Spatio-temporal variability of heartwood proportion in Pterocarpus erinaceus Poir.

Abstract Pterocarpus erinaceus Poir. is a species found in the Guineo-Sudanian and Sudano-Sahelian zones, known for its high-quality wood. However, there is limited understanding of its forestry and technological properties, which currently prevents its inclusion in reforestation programs. The objective of this study was to analyze the factors influencing heartwood variability in P. erinaceus. The study was conducted on 40 wood cores collected from three climatic zones (Sudanian, Guinean, and Sahelian). The results revealed significant variation in the percentage of heartwood across agroecological zones, with the highest percentage observed in the Sahelian zone (90.16 ± 3.21%) and the lowest in the Guinean zone (75.20 ± 6.85%). The study also found a significant correlation between the percentage of heartwood and tree diameter, as well as between the percentage of heartwood and tree age. Duraminization initiation was found to occur early in trees from the Guinean (14 years) and Sudanian (16 years) zones, while in the Sahelian zone, it starts at the age of 21 years. The results also reveal a decrease in duraminization rate with age, regardless of climatic zone.