Fuel dynamics of a longleaf pine (pinus palustris mill.) woodland under a prescribed fire rotation

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University of Alabama Libraries

As a result of historical logging and fire exclusion, longleaf pine (Pinus palustris Mill.) ecosystems have experienced extensive decline, now occurring on only 2–5% of its native range. Attempts to re-introduce fire into these forests where fuels have been altered by previous fire-exclusion or disturbance may not achieve desired management goals because fire effects are largely dependent on available fuels. To understand how fire impacts longleaf pine woodlands where fuels have been altered, fuel was collected before (2017) and after (2019) a prescribed fire on undisturbed, wind-disturbed, and wind-disturbed and salvage-harvested treatment types. In conjunction with percent consumption values calculated form laboratory burns, decomposition rates, and accumulation rates, fuel dynamics models were created and validated against post-fire fuel loadings. Total fuel loadings for undisturbed plots decreased 43%, wind-disturbed plots decreased 67%, and wind-disturbed and salvage-harvested plots decreased 53%. Fuel dynamics models successfully predicted post-fire fuel loadings for pine needles (rs = 0.782; p < 0.0001) and high flammability fuels (leaves, grass, bracken fern; rs = 0.529; p < 0.001) by plot, and further indicated that percent consumption values for other leafy fuels were accurate. I therefore concluded that laboratory burns can inform fire behavior in the field for leafy fuels. Forest structure models elucidated the varied effects of fire and time on the relationships between forest structures and fuel loading and composition. These models also showed stronger relationships between forest structures and leafy fuels (r2 = 0.655 to 0.811). Both models provide detailed depictions of how diverse longleaf pine woodland fuels change before and after a prescribed fire and may be used to accurately guide fuels management to achieve desired stand conditions.

Electronic Thesis or Dissertation
Natural resource management, Forestry, Physical geography