Biological activity in Cerrado soils: evaluation of vegetation, fire and seasonality effects using the “bait-lamina test”

Abstract

Aims The Cerrado, a South American savanna, is con- sidered a priority for conservation. In this case study, we assessed soil feeding activity as a way to improve un- derstanding of the ecosystem functioning, in order to support and refine conservation strategies. Methods Soil feeding activity was assessed using the bait-lamina method under different environmental con- ditions: in the dry and rainy seasons, in burned and unburned areas, and under native and invasive grasses. Results Feeding activity was significantly reduced after fire, but recovered to pre-fire levels with the rains. Activity increased significantly during the rainy season in both areas, being more pronounced in the unburned area. The highest feeding activity was observed under the invasive grass (Melinis minutiflora). Feeding activ- ity declined with soil depth and was affected by season and fire. Conclusions Seasonality was the most important factor affecting the feeding activity of soil organisms, followed by the fire history and the extant vegetation. Although this method does not allowdistinguishing between feed- ing activity of different organisms, it can provide valu- able insights into differences in soil functioning due to changes in environmental conditions.