Evaluation of forest litter mineralization capacity on the growth of Irvingia gabonensis in Ogwashi-Uku Forest Reserve, Delta State, Nigeria

Abstract

The study evaluated litter production capacity of three forest plantation foliage litters as potential mineralization sources for the growth of Irvingiaga bonensis. Litter production capacity of Bamboo, Teak and Gmelina forest plantations was monitored for 70 days before Irvingia seeds were sown in open germination beds containing litters soil samples for vegetative development assessment. Data collected were analyzed using ANOVA and significant means separated with the DMRT. Results showed the mean litter production as Teak (3.65t/ha) >Gmelina (3.60t/ha)> Bamboo (2.67t/ha) and germination percentage was highest for soils of Bamboo plantation. The carbon nitrogen ratio was Gmelina (2.60)> Teak (2.24)> Bamboo (1.90) and bulk density as Gmelina (1.59 g/cm3) > Teak (1.47 g/cm3) > Bamboo (1.45 g/cm3). The plant height, leaf area and leaf to stem ratio were Bamboo >Gmelina> Teak while the collar diameter was highest in Teak forest plantation soils. The study showed soils under the Bamboo forest as the best growth media for I. gabonensis, and therefore implied soils under the Bamboo forest as potential natural nursery and forest regeneration materials, especially in the current global deforestation menace that have adversely limited the preponderance of silvical floor litters.  Key words: Soil organic matter, litter production, forest soils, decomposition, vegetative development.