Understorey Regeneration of Lophira alata as Affected by Seed Tree Size and Growing Conditions

• Main Authors: Bongjoh, CA., Ngono, G.
• Format: Article
• Language: English
• Published: Presses Agronomiques de Gembloux 2005-01-01
• Series: Tropicultura
• Subjects: Biomass; Deforestation; Morphology; Natural regeneration; Pioneer species; Seedlings; Cameroon
• Online Access: http://www.tropicultura.org/text/v23n2/71.pdf

Demographic pressure and slash and burn practices are two factors which reduce the number of Lophira alata plants in its natural range where it is more represented by young plants. The hypothesis that its understorey regeneration may be affected by seed tree size and growing conditions was investigated in the tropical moist forest in southern Cameroon using mature trees of various diameter classes for a sustainable management of the species. Biomass partitioning was also examined in regenerating seedlings growing in loading bays and forest understorey. Seedling density was highest when seed tree diameter at breast height (dbh) was 100 cm or more. A strong positive correlation was found between seed tree diameter dbh and crown size expressed as mean diameter of projected crown area, but crown size correlated much better with seedling density. Compared with their counterparts of the same height growing in loading bays in full sunlight but devoid of litter and topsoil, seedlings found in understorey exhibited lower root: shoot ratio, indicating that soil-derived resources were more limiting in loading bays than on undisturbed forest floor. Leaf weight per area (leaf dry weight/leaf area) (LWA) and leaf packing (leaf number/cm shoot height) were almost 2-fold greater in loading bays than in understorey. As seedlings seldom grew taller than 50 cm in the latter environment, it may be inferred that root: shoot ratio, LWA, and leaf packing can be used to assess the sustainability of growth and development of this pioneer species at the seedling stage.