Minnesota Forests Show Rapid Changes As Warming Accelerates - MPR

[hatrack]

St. Paul, Minn. — Lee Frelich has been studying trees in the Boundary Waters Canoe Area Wilderness for the past 18 years. In that time the University of Minnesota hardwoods researcher says he's witnessed dramatic changes.

"There is a lot more red maple," says Frelich. "And red maple's a species that normally would not be part of the boreal forest in the Boundary Waters. The climate used to be too cold for red maple." It's not just Minnesota's mild winters that are helping the red maple. Summers are different too. They've been wetter. Frelich says that's kept wildfires in check, giving the red maple a chance to flourish. But the red maple's gain is a loss for the native northern pines.

"The pines which were historically the species that dominated the forest there are just not reproducing very well and red maple is," says Frelich. "Pines need fire and jack pine in particular is a cold weather species." These changes are happening quickly, according to Frelich. But that's not unusual along the edges of a biome -- a region characterized by its dominant forms of plant life and climate. Minnesota has three biomes -- the boreal forest in the north, deciduous forests of oak and maple in the central part of the state, and the prairies and savannahs of southern Minnnesota. Even a small change in a biome's climate can cause a big change in the vegetation.

The way Frelich sees it, Minnesota's climate will continue to warm. The real question is whether it will stay wetter or become drier. If it's wetter, the woods could end up looking a lot more like Ohio where poplar, sycamore and walnut trees are common. If the climate becomes drier, the forests will retreat and the landscape will look similar to the grassland around Omaha.

EDIT

http://minnesota.publicradio.org/display/web/2006/03/03/globaltrees/

[megatherium]

1. Meanwhile, my bermuda grass is gaining on my tall turf fescue.

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