Insights on the Potential of Natural Regeneration to Restore Cerrado Open Ecosystems

Natural regeneration in tropical open ecosystems has proved to be an effective mechanism for recovering degraded areas when considering the woody vegetation layer. However, little is known about the potential of the ground layer to recover after anthropogenic disturbances. Here, we aim to deepen the current understanding of community assembly in tropical open ecosystems by studying the natural regeneration potential in the Cerrado, with a focus on the ground layer. By inducing disturbance in conserved and degraded Cerrado grasslands, we tested the hypothesis that typical (native) Cerrado species colonise the disturbed patches primarily through vegetative propagation rather than by seed germination. Therefore, the vegetation would resemble the surrounding area instead of forming a novel species assembly. We induced disturbance by creating small gaps and monitored species colonisation strategies under both conditions. Non-native species dominated the degraded site, whereas the conserved site—an old-growth grassland—was dominated by native species. After 18 months (two reproductive seasons after the gaps opening), few native species colonised the degraded area, despite the removal of the non-native species in the gaps and the proximity to the conserved vegetation. Only exotic and ruderal species colonised the gaps in the degraded area, primarily through seed germination. Conversely, in the conserved area, the most common regeneration strategies were resprouting from deep and lateral underground structures (bud-banks) and stolon propagation. Therefore, we provide evidence that natural regeneration is dominated by vegetative propagation and resprouting in the Cerrado, with limited scope for native plants to colonise, even over short distances. Without a viable belowground bud-bank, restoring the Cerrado open ecosystems requires active techniques.