Rupestrian Grassland Vegetation, Diversity, and Origin

摘要: Rupestrian grasslands (campos rupestres) are tropical landscapes consisting of a mosaic herbaceous and shrubby physiognomies on quartzite or ironstone that occur in highlands , usually above 900 m. These encompass high diversity habitats under different environmental conditions, such as rock outcrops dominated by desiccation-tolerant species, well shrublands resprouter species. Therefore, water availability is one the most significant selective pressures outcrops, while fire more important shrublands. Poaceae Velloziaceae two dominant plant families terms cover area. There predominance hemicryptophytes, chamaephytes, phanerophytes. Autochory main dispersal syndrome contributes to endemism. Floristic vegetation structural patterns affected geology, geography, habitat, disturbance. Old Stable Landscapes specialization, phylogenetic conservatism, low ability characterize lineages these landscapes. Rather than refuges during warmer moister Pleistocene interglacial periods, have probably worked for fire-sensitive since expansion fire-prone savannas (cerrados) late Tertiary. Most from mountain ranges then diversified Quaternary rupestrian were finely fragmented The rich biodiversity naturally vulnerable anthropogenic disturbances. protected areas even if small, scattered along whole landscape, will help protect them while. However, suitable be greatly reduced next few decades seasonality increases. This scenario calls immediate ex situ conservation measures.