Diversity In South America Research Articles

Vascular epiphytes of the South America Dry Diagonal: characterising their occurrence and richness in this neglected region

ABSTRACT The South America Dry Diagonal (SADD) is the most extensive and continuous portion of dry vegetation on the continent, characterised by lower rainfall and a marked dry season. Epiphytes are very poorly known and understudied in this area, even though they represent a high proportion of plant diversity in South America. Here, we compiled a dataset of epiphyte records from the SADD. The compiled epiphyte records date from 1859 to 2021, covering all four SADD domains, four countries, and 24 ecoregions. We utilised two databases for life form classification: Epilist and Brazil Flora Group. Our dataset contains 41,039 records distributed among 1119 epiphyte and hemiepiphyte species belonging to three main groups: angiosperms, ferns, and lycophytes. The SADD domains host a high number of unique species in each domain, with the Cerrado and Caatinga regions serving as primary hosts for the majority of species in the SADD dataset. Despite notable differences in species composition among domains, the least significant differences were observed between the Caatinga and Cerrado, as well as between the Chaco and the Pantanal. Orchidaceae, Bromeliaceae, and Polypodiaceae families exhibited the highest species diversity within the region. However, the species containing the highest number of specimens collected varied considerably among the domains. Herein, we also outlined some inconsistencies in the life-form classification across taxonomic bases, acknowledging the challenges of categorising epiphyte species while considering their intraspecific life-form variation.

Taxonomic Revision and Morphometric Analysis of Gamochaeta (Asteraceae, Gnaphalieae)

Gamochaeta Wedd. (Asteraceae, Gnaphalieae) is a New World genus with a center of diversity in South America. The genus is characterized by capitula usually arranged in spikes or headlike clusters; pistillate florets outnumbering the bisexual florets; truncate style branches with apical sweeping trichomes; pappus bristles connate at the base into a ring that falls as a unit; and achenes with usually globose twin trichomes. We present here the first morphometric analysis of this genus. Based upon these results, 53 species are recognized, and two are newly synonymized: G. neuquensis Cabrera under the name G. chamissonis (DC.) Cabrera, and G. impatiens G. L. Nesom under the name G. americana (Mill.) Wedd. A lectotype is newly designated for Gnaphalium spiciforme Sch. Bip. The occurrence in southern Argentina of Gamochaeta procumbens (Phil.) Cabrera is reported for the first time, and G. standleyi (Steyerm.) G. L. Nesom is new for Colombia. One species, Gamochaeta thouarsii (Spreng.) Anderb., is treated as dubious. A key to the species is provided, as well as morphological descriptions, synonymy, distribution and habitat information, distinguishing characters, taxonomic affinities, distribution maps, illustrations of the species, and additional material examined.

Bats (Mammalia: Chiroptera) from two priority areas for biodiversity conservation in the Brazilian Amazon and range extension for Carollia benkeithi (Phyllostomidae)

Abstract Amazonian tropical forests host the highest bat diversity in South America. The central area Brazilian Amazon encompasses one of the largest pristine areas within this biome, where Amanã and Mamirauá Sustainable Development Reserves (SDRs) are located. These two reserves hold the status of Priority Areas for Biodiversity Conservation due to their high biological relevance. The aim of this study was to identify the bat species richness within these SDRs to minimize the Wallacean shortfall of the chiropterofauna in the Amazon. A total of 274 specimens, collected 20 years ago and housed in the mammal collection at the Museu Paraense Emílio Goeldi, were sorted and identified. They are distributed across four families, 18 genera, and 26 species: Artibeus planirostris and Carollia perspicillata were the most abundant vouchers. We identified a range extension for Carollia benkeithi and a possible new taxon for the genus Micronycteris.

Illuminating the Mysteries of the Smallest Birds: Hummingbird Population Health, Disease Ecology, and Genomics.

