Contrasting the influence of overstory tree species identity on microclimate, fuels, and tree regeneration in a longleaf pine forest

Abstract

Fire-dependent ecosystems worldwide are facing a significant threat from anthropogenic activities, particularly land use changes and decades of fire exclusion. These alterations have led to a transformation in once open canopy landscapes, to closed canopies with mid-story dominated by shade-tolerant trees and leaf litter fuels. Consequently, the understory becomes wetter and cooler, with a higher accumulation of leaf litter on the fuel bed due to the encroachment of shade-tolerant and fire-sensitive species. To understand the impact of these species on the understory, we conducted a study and experiment focusing on tree microclimate, fuel loads, and tree regeneration in a longleaf pine forest located at the Jones Center at Ichauway in Georgia, USA. Our study revealed that encroaching species have distinct influences on microclimate, fuel loads, and moisture retention, which could affect flammability. By understanding these effects, we can better comprehend the dynamics of the understory and its potential for flammability.