Aryanne Gonçalves Amaral

Vascular flora in dry-shrub and wet grassland Cerrado seven years after a fire, Federal District, Brazil

Studies of temporal dynamics for grassland sites report that fire suppression plays a crucial role in floristic changes. The objective of this study was to verify whether after seven years without fire, communities showed variations in terms of composition, life forms, pollination and dispersal syndromes. The first survey (T0) was conducted from September 1999 to October 2000, while the second (T1) took place from August 2006 to August 2007. The floristic results in T1 were compared with the survey in T0 through the Sorensen similarity index and Chi-square tests. Over time, there were differences in the composition, life forms and pollination and dispersion syndromes. The evidence of changes suggests that the frequency of the fire regime can be considered the main agent for change in the flora of these communities.

Richness pattern and phytogeography of the Cerrado herb–shrub flora and implications for conservation

Aims The herb–shrub flora has been widely neglected in science and conservation policy throughout the world, so that this biodiversity component remains largely unknown. The objective of this study was to elucidate the spatial patterns of species richness and phytogeographic regions of the Cerrado herb–shrub flora, and to estimate the percentage of areas with high species richness that is still covered by natural vegetation and is located in protected areas or priority areas for conservation. Location Central Brazil and surrounding territories. Methods To estimate the pattern of species richness we produced species distribution models (SDMs) for 5362 species using botanical records combined with 17 least correlated environmental variables. All SDMs were tested against a bias-corrected null model and the 5039 significant SDMs were stacked to generate the pattern of botanical richness. The resulting presence–absence matrix was subjected to a partitioning around medoids (PAM) cluster analysis to delineate phytogeographic regions. Results The pattern of species richness indicated that highest levels of richness are in the central–south and west parts of the Cerrado. The study recognized two floristically distinct clusters at the core of the Cerrado region, and seven additional regions that share floristic elements with the two core clusters. Many areas with high levels of modelled species richness are located outside protected and priority areas for conservation. Conclusions We recognized patterns of regional variation, reflected in the phytogeographic division. Furthermore, we show that the current protected areas in Brazil do not effectively protect high richness areas of the herb–shrub flora.