing needed acorn perspective. A year after few fell in parts of the U.S., the botanist says hungry squirrels and an anxious press--which breathlessly wondered, Is it climate change?--can relax.

Oak trees, he explains, don't have regular cycles or produce big harvests every year. Factor in weather--cold, wet springs impair pollination; hot, dry summers hinder maturation--and you've got acorn variability.

UCLA biologist Victoria Sork concurs. Back in the 1980s she tallied two near-zero year in eastern Missouri. The next fall? A bumper acorn crop. "We have to be careful about reading too much into one year," she says.

Meantime, says botanist Rod Simmons, the next boom year will be a boon year for all. One huge oak can drop up to 10,000 acorns, so well-fed squirrels are likely to heard and forget their leftovers--and thus plant trees far and wide.