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Aim: The efficiency of animal‐mediated seed dispersal is threatened by the decline of animal populations, especially in tropical forests. We hypothesise that large‐seeded plants with animal‐mediated dispersal tend to have limited geographic ranges and face an increased risk of extinction due to the potential decline in seed dispersal by large‐bodied fruit‐eating and seed‐dispersing animals (frugivores). Location: Atlantic Forest, Brazil, South America. Taxon: Angiosperms. Methods: First, we collected dispersal‐related traits (dispersal syndrome, fruit size, and seed size), growth form (tree, climber, and other) and preferred vegetation type (open and closed) data for 1052 Atlantic Forest plant species. Next, we integrated these with occurrence records, extinction risk assessments, and phylogenetic trees. Finally, we performed phylogenetic generalised least squares regressions to test the direct and interactive effects of dispersal‐related traits and vegetation type on geographical range size. Results: Large‐seeded species had smaller range sizes than small‐seeded species, but only for species with animal‐mediated dispersal, not for those dispersed by abiotic mechanisms. However, plants with abiotic dispersal had overall smaller range sizes than plants with animal‐mediated dispersal. Furthermore, we found that species restricted to forests had smaller ranges than those occurring in open or mixed vegetation. Finally, at least 29% of the Atlantic Forest flora is threatened by extinction, but this was not related to plant dispersal syndromes. Main Conclusions: Large‐seeded plants with animal‐mediated dispersal may be suffering from dispersal limitation, potentially due to past and ongoing defaunation of large‐bodied frugivores, leading to small range sizes. Other factors, such as deforestation and fragmentation, will probably modulate the effects of dispersal on range size, and ultimately extinction. Our study sheds light on the relationship between plant traits, mutualistic interactions, and distribution that are key to the functioning of tropical forests. [ABSTRACT FROM AUTHOR]

Premise: Pilosocereus (Cactaceae) is an important dry forest element in all subregions and transitional zones of the neotropics, with the highest diversity in eastern Brazil. The genus is subdivided into informal taxonomic groups; however, most of these are not supported by recent molecular phylogenetic inferences. This lack of confidence is probably due to the use of an insufficient number of loci and the complexity of cactus diversification. Here, we explored the species relationships in Pilosocereus in more detail, integrating multilocus phylogenetic approaches with the assessment of the ancestral range and the effect of geography on diversification shifts. Methods: We used 28 nuclear, plastid, and mitochondrial loci from 54 plant samples of 31 Pilosocereus species for phylogenetic analyses. We used concatenated and coalescent phylogenetic trees and Bayesian models to estimate the most likely ancestral range and diversification shifts. Results: All Pilosocereus species were clustered in the same branch, except P. bohlei. The phylogenetic relationships were more associated with the geographic distribution than taxonomic affinities among taxa. The genus began diversifying during the Plio‐Pleistocene transition in the Caatinga domain and experienced an increased diversification rate during the Calabrian age. Conclusions: We recovered a well‐supported multispecies coalescent phylogeny. Our results refine the pattern of rapid diversification of Pilosocereus species across neotropical drylands during the Pleistocene and highlight the need for taxonomic rearrangements in the genus. We recovered a pulse of diversification during the Pleistocene that was likely driven by multiple dispersal and vicariance events within and among the Caatinga, Cerrado, and Atlantic Forest domains. [ABSTRACT FROM AUTHOR]

