Solutes in overland flow following fire in eucalyptus and pine forests, northern Portugal

Small bounded plots were used to investigate dissolved nutrient losses in overland flow in eucalyptus and pine forests in northern Portugal following understorey fires. Losses of NON, POCa2+, Mg2+ and K+ were measured over 19 months during the first 2-3 years after fire. Solute losses in overland flow increased after fire in eucalyptus and pine terrain due to the mineralization of litter and vegetation and increased overland flow. The data suggest that (i) elevated losses persist for at least 2 and 3 years at the pine and eucalyptus sites respectively and (ii) soluble losses of POK+ in a post-fire cycle may exceed those adsorbed to eroded material. Losses of POalthough relatively small, are potentially the most detrimental to soil fertility and forest productivity because of the limited opportunity for P replenishment and correspondingly high P losses adsorbed to eroded sediment. Copyright © 2000 John Wiley & Sons, Ltd.