Impact of land use changes to a natural forest on some soil microbiological properties

Abstract

The major aim of this study was to assess the value of parameters associated with the total microbial biomass as indicators of changed soil quality following various changes in land use to a dry mixed evergreen forest in Sri Lanka. The most striking effects of land disturbances are seen in the data for total Nitrogen and available phosphate. While there were no consistent changes in total microbial biomass associated with changes in season, there was generally higher total microbial biomass in the Natural Forest and plantation soils than in the disturbed sites. Data on metabolic quotient of the microbial biomass, % contribution of microbial C to total soil C and time for microbial biomass to achieve peak CO2 evolution did not indicate any consistent pattern of stress due to the disturbance of the Natural Forest. However, the results clearly confirmed that both chemical and biological properties of soil are highly vulnerable for any stress caused by land use changes there by reducing the quality of soil.