Free access
Issue
Ann. For. Sci.
Volume 49, Number 2, 1992
Page(s) 111 - 131
DOI http://dx.doi.org/10.1051/forest:19920203
Ann. For. Sci. 49 (1992) 111-131
DOI: 10.1051/forest:19920203

Développement des plants de hêtre (Fagus sylvatica L) dans une régénération naturelle, équienne, âgée de 18 ans

B Thiébauta, b, B Compsc, M Rucarta, S Sorostea and C Ntsame Okwoa

a  Université des sciences et techniques du Languedoc, institut de botanique, 163 rue Auguste-Broussonnet, 34000 Montpellier
b  CNRS, centre Louis Emberger, BP 5051, 34033 Montpellier Cédex
c  Université de Bordeaux I, département de biologie des végétaux ligneux, avenue des facultés, 33405 Talence, France

Résumé - Dans une régénération naturelle de hêtre, équienne, âgée de 18 ans, le développement des plants est étudié en analysant la morphologie de leur tige principale, sous 3 éclairements : à la lumière, en demi-lumière et à l'ombre. La régénération est pluristrate dans les 2 premiers cas et monostrate dans le dernier. La structure se dessine tôt et son caractère mono- ou pluristrate apparaît rapidement. La stratification a une influence sur le développement des plants à l'âge de 18 ans ainsi que sur leur croissance annuelle et cumulée, chaque année pendant 18 ans. Les reclassements des individus seront examinés dans un prochain article.


Abstract - Growth of young beeches (Fagus sylvatica L) in an even-aged, 18-year old natural beech regeneration. In an even-aged 18-year old natural beech regeneration, the growth of young plants has been analysed using only the main stem under 3 daylight intensities: full-light, half-light, and shade. The structure shows 3, 2 and 1 layers respectively under these light conditions (table I). The variations in total height and root collar diameter had 2 components in full-light and in half-light only, ie among- and within-layers (figs 1, 2 and 3). In full-light, the height variations were responsible for the differences among the layers and those of root collar diameter for the differences within the layers, fig 1. In half-light the variations in height and root collar diameter were simultaneously responsible for the differences among and within the layers (fig 2). The structure appeared early with a single or several layer(s) (fig 8). The annual and multiannual growth exhibited 3 periods: establishment, differentiation, and regression or stabilisation, (figs 5, 6, 8 and 9). In full-light where differentiation is best between the layers, stratification had an influence on the vigour of the seedlings and to some degree on their shape, but not in half-light (fig 10). The layers may be considered as reflecting social status in full-light where the height is regulated by stratification. The classification of seedlings according to their total height over the 18-year period will be analysed in a subsequent paper.


Key words: natural seedling / Fagus sylvatica = beech / stratification / growth

Mots clés : régénération naturelle / Fagus sylvatica = hêtre / stratification / croissance