ABSTRACT We investigated the influence of Quaternary climate fluctuations on the current distribution of three species of Leguminosae (Fabaceae) occurring in the Chaco. Potential distribution models of Bauhinia hagenbeckii, Muellera nudiflora and Neltuma rubriflora with a supposed endemism area were generated. The Last Interglacial, Last Glacial Maximum, Holocene Middle and current scenarios were used. The species showed a potential distribution according to the South American biogeographic history regarding the glacier regression and the formation of the Dry Diagonal. The models for each Quaternary event exhibited a tolerable AUC ≥ 0.9 for the validations. The LGM was the event that favoured the current species establishment areas in the Dry Diagonal. Quaternary climatic events were related to the current Leguminosae distribution. Bauhinia hagenbeckii and Neltuma rubriflora present similar areas of environmental suitability. Muellera nudiflora models with areas of environmental suitability were larger for the LIG and Holocene than for areas from other periods. All scenario models (LGM, HM and current scenario) highlighted the potential distribution of the three species concomitant with the glacier regression events and were consistent with the history of formation of South American dry areas.

ABSTRACT The distributions of species of Fabaceae are strongly related to the soil. Their presence can alter restrictive conditions and favour the establishment of other species. However, it is still not known how the relationship between species of Fabaceae and edaphic factors interact in structuring woody Chaco vegetation. In this context, we aimed to test the hypothesis that restrictive edaphic conditions can explain the difference in floristic patterns of two types of vegetation through their species representativeness of Fabaceae. We analysed floristic consistency between wooded and forested Chaco to address how spatial and environment components might explain differences between them along with the effects of the interaction between Fabaceae and the soil. We observed that the association between environmental and spatial variables was more important than any individual factor in explaining the structuring of the communities. Both the percentage of species of Fabaceae present and the soil influence the structure of the two types of vegetation. Species of Fabaceae have greater potential as indicators in the wooded Chaco. Therefore, we suggest the interaction between soil types and species of Fabaceae plays a role during the structuring of the communities through the establishment of these species in more restrictive soils.

ABSTRACT The growth-survival trade-off hypothesis states that functional traits of stem, wood, leaves and fruits govern acquisitive and conservative strategies of plant species that grow/survive differently in forests. We aimed to determine whether heterogeneity during the colonization of a secondary Atlantic Forest fragment causes differences in colonization-related traits and determines taxonomic composition of subplots. A total of 5,078 subplots were censused with leaf and fruit traits and height measurements being determined for each tree of each species, and with averaged-abundance-weighted values calculated for each subplot. A dendrogram was generated from the taxonomic composition of subplots using Sorensen similarity and UPGMA clustering. A total of 74,335 trees of 178 species were recorded. Clustering revealed five main groups of subplots that were tested against each other and found to differ in terms of average leaf width, leaf-width/petiole-width, wood density, mean height, height mode, fruit width and fruit length. Greater leaf averages in subplots were associated with greater fruit averages, and with higher wood densities and greater heights among groups of subplots, revealing that heterogeneity during colonization directed the communities of the 50-ha plot. The averaged values of functional traits detected subplots associated with conditions favorable to colonization, thereby reinforcing the growth-survival trade-off hypothesis.

ABSTRACT The objective of this study was to model the potential effect of future climate change on the distribution of a tree species indicator of Cerrado. For the modeling, we used 488 occurrence points of the species and also bioclimatic variables corresponding to 2050 and 2070, for the more optimistic and pessimistic scenarios. All generated models were classified as consistent, getting an area under curve higher than 0.90. The current modeling of Connarus suberosus showed that 88% of the area with a high probability of species occurrence is inside the Cerrado domain. Future projections suggest losses in the environmental suitability area around 40.8% and 44.8% in the optimistic scenario, 61.6% and 81.6% in the pessimistic scenario considering 2050 and 2070, respectively. Furthermore, we found a tendency of the C. suberosus to move in the Atlantic Forest direction. This modeling is an alert that the C. suberosus will suffer from future climate change.

This study describes the influence of edaphic factors on the floristic composition of an area of cerradão (woodland savanna) in the city of Campo Grande, located in the Brazilian central-west. In 10 plots (5 × 20 m each), we evaluated all trees with a diameter at breast height > 4.77 cm. Soil samples were analyzed for each plot in order to determine edaphic variables correlated with species composition. We sampled 1180 individuals of 61 species. The evenness index was 0.74, which indicates uneven distribution of species, which was explained by a high abundance of Qualea parviflora, Curatella americana, Qualea grandiflora, Terminalia argentea and Astronium fraxinifolium. We registered more trees in the smallest diameter class and in the middle layer of the vertical structure. The soil was dystrophic with a clay texture, which explains the higher abundance of species related to dystrophic cerradão. However, we also found some trees typical of mesotrophic cerradão and deciduous forests, which could be attributable to the presence of patches of fertile soil within the dystrophic cerradão or could indicate that those mesotrophic species are tolerant of lower levels of soil nutrients.