Effects of Initial and Repeated Wildfire in the Southern Appalachian Mountains
Event Website
http://www.nafew2009.org/
Start Date
6-22-2009 11:50 AM
End Date
6-22-2009 12:10 PM
Description
The infrequent occurrence of large wildfires in the southern Appalachian Mountains over the last several decades has offered few opportunities to study the impacts of these types of disturbances. As a result, relatively little is known about how heterogeneity in topography, vegetation, and recent disturbance history interact to influence patterns of fire severity across the landscape. In the spring of 2007, three separate wildfires burned a large portion of the area in, and surrounding the Linville Gorge Wilderness in western North Carolina. Much of this area had been affected by a southern pine beetle (Dendroctonus frontalis) infestation in the late 1990ís and burned in a previous wildfire in the late fall of 2000. The effects of the 2000 fire have previously been studied using a series of pre-existing vegetation plots and remotely sensed images and provide us with data on patterns of severity and vegetative response. The situation offers a unique opportunity to compare fire severity and effects across a diverse landscape subject to multiple disturbances. We used multi-temporal Landsat imagery to create a fire severity map from the 2007 wildfires by calculating the differenced Normalized Burn Ratio (dNBR) and modeled the resulting spatial patterns of fire effects on soils and vegetation. We also incorporated data from the 2000 fire to model spatial patterns of regenerating coniferous and ericaceous vegetation and investigate the effects of initial burn severity in 2000 on severity of the reburn in 2007. Results show that fire severity and effects were greater in those areas subject to repeated wildfire. In addition, topography and patterns of severity and vegetative response following the 2000 fire impose constraints on patterns of reburn severity. These findings emphasize the importance of landscape heterogeneity in determining patterns of fire severity and effects after both initial and repeated wildfire.
Effects of Initial and Repeated Wildfire in the Southern Appalachian Mountains
The infrequent occurrence of large wildfires in the southern Appalachian Mountains over the last several decades has offered few opportunities to study the impacts of these types of disturbances. As a result, relatively little is known about how heterogeneity in topography, vegetation, and recent disturbance history interact to influence patterns of fire severity across the landscape. In the spring of 2007, three separate wildfires burned a large portion of the area in, and surrounding the Linville Gorge Wilderness in western North Carolina. Much of this area had been affected by a southern pine beetle (Dendroctonus frontalis) infestation in the late 1990ís and burned in a previous wildfire in the late fall of 2000. The effects of the 2000 fire have previously been studied using a series of pre-existing vegetation plots and remotely sensed images and provide us with data on patterns of severity and vegetative response. The situation offers a unique opportunity to compare fire severity and effects across a diverse landscape subject to multiple disturbances. We used multi-temporal Landsat imagery to create a fire severity map from the 2007 wildfires by calculating the differenced Normalized Burn Ratio (dNBR) and modeled the resulting spatial patterns of fire effects on soils and vegetation. We also incorporated data from the 2000 fire to model spatial patterns of regenerating coniferous and ericaceous vegetation and investigate the effects of initial burn severity in 2000 on severity of the reburn in 2007. Results show that fire severity and effects were greater in those areas subject to repeated wildfire. In addition, topography and patterns of severity and vegetative response following the 2000 fire impose constraints on patterns of reburn severity. These findings emphasize the importance of landscape heterogeneity in determining patterns of fire severity and effects after both initial and repeated wildfire.
https://digitalcommons.usu.edu/nafecology/sessions/fire_effects/2