Soil phosphorus of stable fraction differentially associate with carbon in the tropical forest and savanna of eastern Cameroon

The forest–savanna transition zone, which contains nutrient-poor soils (Oxisols), is found throughout central Africa. To evaluate the effect of deforestation on soil phosphorus dynamics, which regulate the plant growth in this area, we quantified the relationship between phosphorus (P) and carbon (C) in different fractions and compared their relationship to forest and savanna (deforested vegetation) in eastern Cameroon. We analyzed the P, C, and nitrogen (N) contents of soil using the physical fractionation method (0.25–2.0 mm as macro-particulate organic matter [M-POM]; 0.053–0.25 mm as micro-POM; and <0.053 mm as Clay+silt) in different land management (young and old forests and annual and perennial grass savannas at 100-cm soil depth). We found larger soil P stock in forests (4.7–4.9 Mg P ha−1) than that in savannas (3.4–4.0 Mg P ha−1), though soil C and N stocks were similar between the vegetation. We also observed lower soil P stock in the active fraction (M-POM) with its higher C:P and lower...