CONTRIBUTIONS OF THROUGHFALL, STEMFLOW AND LITTERFALL TO NUTRIENT CYCLING IN A SECONDARY LOWLAND RAIN FOREST IN ILE-IFE, NIGERIA
Inputs of nutrients through precipitation and transfer of nutrients to the soil from canopy via litterfall, throughfall and stemflow were investigated on a secondary lowland rain forest at Ile-Ife, Nigeria. The objective was to determine the relative contributions of litterfall and net precipitation components to nutrient cycling in the forest. The results indicated that the concentration of all nutrients (N, P, Ca, Mg, K, Na, Mn, Fe, Zn, Cu) in the different litter components (leaves, small wood, fruits and flowers) were consistently higher than in the precipitation components. Net precipitation contained bulk of the amounts of K, Mg, Na, Zn and P transferred to the forest floor. Throughfall accounted for the highest proportion of nutrients reaching the forest floor from the canopy except for Ca, N and micronutrients (Mn, Fe, Cu), which were greater in leaf litter. Stemflow, wood and reproductive litter contributed only small amounts to the cycling of the elements. The period of highest nutrient deposition to the forest floor via litter occurred in the dry season, from November till March. The highest nutrient transfers via precipitation took place in the rainy season from March till November.