Temporal evolution of organic carbon and nitrogen forms in volcanic soils under broom scrub affected by a wildfire.

The evolution of total N, total oxidizable C, water-soluble NH(4)(+)-N, exchangeable NH(4)(+)-N and soluble NO(3)(-)-N was studied in Canarian volcanic soils under mountainous legume scrub affected by a wildfire by June 2003. Three systematic soil samplings in the burned area and in neighbouring non-burned sampling points were carried out 3, 7 and 12 months after the fire event. The results showed an important mobilization of N (as total N and soluble and exchangeable NH(4)(+)-N) in the soil within the burned area at short term, with a simultaneous depletion of nitrates.