The objective of this study was to determine the effects of a simulated light fire (250°C) on the availability of N and P, and on concentrations of ions in solutions of two typical Mediterranean soils (Chromic Luvisol and Lithic Xerothent) that support an oak shrubland and an Aleppo pine forest respectively. Likewise, the effect of fire on soil taken from beneath pine trees (Pinus halepensis) and from the adjacent interspace was investigated. Soil nutrients in all the types of soil and in all the treatments increased after the fire. However, the extent of the increase of the nutrients and their dynamics depends on the characteristics of the soil and of the microhabitat (the underlying and nearby interspace), on the tree species burnt during the fire, and on the leaching process. The overall conclusion in this study is that fire increases nutrient concentrations in mineral soil. Yet, changes are distributed in a mosaic pattern, a fact which contributes to the complexity of the ecosystem.