The basswood and maple appear to have moved the most, perhaps as much as 30 miles (50 kilometers).
"This is the first serious attempt at documenting a forest shift for a wide array of species across a broad geographical setting," said Mark Schwartz, a plant-conservation biologist at the University of California, Davis, who was not involved in the study.
"I find it very significant that a cohesive climate change signal emerges from the data."
"Baseball Bat" Trees
Northern trees don't do well in very warm conditions, so the hope is that the climate won't change faster than the species can move.
Some tree species, however, are at the mercy of intervening wildlife when it comes to where and when their seeds take root.
Unless a cedar's pinecone is snatched up by a waiting blue jay, for example, the seed likely won't fall far from the tree.
Meanwhile, cottonwoods, poplars, ashes, and maples have seeds that are light enough to be dispersed by the wind over several miles.
Such highly mobile seeds might allow some species to migrate at rates that even exceed the Forest Service estimate—creating the potential for economic busts—said Dan Botkin, an ecologist at the University of California, Santa Barbara, who was also not a part of the research.
"Northern Pennsylvania and southern New York State are where the best white ash for baseball bats are grown," Botkin noted, "so few [people in those states] would be happy if the trees head north."
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