Doctor of Philosophy (PhD)


Environmental Science

Document Type



Microbes (both fungi and bacteria) serve important ecosystem functional roles in nutrient cycling and decomposition, which affect ecosystem response following disturbances such as prescribed fire. A multitude of abiotic and biotic factors influence microbial community compositions, which then drive microbial ecosystem functions. The factors driving microbial communities further change due to fire disturbances and progression with time. Although prescribed fire is commonly used as a technique for ecosystem management, the effects of fire on microbial communities or their functions are simply understudied. Ecosystem management decisions tend to focus on plant and ecosystem post-fire responses. Thus, incorporation of fire effects on microbial communities is crucial to improving these decisions because microbes influence those plant and ecosystem post-fire responses and thus affect future ecosystem trajectories and adaptive management.

This dissertation focuses on microbial community composition and their functions related to nutrient cycling and litter decomposition, and how they respond to prescribed fire in two managed ecosystems. Chapter one introduces general microbial interactions in litter and soil fire ecology, the abiotic and biotic factors that drive microbial communities in the litter and soil horizons (referred to as litter and soil substrates), and how those factors in each substrate change with fire. Chapter two analyzes prescribed fire effects on bacterial communities in an old-growth pine savanna. Chapter three analyzes frequent fire effects on fungal and bacterial communities and functions in a brackish marsh. Chapter four discusses similarities and differences in the responses of the microbial communities, as well as the specific taxa shared by both ecosystems, and their potential functions in the ecosystems. Chapter five discusses management implications and potentially important microbial taxa and functions that may influence prospective ecosystem management goals. Together, this dissertation is a study of microbial communities in fire-affected ecosystems, with applications in ecosystem management.



Committee Chair

Johnson, Crystal N.