Diversity and distribution of orchid bees (Hymenoptera: Apidae) with a revised checklist of species

The aim of this study was to investigate the diversity and distribution patterns of orchid bees (Euglossina). Cluster and correlation analyses were applied to data extracted from 28 orchid-bee surveys throughout the Neotropical Region. The 28 sampling sites were grouped in three main biogeographic areas that roughly correspond to the Amazonian Basin, the Atlantic Forest and Central America. These three regions, as well as subregions within each of them, correspond approximately to biogeographic components identified through phylogeny-based analyses for other bees and organisms. The Amazonian Forest as a whole has the richest fauna and the highest levels of endemism. The Atlantic Forest, on the other hand, showed the poorest fauna and the lowest levels of endemism. However, a major neotropical biome, in which orchid bees are known to occur, has not been sampled yet, the savanna-like cerrado. At least 30% of the species are endemic to each biome. An updated checklist of the species of Euglossina is provided.     

Neotropical savanna ants show a reversed latitudinal gradient of species richness,with climatic drivers reflecting the forest origin of the fauna

Aim

To evaluate the extent to which ant species richness in Neotropical savannas varies with macrogeographic variables, and to identify the potential climatic drivers of such variation.

Location

The Cerrado savanna biome of central Brazil, in a region spanning ca. 20° of latitude and 18°of longitude.

Methods

Standardized sampling of the arboreal and ground‐dwelling faunas was performed in 29 well‐preserved savanna sites using pitfall traps. Species were classified according to their habitat affinities: open‐savanna specialists, forest‐associated species or habitat generalists. We used generalized linear models to evaluate the importance of geographic (latitude, longitude and elevation) and climatic (mean temperature and three metrics of rainfall) variables as predictors of species richness.

Results

The total number of species recorded at each site varied more than twofold (from 59 to 144), and latitude was the best geographic correlate of overall species richness. However, contrary to the expected pattern, more species were found at higher than lower latitudes. This reversed latitudinal pattern of diversity occurred for both the arboreal and ground‐dwelling faunas, and for the habitat generalists and forest specialists. The savanna specialists showed a mid‐latitudinal peak in diversity. Overall, there was a significant positive association between rainfall and species richness, but the strength of this relationship varied with ant habitat affinity.

Main conclusions

The Cerrado ant fauna shows a reverse latitudinal gradient in species diversity, and this can be explained by increasing rainfall during the warmest months of the year (and therefore in plant productivity) with increasing latitude. The sensitivity of Cerrado ant diversity to declining rainfall contrasts with the high resilience to aridity of the Australian savanna ant fauna, and this reflects the contrasting evolutionary histories of these faunas. Our findings highlight the importance of historical processes as drivers of intercontinental contrasts in macroecological patterns.     

Characterization of Soil Bacterial Assemblies in Brazilian Savanna-Like Vegetation Reveals Acidobacteria Dominance

The Brazilian Cerrado is the second largest biome in Brazil and is considered a biodiversity hotspot. In this work, we compared the bacterial communities in Cerrado soil associated with four types of native vegetation (Cerrado Denso, Cerrado sensu stricto, Campo Sujo, and Mata de Galeria) by ribosomal RNA intergenic spacer analysis, terminal fragment restriction length polymorphism and pyrosequencing. The fingerprinting results were very similar. The bacterial communities of Cerrado Denso and Cerrado sensu stricto grouped together and were distinct from those in Campo Sujo and Mata de Galeria. Pyrosequencing generated approximately 40,000 16S rRNA gene sequences per sample and allowed the identification of 17 phyla in soil samples under Cerrado vegetation. Acidobacteria were dominant in all areas studied with a relative frequency of 40-47?%, followed closely by Proteobacteria accounting for 34-40?% of the sequences. Results from all molecular techniques used suggested that the bacterial communities of Cerrado sensu stricto and Cerrado Denso are very similar to each other, while Campo Sujo forms a separate group, and Mata de Galeria is the most distinct with higher species richness. This is the first extensive study of native Cerrado soil microbiota, an important but endangered biome.     

Entomopathogenic nematode distribution and edaphoclimatic conditions in the Cerrado of Minas Gerais,Brazil

Based on the high diversity of Brazilian fauna and flora, edaphoclimatic conditions in the Cerrado of Minas Gerais, and the situation of utilization of EPNs in Brazil, a survey was conducted in order to relate the presence of these organisms with the physical and chemical attributes of the soil, combined with precipitation. To this end, soil samples were collected in areas with diversified vegetation types in Monte Carmelo, MG, at Juliana Farm. The samples were obtained every 15 days for 6 months. From each spot, soil samples (about 500 g) were collected for soil moisture characterization, nematode isolation and determination of pH, organic matter, potassium (K), calcium (Ca), magnesium (Mg), phosphorus (P), potential acidity (H + Al) and precipitation data (mm). Three populations of entomopathogenic nematodes of the Heterorhabditis amazonensis species were isolated in Cerrado stricto sensu and Gallery forest areas. The occurrence H. amazonensis could not be considered restricted to specific soil condition, as organic matter, humidity, pH, Ca, K, Mg and H + Al, especially considering the organic matter and K values, which had variable levels between the places of collection. The p values of the positive soil samples were at a lower level than the mean of the Gallery forest and Cerrado, and at the same level as maize and pasture area. The soil moisture in the Cerrado area increased with the higher values of precipitation; however, in the Gallery forest area this association was not observed. Also, the nematodes were isolated when the temperature began to decrease.     

