ABSTRACT:

An assessment of the pattern of litterfall and quality of litter were carried out in plantations of pure exotic Pine and Pine/Gmelina mixed plantations at Forestry Research Institute of Nigeria (FRIN) station Umuahia, Abia State. Litterfall was continuous with much of the litter falling between March and April in the pure Pine stand. April 2004 gave significantly (P<0.05) the highest litterfall (165.9g/m2), followed by March 2004 (104.7g/m2) in pure Pine plantation. In the Pine/Gmelina mixed stand, the highest litterfall occurred in the month of September. The annual litterfall in the pure Pinus caribea and pure Gmelina arborea/Pinus caribea plantations were 625.12g/m2 and 450.9g/m2 respectively. Statistically, no significant difference existed in the mean monthly litterfall in the Pine/Gmelina mixed stand. Also, no significant difference occurred in the mineral content of the plant litters of pure Pine and Pine/Gmelina mixed plantations. Of the two exotic species studied, N (2.03%) and P (0.19%) were more in the litters of pure Pinus caribea than in the litters of pure Pinus caribea/Gmelina arborea mixed plantation. K (0.9533%), Ca (1.5533%), and Na (0.2033%) were more in the litters of Pinus caribea/Gmelina arborea mixed plantation than in the litters of pure Pinus caribea plantation. The high litter production of pure Pine stand makes it suitable for soil erosion control. However, mixed plantation of Gmelina arborea/Pinus caribea will make better contribution in nutrient-poor soils.