Termite Control of Leaf Litter Decomposition of Eight Selected Plant Species of Sudano-guinea Savannahs of Ngaoundere, Cameroon

Abstract

Few studies on effects of termites on litter decomposition have been done in African savannahs, particularly in the Adamawa savannahs of Cameroon. In the framework of management of resource quality to restore or improve soil fertility of farming systems of Sudano-guinea savannahs of Ngaoundere, Cameroon, study on termites’ control of leaf litter decomposition of eight plant species was conducted on the field. The selected plant species are Bixa orellana, Erythrina sigmoïdea, Ficus polita, Maytenus senegalensis, Mucuna stans, Piliostigma thonningii, Vitex madiensis and Vitellaria paradoxa. Leaf litter samples were incubated in situ using litterbags of 2 mm mesh during 24 weeks in two plots out of canopy, corresponding to two treatments, with and without termites. Experimental design was split-plot with three replications. Collected data was carried out on litter dry mass remaining (LMR). Results showed total mass loss at the end of incubation time (24 weeks) and decomposition rate constants (k) differed significantly among plant species for the two treatments. The values ranged respectively from 23.05% and 0.012 week-1 in V. madiensis to 61.93% of initial dry mass and 0.046 week-1 in P. thonningii for treatment without termites and from 43.88% and 0.022 week-1 in B. orellana to 91.51% and 0.095 week-1 in P. thonningii for treatment with termites. These macro organisms fasted litter decomposition in all plant species, with intensity variation according to species. Litter mass loss and decomposition rate constant (k) correlated with litter thickness, density, area and specific area mass, and these relationships were influenced by the presence of termites. Globally litter decomposition was influenced by termite activities and resource quality. These results contributed to understand litter decomposition process in the sudano-guinea savannahs of Ngaoundere in order improve soil fertility, nutrient cycling and some plant species domestication.