Hummingbirds share biologically distinctive traits: sustained hovering flight, the smallest bird body size, and high metabolic rates fueled partially by nectar feeding that provides pollination to plant species. Being insectivorous and sometimes serving as prey to larger birds, they fulfill additional important ecological roles. Hummingbird species evolved and radiated into nearly every habitat in the Americas, with a core of species diversity in South America. Population declines of some of their species are increasing their risk of extinction. Threats to population health and genetic diversity are just beginning to be identified, including diseases and hazards caused by humans. We review the disciplines of population health, disease ecology, and genomics as they relate to hummingbirds. We appraise knowledge gaps, causes of morbidity and mortality including disease, and threats to population viability. Finally, we highlight areas of research need and provide ideas for future studies aimed at facilitating hummingbird conservation.

Evolutionary Analysis of a Parrot Bornavirus 2 Detected in a Sulphur-Crested Cockatoo (Cacatua galerita) Suggests a South American Ancestor.

Parrot bornavirus (PaBV) is an RNA virus that causes Proventricular Dilatation Disease (PDD), neurological disorders, and death in Psittaciformes. Its diversity in South America is poorly known. We examined a Cacatua galerita presenting neuropathies, PDD, and oculopathies as the main signs. We detected PaBV through reverse transcription polymerase chain reaction (RT-PCR) and partial sequencing of the nucleoprotein (N) and matrix (M) genes. Maximum likelihood and Bayesian phylogenetic inferences classified it as PaBV-2. The nucleotide identity of the sequenced strain ranged from 88.3% to 90.3% against genotype PaBV-2 and from 80.2% to 84.4% against other genotypes. Selective pressure analysis detected signs of episodic diversifying selection in both the N and M genes. No recombination events were detected. Phylodynamic analysis estimated the time to the most recent common ancestor (TMRCA) as the year 1758 for genotype PaBV-2 and the year 1049 for the Orthobornavirus alphapsittaciforme species. Substitution rates were estimated at 2.73 × 10-4 and 4.08 × 10-4 substitutions per year per site for N and M, respectively. The analysis of population dynamics showed a progressive decline in the effective population size during the last century. Timescale phylogeographic analysis revealed a potential South American ancestor as the origin of genotypes 1, 2, and 8. These results contribute to our knowledge of the evolutionary origin, diversity, and dynamics of PaBVs in South America and the world. Additionally, it highlights the importance of further studies in captive Psittaciformes and the potential impact on endangered wild birds.

A TIME-CALIBRATED PHYLOGENY OF VERBESINA (HELIANTHEAE – ASTERACEAE) BASED ON NUCLEAR RIBOSOMAL ITS AND ETS SEQUENCES

Verbesina L. is a genus of the tribe Heliantheae, subtribe Verbesininae (Asteraceae), with distribution in the Americas, where Mexico and the Andes harbour the richest concentration of species. The approximately 325 species in the genus are shrubs, subshrubs, trees and rarely herbs. Despite its high species diversity and biogeographical importance, the only available phylogenetic hypothesis for Verbesina was based on chloroplast DNA restriction site data. In the present study, nuclear ITS and ETS DNA sequence data were used with an expanded taxon sampling, particularly among the South American Verbesina species, to improve phylogenetic resolution and support, clarify infrageneric relationships, and resolve biogeographical questions in the genus. The results of our new analysis corroborate the monophyly of Verbesina, but its current classification into 12 taxonomic sections, based on morphological characters such as phyllotaxis, head size, corolla colour, and presence of ray flowers, is not congruent with the molecular phylogeny, in which most sections are polyphyletic. We also show that Verbesina diverged in the late Miocene of North America, about 8 Ma. At least two independent Pleistocene dispersals into South America across the Isthmus of Panama and along the Southern Andes are evident, beginning around 3.23 Ma (1.27–3.23 Ma) in the Middle Pliocene, and resulting in an extra-Amazonian distribution of the genus inSouth America. Diversification in South America began around 2.83 Ma with occupation of the Andes. Colonisation of Brazil is estimated to have occurred around 2.15 Ma, from Andean lineages.

Angiosperm phylogenetic diversity is lower in Africa than South America.

