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Formed by tall flat-topped mountains known as tepuis, the Pantepui is an important center of vascular plant endemism and diversity in South America. In Brazil, the Pantepui is mostly on the border of Venezuela, and an isolated area, Serra do Araca, stands out as the tepui southernmost. In this paper we present a floristic survey of the vascular plants that occur on Serra do Araca, compare the richness to other tepuis, and commented on the conservation of Amazonian 'campos rupestres'. Our dataset includes over 1600 records, either collected by us in three field expeditions, or by other botanists. A checklist with 436 species of vascular plants is provided. Our study also shows that among the 34 tepuis of the Pantepui, Serra do Araca ranks tenth in species richness and has 24 endemic species. Serra do Araca, like other tepuis, houses representatives of ancestral lineages of vascular plants of South America, showing how important tepuis are as cradles of lineages. Despite its importance for Amazonian biodiversity, Serra do Araca is one of the natural reserves in the Amazon with the highest number of requests for mining. Formado por altas montanhas de eumes chapados conhecidos como tepuis, o Pantepui e um importante centro de endemismo e diversidade de plantas vasculares na America do Sul. No Brasil, o Pantepui encontra-se principalmente na fronteira com a Venezuela, e urna area isolada, a Serra do Araca, destaca-se como o mais meridional dos tepuis. Neste trabalho apresentamos um levantamento floristico das plantas vasculares que ocorrem na Serra do Araca, comparamos a riqueza com outros tepuis, e comentamos sobre a conservacao dos campos rupestres amazonicos. Nosso conjunto de dados inclui mais de 1600 registros, coletudos por nos em tres expedicoes de campo, ou por outros botanicos. Urna lista de verificacao com 436 especies de plantas vasculares e fomecida. Nosso estudo tambem mostra que entre os 34 tepuis do Pantepui, a Serra do Araca ocupa a decima posicao em riqueza de especies e possui 24 especies endemicas. A Serra do Araca, como outros tepuis, abriga representantes de linhagens ancestrais de plantas vasculares da America do Sul, mostrando a importancia dos tepuis como bercos de linhagens. Apesar de sua importancia para a biodiversidade amazonica, a Serra do Araca esta em urna das unidades de conservacao estaduais da Amazonia com o maior numero de processos para mineracao. Keywords Neotropical * Biodiversity * Highlands * Campos rupestres, Introduction Amazonia is a tropical forest of great biological importance with high plant species richness compared to other regions of the world (Gentry, 1988; Fiaschi & Pirani, 2009; Antonelli & [...]

The understanding of genetic diversity and evolutionary relationships within the genus Anadenanthera Speg. (Fabaceae) is limited. Brenan's classification recognized four species, but Altschul's classification currently recognizes only two species, each with two varieties. Both classifications were based solely on morphology. We analysed molecular data from 283 specimens using 12 SSRs and 186 specimens using ITS sequence data. The results showed that neither SSR-based genotyping nor ITS-based phylogeny supported Altschul's classification. Instead, they provided evidence of four reproductively isolated taxa and a single clade corresponding to one of Altschul's varieties. Additionally, ecological niche modelling (ENM) investigated the influence of past climate on the geographic distribution of Anadenanthera. The ENM results suggest that the 'varieties' may have occupied different regions of South America with distinct paleoclimates. On the basis of these findings, the authors suggest recognizing four species, as per Brenan's original classification. [ABSTRACT FROM AUTHOR]

