Microevolutionary Perspectives for Conserving Plant Diversity in South Brazilian Grasslands (Campos Sulinos)

Grassy ecosystems occupy 27% of Brazilian territory and have historically been neglected in conservation efforts and studies about biodiversity. The Campos Sulinos region in Southern Brazil includes open formations in the Pampa and Atlantic Forest domains. This region has the smallest coverage by protected areas in the country and presents high levels of biodiversity and endemism. Besides, this region is under threat due to croplands and exotic tree plantations. Here, we compile a plant population genetics and phylogeography dataset from published studies focusing on species native to the Campos Sulinos to synthesize findings in plant evolution and genetics to better understand the dynamics of genetic diversity in this open ecosystem. We found 58 works on 51 plant species, published from 2005 to 2022. Most studies used only one kind of molecular marker and few loci. The climatic changes during the Pleistocene are likely the main speciation driver either due to the dynamics between grassland and forest or marine transgressions. Overall, high genetic variability and clear structuring of populations were found for the species studied. Regions with high genetic diversity do not coincide with protected areas. We reinforce the necessity of considering high intraspecific genetic diversity and population structure into both conservation and restoration planning, as well as in research within the Campos Sulinos.