Although originating from a common Gondwanan flora, the diversity and composition of the floras of Africa and South America have greatly diverged since continental breakup of Africa from South America now having much higher plant species richness. However, the phylogenetic diversity of the floras and what this tells us about their evolution remained unexplored. We show that for a given species richness and considering land surface area, topography, and present-day climate, angiosperm phylogenetic diversity in South America is higher than in Africa. This relationship holds regardless of whether all climatically matched areas or only matched areas in tropical climates are considered. Phylogenetic diversity is high relative to species richness in refugial areas in Africa and in northwestern South America, once the gateway for immigration from the north. While species richness is strongly influenced by massive plant radiations in South America, we detect a pervasive influence of historical processes on the phylogenetic diversity of both the South American and African floras.

Giants of the Amazon: How does environmental variation drive the diversity patterns of large trees?

For more than three decades, major efforts in sampling and analyzing tree diversity in South America have focused almost exclusively on trees with stems of at least 10 and 2.5 cm diameter, showing highest species diversity in the wetter western and northern Amazon forests. By contrast, little attention has been paid to patterns and drivers of diversity in the largest canopy and emergent trees, which is surprising given these have dominant ecological functions. Here, we use a machine learning approach to quantify the importance of environmental factors and apply it to generate spatial predictions of the species diversity of all trees (dbh ≥ 10 cm) and for very large trees (dbh ≥ 70 cm) using data from 243 forest plots (108,450 trees and 2832 species) distributed across different forest types and biogeographic regions of the Brazilian Amazon. The diversity of large trees and of all trees was significantly associated with three environmental factors, but in contrasting ways across regions and forest types. Environmental variables associated with disturbances, for example, the lightning flash rate and wind speed, as well as the fraction of photosynthetically active radiation, tend to govern the diversity of large trees. Upland rainforests in the Guiana Shield and Roraima regions had a high diversity of large trees. By contrast, variables associated with resources tend to govern tree diversity in general. Places such as the province of Imeri and the northern portion of the province of Madeira stand out for their high diversity of species in general. Climatic and topographic stability and functional adaptation mechanisms promote ideal conditions for species diversity. Finally, we mapped general patterns of tree species diversity in the Brazilian Amazon, which differ substantially depending on size class.

Geographical distribution and notes on the nests of the “uruçu-do-chão” bee, Melipona (Melikerria) quinquefasciata Lepeletier, in Bahia, North-eastern Brazil

The Neotropical genus of stingless bees Melipona Illiger, 1806 is exclusive to Tropical America and has its greatest diversity in South America, with about 74 described species. In Bahia, there is an occurrence record for 12 species of Melipona, distributed in four subgenera. Among the Melipona (Melikerria) that occur in Bahia, we highlight Melipona (Melikerria) quinquefasciata Lepeletier, 1836. Although widely distributed in Brazil, its underground nesting habit associated with its preference for high altitude areas, make the species extremely vulnerable. This work sought to describe nests and map the occurrence of this species for the State of Bahia, since its record is limited to areas of Chapada Diamantina. Knowledge about the biogeography of the species is extremely important, strengthening its sustainable creation that respects the area of ​​occurrence of the species, as well as seeking alternatives and public policies for sustainable conservation, since its area of ​​occurrence is extremely vulnerable to the expansion of the agricultural frontier in the State.

Late Quaternary Isoëtes megaspores as a proxy for paleolimnological studies of the southeastern Amazonia

Isöetes have higher diversity in South America, with two endemic species (I. serracarajensis and I. cangae) recently discovered in the Carajás Mountain Range (CMR), southeastern Amazonia. I. serracarajensis is observed in upland oligotrophic to eutrophic swamps and ponds, while I. cangae is restricted to a single oligotrophic upland and active lake (Amendoim) the CMR since it is very sensitive to algal blooms and the eutrophication process. In this study, a species level identification and quantification of Isöetes megaspores were carried out for the first time in sediment cores of upland lakes of the CMR during the last 50k cal yr BP, and the main factors influencing population dynamics and conservation status were discussed. Generally, during millennial-scale drier hydroclimate conditions, swamps and ponds mostly dehydrated, and I. serracarajensis were restricted to active lakes, which became eutrophicated due to the increase in nutrient production from the remineralization of organic matter deposited in bottom sediments triggered by the decrease in water levels. On the other hand, the highly-sensitive population of I. cangae contracted since the Amendoim Lake become eutrophicated. During wetter climate, these species reappeared in their preferred habitats. However, the CMR is currently under climate and hydrological stress mainly due to an intense land use–land cover changes during the last four decades, with a worst-case scenario for the next 30 years, according to recent hydrological models. This may strongly impact the natural habitats of Isöetes and further increase pressure on already endangered populations.

