The forests we walk through today are not the same as the ones that existed hundreds of years ago. Human activities such as agriculture, development, and logging have changed them. Fire, or really the lack of it, also changed forests, to the detriment of some species like Oaks and Pines.
Can we use fire to turn back time, bring forests closer to their original state, and maintain these ecosystems over the long term?
Previous studies show mixed results depending upon when, how often, how severe and in what season a prescribed burn was conducted. Anthony Zhao, a master’s degree student in geography, in the College of Earth and Mineral Sciences, is using computer model simulations to try to get a clearer answer to this question with his master’s research project, “Modeling Prescribed Fire Effects on Vegetation Dynamics in Pitch Pine and Mixed-Oak Forests.”
“Prescribed fire is a planned fire ignited by fire managers under known weather and fuel conditions to alter vegetation for specific purposes,” said Alan Taylor, professor of geography and Zhao’s adviser. “Typical reasons for using prescribed fire include reducing fuels and fire hazard, improving wildlife habitat for certain species and changing or maintaining certain combinations of forest tree species.”
Zhao said he has always been interested in nature. "In high school I volunteered at the Maryland Zoo in Baltimore, where I educated zoo guests on wildlife and conservation using biofacts, activity kits, and games, and through handling of live animals such as turtles, tortoises and hissing cockroaches.”
As an undergraduate student at the University of Maryland, Zhao majored in ecology and evolution with a minor in GIS. “When I applied to grad school I wanted the opportunity to combine these interests,” Zhao said. “I’m working on part of The Firescapes in the Mid-Atlantic multidisciplinary project led by Erica Smithwick in the Center for Landscape Dynamics. There are social and ecological sides to this project, and my part is on the ecological side.”
Zhao’s project is unique in that it is primarily computer model simulations and little or no fieldwork. He is using forest data collected by various partner agencies such as the U.S. Forest Service, the National Park Service, the New Jersey Forest Service, the Pennsylvania DCNR Bureau of Forestry and the Pennsylvania Game Commission. Those agencies have provided forest plot data for sites across Pennsylvania, southern New Jersey and the Virginia Appalachians. The databases include information such as tree species, diameter, height, mortality and damage, fuel load, observed burn effects, and more.
All that information will be loaded into the Forest Vegetation Simulator (FVS), a tree-growth modeling program routinely used by forest researchers. An add-on for the model, the Fire and Fuels Extension (FFE), will also be used to simulate and model prescribed burning.
Once all the data have been entered, Zhao plans to run many simulations using different combinations of parameters and fire management scenarios and repeat them multiple times. “This model should predict long-term effects, the effects over six decades,” Zhao said, adding, “It would be difficult or impossible to do that in a field study, especially across such a large geographic region.”
“Anthony's simulation experiments will help us determine and understand how various regimes of repeated prescribed fire are likely to alter forest conditions in the mid-Atlantic,” Taylor said.
One of the challenges is the condition of the data from state and federal agencies. “The raw data is messy. It came in different formats and has to be converted into the standard formats that FVS will accept. That is time-consuming.” Zhao said.
To take a break from all the database work, Zhao has also helped conduct field surveys for the Firescapes in the Mid-Atlantic project. That involved going to forests and outdoor recreation areas to ask random members of the public there to complete a short survey on how they use forest areas and their perceptions of prescribed burning. “That was a good experience,” Zhao said. “It helped me to understand how my work could impact people’s lives, too.”
When his research project is done, Zhao said he hopes the findings can be used to demonstrate the value of prescribed burns as a landscape management tool to aid forest management across the Mid-Atlantic region.