Effects of Fire on Post-burn Soil Temperature and Moisture

Fire can lead to increased soil temperatures in the months following a burn by removing the forest floor, blackening soil surfaces, and opening the canopy. At the same time, removal of above-ground biomass may increase soil moisture by reducing evapotranspiration. For example, Swift et al. (1993) found that using the fell-and-burn technique in the Southern Appalachians increased soil temperatures 2 to 5°C at 10 cm depth during the first 16 months after treatment.  In the same study, they also observed increased soil moisture.

Because soil temperature and moisture regulate many processes (including microbial activity, organic matter decomposition, and herbaceous and woody plant growth), these responses to burning will tend to accelerate rates of microbial transformations and decomposition of residual forest floor and extend the active growth season for some sprouts and seedlings.