Aim: We used a phylogenetic approach to group assemblages of woody plant into major vegetation units in the Atlantic Forest, thus for the first time incorporating information on species evolutionary relationships into a bioregionalization of this critical hotspot. A phylogenetic regionalization will provide a spatially explicit framework for answering many basic and applied questions in biogeography, ecology and conservation. Location: Atlantic Forest. Taxon: Angiosperms Methods: Our data set comprises 614 genera and 116 families, spread over 1,755 assemblages. To place assemblages in a multivariate evolutionary composition space, we used a phylogenetically informed ordination analysis, and to determine what the main phylogenetic groups of assemblages were, we used K‐means clustering based on phylogenetic dissimilarity of assemblages. To quantify how well environmental variables distinguish the phylogenetic groups found, we implemented classification tree approaches. Then, to explore the evolutionary turnover between the phylogenetic groups, we calculated phylogenetic beta diversity. Finally, we determined the lineages that are most strongly associated with individual phylogenetic groups using an indicator analysis for lineages. Results: Our analyses suggest that there are seven principal groups, in terms of evolutionary lineage composition, in the Atlantic Forest. The greatest turnover of phylogenetic lineage composition separates tropical evergreen rain forest and semideciduous assemblages from subtropical and highland assemblages. The mixed subtropical forest showed the lowest phylogenetic compositional similarity values with other groups. Tropical rain forest had the highest number of significant indicator lineages, and the highest values of the indicator statistic for lineages. Main conclusions: We found that the most pronounced evolutionary division separates southern and highland tree assemblages from those occurring under more tropical climates and at lower elevations. Our phylogenetic analyses point to an environmentally driven compositional division, likely based on the regular occurrence of freezing versus non‐freezing temperatures. Precipitation and edaphic regimes that assemblages experience had less definitive effects on their evolutionary lineage composition. [ABSTRACT FROM AUTHOR]

Questions: The growth–survival trade‐off is a central concept for the conflicting strategies of acquisitive species that grow quicker and conservative species that grow slower. Understanding which, and how, cross‐species functional traits contribute to the growth–survival trade‐off is a key topic for understanding the functioning of tropical forests. The present study aimed to: (a) determine if leaf traits, wood density and fruit size influence the growth–survival trade‐off at the community level; and (b) test the hypothesis that averaged leaf traits, averaged wood density and averaged fruit size among all trees of subplots explain tree height in a 50‐ha plot of secondary Atlantic Forest in Brazil. Methods: All trees with DBH > 3 cm had their heights estimated and were taxonomically identified. The functional traits used were leaf length (LL), leaf width (LW), petiole length (PL), petiole width (PW), leaf width/petiole width (LW/PW), leaf length × leaf width (LL*LW), wood density (WD), fruit length (FL) and fruit width (FW). Results: A total of 74,335 trees of 178 species were recorded in 5,076 subplots of 100 m2. Associations between functional traits and mean height (Hmean) and height mode (Hmode) were congruent with expected trends of LW, LL, LW/PW, WD and FW with the top‐ranked global model explaining most of the found variance suggesting that Hmean and Hmode are the best averaged response variables. The growth response represented by Hmean and Hmode had the most distinctive, congruent and consistent association with LW/PW, WD and FW. Conclusions: Higher LW and higher LW/PW indicated higher dependence of leaf blade on local microclimatic conditions, and lower dependence on petiole support for plant growth, which is beneficial for the acquisitive strategy. Smaller fruits and higher WD were also associated with the acquisitive strategy. Therefore, LW, LW/PW, WD and FW influenced the growth–survival trade‐off at the community level and explained tree height variation in the studied tropical forest. [ABSTRACT FROM AUTHOR]

Highlights • The southern portion of South America has a unique flora, distinct from that of the rest of the Neotropical Domain. • Community composition are explained by environmental and spatial variables; however, the spatial fraction is more significant. • Important for conservation issues since extratropical areas receive much less attention than tropical areas. Abstract The southern portion of South America, which encompasses high and exceptional lineage diversity, is well-suited to studies addressing the interaction between biogeography and local environmental conditions and how this historical process and environmental variables affect distribution patterns. We here assessed the role of environmental variables and spatially autocorrelated processes in driving tree species distribution patterns in the whole southern South America forests. We compiled a dataset containing 110,087 occurrence records of 3183 species distributed into 742 sites across six countries and 13 biomes. We modeled the influence of both environmental and spatial variables related to geographic distribution limitations on the variations of species composition through partial canonical redundancy analysis. We built such models for each of our four datasets: the whole extratropical area of South America; Atlantic and Pampa Biomes; dry communities east of the Andes; and communities west of the Andes. Both spatial and environmental variables affect tree species composition in the southern region of South America, although a major role is played by the "pure" spatial fraction. This greatest significance of spatial structures reinforces the importance of historical process for this region and the floristic dissociation existing between the tropical and extratropical portion of South America. We argue that the southern South American forests (especially their temperate portion) should not be lumped into the Neotropical Floristic Province, an idea of utmost importance for the conservation of these high-diversity austral forests. [ABSTRACT FROM AUTHOR]

