Ecological Structure and Prediction Equations for Estimating Tree Age, and Dendometric Parameters of <i>Acacia senegal</i> in the Senegalese Semi-Arid Zone—Ferlo

Abstract

The development of equations to predict tree height, crown diameter, crown depth from stem diameter of a tree species enables arborists, researchers, and urban forest managers to model costs and benefits, analyze alternative management scenarios, and determine the best management practices for sustainable forests. The objective of this study was to develop regression prediction models for tree age, tree height, crown diameter, crown ratio and crown depth for A. senegal growing in Ferlo, in the northern Senegal. Four plantations of different years old (ISRA, 10 years old plantations, Ndodj, 8 years old plantations, Boulal, 5 years old plantations and Déali, 4 years old plantations) were selected. The following dendometric variables: crown height, crown diameter, stem diameter at the breast height, stem basal diameter (at 0.30 m) and the height from the tree base to first branch were measured on a total of 489 trees. The results suggested that the ecological structure of the different year old A. Senegal plantation revealed a bell-shaped form with left dissymmetric distribution indicating a predominance of individuals with small diameter at breast height. Allometry study of A. Senegal showed highly significant positive correlations (p = 0.00) between stem diameter at breast height, stem basal diameter, tree height, crown diameter and crown depth. Positive correlations were also found between crown diameter, tree height and crown height. Prediction models derived from these relationships can be used to estimate the tree height, stem diameter at breast height and crown depth from crown diameter with greater precision. As for A. Senegal age estimation, the established model is not strong as it can explain only 49.1% of the age variation.

Influence de la litière foliaire de cinq espèces végétales tropicales sur la diversité floristique des herbacées dans la zone du Ferlo (Senegal)

“…Sur le plan morphopédologique, la zone d'étude appartient au Ferlo sableux caractérisée par un relief peu accidenté avec des sols subarides tropicaux et brun-rouge formés de matériaux sableux pauvres en argile (Diallo et al, 2013 (Stancioff et al, 1986).…”

Linking Dendrometry and Dendrochronology in the Dominant Azorean Tree Laurus azorica (Seub.) Franco

“…Franco, since the number of growth rings can be used as a good estimate of stand age [2,68]. Although tree growth is the result of very complex processes [69], allometric models can be a robust alternative to predict the growth and the mean age of tree populations [70]. Furthermore, models relating tree age and other dendrometric variables are available for different species and different geographic areas (e.g., [2][3][4]54,55]).…”

Flore et structure de la végétation ligneuse le long de la Grande Muraille Verte au Ferlo, nord Sénégal.

“…La régénération est importante chez B. aegyptiaca et très faible chez les autres espèces dont la densité était élevé autrefois. C'est le cas de A. senegal (Diallo et al, 2013), A. tortilis, S. birrea, A. seyal, C. glutinosum, Z. mauritiana, A. leiocarpa et G. bicolor. La faible régénération de ces espèces peut s'expliquer par plusieurs facteurs selon Boussim et Gampine (1995) et Ndiaye (2013.…”

“…De plus, le couvert aérien de B. aegyptiaca est privilégié par les ruminants et cette fréquentation augmente les chances de dissémination des semences qui y trouvent par ailleurs des conditions favorables à leur implantation (Akpo et Grouzis, 1996). La faible régénération des espèces comme A. senegal s'explique par l'intérêt qu'il présente pour le bétail et la gomme (Diallo, 2007;Diallo, 2013).…”