The productivity of a pasture soil (caatinga) located in the region of São João do Cariri, PB, Brazil was evaluated based an the following microbiological parameters: biomass (measured by fumigation-incubation method), activity (estimated from basal respiration and cellulose decomposition rate), qCO2, and Cmic : Corg ratio. This analysis demonstrated that livestock management in the 'caatinga' is probably causing environment damage by affecting the soil properties, reducing the microbial biomass and soil respiration and increasing the qCO2, affecting the recovery of this ecosystem.
Keywords: biomass; caatinga; microbial activity; pasture; semi-arid.