Biochemical activity and microbial biomass in wetlands (Vereda) and well-drained soils under native vegetation types in Brazilian Cerrado

Abstract The Cerrado is the second largest Brazilian biome, a world biodiversity hotspot and home to important hydrographic basins. In this biome, native vegetation types play crucial environmental roles as natural repositories of carbon, water and biodiversity. However, the Cerrado is threatened by deforestation and land degradation. The soil microbiology knowledge of these areas would provide a better understanding of how this threatened environment functions and a basis for monitoring and conservation. This study investigates soil respiration, microbial biomass and enzymes activity of the native wetlands (veredas), and well-drained soils under native cerrado sensu stricto and semi-deciduous dry forest. Vereda soils produced the highest levels of soil biological attributes, while the semi-deciduous dry forest produced intermediate values and the Cerrado, the lowest values. Regardless of season, differences in soil activity were best correlated with five biological attributes: basal respiration, FDA, urease, β-glucosidase and acid phosphatase activity. Partial redundancy analysis indicated that variance in soil microbial and biochemical attributes was better correlated with soil physicochemical attributes than with vegetation type. Redundancy analysis and a Pearson correlation showed that the differentiating biological variables were best correlated with nitrogen concentration. Vereda soils have a far greater biochemical potential for metabolizing organic carbon under standard (i.e. aerobic) conditions, suggesting that draining vereda soils may lead to losses of organic matter and increased greenhouse gas emissions. The findings of this study provide a basis of ecological information on native Cerrado soils that can be used to manage and monitor the quality of this threatened biome.