Articles

La structure et la composition de groupes de régénération de hêtre dans la forêt de Soignes. Comm. N° 2 : Croissance et Accroissement

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Abstract

The structure and composition of beech regeneration groups in  the forest of Soignes. Comm. N° 2 : Growth and increment - Comparison between natural (RN) and artificial (RA)  regeneration groups of beech, from 16 to 26 years old, clearly indicates  quicker growth in the RA during the first years. This lead disappears within  a short time, as a consequence of premature culmination of growth (height and  girth) in the RA at a moment where growth is accelerating in the RN. An  analogous inversion in basal area of the groups occurs the relation GRA >  GRN in 16 years old groups changes into GRN > GRA at 26 years old groups.     The analysis of biomass as characterized by total shoot length and basal  area pro surface unit, also proves the relative and absolute superiority of  the RN in regard to standing stock and increment. The confrontation with  values, deduced from the production tables by WIEDEMANN, indicates a far  reaching similarity under many aspects between older stands and the RN,  whereas important differences between older stands and the RA exist.    Dynamic evolution, on the other hand, is characterized in both cases by  social degradation and progression concentration of biomass in the upper  story. In the RN it is further accompanied by concentration of the highest  number of stems in the lower story. As a direct consequence treatment chooses  the upper story, in which all real value is to be found, as its immediate  object. In no case it endeavours to stimulate social promotion considered  impossible in RA on account of extremely low stand density and in RN because  of far reaching social stratification.     In groups with RN, treatment goes out from high stand density and all kind  of inegalities between stand components. It stresses the necessity of early  individualisation of the better trees in the upper story creating at the same  time good conditions for the development of the cultural function, to be  fulfilled by a well balanced intermediate and lower story.     In the RA, on the contrary, the maintenance of the maximal number of stems  in the upper story is a principal objective of treatment, as this story is  not only considered as the source of future value development but also as the  nearly exclusive bearer of the cultural function. In doing so the tendency  toward structural uniformisation is accentuated.     The evident superiority of the RN over the RA regarding, qualitative and  quantitative aspects of structure, growing stock, biomass and increment is a  fact to be taken permanently into consideration.

How to Cite:

Van Miegroet, M. & Réh, J., (1977) “La structure et la composition de groupes de régénération de hêtre dans la forêt de Soignes. Comm. N° 2 : Croissance et Accroissement”, Silva Gandavensis 44. doi: https://doi.org/10.21825/sg.v44i0.975