In the Great Lakes states, many of the original forests were cut down. They were cleared for homesteading, farming, and for the wood that fueled the age of steam. But over the past several decades, some of the forests have been growing back. Many of the new forests are confined to small patches or woodlots surrounded by farm fields. These woodlots are small havens for animals. But some foresters, biologists, and environmental groups are concerned that those forests are simply too small and too fragmented. The Great Lakes Radio Consortium’s Cristina Rumbaitis-del Rio prepared this report:
Transcript
In the Great Lakes States, many of the original forests were cut down. They were cleared for
homesteading, farming, and for the wood that fueled the age of steam. But over the past several
decades, some of the forests have been growing back. Many of the new forests are confined to
small patches or woodlots surrounded by farm fields. These woodlots are small havens for many
animals. But some foresters, biologists, and environmental groups are concerned that those
forests are simply too small and too fragmented. The Great Lakes Radio Consortium’s Cristina
Rumbaitis(rum-bite-us)-del rio (del-rhee-o) prepared this report:
(Natural sounds – walking through leaves underneath) & Thomas Grubb talking:
“This little woodlot is large enough to house one pair of downy woodpeckers and one pair of
white breasted nuthatches.”
Thomas Grubb is a Biology Professor at Ohio State University. Instead of lecturing to a classroom
today, he’s strolling through a small, private woodlot next to a cornfield in central Ohio. This is
one of the study sites where he looks at how forest fragmentation affects woodland bird species.
He says just as in many areas of the Midwest, Ohio’s forests are highly fragmented because
instead of having the forest concentrated in one big area, the forests are carved up into small
patches, scattered throughout a largely agricultural landscape. While 90% of Ohio was covered
with forest before European settlement, now less than a third of the state is considered forested.
And according to Grubb, this part of Ohio has even less forest.
“This plot is about 3% forested and that’s not much forest. This landscape is probably as little
forested as any you’re likely to find.”
Grubb and his students are working with woodlot owners to see if the size of a woodlot affects
the number of birds living there and their survival. He says bird survival is better in larger
woodlots than in smaller ones.
“One of the things we think is happening in these small woodlots, these permanent resident birds
that are there all winter- they can’t get out of the wind, and so they have tremendously high
metabolic rates trying to stay warm.”
Smaller woodlots may be colder than larger ones because there’s fewer trees to block the wind.
Smaller woodlots also have less food for birds, and in the winter birds may starve trying to get
enough food to stay warm.
(Natural sounds of leaves and birds)
“Oh that’s a Carolina Wren.”
Forestry officials, scientists, and environmental groups agree forest fragmentation is one of the
most serious problems facing Ohio’s forests. Fragmentation is a problem for a number of reasons
beyond the fact that it represents a loss of forest habitat. According to Ohio State University
Ecologist, Ralph Boerner, the smaller a forest patch is, the fewer number of species that can live
there.
“The smaller a forest patch, the less diverse it is. And you particularly lose species that need
large areas in which to gather food.”
Boerner says smaller patches may also have a harder time recovering from disturbances – like an
insect outbreak or a tornado.
“We also believe there is a link between how diverse an ecosystem is and how stable it is in the face of disturbnace, so when you lose diversity there’s the potential to lose stability, lose the ability to bounce back
from disturbance.”
Breaking up the forest into patches also isolates animal and bird species that can’t or won’t cross
agricultural fields to get from one forest patch to another, and that means less genetic diversity
because they can’t mate with animals outside of their forest patch. So some woodlots are just too
small for certain species to survive.
Fragmentation also makes managing forest land more difficult. Most of Ohio’s forested land is
privately owned. Ohio Division of Forestry official, Tom Berger, says this makes managing
almost an impossible task.
Well, you’ll have 10 people and they’ll have 10 different views on how to manage it or what’s
valuable to them and they all have that right.”
Division of Forestry officials can give landowners advice, but they can’t tell a landowner what
their priorities should be. Berger says this often means neighboring patches of forest are managed
for completely different interests. Berger wishes he had more tools at his disposal to get land
owners to manage their land collectively.
“I wish we could put together some programs or some incentives, monies available through the
state or federal government that would really encourage landowners to work together to form
blocks or units that would be managed in the same way.”
Managing isn’t the only challenge. Berger says keeping the land at least partially forested is
becoming a problem as people choose to build homes in woodlots, particularly in areas near
cities.
“Not only is the woods scattered that we have fragmented, but a lot of them continue to
disappear too, especially in the urbanized areas in Columbus and around the state.”
Ohio State University Biologist, Thomas Grubb, says there are may reasons for protecting
woodlots, but his favorite reason is because it’s a pocket of nature in a sea of developed land.
“This is worth preserving just because it’s like it is and we ought to just leave it alone. This enriches our lives.”
The average woodlot size in Ohio is 20 acres, and it changes hands frequently – every seven years on average. The small size and the quick turnover make it nearly impossible for the state to
encourage owners to establish any kind of useful management practices. That means there’s little
to be done to help keep the forests from further deterioration.
For the Great Lakes Radio Consortium, I’m Cristina Rumbaitis-del Rio.