Wildfire effects on extractable elements in ash from aPinus pinasterforest in Portugal

The aim of this work is to study the effects of a wildfire on water‐extractable elements in ash from a Pinus pinaster forest located in Portugal. The pH, electrical conductivity (EC), calcium (Ca 2+ ), magnesium (Mg 2+ ), sodium (Na + ), potassium (K + ), sodium and potassium adsorption ratio (SPAR), aluminium (Al 3+ ), manganese (Mn 2+ ), iron (Fe 2+ ), zinc (Zn 2+ ), sulphur (S), silica (Si) and phosphorous (P) were analysed in ash sampled from a sloped area burned in a wildfire and from litter from a contiguous unburned area, with similar morphological conditions. The results showed that ash leachates had higher pH and EC, and were significantly richer in water‐extractable Ca 2+ , Mg 2+ , Na + , K + , SPAR, S and Si and significantly poorer in water‐extractable Al 3+ , Fe 2+ , Mn 2+ and Zn 2+ than litter solutions. No significant differences were observed in water‐extractable P. The fire changed the ash solute chemistry compared with the unburned litter and increased the sample variability of nutrient distribution with potential implications for plant recovery.