Organic matter, nutrient content and biological activity in burned and unburned soils of a Mediterranean maquis area of southern Italy.

摘要

Experimental fires were performed during the summer-drought period in a Mediterranean maquis in the Castel Volturno Nature Reserve in south-western Italy. The two different fuel loads applied (4 kg m-2 and 2 kg m-2) resulted in complete and partial combustion of the vegetation, respectively. Soil organic matter content (SOM), total and available element concentrations (K, Mg, Na, Mn, Fe, Cu, Pb, Cd), microbial carbon, respiration, metabolic quotient (qCO2), and the coefficient of endogenous mineralization (CEM) were measured at intervals in the dry and wet seasons over a period of about 3 years, in burned and adjacent unburned soils. Soil samples (0-5 cm depth) were collected under the cover of Phillyrea angustifolia L., a dominant species in the study area. Both fires induced long-lasting increases in SOM. As indicated by the increase in CEM, part of the accumulated SOM was mineralized in the first 3 months after fire whereas part of the accumulated SOM was instead stable. Both fires increased the total and available fractions of nutrients and trace elements. During the first 3 months after fire, microbial biomass and qCO2 were higher in the burned soils, which were richer in nutrients, but were characterized by harsher environmental conditions compared to unburned soils..