The cerrado is a large savanna in central Brazil, which extends north to the Amazon Forest and the caatinga (xeric vegetation) and includes disjunct areas in both of those biomes. Cerrado plant diversification is understudied, especially in disjunct areas and in peripheral areas bordering other biomes. Here we investigated the effects of Quaternary climatic fluctuations on the distribution, genetic diversity and divergence of two closely related species, Qualea multiflora and Qualea parviflora. Both species are widely distributed in the cerrado, including disjunct and peripheral areas. We sequenced plastid DNA from individuals of both species across their distributions, including core, disjunct and peripheral areas of the cerrado. Both species showed similar responses to Quaternary climatic fluctuations with range retractions during the Last Glacial Maximum (LGM). Phylogeographic analyses and ecological niche modelling revealed a large historical glacial refugium across central Brazil and multiple refugia in peripheral areas of the south-west, north-west (bordering the Amazon) and north-east (in transition with the caatinga). The genetic diversity, diversification and geographical structuring of Q. multiflora and Q. parviflora were mainly shaped by Pleistocene climatic fluctuations. The presence of several refugia at the Amazon Forest boundary suggests that savanna vegetation could have covered parts of the south-western Amazon during the LGM. [ABSTRACT FROM AUTHOR]

• Old Growth and Second Growth Forests after eucalyptus plantation are clearly unlike. • Second Growth Forests are similar between them concerning richness and carbon stock. • There was a slow recovery of species richness and carbon stock after eucalyptus plantation. • After 32 years, forests recovered 38% of species richness and 14% of carbon stock. • There were carbon-species-richness co-benefits among zoochoric and shade-tolerant species. Currently, about a third of the world's forest areas that have been deforested are regrowing. These second-growth forests (SGF) promote carbon stocks and tree species richness recovery (co-benefits recovery), which is central to mitigating the negative impact of climate change and loss of biodiversity. In Brazil's Atlantic Forest, second-growth forests that are regrowing after long-term land use can recover diversity and carbon and can have important carbon-tree diversity co-benefits. Thus, we evaluate the recovery of tree species richness and above-ground carbon stock (AGC) in SGF that are regrowing after a long-period of eucalyptus plantations. For this we sampled 43 SGF with stand ages varying from 1−32 years after eucalyptus plantations cutting and three reference old-growth forests (OGF). We considered all individuals with more than 15 cm of circumference at breast height in one 20 × 50 m plot by patch. We identified all tree species, which were categorized into functional attributes, such as zoochoric and non-zoochoric, pioneer and shade-tolerant, and fleshy and dry fruits species. There were marked differences in species richness and AGC between OGF and SGF, but SGFs were not different between then. However, in 32 years these second-growth forests recovered ∼38% of species richness and ∼14% of carbon stock of old-growth forests. In addition, there was a carbon-biodiversity co-benefits mainly between zoochoric and shade-tolerant species richness. These results showed that these second-growth forests could naturally recover biodiversity and AGC. Possibly, this is due to the connectivity provided by land-use for eucalyptus plantations that induces favorable conditions for the recruitment of zoochoric and shade-tolerant species and thus for the recovery of biodiversity and AGC after eucalyptus cutting. Thus, this second-growth forest management can contribute to Atlantic Forest biodiversity conservation and carbon stock initiatives. [ABSTRACT FROM AUTHOR]