The Madden Julian Oscillation (MJO) is the main source of intraseasonal variability in the tropics. MJO modulates rainfall in remote areas in the Southern Hemisphere by exciting tropical and extratropical wave trains. We use newly released reanalysis data to analyze how the Quasi‐Biennial Oscillation (QBO) can influence the MJO's effects over the Southern Hemisphere, focusing on precipitation anomalies over South America. The anomalies in the intensity of the South Atlantic Convergence Zone (SACZ) and precipitation over Southeastern South America during MJO phases 1 and 4 are intensified during the easterly QBO. The extratropical wave train excited by the anomalous convection over the maritime continent during MJO phase 4 is affected by the QBO, with a stronger, better‐defined pattern during westerly QBO. The conclusions are supported by a perturbation experiment of a case study, conducted using a high‐top atmospheric global climate model where the QBO and MJO are controlled. Plain Language Summary: Subseasonal to seasonal prediction remains challenging in the current forecast models. Previous studies have shown that the Quasi‐Biennial Oscillation (QBO) can influence the intensity and development of the Madden Julian Oscillation (MJO). Here, the consequences of this modulation on the remote effects of the MJO in the Southern Hemisphere are analyzed using reanalysis and perturbation experiments in an atmospheric global climate model. The rainfall anomalies related to the MJO in South America are more intense and widespread during easterly QBO over the South Atlantic Convergence Zone and southern Brazil than during westerly QBO. Thus, the inclusion of the state of the QBO in the estimate of the expected rainfall associated with the MJO is crucial to improve forecasts in the region. Key Points: The Quasi‐Biennial Oscillation (QBO) modulates the impacts of the Madden Julian Oscillation (MJO) in the Southern HemisphereMJO‐related rainfall anomalies in the South Atlantic Convergence Zone are intensified during easterly QBOEThe extratropical wave train forced by the anomalous convection in MJO phase 4 is intensified under QBOW [ABSTRACT FROM AUTHOR]

Summary: The genus Manihot, with around 120 known species, is native to a wide range of habitats and regions in the tropical and subtropical Americas. Its high species richness and recent diversification only c. 6 million years ago have significantly complicated previous phylogenetic analyses. Several basic elements of Manihot evolutionary history therefore remain unresolved.Here, we conduct a comprehensive phylogenomic analysis of Manihot, focusing on exhaustive sampling of South American taxa.We find that two recently described species from northeast Brazil's Atlantic Forest were the earliest to diverge, strongly suggesting a South American common ancestor of Manihot. Ancestral state reconstruction indicates early Manihot diversification in dry forests, with numerous independent episodes of new habitat colonization, including into savannas and rainforests within South America. We identify the closest wild relatives to Manihot esculenta, including the crop cassava, and we quantify extensive wild introgression into the cassava gene pool from at least five wild species, including Manihot glaziovii, a species used widely in breeding programs. Finally, we show that this wild‐to‐crop introgression substantially shapes the mutation load in cassava.Our findings provide a detailed case study for neotropical evolutionary history in a diverse and widespread group, and a robust phylogenomic framework for future Manihot and cassava research. [ABSTRACT FROM AUTHOR]

Our aims were to quantify and map the plant ecoregions of the Atlantic Forest, a biodiversity hotspot that covers ca 150 million ha in eastern South America. We used a data set on the distribution of 4378 shrub and tree species across 711 localities. Plant ecoregions were identified using analyses of species turnover for both species occurrences and relative abundances. We interpolated NMDS axes of compositional variation over the entire the Atlantic Forest extent, and then classified the compositional dissimilarity according to the number of biogeographical ecoregions previously identified through K‐means analyses. We assessed the ability of environmental, historical vegetation stability and the current human footprint to explain the occurrence of the identified ecoregions through multinomial logistic regression models. We identified 21 spatially cohesive occurrence and 14 abundance ecoregions. Aridity, soil and historical biome stability were retained in the best model explaining both occurrence and abundance ecoregions. Broad compositional zones were identified through UPGMA cluster analysis of ecoregions, and formed north and south compositional blocks. Our work confirms the existence of a broad north–south divide within the Atlantic Forest, previously suggested based on climatic and amphibious data. Differences between the occurrence and abundance maps suggest the location of transition zones to neighbouring domains and endemism centres. Due to the aggregate nature of our analyses, site‐level disturbance degree was not considered, implying that human impacts could be broader then we could detect. There was limited overlap between our results and previous Atlantic Forest regionalization efforts, indicating that multi‐taxa, physiognomic and environmental regionalization schemes based on expert opinion or vegetation maps are poor proxies for compositional ecoregions. [ABSTRACT FROM AUTHOR]

