Analysis of Land Use Change and Associated Implications on Soil Ecosystem Functions in South Eastern Nigeria

Abstract

Land use change affects soil functions and its capacity to provide ecosystem services. Though much of the tropics are experiencing accelerated increases in land use change, associated impacts of such changes are poorly understood and studied. This study assessed the extent to which land use changes affect the soil ecosystem functions in a rainforest zone of south eastern Nigeria. Soil samples were collected from 24 sample locations in selected natural forest, cashew and palm plantations. Samples were analyzed in triplicate in the laboratory for geochemical analysis, after which the result was subjected to statistical analysis—ANOVA, correlation and regression. Forest carbon had higher % mean carbon content; though there was no significant difference (F (2, 21) = .246, p = .784) in carbon level across land uses. R value of .301 showed low correlation between % carbon, organic matter and % loss in ignition. Furthermore, R2 value of 9.1% total variation in the dependent variable could only be explained by the independent variables. CEC, Nitrogen, Potassium and Phosphorus content of the land uses did not differ significantly: CEC (F (2, 21) = .844, p (.44); Nitrogen (.243), p (.79), Potassium (.140), p (.87), Phosphorus (.783), p (.47). This showed that there was no significant variation in soil fertility of the land uses, although natural forest had higher concentrations for these variables. Across the land uses, soil texture equally had no significant variations: % sand (F (2, 21) = .320, p (.729) % clay (.430), p (.656), % silt (.043), p (.958). Soil carbon was seen to be more enhanced in natural forest ecosystems than other land uses. Though plantations had reduced capacities to provide ecosystem functions, establishing such in modified landscapes is still advocated as they can coexist with such and yet ensure ecosystem functions.