Xingu State Park vascular plant survey: filling the gaps

Located in the southeastern limit of the Amazon biome, the Xingu State Park (PEX) was identified as a knowledge gap, leading to a floristic and vegetation survey of the area. During this work, 463 species distributed in 295 genera and 111 families of vascular plants were recorded, including dozens of new records for the state of Mato Grosso and at least five species new to science. Seven vegetation types were found, among which the Open Ombrophilous forest and the “Varzea” (floodplain) and lake vegetation showed the highest species richness. The vegetation of the Alto Xingu River was hitherto undocumented although this area is subject to strong deforestation pressure for cattle ranching from the southwest and soybean cultivation from the southeast, and is currently a focus of international attention due to the plans for the Belo Monte hydroelectric plant downriver in the state of Para. When compared with a survey of the neighbouring Cristalino State Park, there was remarkably little overlap in vegetation types and plant species, highlighting the importance of increasing the intensity of plant surveys and collections in the Amazon including protected areas, so as to address the many, vast lacunae in our understanding of this biodiverse and threatened biome. Historic and geographic factors have polarized research in Brazil such that the Amazonian biome lags behind the eastern part of the country in terms of plant knowledge, and this type of initiative helps in providing much needed data to address this situation.