PHYTOCHEMICAL AND ANTIMICROBIAL EVALUATION OF SUBSTANCES IN THE BIGNONIACEAE FAMILY

The ipê belongs to the Bignoniaceae Family, which has approximately 120 genera and 800 species, the largest genus belonging to this family is Tabebuia, found with great diversity in South America, due to its tropical and subtropical climate. Due to the enormous variety of plants of this genus, it was necessary to create a division based on their specific characteristics: Tabebuia, Handroanthus (exclusive to represent the species existing in Brazil) and Roseodendron. This work sought to gather information on the antimicrobial and phytochemical activity of substances found in the Bignoniaceae family, respectively, in the genera: Tabebuia rosea-ipê rosa; Handroanthus impetiginosus- purple ipe; Handroanthus albus-ipe yellow; Tabebuia roseo-alba-ipê (white) through the extraction of lapachol. With the present study, it is possible to evidence the great benefits arising from the extracts of ipês. However, the scarcity of studies of this type is clear, this fact makes it difficult to disseminate proof of the beneficial effects of ipês.

Genomic and phenotypic divergence‐with‐gene‐flow across an ecological and elevational gradient in a neotropical bird

AbstractAimSome species have populations that vary in ecologically relevant traits along environmental gradients, which is a pattern often generated by secondary contact post divergence in allopatry. However, an alternative explanation for such a pattern would be primary contact, where populations diverge in the presence of gene flow through the action of strong natural selection. We aimed to test the divergence‐with‐gene‐flow model across an environmental gradient in a Chaco‐Andes dry forest bird.LocationCentral Andes Mountain range and Chaco region of Argentina and Bolivia.TaxonPhytotoma rutila (Aves, Cotingidae).MethodsWe generated ddRADseq loci for 23 individuals and obtained body size variation data for 146 museum specimens. We evaluated population genetic structure and tested the effects of elevation and isolation by geographic distance on genomic divergence. To distinguish divergence in allopatry from divergence‐with‐gene‐flow, we compared the divergence of phenotypic traits (bill, tarsus and wing) with neutral genomic variation (S‐test and PST–FST comparisons), conducted coalescent analyses to estimate gene flow and divergence time, and calculated relative (FST) versus absolute (DXY) genomic divergence.ResultsWe found (a) P. rutila differs genomically and phenotypically following the highland‐lowland axis of the study region, with altitudinal variation explaining genomic variation; (b) larger phenotypic than neutral genomic divergence; (c) asymmetric gene flow between Andean and Chacoan populations; and (d) a pattern of relative and absolute genomic differentiation compatible with divergence‐with‐gene‐flow.Main conclusionsThe mechanism behind the morphological and genomic diversification along the Chaco‐Andes dry forest belt in P. rutila is divergence‐with‐gene‐flow. Diversification in South America implicates gene flow between populations and natural selection following environmental gradients, as well as vicariance. This complex combination contrasts with the traditional idea that speciation in birds occurred primarily in allopatry.

Ecological and Phenotypic Diversification after a Continental Invasion in Neotropical Freshwater Stingrays.

