The Transylvania Times -

Scientists Studying Historic Impact Of Fires On Forests


December 18, 2017

During the most recent Transylvania Natural Resources Council meeting, the council and audience heard from Katie Greenberg, an uplands hardwoods ecologist.

Greenberg works for the U.S. Forest Service in a branch called research and development, which manages experimental forests, such as Bent Creek, where Greenberg is stationed.

Greenberg gave the council a primer on some of her research as it pertains to the forest plan revision process.

As a hardwoods ecologist, Greenberg’s mission is to provide forest managers with the applied science to make their decisions and meet their management goals.

She went through the different kinds of forests that can be found locally and discussed the age structure of the forest. Greenberg noted that the forest, and its animals, have developed along with thousands of years of human cultivation. She said Native Americans had been burning and clearing tracts of land to help with things such as acorn regeneration, their own agricultural needs and what we now call early successional habitat, which are ripe with fruits and berries that attract the entire food chain spectrum.

Greenberg told the council that each age structure of the local forests had their own population of inhabitants — from the flying squirrels of the Red Spruce high elevation forests to the Ruffed grouse that likes dense forests.

Work specific to each of the age structures is ongoing in the forest, with a push from local contingents to develop more early successional habitat. At least 128 bird species found locally require early successional habitat, and several species are in decline because there is little of this habitat being created.

“As early as at least 3,000 years ago (Native Americans) did a lot of land management,” she said. “They burned a lot. You can see they created a lot of different habitats. They would move around, too, creating a heterogeneous age habitat, as well. Before Euro-Americans arrived here, 7 percent of the landscape was directly impacted by humans, and 45 percent was impacted by their footprint.”

Historically, there have been natural disturbances to create some of this habitat though.

For example, the beaver population in the southern part of the continent was once much higher.

The animals would create their signature dams, flooding large areas of the forest and creating open areas that became fields in periods of drought.

Passenger pigeons once flocked in the millions throughout the country, which Greenberg said probably opened up some canopy when they roosted, breaking limbs and letting light onto the forest floor. Bison and elf once roamed freely.

Elk once created habitat in wetlands, their hoof prints filling with water creating miniature pools where bog turtles lay.

How does forest management affect wildlife communities?

Since it is well known that the Native Americans freely burned the forest and created habitat that is now in decline, there have been adaptations in studying fire management as nearby as Polk County, where there are several ongoing studies about fire.

Sometimes a research plot is checked once a month, sometimes every 10 years.

Researchers like to conduct these studies on Game Lands, where there is less regulation and they can implement their modes of research all in the same year, which Greenberg said is more difficult on federal land.

Greenberg said that they have been looking at the impacts of burning on eastern forests and how the animal populations are affected.

Through several different kinds of burns, they are studying how the animals repopulate. For example, when the researchers mechanically remove understory — plant life growing beneath the forest canopy — and leave the brush on the ground for one year, then burn, they find higher populations of lizards, which like dry climates. Greenberg said this is because the fires burn hotter, removing much of the moisture-holding debris.

“But what is it about these early successional forests that drive population growth?” she asked. “It’s probably protection, with those thicker shrubs, insect abundance and fruit production. When you get these bigger openings, native fruit production like blackberries goes way up. The same holds true in our studies of other fruits. In the young stands, fruit production sky rockets for a few years and then goes back to normal levels. The result is a boom in the population of birds and rodents, which carries up the food chain.”

Seeing some of the results of these studies can take a lifetime, said Greenberg.


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