Relations between the ecological conditions and the properties of Pterocarpus erinaceus Poir. wood from the Guinean-Sudanian and Sahelian zones of West Africa
Résumé
Pterocarpus erinaceus (Poir) is currently the most exploited and threatened spontaneous tree species in the Guinean-Sudanian and Sudano-Sahelian zones in West Africa. This work analyzed the density and color parameters of P. erinaceus wood in the phytogeographic zones (Sudanian, Guinean and Sahelian) in three countries in West Africa (Togo, Burkina Faso and Niger). The results obtained by studying 451 specimens taken from 95 trees showed significant differences in basic density and color parameter values (P <0.001) based on phytogeographic zones. Individual tree samples from the Sahelian zone were denser (780 +/- 63 kg m(-3)), darker (L*= 48.3 +/- 0.6) and redder (a*= 8.2 +/- 2) than those in the Guinean zone (basic density = 684 +/- 53 kg . m(-3); L*= 59.7 +/- 0.5; a*= 6 +/- 0.2) and the Sudanian zone (basic density =725 +/- 70 kg . m(-3) ; L*= 53.7 +/- 0.40; a*= 7.30 +/- 0.2). At intra-tree scale, the results did not show a significant variation of basic density according to the number of rings counted from the pith (P > 0.05). This indicated that the age of the trees has little influence on the basic density of P. erinaceus wood.