DEMOGRAPHIC STRUCTURE AND STAND DYNAMICS OF THE EL HAMIMET FOREST MODELED BY THE WEIBULL DISTRIBUTION

Abstract

This study involved dendrometry analysis and modelling of the demographic structure of stands in the El Hamimet forest (Oum El Bouaghi, Algeria), dominated by Aleppo pine (Pinus halepensis Mill.) and green cypress (Cupressus sempervirens L.). Four representative plots were studied in order to assess the variability of dendrometry and structural parameters. The average diameters observed ranged from 13.4 to 22.8 cm, and the average heights ranged from
3.2 to 4.5 m, reflecting marked heterogeneity between young and mature stands. The average basal area ranged from 15.2 to 27.6 m²/ha, with a density of 820-1,150 stems/ha, reflecting varying conditions of competition and growth. By fitting the diameter and height distributions to a three-parameter Weibull distribution, we characterized the demographic structure in detail. The values of the shape parameter (k) ranged from 1.46 (P2) to 2.70 (P4), indicating structures ranging from young, regenerating stands to mature, homogeneous stands. The scale parameter (λ), ranging from 3.22 to 4.53, reflects the dispersion of heights and diameters across development stages. These results show that plots P1 and P4 have stable structures with a predominance of mature trees, whereas P2 and P3 exhibit active regeneration dynamics. All of these observations highlight the structural complexity and functional diversity of the El Hamimet forest. The use of Weibull’s law proved particularly effective for interpreting the distributions of heights and diameters, enabling assessment of the dynamics of stand growth and succession. These results provide an essential basis for guiding silvicultural practices toward sustainable, resilient management of Mediterranean forest ecosystems