Fire Research: A Hot Topic

Bent Creek researchers study the effects of fire on upland hardwood forests and wildlife

Low-intensity prescribed fire set on research plots in the Bent Creek Experimental Forest in April. Photo by U.S. Forest Service.
Low-intensity prescribed fire set on research plots in the Bent Creek Experimental Forest in April. Photo by U.S. Forest Service.

For centuries landowners in the southern Appalachians have used fire as a tool to clear land, control insects, encourage forage, and eliminate unwanted vegetation. But little is known about how fire affects regeneration of oak or other hardwood trees, and how it can be used to meet specific management or restoration goals for upland hardwood forests and wildlife of the southern Appalachians.

Many questions still remain unanswered. Do effects of prescribed burns during the growing season differ from winter burning, when most trees and other plants are dormant? How does fire affect hardwood regeneration, herbaceous plant diversity, fuel accumulation, or breeding bird communities?  Can prescribed fire be used to control unwanted advance white pine seedlings, a native species that can take over in many oak stands?

These are just some of the questions researchers with the U.S. Forest Service Southern Research Station (SRS) are trying to answer in a multi-year research study on the Bent Creek Experimental Forest, a part of the Pisgah National Forest

Paint stripes on the metal tags melt at successively higher temperatures, allowing researchers to determine maximum temperature at each tag location. Photo by U.S. Forest Service.
Paint stripes on the metal tags melt at successively higher temperatures, allowing researchers to determine maximum temperature at each tag location. Photo by U.S. Forest Service.

On Friday, April 26, fire managers from the Pisgah National Forest set a prescribed burn on the experimental forest on three small parcels of 10, 14, and 9 acres, for a total of 33 acres. Researchers installed temperature sensitive heat tags before the fire to record fire temperatures at each vegetation plot. Paint stripes on the metal tags melt at successively higher temperatures, allowing researchers to determine maximum temperature at each tag location. Fire temperatures can then be correlated with effects of the fire on fuel reduction and different species or sizes of trees and other plants.

Researchers timed this prescribed fire for growing season, when the trees are using stored energy to grow new leaves, awakening from their winter dormancy. Three different areas will be burned during the dormant season in fall and winter, when trees have stopped growing for the year and start to lose their leaves.

The study will include repeated prescribed burning at approximately 3- to 5-year intervals, depending on weather, fuels and the availability of personnel. Forest response will be compared between growing season burns, dormant season burns, and unburned controls by measuring growth and regeneration of different tree species, herbaceous plant diversity, changes in fuels, and breeding bird communities. 

Burned plots on the left vs. unburned on the right. Photo by U.S. Forest Service.
Burned plots on the left vs. unburned on the right. Photo by U.S. Forest Service.

This study is an important partnership between land managers on the Pisgah National Forest and SRS research scientists at the Bent Creek Experimental Forest. Results will help land managers make science-based forest management decisions and will help guide goals and methods for forest restoration. This study also serves as an important site for demonstration and education on prescribed fire in mountain hardwood ecosystems to professional foresters and land managers, as well as the hundreds of graduate and undergraduate students who tour the experimental forest annually.

In addition, students with University of North Carolina at Asheville and the University of Texas at San Antonio have access to the experimental burns to conduct their own research under the direction of professors or SRS scientists. Informational signs also inform recreational users of the experimental forest about this and other research on the Bent Creek Experimental Forest.

For more information, email Tara Keyser at tkeyser@fs.fed.us.

 Access the latest publications by SRS scientists.

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