Tropical South America plays a central role in global climate. Bowen ratio teleconnects to circulation and precipitation processes far afield, and the global CO2 growth rate is strongly influenced by carbon cycle processes in South America. However, quantification of basin‐wide seasonality of flux partitioning between latent and sensible heat, the response to anomalies around climatic norms, and understanding of the processes and mechanisms that control the carbon cycle remains elusive. Here, we investigate simulated surface‐atmosphere interaction at a single site in Brazil, using models with different representations of precipitation and cloud processes, as well as differences in scale of coupling between the surface and atmosphere. We find that the model with parameterized clouds/precipitation has a tendency toward unrealistic perpetual light precipitation, while models with explicit treatment of clouds produce more intense and less frequent rain. Models that couple the surface to the atmosphere on the scale of kilometers, as opposed to tens or hundreds of kilometers, produce even more realistic distributions of rainfall. Rainfall intensity has direct consequences for the "fate of water," or the pathway that a hydrometeor follows once it interacts with the surface. We find that the model with explicit treatment of cloud processes, coupled to the surface at small scales, is the most realistic when compared to observations. These results have implications for simulations of global climate, as the use of models with explicit (as opposed to parameterized) cloud representations becomes more widespread. Key Points: Ecophysiological function during seasonal drought is dependent upon storage and availability of rainfall that falls during the wet seasonThe scale of coupling between land and atmosphere strongly influences this "fate of water" in simulationsSimulations tend toward "water limitation" or "light limitation" depending on this scale of coupling [ABSTRACT FROM AUTHOR]

The responses of forest communities to interacting anthropogenic disturbances like climate change and logging are poorly known. Subtropical forests have been heavily modified by humans and their response to climate change is poorly understood. We investigated the 9‐year change observed in a mixed conifer‐hardwood Atlantic forest mosaic that included both mature and selectively logged forest patches in subtropical South America. We used demographic monitoring data within 10 1 ha plots that were subjected to distinct management histories (plots logged until 1955, until 1987, and unlogged) to test the hypothesis that climate change affected forest structure and dynamics differentially depending on past disturbances. We determined the functional group of all species based on life‐history affinities as well as many functional traits like leaf size, specific leaf area, wood density, total height, stem slenderness, and seed size data for the 66 most abundant species. Analysis of climate data revealed that minimum temperatures and rainfall have been increasing in the last few decades of the 20th century. Floristic composition differed mainly with logging history categories, with only minor change over the nine annual census intervals. Aboveground biomass increased in all plots, but increases were higher in mature unlogged forests, which showed signs of forest growth associated with increased CO2, temperature, and rainfall/treefall gap disturbance at the same time. Logged forests showed arrested succession as indicated by reduced abundances of Pioneers and biomass‐accumulators like Large Seeded Pioneers and Araucaria, as well as reduced functional diversity. Management actions aimed at creating regeneration opportunities for long‐lived pioneers are needed to restore community functional diversity, and ecosystem services such as increased aboveground biomass accumulation. We conclude that the effects of climate drivers on the dynamics of Brazilian mixed Atlantic forests vary with land‐use legacies, and can differ importantly from the ones prevalent in better known tropical forests. [ABSTRACT FROM AUTHOR]

Identifying the processes that determine avian migratory strategies in different environmental contexts is imperative to understanding the constraints to survival and reproduction faced by migratory birds across the planet.We compared the spring migration strategies of Fork‐tailed Flycatchers (Tyrannus s. savana) that breed at south‐temperate latitudes (i.e., austral migrants) vs. tropical latitudes (i.e., intratropical migrants) in South America. We hypothesized that austral migrant flycatchers are more time‐selected than intratropical migrants during spring migration. As such, we predicted that austral migrants, which migrate further than intratropical migrants, will migrate at a faster rate and that the rate of migration for austral migrants will be positively correlated with the onset of spring migration.We attached light‐level geolocators to Fork‐tailed Flycatchers at two tropical breeding sites in Brazil and at two south‐temperate breeding sites in Argentina and tracked their movements until the following breeding season.Of 286 geolocators that were deployed, 37 were recovered ~1 year later, of which 28 provided useable data. Rate of spring migration did not differ significantly between the two groups, and only at one site was there a significantly positive relationship between date of initiation of spring migration and arrival date.This represents the first comparison of individual migratory strategies among conspecific passerines breeding at tropical vs. temperate latitudes and suggests that austral migrant Fork‐tailed Flycatchers in South America are not more time‐selected on spring migration than intratropical migrant conspecifics. Low sample sizes could have diminished our power to detect differences (e.g., between sexes), such that further research into the mechanisms underpinning migratory strategies in this poorly understood system is necessary. [ABSTRACT FROM AUTHOR]

