As a result of reduced water content and increased oxygen concentration, decomposition rates will increase leading to acidification (Gandaseca et al., 2014); this lowering of pH is caused by the formation of sulphuric acid following the oxidation of pyrite (FeS2) (Brouns et al., 2014; Shamshuddin et al., 2014). OPPB and RA soils were similar in terms of pH (4.1 and 4.3 respectively), significantly lower than the natural forest soil’s (4.7, ANOVA p < 0.05) (Table 2). CO2 exchange rates on the site of RA area were the highest (4.9 g CO2m2 h) while agricultural areas were not significantly different with the natural forest soil sample.