Habitat transitions are key potential explanations for why some lineages have diversified and others have not-from Anolis lizards to Darwin's finches. The ecological ramifications of marine-to-freshwater transitions for fishes suggest evolutionary contingency: some lineages maintain their ancestral niches in novel habitats (niche conservatism), whereas others alter their ecological role. However, few studies have considered phenotypic, ecological, and lineage diversification concurrently to explore this issue. Here, we investigated the macroevolutionary history of the taxonomically and ecologically diverse Neotropical freshwater river rays (subfamily Potamotrygoninae), which invaded and diversified in the Amazon and other South American rivers during the late Oligocene to early Miocene. We generated a time-calibrated, multi-gene phylogeny for Potamotrygoninae and reconstructed evolutionary patterns of diet specialization. We measured functional morphological traits relevant for feeding and used comparative phylogenetic methods to examine how feeding morphology diversified over time. Potamotrygonine trophic and phenotypic diversity are evenly partitioned (non-overlapping) among internal clades for most of their history, until 20-16 mya, when more recent diversification suggests increasing overlap among phenotypes. Specialized piscivores (Heliotrygon and Paratrygon) evolved early in the history of freshwater stingrays, while later trophic specialization (molluscivory, insectivory, and crustacivory) evolved in the genus Potamotrygon. Potamotrygonins demonstrate ecological niche lability in diets and feeding apparatus; however, diversification has mostly been a gradual process through time. We suggest that competition is unlikely to have limited the potamotrygonine invasion and diversification in South America.

First titanosaur dinosaur nesting site from the Late Cretaceous of Brazil

Titanosaurs were successful herbivorous dinosaurs widely distributed in all continents during the Cretaceous, with the major diversity in South America. The success of titanosaurs was probably due to several physiological and ecological factors, in addition to a series of morphological traits they achieved during their evolutionary history. However, the generalist nesting behaviour using different palaeoenvironments and strategies was key to accomplish that success. Titanosaur nesting sites have been found extensively around the world, with notable records in Spain, France, Romania, India, and, especially, Argentina. Here, we describe the first titanosaur nesting site from the Late Cretaceous of Brazil that represents the most boreal nesting site for South America. Several egg-clutches, partially preserved, isolated eggs and many eggshell fragments were discovered in an Inceptisol palaeosol profile of the mining Lafarge Quarry, at the Ponte Alta District (Uberaba Municipality, Minas Gerais State), corresponding to the Serra da Galga Formation (Bauru Group, Bauru Basin). Although classical mechanical preparation and CT scans have not revealed embryonic remains in ovo, the eggs and eggshell features match those eggs containing titanosaurian embryos found worldwide. The morphology of the egg-clutches and observations of the sedimentary characteristics bolster the hypothesis that these sauropods were burrow-nester dinosaurs, as was already suggested for the group based on other nesting sites. The egg-clutches distributed in two levels along the Lafarge outcrops, together with the geopalaeontological data collected, provide clear evidence for the first colonial nesting and breeding area of titanosaur dinosaurs in Brazil.

Systematic studies of the subgenus Crewella of Ceratina (Hymenoptera, Apidae, Xylocopinae), with a revision of the species occurring in Argentina

The subgenus Crewella Cockerell of Ceratina Latreille is found only in the Neotropical region, with maximal diversity in South America. A morphological study of the species in the subgenus led to the recognition of five species groups, based on several characteristics of the head, the first metasomal tergum, and the female sixth metasomal tergum. A key to the species-groups is presented. The following new species are described: C. dalyana , from Colombia, C. amazonica , C. crassipunctata , and C. foveinasis from Peru, C. duplocarinata , C. guaranitica , and C. lobata from Argentina, C. acuminata from Brazil and Paraguay, and C. carbonaria from Argentina and Brazil. Lectotypes are designated for C . brunneipes Friese, C . diligens Smith, and C . vernoniae Schrottky. The following are new synonyms: C . brunneipes Friese, 1910 of C . maculifrons Smith, 1854, and C . gossypii var. asuncionis Strand, 1910 of C . gossypii Schrottky, 1907. A revision of the species in Argentina, with a key to species, is presented.

