Impact of the conversion of Brazilian woodland savanna (cerradão) to pasture and Eucalyptus plantations on soil nitrogen mineralization Rosario López-Poma a , Vânia R. Pivello b , Gisele S. de Brito b , Susana Bautista a,⇑ a Department of Ecology and IMEM, University of Alicante, Spain b Departament of Ecology, Institute of Biosciences, University of São Paulo, São Paulo, SP, Brazil highlights  Conversion of Cerrado into pastures or Eucalyptus forestry reduces available N.  Cerrado conversion reduces soil potentially mineralizable N and urease activity.  Impact of land conversion surpasses the spatial and seasonal variation in N cycling.  Impact of land conversion concentrates in the top 30 cm of the soil profile.  Conversion to pastures and to Eucalyptus forestry result in similar level of impact. graphical abstract article info Article history: Received 30 August 2019 Received in revised form 4 November 2019 Accepted 4 November 2019 Available online xxxx Keywords: Cerrado Eucalyptus plantation Land use change Nitrogen cycling Soil enzyme activity Urochloa pasture abstract The Brazilian savanna (Cerrado) has been extensively converted to croplands, pastures and forestry plan- tations, and the deforestation frontier continues expanding. Land conversion may cause critical changes in soil functioning, yet very little is still known about the impact of Cerrado conversion on nutrient cycling and soil fertility. Here, we addressed this knowledge gap by investigating the effects of the wood- land cerrado (cerradão) conversion into pastures and Eucalyptus plantations on nitrogen availability and mineralization potential, considering a wide range of spatial and temporal variability due to soil depth, site conditions, and seasonal variation. For three sites in São Paulo state and each of the target land cover types, we assessed the total N and inorganic N (NH 4 -N and NO 3 -N) pools, potentially mineralizable nitro- gen (PMN) and soil urease activity in the first 2 m of the soil profile. Cerrado conversion to either pastures or Eucalyptus plantations significantly reduced NH 4 -N, while NO 3 -N showed similar values in Cerrado and Eucalyptus and lower values in pastures. We found a consistent pattern of lower N mineralization in the uppermost soil layers associated to Cerrado conversion, with decreases in PMN rate and urease activity. The soil below 30 cm depth showed no relevant changes. Considering the first 30 cm of the soil profile, the reduction in the stocks of inorganic N (NH 4 -N + NO 3 -N) ranged from ~14% for the conversion to Eucalyptus to v 20% for the conversion to pasture. The impact of land conversion on N cycling surpassed the influence of the spatial (between-site) and seasonal variation. Overall, the results indicate a decline in available N and overall soil fertility due to Cerrado conversion, which could further increase N limitation in the Cerrado region, increase fertilization needs for future exploitation, and compromise the recovery of Cerrado in case of land abandonment or restoration. Ó 2019 Elsevier B.V. All rights reserved. https://doi.org/10.1016/j.scitotenv.2019.135397 0048-9697/Ó 2019 Elsevier B.V. All rights reserved. ⇑ Corresponding author. E-mail addresses: rosario.lp@ua.es (R. López-Poma), vrpivel@ib.usp.br (V.R. Pivello), s.bautista@ua.es (S. Bautista). Science of the Total Environment xxx (xxxx) xxx Contents lists available at ScienceDirect Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv Please cite this article as: R. López-Poma, V. R. Pivello, G. S. de Brito et al., Impact of the conversion of Brazilian woodland savanna (cerradão) to pasture and Eucalyptus plantations on soil nitrogen mineralization, Science of the Total Environment, https://doi.org/10.1016/j.scitotenv.2019.135397