Dissertation Defense - Department of Geography and Geoinformation Science

PhD Candidate: Ioana Bouvier

PhD of Science, Earth Systems and Geoinformation Sciences

Department of Geography and Geoinformation Science 

Title: Spatio-temporal vegetation and catchment dynamics following infrequent forest wildfires

Dissertation Chair:  Dr. Paul Houser (GMU, GGS)

Committee Members:

Dr. Viviana Maggioni (GMU, CEIE)

Dr. Matthew Rice (GMU, GGS)

Dr. Donglian Sun (GMU, GGS)

Abstract:

While wildfire is an important driver of annual forest disturbance in Western United States, forest disturbance due to fire is infrequent in Eastern United States and in the Western United States Cascades Range. Changes in wildfire frequency and intensity amid climate variability are anticipated to increasingly impact forest ecosystems in regions with rare fire occurrence, and where fire effects on vegetation and watershed hydrology are under-studied. This research knowledge gap could impact managers that need dependable data and models to anticipate and plan for potential impacts on forested watershed and the water supply. This dissertation used a combination of statistical methods to control for climate variability and to examine historical streamflow in watersheds impacted by rare wildfire outbreaks. Additionally, cloud-computing approaches to estimate fire burn severity and vegetation recovery at fine temporal scales were evaluated.  This dissertation found that vegetation recovery varied by burn severity and topography. An important finding from this research was that annual water yield increased following an uncommon fire outbreak in the Southern Appalachian Ecoregion. In a burned forested watershed, annual water yield was significantly impacted by forest disturbance, with an increase of up to 25% in the years following wildfire. These results are novel and significant for improving our understanding of infrequent wildfire impacts on vegetation recovery and water supply