Article révisé par les pairs
Résumé : Key message : Light drives mortality, growth, and functional strategies of Pericopsis elata, guiding optimal silvicultural practices from early shading to timely thinning. Abstract: The low natural regeneration of many exploited tree species in Central Africa highlights the need to more precisely define appropriate silvicultural practices. Understanding how seedlings adjust their functional traits and growth in full sunlight and under the shade of other trees is essential to optimise enrichment planting protocols. To address this topic on Pericopsis elata, an important light-demanding timber species exploited in Central Africa, 230 seedlings were transplanted between 2022 and 2024 in the buffer zone of the Yangambi Biosphere Reserve, Democratic Republic of Congo, either in full sunlight or shaded environments (under Acacia auriculiformis). Twenty-three morpho-physiological and chemical traits were measured, alongside growth dynamics. Mortality was higher in full sunlight (10.7%) during the first ten months after transplantation, but converged to similar rates (about 13%) in both environments after three years in the field. Diameters were higher in full sunlight after 310 days, and heights were greater after 600 days of planting. Seedlings in full sunlight exhibited a conservative resource-use strategy contrasting with a more acquisitive strategy under shade. Light environment explained over 58% of the variation in key traits such as specific leaf area, stomatal density, and maximum stomatal conductance. Trait correlations were stronger and more coordinated in full sunlight, while they weakened or disappeared under shade, reflecting a shift along the resource acquisition-conservation continuum in response to light availability. These results provide one of the first experimental insights into how light influences growth and functional strategies in juvenile P. elata. We conclude that shading with a canopy openness of about 20–65% promotes early establishment after transplanting seedlings, but a gradual thinning of shade trees is needed from the second year to enhance growth and survival.

Documents en relation

DI-fusion