Processus hydriques dans des écosystèmes forestiers

This paper highlights the results of a research on hydric processes in different forest systems to evaluate the effectiveness on sail conservation. Reafforestations of pine (P. laricio Poir.) and ook coppices (Q. pubescens Willd. and Q. frainetto Ten.) where chosen becau.se they are representative of conditions throughout the Mediterranean area. The intrerception, which is a function of the forest cover, is a significant factor in the hydrological balance and represents a variable fraction of the occurent rainfall while the stemf1ow represents a small fraction of the precipitation. In the pine ,stands rainfall did not cause any runoff. This was both because of the crown interception and the infiltration in the soil. It was, moreover possible to confirm that the reduction of density did not substantially modify the hydrological balance.