Recrû naturel dans des taillis de chêne vert (Quercus ilex L) à la suite d'exploitations partielles

Abstract

The aim of this article was to study the influence of coppice age (4 to 57 years old) and of intensities of cleaning (light and heavy) or thinning (26-78% of removed basal area) on the appearance and growth of new stump sprouts in Quercus ilex coppice. The sprout layer at soil level can be quantified by degree of closure, biomass and Quercus ilex sprout height. This layer grew regularly for the 5 years following harvest and increased in direct proportion to increase in thinning intensities; it was found to be greater for young coppice (25 years old and less) than for old coppice. Coppice functioning was then studied at the stool level. Number and growth of new sprouts inside each stool were then related to the initial characteristics of the initial stool as well as to the degree of thinning in the stool. Sprout number was proportional to number of cut shoots, while sprout growth tended to be related to percentage of shoot or basal area removed by thinning. Finally an attempt has been made to explain the functioning of the stools by separating the effects of the mean thinning intensity of each plot and of the degree of cutting for each stool. In conclusion, hypotheses have been proposed on physiological origin of the observed phenomena.