This dataset contains measurements of aboveground biomass, belowground organ biomass, belowground bud bank density, root biomass, soil fertility, and soil carbon and nitrogen stocks from invaded and non-invaded vegetation patches of a tropical savanna (Cerrado). Sampling was conducted in an area invaded by Urochloa brizantha, where invaded and non-invaded patches were paired, totaling 10 patches with 2 plots each. The study site is located within the Estação Ecológica de Itirapina, a natural reserve in southeastern Brazil, spanning the municipalities of Brotas and Itirapina, São Paulo State. Data were collected during a field campaign in November 2022. The dataset was generated to assess the effects of the invasive grass Urochloa brizantha on the belowground components of open Cerrado ecosystems, with a focus on the bud bank, biomass allocation among belowground organs, and soil properties. Full details about this dataset can be found at https://doi.org/10.5285/fe698eec-2868-43bf-8029-faa823a6f7d9