Fire effects on soil water dynamics in a Mediterranean shrubland

摘要

With the purpose of studying the effects of fire on the natural dynamics of soil water, an experiment was set in a Mediterranean shrubland in Central West Portugal. Soil moisture was measured in two closely located plots at six depths down to 170 cm, during 2000 (reference period) and after an experimental fire set on one of the plots in June 2001 (treatment period). Moisture differences between homologous days (I) of the treatment and the reference periods were computed both for the control (Dci) and for the burned (Dbi) plots. Results showed significantly higher values of Dbi both at the dry and at the rainy seasons. Values of Dci were subtracted from Dbi in order to estimate the net effect of fire on soil water storage (Si). Values of Si showed a maximum of 108.2 mm in the dry season and a maximum of 145.2 mm in the rainy season. At the upper soil layers values of Si decreased as vegetation recovery proceeded along the dry season.