Interception des précipitations par le couvert forestier

Abstract

Our measures have been done to evaluate the importance of the interception in different forest stands which were approximately 30 years old. The net annual interception has been found to be 30% for a Pinus silvestris stand, 34% for a Picea abies stand, 42% for an Abies grandis stand, and 17% for a deciduous stand consisting mainly of Fagus silvatica and Carpinus betulus. The maximum amount of water necessary to saturate the crowns was respectively 3.0 mm, 3.1 mm, 3,8 mm and 1.9 mm of rainfall in the case of Pinus silvestris, Picea abies, Abies grandis and the deciduous stand. In each of these stands, we could establish an equation of the relationship between the précipitations under the canopy on one hand, and the incident rainfall above the canopy and the relative light intensity under the canopy on the other hand. According to the results, we suggest a new and more accurate technique of évaluation of the throughfall. The importance of the data have been discussed from an ecological stand point.