Ecosystem Threat What Global Warming Means to Illinois Plants and Animals

Article excerpt

Byline: Marni Pyke Daily Herald Staff Writer


CORRECTION/date 05-08-2007: An article on global warming in some Saturday editions incorrectly referenced turtles. They are reptiles.


With images of melting glaciers and drowning polar bears grabbing attention, the threat of global warming is frequently associated with the Arctic.

But projections by some scientists indicate that if carbon emissions continue at the current rate or accelerate, plants and animals in the Midwest also will suffer as a result of rising temperatures.

In a worst-case scenario, it could mean reductions in lake fish, waterfowl and species such as white oaks - Illinois' state tree.

Friday marked the release of a United Nations-sponsored group's report on global warming.

Written by hundreds of scientists, the study by the Intergovernmental Panel on Climate Change finds that human activity - particularly burning fossil fuels, which send carbon dioxide into the atmosphere - is warming the planet.

Unless abated, emissions could rise an extra 90 percent by 2030, causing higher temperatures and sea levels. The report asks countries to reduce emissions or face irreversible environmental damage.

Dramatic alterations occurring in the Arctic likely won't happen in Illinois in our lifetime, experts say.

But shifts in temperature are occurring now and having an impact on local ecosystems, sending a signal that can't be ignored, advocates say.

Future shock

The National Wildlife Federation warns that average temperatures in Illinois could increase between 9 and 17 degrees Fahrenheit by 2100 if greenhouse gases aren't curbed.

Hotter weather leads to less wetlands, drier forests and warmer lakes and rivers. That would alter life for species ranging from ducks to white oaks to violets to brook trout and yellow-headed blackbirds, the NWF contends.

But changes won't be noticeable for generations, said Lesley Rigg, a Northern Illinois University professor specializing in bio- geography.

Trees can live for hundreds of years so if germination rates start dropping in the coming decades, it won't be noticed until those already established start dying off. "There's a huge time lag," she said.

Using U.S. Department of Agriculture computer models, Rigg is studying sugar maples with troubling results.

Under a scenario with a doubled carbon dioxide output, "sugar maple disappears essentially from the continental United States," she said.

Sugar maples are a cold-loving species that germinate at low temperatures.

"When you start fussing with temperature, one thing that's hypothesized is that sugar maples won't be able to germinate in numbers it did previously," Rigg said.

Simultaneously, species from southern climes, such as the shortleaf pine, could move north. "The forest will take on a more southern look," Rigg said.

Not everyone in the environmental community agrees with such long-range forecasts.

"I don't like speculating," said John Oldenburg, director of natural resources for the DuPage County Forest Preserve District, which owns 25,000 acres providing habitat for hundreds of native species.

"The average temperature is increasing, no doubt, but the range of what we're experiencing on an annual basis is well within the extreme limits of cold or warmth experienced over many generations," he said. …