Seasonal Variation In Litterfall In An Age Series Gmelina Arborea Plantation In A Nigerian Rain Forest

The study aimed at investigating the nutrient dynamics of Gmelina arborea stands aged 28, 29 and 30 years planted in a degraded soil in Shasha Forest Reserve, Osun State, Nigeria. Monthly variation in litter fall of Gmelina arborea stands aged 28, 29, and 30 years were studied for 13 months with litter traps in three 20m x 20m plots randomly selected in each stand. Monthly collections of litter fractions per stands were sorted into leaves, twigs, reproductive structures and others. Litters according to fractions per stand per month were oven dried at 800C for 48 hours. Samples were created for chemical analysis. Data collected were analysed using descriptive statistics and inferential at 0.05 level of significance. Litter fall (especially leaf fall) occurred throughout the period of collection (13 months), in the stands(S). The peak of total litter fall was recorded in October 2005 in S1 (18.2%) while peaks were recorded in September in S2 (11.21%) and S3 (13.67%). The analysis of variance to determine interaction effect between fall of the litter fractions and age of the stands did not show any significant differences. Leaves constituted the bulk of litterfall across the three stands. The percentage of leaf litter to the total litter per hectare in stand ages 28, 29 and 30 years were 41.32, 34.19 and 24.48% respectively. While the contribution of unidentified litter thrash was highly insignificant. The study reveals that nutrient dynamics under Gmelina arborea plantations demonstrate a high restorative potential under a degraded soil in Shasha Forest Reserve.