SOIL AGGREGATE FRACTIONS AND ORGANIC CARBON POOLS AS INFLUENCED BY TREE DIVERSITY IN FOREST RESERVE OF SEMI ARID NIGERIA

Abstract

The ability of trees to sequester carbon vary from species to species, this study therefore evaluates the influence of seven tree species (Acacia senegal, Azadirachta indica, Eucalyptus camadulensis, Khaya senegalensis, Prosopis africana, Tamarindus indica and Tectona grandis) on soil aggregate fractions and various pools of carbon in soil at three soil depth (0-5, 5-15 and 15-25cm). Results revealed that most soil quality enhancing properties concentrated more at the soil surface (0-5cm) relative to other depths. Soil planted to T. indica stood out in possessing high proportion of large and small macro aggregates, mean weight diameter (MWD) and least proportion of silt plus clay particles. High proportion of fine particulate organic carbon, particulate organic carbon, silt plus clay associated organic carbon and non hydrolysable organic carbons were attributed to soil under T. indica. Tamarindus indica might be a better choice of the seven tree  species in mitigating green house effects by sequestering atmospheric carbon and improving soil aggregate stability.