ABSTRACT Land-use change is the main cause of biodiversity losses, and for grasslands includes changes in management. The last 10 years has seen afforestation of traditionally grazed grasslands increase considerably in the understudied Serra do Sudeste region of the Brazilian Pampa, turning the region into a mosaic of tree plantations, natural ecosystems (partly in conservation areas without grazing management) and other land uses. We evaluated grassland plant community structure and composition in conservation areas considering two distinct types of land-use history and compared them to grasslands under traditional management. The study was carried out at 58 sites. Per site, three plots were established to sample the plant composition of the herbaceous and shrub layers. We used ordination techniques and indicator species analysis to describe patterns of community composition. We recorded a total of 516 species, thus confirming the high biodiversity of the region. We detected differences in vegetation structure and composition between primary and secondary grasslands. Our study emphasizes the need to increase conservation efforts in the region and points out that current conservation approaches should be evaluated critically regarding their effects for biodiversity conservation and that adequate grazing management is key for grassland biodiversity conservation.

A ocorrência da giesta-brava Cytisus scoparius (L.) Link (Fabaceae) é citada pela primeira vez no Brasil. A espécie foi localizada em áreas com alta diversidade biológica nos Campos Sulinos, nos Campos de Cima da Serra, e na Serra do Sudeste. As populações naturalizadas são formadas frequentemente em habitats naturais, próximos a zonas povoadas, onde os diferentes usos da terra e os distúrbios facilitam a dispersão e o estabelecimento. A giesta-brava é uma espécie invasora que tem causado significativos danos à biodiversidade e perdas econômicas globalmente. No Brasil, a espécie tem um forte potencial de se propagar a um vasto conjunto de ecossistemas. O bioma Mata Atlântica e parte do bioma Pampa, conhecidos como os Campos Sulinos, representam áreas ótimas para a espécie. São apresentadas as características observadas nas populações e recomendações para o manejo.

The occurrence of Scotch broom Cytisus scoparius (L.) Link (Fabaceae), is reported for the first time in Brazil. The species has been registered in the species-rich Campos Sulinos grasslands, in the Campos de Cima da Serra, and in the Serra do Sudeste. Naturalizing populations were frequently formed in natural habitats near to human settlements, where prevailing land uses and disturbances facilitate dispersal and establishment. The plant is an invasive species that has globally caused significant damage to biodiversity and economic losses. In Brazil, the species has a strong potential for spreading into a wide range of ecosystems. The Atlantic Forest biome and part of the Pampa biome, together known as the Campos Sulinos, represent optimal areas for the species. Features of the observed populations and recommendations for management are presented.