Date of Award

8-2012

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Forest Resources

Advisor

Wang, Geoff

Committee Member

Waldrop , Thomas A

Committee Member

Rieck , James R

Abstract

The increase in both southern pine beetle (SPB) (Dendroctonus frontalis Zimm) outbreak and wildfire occurrence in recent decades has resulted in a growing concern regarding possible interactions. Few studies have quantified fuel characteristics of SPB-killed stands, and none has studied the dynamics of this fuel complex over time. Moreover, how changes in these fuels affect fire behavior remains unknown. To address this lack of empirical data, field measurements and modeling were combined to study fuel dynamics and potential fire behavior within control and post-outbreak loblolly pine-dominated forest stands across a chronosequence ranging from 0 to 8 years since outbreak. Fuels data were collected on three study areas within the Piedmont of Georgia and South Carolina, USA. Fuel loading was significantly greater in post-outbreak stands than in control stands for several types of fuels. Stand structure was altered between stand types, containing fewer live pines and more hardwoods in post-outbreak stands. The Fuel Characteristic Classification System (FCCS) was used to construct representative fuelbeds from the measured data. The customized fuelbeds were then used to model surface fire behavior as a measure of the change in fuel loading and stand structure resulting from SPB outbreak. Flame length and rate of spread (ROS) were derived as metrics of predicted surface fire behavior. BehavePlus was used to further understand the consequences of these fuel changes. Both FCCS and BehavePlus predicted faster ROS and higher flame lengths in post-outbreak stands than in uninfested stands. Stands measured 8 years after outbreak under extremely dry moisture conditions were predicted to have the most extreme fire behavior. These results were compared to existing standard fuel models and discussed in the context of management implications for SPB-killed Piedmont forests.

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