Articles

La structure et la composition de groupes de régénération de hêtre dans la forêt de Soignes. Comm. N° 1 : Nombre de pieds, le diamètre et la hauteur.

---

Abstract

Structure and composition of beech regeneration groups. Comm.  N° 1 : Number of stems, diameter and height. - For  the analysis and subsequent comparison of natural (RN) and artificial (AR)  regeneration of beech, 2 x 7 plots of 1 are each and 16 tot 25 years old,  were established in the Forêt de Soignes near Brussels.     With an average of 5.000/ha the actual number of stems was much lower in  the AR as in the NR with an average of 19.900/ ha. However AR can be  considered as growing more rapidly if mean diameter and mean height of all  trees are judged acceptable as parameters. Eventual differences of this kind  between AR and NR tend to disappear pretty soon as culmination of growth  takes place in AR-groups before the age of 16 years and is not yet evident in  the older NR-groups of 26 years old.    The differences in rate of growth are rather unsignificant if comparison is  limited to dominant and predominant elements, present in greater numbers in  NR ( 40 - 70 dominant trees, 20-35 of which are predominant ) as in AR ( 109  - 30 dominant trees, B - 12 of which are predominant ). The NR have a bigger  material reserve, their structuration is better, the variation in growth is  greater and, as a consequence, social differentiation takes place very early.  The relationship by number of stems between dominant, codominant and  dominated trees can be represented by 1/1/2 for NR and by 3/2/1 for AR.      The presence of a well-developed under-story, with a positive influence on  the stabilisation of microclimatic conditions in the forest, permits more  freedom of intervention in NR, where early concentration of elite-material in  the upperstory takes place. In AR-groups the possibilities of selection and  intervention are limited as each element has to be maintained as long as  possible.     Stand formation and social differentiation are the result of collective  dynamics of development in NR. These phenomena are stimulated by greater  stand density and early competition is the result of early restrictions of  the individual growing space. As a direct consequence a evolutive, structural  and functional link exists between predominant, codominant and dominated  elements.     In the AR, social differentiation follows a different pattern. It is an  individualisation phenomenon directly produced by individual genetic  differences and by accidental variations in growing conditions within a very  restricted area.

How to Cite:

Van Miegroet, M. & Réh, J., (1976) “La structure et la composition de groupes de régénération de hêtre dans la forêt de Soignes. Comm. N° 1 : Nombre de pieds, le diamètre et la hauteur.”, Silva Gandavensis 41. doi: https://doi.org/10.21825/sg.v41i0.978