Red maples are great to look at in the fall -- leaves can turn vibrant yellow, red, orange or purple.

So what if we look more like Vermont, you say?

Turkeys, ruffed grouse, deer, squirrels, mice and assorted other wildlife can't live off of maples like they do the acorns from oaks. The smooth bark of maples doesn't hold insects the way oak trees do, to the demise of insect-eating birds.

Timber companies can't make a living off of maples the way they do oaks, hickories and black cherry.

And forests simply aren't healthy without diversity, without the tulip poplars, pines and sundry other trees.

There are now more red maples in Pennsylvania than any other state.

Scientists all bemoan the makeover. They just can't agree on why it's happening.

Red maples are elbowing out other trees because:

A)We don't let forest fires burn anymore.

B)Deer browse everything else.

C)Acid rain is making the soil so harsh only maples and a few other trees can grow.

D)All of the above.

There are researchers who subscribe to each theory.

In one corner is Marc Abrams, a Penn State professor of forest ecology and physiology. Abrams believes the current policy to snuff out forest fires is enabling red maples to come out of the swamps and march up mountainsides.

The tree's shallow roots and thin bark can't withstand forest fires that historically burned periodically across the landscape. That's why red maples used to be called swamp maples.

Conversely, the thick bark of oak, chestnut, hickory and pine trees helped them survive fires.

Around 1900, the state's woodlands held no or very few red maples. Now, he estimates the maples make up one in every three or four trees in forests statewide.

Abrams is trying to convince the main caretakers of our vast forests -- people like the Pennsylvania Game Commission, state Bureau of Forestry and private timber companies -- to start controlled burns in the forest understory to stem the invasion.

No one is rushing to action, but he says each of the affected parties has at least initiated research projects on controlled burning.

No, no, no, says colleague Bill Sharpe, a forest hydrology professor and researcher. That's barking up the wrong tree.

All the fires in the world and elimination of Pennsylvania's voracious deer herd wouldn't stop the decline of oaks and other trees in Pennsylvania because the underlying culprit is a buildup of acidity in soil.

"We're going to be treating the symptoms and not curing the patient,'' he frets.

The root problem is the slow but ever-cumulative effect of acid rain falling on Pennsylvania soil from Ohio Valley power plants and in-state sources, he preaches.

The acid deposition leaches aluminum out of the soils, which is toxic to many plants, and lowers the availability of nutrients needed for plant growth. Red maples, he says, are acid tolerant.

"Acid soils are the fundamental reason why this is happening and they will be the fundamental reason why there might be denuded forests in the long run,'' warns Sharpe, who has loudly sounded the acid rain alarm in Pennsylvania for decades.

"We have a forest regeneration problem and a forest health problem -- our forests are sick. We know there is very little regeneration of red oak and large, mature red oaks are dying.

"That cannot be blamed on deer or the lack of fire,'' he says.

Soils in northcentral Pennsylvania -- where most of our trees are -- are the most sensitive to acidity.

Already, Sharpe says, there are open fields of hay-scented ferns within forests where trees have been cut and no trees grow back.

While strengthening the nation's air pollution laws is a long-term solution, he offers a short-term fix.

His three-year study of new forest growth in Somerset County suggests a mixed forest can be restored after tree cutting with a combination of lime, fertilizer and selective use of herbicides.

None of the forest caretakers has leaped at his earnest recommendations. But Sharpe says the Pennsylvania Game Commission is working with him on a demonstration site in Blair County and the Bureau of Forestry is doing likewise in southwestern Pennsylvania.

And he is gaining disciples. At a Pennsylvania Game Commission meeting last summer, two sportsmen's groups, Unified Sportsmen of Pennsylvania and the Pennsylvania Flintlock Association, voiced concerns that the stifling effects of acid rain on forests was more to blame for declining forests than deer.

Sharpe and Abrams are both right, says Gary San Julian, a Penn State wildlife resources professor. So are those who see marked reductions in deer numbers necessary for forest regeneration.

Acid rain and fire suppression play a part in declining native forests. But getting a handle on deer is an immediate first step, San Julian argues.

"There's nothing out there that a deer won't eat if they're hungry -- except maybe ferns,'' he says, noting the loss of many native wildflowers to whitetails.

"It's not an easy thing. These are holistic systems in which there are a lot of factors involved. Deer happen to be one we can get a handle on very quickly.''

Then, further research can sort out whether acid rain, the lack of forest fires -- or both -- are responsible for the slipping away of Pennsylvania's oak forests.


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