The process of human occupation in the tropics led to the conversion of hyperdiverse native vegetation into degraded states of ecosystems. Species loss leads to changes in the functioning of these ecosystems and consequently affects the provision of services for human beings. To circumvent this situation, there are countless efforts and political incentives to restore these landscapes. Vast areas of former old-growth savannas are currently degraded and need to be restored. The practices and techniques to restore these systems are still limited and the restoration outcomes unpredictable, mainly because of the high because high invasion potential of exotic species and lack of knowledge on species traits that allow survival. Therefore, the studies focusing on species traits might improve restoration outcomes and provide pathways to underpin the ecosystem's resilience. Here, we show how using trait‐based approaches might offer insights to deal with the challenges of current restoration practices in the Brazilian savanna ecosystem. We evaluate the functional composition, microbial activity, nutrient cycling, and decomposition rates of early savanna-stage restored by direct seeding of native species and compared to areas dominated by exotic grasses and well-preserved old-growth vegetation. We used multiple leaf traits linking to drought, productivity, and ecological strategies. Additionally, we measured below and above-ground biomass as vegetation parameters. We assessed soil nutrient cycling, comparing the activity of soil enzymes related to carbon and nitrogen and phosphorus cycling, as well as soil microbial biomass and soil fertility properties. Also, we access wood decay by microorganisms using an experiment with woody-blocks decomposition. We found that large-scale techniques for restoring Brazilian savannas did not recover the slow-growth component of old-growth savannas, recovering only a small fraction of the hydraulic diversity and the functional composition. Restored sites are dominated by acquisitive traits such as low belowground biomass and higher aboveground biomass. The soil microbial community and fertility are impacted by burning and plowing before sowing, which leads to low microbial biomass, low microbial enzyme activity, and consequently low microbial wood decay in the restored sites. The low immobilization of nutrients in microbial biomass, low retention of nutrients, and the lack of a belowground biomass pool in restored savannas may threaten long-term restoration success that implies low resilience and invasion resistance. The challenge of future savanna restoration practices is to promote a restoration that uses slow-growth and drought-tolerant species and that considers the soil treatment to restore soil carbon and nutrient cycling processes.
Savannas restoration ecology, functional composition, Direct seeding