Hugh, All of this is quite scary if you think about it. I have thought of this many times while hiking the boreal climate forests of the high Appalachians. In 100 years many of these trees ( Red Spruce, Fraser and Balsam Fir, Mountain Ash, American Beech, Sugar Maple etc ) may migrate northward while local populations die out. Warmer climate trees will migrate up the slopes. I won't be alive to see it, but it will sadly affect the forests on the roof of the Appalachians.
James Parton On Feb 9, 6:28 pm, "Hugh Irwin" <[email protected]> wrote: > Trees Migrating North Due to Warming > Bruce Dorminey > for National Geographic News > February 9, 2009 > > Other than the Ents of Lord of the Rings fame, trees generally aren't known > for their mobility. So news that some tree species may be headed north at an > average clip of 62 miles (100 kilometers) a century may come as a surprise. > > At that rate, stands of yellow birch in the U.S., for example, may move well > north of the Canadian border by the early 2100s. > > That's the finding of a new study led by the U.S. Forest Service, which > concludes that a few dozen tree species in the eastern U.S. are moving north > at an unexpected rate, likely due to global warming. > > In a paper appearing this month in the journal Forest Ecology and > Management, the study authors documented the northward march of 40 major > tree species over 30 eastern states based on the distribution of seedlings > versus mature trees. > > Previous studies of plant migrations had been done using only computer > simulations, or they focused on how some species are climbing up hills and > mountains, said co-author Chris Oswalt, of the Forest Service's Southern > Research Station in Knoxville, Tennessee. > > By contrast, the new study looked at movement based on latitude, using a > sampling of the forest service's most recent ground-based data. > > The finding confirms a link between global warming and forest migration, > said lead study author Chris Woodall, of the Forest Service's Northern > Research Station in St. Paul, Minnesota. > > "This is no longer conjecture," he said. > > Trees on the Move > > Woodall and colleagues studied data from 15 northern species, 15 southern > species, and 10 species found in both regions. They compared the latitudes > of seedlings-trees less than 20 years old, on average-with those of their > older counterparts. > > Eleven of the 15 northern species appear to have shifted more than 12 miles > (20 kilometers), on average, from their historic ranges. > > Among the species headed north are the northern white cedar, American > basswood, sugar maple, black ash, bigtooth aspen, and yellow birch. > > 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." > > C 1996-2008 National Geographic Society. All rights reserved. > > http://news.nationalgeographic.com/news/pf/25299927.html --~--~---------~--~----~------------~-------~--~----~ Eastern Native Tree Society http://www.nativetreesociety.org You are subscribed to the Google Groups "ENTSTrees" group. To post to this group, send email to [email protected] To unsubscribe send email to [email protected] For more options, visit this group at http://groups.google.com/group/entstrees?hl=en -~----------~----~----~----~------~----~------~--~---
