Land-use conversion simplifies regeneration niches, but deep belowground bud banks sustain regenerative capacity in Cerrado grasslands

Background and Aims Belowground bud-bearing organs are key to plant resilience in disturbance-prone ecosystems, forming bud-banks that persist under natural disturbance regimes but are highly affected by anthropogenic impacts. Given their importance for ecosystem function, restoration and resilience, we investigated the diversity and vertical distribution of these organs in conserved and degraded Cerrado grasslands, and how land-use conversion affects the organization of regeneration niches and the persistence of regenerative capacity within the soil profile. Methods We examined the vertical distribution of belowground structures within the soil profile and assessed their diversity and composition by excavating ten 1 m × 1 m pits per site. In each pit, we sampled 10 cm layers down to 60 cm and recorded the structures for site comparisons. To assess persistence, we estimated organ age using radiocarbon dating, and to assess resprouting potential, we compared a topsoil-removal treatment with conserved and degraded controls in a field experiment. Key Results Belowground bud-bearing organs showed a stratified vertical distribution. Some organ types occurred exclusively in the uppermost soil layer of the conserved site, contributing to greater organ diversity compared to the degraded site. These shallow-layer structures were absent from the degraded area, indicating loss from land-use conversion. Consequently, belowground structure composition differed between sites, with organ types varying in their persistence to anthropogenic degradation. Deep soil layers contained persistent regenerative structures, some over 60 years old, suggesting that they function as long-term reservoirs of regenerative capacity and may contribute to vegetation recovery following interventions such as topsoil removal. Conclusions Land conversion simplifies belowground regeneration niches through the loss of superficial regenerative structures, whereas deeper structures may persist for decades despite degradation. These persistent structures reveal a previously overlooked regeneration niche that may contribute to ecosystem resilience, persistence, and vegetation recovery following restoration interventions in tropical grassy biomes.