Scientists are growing trees in a Northern Wisconsin forest - in a bath of greenhouse gasses. There's a theory that forests can help limit the predicted increase in world temperatures from global warming... and its dire consequences. But early results suggest that Great Lakes forests might struggle to survive the century; doing little to help survival of the planet. The Great Lakes Radio Consortium's Bob Kelleher has more:

On a research plantation near Rhinelander Wisconsin, some twelve thousand trees are planted in wide rings. It's called the Aspen FACE project ...for Free Air Carbon Dioxide Enrichment.

Some trees are growing in high concentrations of carbon dioxide .. a gas that's building in the world's atmosphere, and considered a leading cause of global warming. Others in elevated ozone ... another global warming pollutant closely associated with auto exhaust.

Dave Karnosky Directs the aspen FACE project from the Michigan Technological University in Houghton, Michigan.

There's still debate over carbon dioxide's role in global warming. But Karnosky says there's no denying the upward trend in temperatures, and the potential consequences.

"Things like glaciers melting on the North Pole, and sea level increasing; violent storms, increased frequency of violent storms; increased temperatures which will change the native range of plant communities and forestry communities."

There's more than fifty studies underway here, from Institutions like the Universities of Illinois and Wisconsin - even the Canadian Forest Service.

The main focus is to find whether forests might absorb significant amounts of carbon. Holding carbon out of the atmosphere could help keep global warming from spiraling out of control. If that's the case, forests could be used like a sponge to soak up CO2 generated by cars and industries.

But Karnosky's a forestry expert. He wants to know how elevated carbon and ozone might affect the region's trees.

"Will these forests remain as productive in the future? Will they be more productive, or less? So, we talk about these as being sort of a window into the future. We like to think of our site as what the future climate will be, say in the year 2050."

The research site is eerily reminiscent of the ancient stonehenge ruins in England.

Each ring is one hundred feet across. The trees are head high, surrounded by a monument of pipes which rise straight up maybe ten feet higher, and connect across the tops. A central computer directs high pressure jets of gas.

Forest Service Biologist Mark Kubiske says early results are surprising.

Trees growing in a high concentration of carbon dioxide do well. Carbon dioxide is to a plant what oxygen is to an animal. But CO2 isn't the only pollutant on the increase. There's others, like ozone.

In the nearby computer shack, Kubiske says trees grown in ozone pollution do poorly. Some aspen strains in ozone won't make it ten years.

"The very sensitive clones are starting to drop out of the experiment; they're dying early. And the less sensitive clones are tending to take over the site. So, the effect of the gasses on the composition of the forests that we're investigating, is altering the way the different species and the different clones seem to interact."

Combine ozone and carbon dioxide, and you find that any benefit trees get from extra CO2 seems to be offset by the damaging effects of ozone.

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Bill Mattson is a Forest Service entomologist. Mattson says trees grown in ozone get attacked by insects and fungus at a much higher rate. They also suffer from animals and birds.

"We've noticed that hares and rabbits, for example. They seem to respond to the smaller plants in a community, and so they start attacking smaller trees. You'll see lots of woodpecker injury; lots of sapsucker injury on those slower growing ozone trees."

The ozone trees are riddled with small holes from wood boring beetles.

"So if you add those two chemicals together; it somehow is enhancing the success of the beetles that bore into the stems of these trees. That was something which I hadn't expected."

There's evidence water moves differently through a tree under the gaseous conditions. Some trees have elevated tannins in leaves but reductions in other chemicals. That can have consequences on an ecosystem level, to the animals and insects that feed on trees.

It might be hard to sustain forestry here in just fifty years. Aspen Face is a relatively small, controlled experiment; but Mattson says the real world is a giant experiment with no controls.

"It's something to be watched very carefully, because we don't know what the ultimate consequences will be as we continue to ratchet up ozone and CO2."

There's a dozen similar experiments worldwide. Each treats plants with CO2 and other predicted factors like high temperatures or drought. There's more than forestry at stake. There's a real risk to world food production. If forests can't lock up carbon, there may have to be new restrictions on the sources of carbon ... the cars and industries burning fossil fuels.

For the Great Lakes Radio Consortium, I'm Bob Kelleher.

© 2002 Great Lakes Radio Consortium