Evaluation of controlled burning conditions that influence the physical and chemical attributes of soils under Echinospartum horridum

Abstract

With the objective of evaluating the effects of fire on soil of varying burning severity, experimental burnings of soil samples under different burning temperatures and times have been conducted. Burned soil monoliths have been sampled immediately after burning and five months after greenhouse conservation, separating layers of 0-1 and 1-3 cm depth. The impact of different burning severities was assessed based on the change of physical attributes (persistency of water repellency) and biological attributes (labile, intermediate, recalcitrant, microbial, and respired organic carbon). The results show that the most severe burns cause a big impact on organic matter, both on quantitative and qualitative levels, affecting the diverse organic carbon fractions, as well as the microbial biomass and activity. Most severe burns also cause a big water repellence on the 0-1 or in the 1-3 layers, depending on burning severity. After five months, most of the assessed parameters have been returned to initial levels and post-fire water repellence have disappeared, suggesting a fast recovery of the soil properties after the disturbance caused by the burnings.