Vegetation and litter production in Southern Guinea savanna, Nigeria

This study examines the woody vegetation, annual leaf-fall and annual wood-fall in Southern Guinea savanna near Mokwa, Nigeria. There were 1425±402 (95% limits) trees ha^-1 of which Caesalpiniaceous legumes made up 53%. Annual leaf-fall was 2.387 t ha^-1 a^-1 equivalent to 11,238,932 kcal ha^-1 a^-1 and was highly seasonal, peaking from November to February, with a maximum in January after the annual bush fires. Annual wood-fall was 1.391 t ha^-1 a^-1 equivalent to 7,598,256 kcal ha^-1 a^-1 and was less seasonal but with two peaks, one from January to March after the fires and another from May to July in the rainy season.The litter-fall data currently available from West Africa are reviewed and indicate a negative correlation between litterfall and latitude (P<0.001). Litter production is found to be positively correlated with rainfall (P<0.001) and it is suggested that seasonal distribution of rainfall may also be a factor contributing to the limits of litter production.