If the global climate change doesn’t transform the northern forests into something we don’t recognize, the invasive species will.
That was the simple but dramatic message delivered by Dr. Lee Frelich to about 100 guests at the 2006 Sigurd Olson Lecture at Vermilion Community College late last week. Frelich is director of the University of Minnesota Center for Hardwood Ecology, and last Thursday he delved into the changes confronting the northern Minnesota forest from global warming and a variety of invasive insect and fungus species. Frelich believes the forest will be transormed within the next 100 years or so.
The question, according to Frelich, isn’t whether the earth’s climate will continue to warm, but whether northeastern Minnesota will become warmer and drier or warmer and wetter than it is now. If the climate dries, the region can expect a rapid evolution toward oak savannah like that seen in portions of central Minnesota. Warm and wet, he said, would change the ecosytem to one dominated by hemlock, oak and maple, with white pine as well. He said such warming likely will push cool-weather species of trees, such as black spruce, north out of Minnesota.
Other impacts will include a deer takeover. Now, deer populations in the boundary waters are thin, about one animal per square mile, and many of those animals migrate to the warmer strip along Lake Superior in the winter. High deer populations will pose a threat to seedlings, Frelich said. Warming also will bring a higher frequency of harsh storms such as the supercell storm system that produced huge downbursts on July 4, 1999, across the boundary waters, stripping 400,000 acres of trees.
“I would love to be completely wrong about this whole (global warming) thing,” he said, “but invasives are coming regardless of global warming.”
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