Short-term changes in soil functionality after wildfire and straw mulching in a Pinus halepensis M. forest

Abstract

Understanding the changes in physicochemical and microbiological soil properties induced by straw soil mulching is very important in the Mediterranean environment, where forest ecosystems are particularly prone to erosion and degradation risks. To fill this gap, this study has evaluated the seasonal changes (from spring to autumn) in important physicochemical soil properties, such as pH or soil organic matter, and enzymatic activities, such as urease or dehydrogenase activities, in burned (treated with mulching or not) plots, compared to non-burned soils, after a wildfire occurred in a Pinus halepensis M. forest. Monitoring activity has confirmed that the treatment of burned soils with straw mulching improves its functionality in the short term. More specifically, although soil pH was stable and electric conductivity noticeably reduced, the organic matter was higher in burned and mulched soils compared to non-burned soils. The increases of basal respiration as well as microbial carbon and glomalin contents after mulching indicated higher activity of soil microorganisms and increased carbon and nitrogen storage. Moreover, all microbiological and enzymatic activities improved, except for dehydrogenase activity (DHA). Overall, this study highlights that soil functionality of wildfire-affected areas significantly benefits with straw mulching treatment.