(This is the last installment of a three-part series on oak
regeneration.)

In a fenced research area in Allegheny National Forest, a
forester uses a knife to scrape off bark from a dead birch tree to
demonstrate the result of what is called a “prescribed burn.”

The birch, which competes with the vanishing oak trees for
survival in the forest, has a smaller root system and is more
vulnerable to these deliberately set fires.

As a result, the oak has a better chance to take root and grow.
And that’s what they’re hoping for.

“It is so darn important because we have already lost so much,”
said Pat Brose, research forester at the forestry science lab in
Irvine. “There was the American Chestnut blight … keeping the
northern oak is very important. I don’t want to see them gone.”

On a recent trip to two sections of the Allegheny National
Forest, research technicians and foresters talked about the use of
prescribed burning to promote regeneration of oak trees.

The dead birch was the result of a prescribed burn which
occurred in the spring of 2005 on a tract of land off Route 59
about midway between Marshburg and Kinzua Reservoir.

The area is a plot that researchers are watching to see results
not only of the burn treatment but of fencing to prevent the
white-tailed deer from browsing.

Brose and other employees of the U.S. Forest Service have been
working on controlled-burn research in an area that had been hit by
the gypsy moth which caused oak mortality.

He explained that seedlings approach life in two ways, growing a
stem and leaves as fast as possible as on a birch, or with an oak
tree – growing the roots first.

The fact that the oak grows a heartier root system first means
that they hold a huge energy reserve.

“Fire takes advantage of the trees with the smaller root
systems,” added Brose.

He said they use prescribed burning in the spring when seedlings
grow.

Research on the tract off Route 59, across from Kinzua Heights,
began about 15 years ago to remove the overstory of trees after the
oak had been ravaged by the gypsy moth. At that time they fenced in
three areas where they would be working on regeneration
techniques.

Scott Reitz, wildlife biologist with the ANF, said the fact that
a 10- to 12-year-old seedling was alive in the area today was
testimony to fencing to prevent deer browsing as well as utilizing
the prescribed burning in the particular area toured.

“It (the seedling) got started with a lot more light, the
competition will not come back as fast,” he said, explaining that
the seedling had a head start without other seedlings blocking the
sun, and then, to its advantage, it produced that heartier root
system that kept it growing.

Kim Steiner, Penn State professor of forest biology, said that
oak is not intolerant of shade, but prefers light and cutting the
overstory helps the seedlings to grow.

Another problem is the fern. Because deer don’t like fern, they
eat their preferred species of seedlings which include oak, leaving
the fern to thrive and shade out oak as well as other types of tree
seedlings that are left.

When Brose scraped off the bark of the birch at the research
plot, the tree was brown rather than the expect light green color.
Even though the birch was still standing, it had been killed in the
2005 prescribed burn. He also said that birch is a major competitor
of oak.

Reitz explained the oak is a Keystone species meaning it is
important to more than economic (or timber) interests.

“It is important to wildlife including the black bear and
turkeys rely on it, too,” he explained. “The seedlings are high in
lipids and fat content – it has high nutritional value. In the fall
the acorns are important as the bears need to eat them for fat and
they favor crops to maintain their body weight.”

Brose said the bark is important to insects and birds as
well.

Reitz added that there are more than 200 species in the ANF that
are helped by the bark and acorns.

“We are getting more of a feel for what we can do for oak
regeneration when the deer herd is down,” added Reitz. “A forest is
healthy with oak and there are other species we would not have
gotten. We need an oak class with diversity – different ages. And
we don’t want all oak only.”

Jason Rodrigue, district silviculturist for the ANF, said,
“These tools allow us to look at the Allegheny at a new level. We
would like to maintain the oak forest type always on the
Allegheny.”

ANF officials explained the process of a prescribed burn saying
that weather conditions play a large role before a burn can begin,
fuel types are taken into consideration as well as wind direction
and speeds.

They said they take drip torches and burn to a control line then
stop, then start again to the next line.

Reitz said there are usually 10 to 20 people involved with some
stationed at the edges of the area during this process.

Rodrigue explained that the first stand where the prescribed
burn was used will likely have another burn if and when researchers
decide to.

“It depends on how well the oak seedlings respond to the first
one a few year ago,” he said.