Effects of Climate Change Will Be Seen In the Skies and on the Ground

By John Weiss, Post-Bulletin, Rochester, Minn.

Apr. 14–Bird lovers will be treated to more frequent sightings of bluebirds, cardinals and robins in this region as the climate warms, which many scientists suspect is happening.

But evening or spruce grosbeaks might become more scarce farther north, said Carroll Henderson, head of the Department of Natural Resources Non-Game Wildlife Section.

In fact, several resource managers and experts expect that global climate change could bring major changes in the local mix of wildlife and plants. Some species will thrive, and some will be gone. Invasive plants and insects that have been held at bay by winter’s cold might move into Minnesota. Trees in forests will change; it’s even possible forests could just about be wiped out.

Wildlife

Wildlife has been moving around, expanding or contracting their ranges, for eons. But with climate change, that will go into overdrive, Henderson believes. “It’s going to be very dynamic, it’s going to be something that changes over decades, it’s occurring much more rapidly.”

In the past, such changes would need a lifetime before they became obvious.

Already, birds that usually migrated south, such as bluebirds and robins, are sticking around, he said. They usually have more food, such as crabapples or seeds, if the ground is bare. Birds such as cardinals are now common as far north as Duluth, but an early 20th-century bird book listed them as common only into southern Iowa. Because of more open water, waterfowl can stay around longer, he added.

Those kinds of birds that need the boreal forests of the northeast will face problems as those forests begin to fade back, replaced by deciduous trees.

Wildlife is also changing, Henderson said. For example, possums are now seen in this region and in central Minnesota, but they were once scarce in the state.

But moose, which can’t tolerate much heat, are being forced farther north and maybe out of Minnesota, the DNR has found. A survey in the northwestern part of the state found only 84 moose this year, down from 253 in 2003 and about 4,000 20 years ago. In the northeast, moose numbers dropped 23 percent from last year.

“In the northwest, results of a recent study suggest climate change, in combination with pathogens and malnutrition caused the decline of the moose population,” said Mark Lenarz, a DNR wildlife researcher.

Minnesota moose are at the very southern edge of their range, and too much warmth forces them to pant more to cool off, sapping their strength, he said.

Fish

Fish will also begin major shifts as temperatures warm in the day and night, said Heinz Steffan, a University of Minnesota fisheries expert said at an Upper Mississippi River Conservation Committee meeting. Water is warming not only because of burning of fossil fuels but also because of urbanization and the loss of trees along streams and rivers, he said. Warmer water is evident from lake ice forming later and melting sooner, he said.

The problem will be that fish that need cold water up north, such as lake trout, won’t have enough places to dive to find that cool water in summer, he said.

In this region, climate change could mean fewer walleye, especially big ones, in Lake Pepin, but more largemouth bass, said Don Pereira, a DNR fisheries official. If the warming continues, Minnesota’s weather by 2095 will be more like Kansas today, he said.

At first, warmer water will mean more growth for some fish, such as walleye, because their feeding season will be longer, he said. Also, some fish they feed on, such as gizzard shad, will be able to live here longer instead of dying back in winter.

But walleye can’t tolerate too much warm water for too long. If they are heat stressed, they need to devote energy to simply surviving and have little left to grow or reproduce, he said. The big ones will die first, he said.

Winter kill has been a problem when too much ice and snow cover shallow lakes, stopping plants from giving off oxygen. But as temperatures warm and winters aren’t as severe, that will be less common and summer stress will get worse, Pereira said.

Forests

Forests in southern Minnesota might begin to give way to grassy savannas, and those up north might change from conifers like balsam to deciduous trees, such as maple, said Lee Frelich, a University of Minnesota forestry professor.

It’s quite possible the border between prairie and forests could move north about 300 miles because of climate change, he said.

The heat alone isn’t the only effect that humans are having on forests, he said. Anglers have released several kinds of worms that weren’t here before Europeans came, he said. The worms eat duff on the forest floor, exposing roots and letting rain run off faster, he said. That can kill trees or leave them more vulnerable to diseases, which are now better able to survive this far north because of milder winters, he said.

“The forest is going to be quite different in the future,” he said.

If the heat waves are severe enough for a few years in a row, it could basically kill the forests, Frelich said. The region has one such heat wave in 1988. If the next few years hadn’t been so wet, the forests could have been severely damaged, he said.

Though several speakers had dire warnings for those at the river committee meeting, Pereira ended his fisheries talk with an upbeat point: “The message is an urgent one, but there is hope, and we know how to solve this problem.”

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Copyright (c) 2007, Post-Bulletin, Rochester, Minn.

Distributed by McClatchy-Tribune Business News.

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