Recovery of burned forest soil by organic residue application - substrate induced respiration in soil

RAMIRAN International ConferenceThe Mediterranean is one of the most vulnerable regions to climatic changes. One of the impacts of these changes is a substantial increase in the meteorological risk of fire. The forest fire regime instantaneously responds to climatic changes and may become the dominant factor of alteration in forest communities (Santos & Miranda, 2006). Therefore, understanding the impact of fire on natural ecosystems may be important in the recovery of post-fire ecosystems, hence allowing a better forest restoration. A fire impacted soil can recover, namely through soil organic matter (OM) correction by the application of organic residues. Applying agricultural (e.g. pig slurry) and municipal solid wastes as organic matter sources to soil may represent a good way to recycle these wastes. Fire leads to important changes in the physical, chemical and biological properties of soils, which are relevant for the future productivity and sustainability of ecosystems (Neary et al., 2005). The extent and duration of these effects on soil properties depend on the intensity and residence time, ergo fire severity (Certini, 2005). Soil microorganisms perform an important and essential role in soil biological processes. Biological properties however, are extremely sensitive to soil warming, where lethal temperature thresholds for most organisms are below 100 oC. Biological diversity represents a sensitive means to determine soil quality. This is related to functional diversity, which comprises the ability of organisms to use a vast range of carbon substrates and be able to perform several biochemical reactions. Soil health and quality can be assessed by microbial community level physiological profiles (CLPP), using different carbon substrates. MicroRespTM can be applied to a vast range of soils and has good sensibility to detect changes in microbial communities, offering a rapid and sensitive method to determine CLPP (Chapman et al., 2007). Soil (Litosol) was collected in Sintra Mountain (Portugal), on a Pinus Pinaster forest, 11 days after a forest fire. The impact on recovery of burned soil by organic residue application and its influence on soil microorganisms was studied using the MicroRespTM method, concerning fire effects on soil microorganisms and the need to recycle wastes