Morphology and anatomy of a fossil nymphaealean plant, Jaguariba wiersemana gen. nov. et sp. nov. from the late Early Cretaceous of northeastern Brazil, and extant aquatic flowering plants are comparatively studied. Characteristic features indicate that Jaguariba gen. nov. is a member of Nymphaeaceae, and may belong to Nymphaeoideae. The occurrence of both Nymphaeaceae and Cabombaceae (e.g., Pluricarpellatia peltata) in the Lower Cretaceous contradicts recent molecular dat-ing implying a Late Cretaceous--Early Tertiary divergence for those families. Furthermore, the morphology of the fossil and sedimentologic and taphonomic data indicate that Jaguariba gen. nov. had an aquatic ecology similar to living Nymphaeaceae. Thus the taxon was part of the aquatic vegetation of the Crato lake in association with Pluricarpellatia peltata, an earlier de-scribed cabombaceaen aquatic angiosperm. [ABSTRACT FROM AUTHOR]

The tribe Liabeae (Compositae) contains ca. 175 species distributed in 18 genera and its members occupy a variety of habitats in the Andes of South America as well as in Mexico, Central America, and the West Indies. The tribe is recognizable by a combination of morphological characters. DNA sequence data from the nuclear ribosomal ITS region and three chloroplast regions (trnL-F, 3' end of ndhF, matK; a total of more than 5 kb of sequence data) were used to infer a phylogeny. The data were analyzed using maximum parsimony, maximum likelihood, and Bayesian inference. The results support the monophyly of the tribe and show a consistent placement for all genera except Cacosmia. Four well-supported clades are recovered in the remainder of the tribe, all recognized as subtribes. Liabineae (Ferreyranthus, Dillandia, Oligactis, Sampera, Liabum) are the sister group of the rest of the tribe. Sinclairineae (Sinclairiopsis and Sinclairia with segregates Liabellum and Megaliabum) are the sister group of Munnoziinae (Chrysactinium nested inside Munnozia s.l.) plus Paranepheliinae (Stephenbeckia, Microliabum, Pseudonoseris, Paranephelius, Chionopappus, Philoglossa, Erato). Cacosmia is placed as the sister group of either all the rest of the tribe or of subtribe Liabineae; morphologically its characters are either autapomorphic or plesiomorphic. Bishopanthus could not be confidently placed in any of the subtribes; it is only known from scraps of the type and a molecular study is not possible. The phylogeny slightly alters previous assumptions about the biogeography and it seems that Liabeae originated in the central and northern Andes and spread north and south with several independent introductions into Mexico and Central America and one into the Caribbean. With the exception of the Liabeae (Andes) and Moquineae (Brazil), all of the tribes in the subfamily Cichorioideae are either restricted to or have their basal grade in Africa. [ABSTRACT FROM AUTHOR]

The article reports on the first record of powdery mildew caused by Oidiopsis haplophylli on Tropaeolum majus in Brazil. This herbaceous plant is native to South America. It is commonly grown as an ornamental plant in Brazil. It is also considered as an edible flower used for decorating salads. In November 2005 plants manifesting symptoms of angular leaf spots with an abaxial whitish fungal covering were gathered in a garden at Embú das Artes, Sao Paolo. The whitish fungal structures were established to belong to a powdery mildew.

Demographic and life-history attributes of the mole crab Emerita brasiliensis were analysed along 2700 km of the Atlantic coast of South America, including sandy beaches at the southernmost limit (Uruguay) and at the core of its geographical range (Brazil). Population features varied markedly within this range and exhibited systematic geographical patterns of variation. Abundance significantly increased from temperate to subtropical beaches, and the same held true for the asymptotic weight of males. Conversely, length at maturity and asymptotic weight of females increased from subtropical to temperate beaches, being inversely related to sea water temperature. Macroecological patterns in abundance and body weight showed the first large-scale evidence of scaling of population density to body size for a sandy beach population. Mortality rates (both sexes) followed a nonlinear increase from low-density temperate beaches to high-density subtropical beaches. The effect of habitat quality and availability could explain discontinuities in the species distribution within its range, and also differential responses in life-history attributes at a local scale. Asymmetries and converse latitudinal trends between sexes suggest that there is not a single general factor determining large-scale patterns in life-history traits of this species. Our results reinforce the view that density-dependent and environmental factors operating together regulate sandy beach populations. The need to develop macroecological studies in sandy beach ecology is highlighted, as knowledge acquired from local to large spatial scales throws light on population structure and regulation mechanisms. [ABSTRACT FROM AUTHOR]