Systematic studies of the subgenus Crewella of Ceratina (Hymenoptera, Apidae, Xylocopinae), with a revision of the species occurring in Argentina

The subgenus Crewella Cockerell of Ceratina Latreille is found only in the Neotropical region, with maximal diversity in South America. A morphological study of the species in the subgenus led to the recognition of five species groups, based on several characteristics of the head, the first metasomal tergum, and the female sixth metasomal tergum. A key to the species-groups is presented. The following new species are described: C. dalyana , from Colombia, C. amazonica , C. crassipunctata , and C. foveinasis from Peru, C. duplocarinata , C. guaranitica , and C. lobata from Argentina, C. acuminata from Brazil and Paraguay, and C. carbonaria from Argentina and Brazil. Lectotypes are designated for C . brunneipes Friese, C . diligens Smith, and C . vernoniae Schrottky. The following are new synonyms: C . brunneipes Friese, 1910 of C . maculifrons Smith, 1854, and C . gossypii var. asuncionis Strand, 1910 of C . gossypii Schrottky, 1907. A revision of the species in Argentina, with a key to species, is presented.

Correction to: New Specimens of Reigitherium bunodontum from the Late Cretaceous La Colonia Formation, Patagonia, Argentina and Meridiolestidan Diversity in South America

Correction to: New Specimens of Reigitherium bunodontum from the Late Cretaceous La Colonia Formation, Patagonia, Argentina and Meridiolestidan Diversity in South America

New Specimens of Reigitherium bunodontum from the Late Cretaceous La Colonia Formation, Patagonia, Argentina and Meridiolestidan Diversity in South America

New Specimens of Reigitherium bunodontum from the Late Cretaceous La Colonia Formation, Patagonia, Argentina and Meridiolestidan Diversity in South America

Population Structure of a Worldwide Phytophthora palmivora Collection Suggests Lack of Host Specificity and Reduced Genetic Diversity in South America and the Caribbean.

Phytophthora palmivora (Butler) is a highly destructive plant pathogen that infects tropical hosts worldwide, many of which are economically important crops. Despite the broad host range and wide distribution, the pathogen has displayed a considerable amount of variation in morphological characters, including virulence. However, the genetic variability at a global level, which is critical to understand the center of origin and the potential pathway(s) of introduction, was unclear. Here, we mapped the genetic variation of P. palmivora using isolates representing four regions, 15 countries, and 14 host species. We designed a large set of simple sequence repeat markers from the P. palmivora genome and picked 17 selectively neutral markers to screen 98 P. palmivora isolates. We found that P. palmivora populations from our collection generally did not cluster according to host; rather, some isolates from North America were generally distinct from all other populations. Isolates from South America and the Caribbean clustered and appeared to share ancestry with isolates from Asia. Populations from North America and Asia were the most genetically diverse, while the South American and Caribbean populations exhibited similar reduced genetic diversity. The isolates collected in various plantations in Colombia did not show host or geographic specificity. Our study brought a further understanding of this important plant pathogen, although the determination for hypothesized source of origin, spread, and evolution would need further sampling. The genomic resources developed in this study would facilitate further studies on P. palmivora diagnostics and management.

A new Oligocene-Miocene tree from Panama and historical Anacardium migration patterns.

Migration of Boreotropical megathermal taxa during the Oligocene and Miocene played a key role in assembling diversity in tropical regions. Despite scattered fossil reports, the cashew genus Anacardium offers an excellent example of such migration. The fossil woods described here come from localities in Veraguas, Panama mapped as Oligocene-Miocene. We studied, described, and identified two well-preserved specimens using wood anatomical characteristics and completed extensive comparisons between fossil and extant material. The studied fossil woods share several diagnostic features with the modern Anacardium genus, including large solitary vessels, large intervessel-pitting, a simple vessel-ray pitting pattern, and mostly 1–3 seriate rays with large rhomboidal solitary crystals. We propose a new fossil species named Anacardium gassonii sp. nov., that adds an essential piece to the understanding of the historical biogeography of the genus. In addition, our findings confirm previous interpretations of this species’ migration from Europe to North America and its crossing through Panama, leading to subsequent diversification in South America. This discovery provides an important link to the historical migration patterns of the genus, supporting the notion of an Eocene migration to the Neotropics via Boreotropical bridges, as well as an Oligocene-Miocene crossing of Central America followed by diversification in South America.