• The beta diversity explains species composition variability along forest succession. • Taxonomic and functional beta diversity showed opposite trajectories along succession. • The functional beta diversity was lower due to a lower functional turnover. • The large overlap between woody communities explains the low functional turnover. • Stand age and soil fertility are the main predictors that explain beta diversity. Predicting how multiple drivers shape beta diversity across tropical forest is one of the most important issues in ecology. However, the relative importance of drivers to the spatial and temporal dissimilarities in woody species composition (beta diversity) along Amazon forest succession remains poorly studied. In this study, we assessed how stand age (factor related to habitat filtering and succession), soil properties (factors related to resource availability and environmental filtering) and forest patches distance (spatial factor related to dispersal limitation) affect the taxonomic and functional beta diversity along an Amazon forest succession. Taxonomic and functional beta diversity indices were quantified based on abundance-based metrics and trait-based approach using functional traits related to plant dispersion and growth. Overall, taxonomic and functional beta diversity was consistently higher in initial successional stage among plots and sites; however, old-growth forest presented the lowest functional beta diversity. We observed differences in beta diversity components among successional stages and old-growth forest. The beta diversity components showed a clear higher pattern in the different second-growth forests than in the old-growth forest. Soil fertility and stand age explained most of the variation in taxonomic and functional turnover and beta diversity. This pattern probably is an outcome of the patches within a continuous old-growth forest as main seed sources for the colonization and establishment of tree species. We observed that functional beta diversity was lower than taxonomic beta diversity; therefore we presumed that there is higher functional redundancy in old-growth forests, compared to taxonomic beta diversity. However, despite the lower functional beta diversity and higher functional redundancy in old-growth forest, probably shade-tolerant species have different functions than second-growth forests that re-growing after shifting cultivation. We argue that an old-growth forest has lower functional diversity than second-growth forests but, it is probably induced by a high turnover of second-growth forests. [ABSTRACT FROM AUTHOR]

• Connectivity is a major concern in landscape ecology and biodiversity conservation. • We used a habitat/non-habitat approach to assess connectivity in a biodiversity hotspot. • Maps of resistance to connectivity, and of least-cost paths were generated. • Well-connected regions will demand conservation practices and reserves creation. • Regions with low connectivity require intervention through restoration projects. The probability that a propagule reaches, establishes and persists in a certain site is affected by the distance and quality of the environment. Fragmented landscapes promote the isolation of forests surrounded by a matrix that hinders or impedes the movement of species, affecting their distribution and threatening their conservation. Studies of landscape connectivity are essential to provide information for ecological conservation planning. Based on the classification of the landcover of the Rio Doce Basin - RDB and on the circuit theory, we used a habitat / non-habitat approach to assess the connectivity of the RDB to tree species. We built six resistance surface models based on habitat and non-habitat areas, using the GIS plug-in and Linkage Mapper to generate least cost paths maps. Three models explained the Jaccard similarity index matrix of 78 fragments used as a proxy of connectivity to test the models by GLMs, and one out the three was the simplest and most parsimonious. The map generated by the chosen model showed that the RDB is very fragmented but still has well-connected regions. The west to northwestern and southeastern portions of the RDB are well-connected and demand conservation of remaining fragments as well as the creation of reserves, while the center-north, east, and the far southwest of the basin are regions with greater resistance to connectivity as a result of anthropic pressures that reduced and fragmented the forests, requiring intervention through restoration projects to re-establish landscape connectivity. [ABSTRACT FROM AUTHOR]

• The interaction between fire and flood reduces richness and abundance of tree species. • The basal area is influenced by floods, mainly by the presence of Attalea phalerata. • The interaction between fire and flood favors the monodominance of Attalea phalerata. • For the preservation of forest islets, controlled fires can be used as management tools. Flood and fire act as ecological filters which can interact to shape forest structure and species composition. Our objective was to investigate how the interaction between fire and flood influences richness, abundance, basal area and species composition of the tree community and the monodominant belts of Attalea phalerata Mart. in forest islets of the Pantanal wetland. We used satellite images to find 12 forest islets without fire events from 1998 to 2014, and 12 forest islets burned only once in the same period in a fire event in 2009. In these forest islets, we set up a transect with 10 to 14 contiguous 5 × 10 m plots and sampled all trees with a diameter at breast height of ≥ 4.7 cm. We also measured the watermark height. Flooding influenced species richness and abundance, increased toward wetter areas of the forest islet flood gradient. In contrast, the interaction between fire and flood inverted that trend, with richness and abundance increasing in flood-free areas. Total basal area increases in the more flooded areas of the gradient. The fire or the interaction between fire and flooding did not influence the basal area. The relative abundance of A. phalerata increased with flood level and even more under the fire-flood interaction. We conclude that the interaction between fire and flood influences forest islet structure and species composition; moreover, it favors A. phalerata monodominance. [ABSTRACT FROM AUTHOR]