Lizards and termites revisited

Abstract We evaluate the hypothesis, originally proposed for arid Australia, that abundant and diverse termite assemblages can promote lizard radiation, based on a reappraisal of published data and on new data from the Cerrado biome in central Brazil. We found a positive correlation between termite and lizard richness in Cerrado. However, termite abundance and richness cannot actively drive lizard speciation, but can be important in maintaining lizard richness. Cerrado shares with arid Australia a rich and abundant termite fauna, but local Cerrado lizard assemblages are relatively impoverished. We suggest that differences in lizard richness between Cerrado and arid Australia may be explained by a combination of variations in area and latitude controlling speciation rates and present‐day ecological factors moderating extinction rates.     

A hawkmoth crossroads? Species richness,seasonality and biogeographical affinities of Sphingidae in a Brazilian Cerrado

Aim The aim of the study was (1) to describe the biodiversity of the sphingid assemblage in a Cerrado area in the Triângulo Mineiro region, south‐east of Brazil; (2) to evaluate the seasonal variations in species composition; (3) to compare the faunistic relationships between the Cerrado biome and adjacent ecosystems; and (4) to analyse the biogeographical pattern of species distribution in the Neotropical region in a historical context. Location Panga Ecological Station (PES), 30 km south of the city of Uberlândia, and other areas of the Triângulo Mineiro region, Minas Gerais state, south‐eastern Brazil. Methods Moth richness and abundance were monitored monthly at the PES from August 2003 to July 2004, with additional collections at this locality in 2001/2002, 2005 and 2006. Complementary moth richness and abundance data were also collected in other areas of the Triângulo Mineiro region. All collections were made using light traps, and the hawkmoths were mounted and identified. Cluster analysis, rarefaction curves and estimators of total species richness were used to compare the Cerrado hawkmoth assemblage with assemblages derived from other surveys in the Neotropics. Results In total, 61 hawkmoth species were recorded for the study region and their occurrence was markedly seasonal. The hawkmoth assemblage in the study area presented the closest similarity with rain forest areas and with a tropical dry forest area in Central America. The area shared species with both rain forest and seasonally dry tropical forest (SDTF) ecosystems, including supposedly endemic species previously recorded only in the latter areas. Rarefaction curves and estimators of the total number of species showed species richness to be comparable with other highly diverse forest areas in the Neotropics, such as the Brazilian Amazon and Costa Rica. Main conclusions This short‐term study is the first systematic survey of hawkmoths in the Cerrado. It has recorded around 22% of the South American fauna and highlighted the high species richness of the region, which compares favourably with that in other rain forest ecosystems. The survey indicates high regional diversity, and has shown that the Cerrado harbours a hawkmoth fauna comprising both rain forest elements, probably distributed along humid gallery forest corridors, and SDTF elements, supporting the idea of a historical Pleistocene arc connecting the Caatinga domain and other seasonal dry forest areas across the Cerrado region.     

Conservation biogeography of mammals in the Cerrado biome under the unified theory of macroecology

Understanding what limits the distribution and abundance of species is critical for adopting optimal conservation planning strategies, although it is still difficult to obtain abundance data at broad spatial scales. Here we propose conservation priorities in the Brazilian Cerrado based on density values of 108 mammal species. These values were estimated by an abundant-centre model coupled with McGill and Collin's unified theory for macroecology. We assumed that species' densities decay with a Gaussian distribution towards the range borders from a maximum density placed at the centre of each species' range. We used allometric equations to estimate maximum densities, at the Cerrado region we corrected the estimated densities by the natural vegetation remnants. Then we used a Simulated Annealing algorithm to select alternative sets of areas that met several levels of minimum viable population sizes (MVPSs) for each species. With low MVPSs, there were a small number of highly irreplaceable areas located in the northwest region of the biome, whereas with high MVPSs, highly irreplaceable areas occurred in up to 95% of the biome. By incorporating principles from the unified theory of macroecology, we were able to generate a conservation network for the Cerrado biome aiming to prioritise species' persistence and not just their presence.     

Sand flies (Diptera: Psychodidae) in a Cerrado area of the Maranhão state, Brazil

The present paper aims to increase the knowledge on the sand fly fauna in the cerrado areas of Maranh?o state in urban, rural and forest environments. The research was carried out from October 2007 to September 2008, between 18:00h and 06:00h, in the municipality of Chapadinha, northeast Maranh?o. For insect sampling, CDC light traps were set up in peridomicile and domicile areas of urban and rural zones as well as in Cerrado and Gallery forests. The total of 1,401 specimens belonging to 17 species were sampled, all within the genus Lutzomyia. Lutzomyia longipalpis (Lutz & Neiva) (52.5%), Lu. evandroi (Costa Lima & Antunes) (18.3%), Lu. whitmani (Antunes & Coutinho) (12.1%), Lu. lenti (Mangabeira) (4.7%) and Lu. termitophila (Martins, Falc?o & Silva) (4.0%) were the most frequently collected. From an epidemiological viewpoint, five from all of the collected species are vectors of leishmaniasis: Lu. longipalpis, Lu. whitmani, Lu. flaviscutellata (Mangabeira), Lu. gomezi (Nitzulescu) and Lu. chagasi (Costa Lima). Lutzomyia chagasi was registered for the first time in Maranh?o state and Lu. saulensis (Floch & Abonnenc), Lu. monstruosa (Floch & Abonnenc) and Lu. gomezi were found for the first time in the eastern part of the state, since they had been reported only in the Amazonian region of Maranh?o. Regarding to the studied environments, the urban chicken house had the highest number of specimens collected (801), while the Gallery Forest was the most diverse (15 species). This study demonstrates that the northeast cerrado exhibits a mixed sand fly fauna characterized by an extremely important species vectors assortment involved in the epidemiological cycle of leishmaniasis in Maranh?o state.     

Phenological variation within and among populations of Plathymenia reticulata in Brazilian Cerrado, the Atlantic Forest and transitional sites

BACKGROUND AND AIMS: Plathymenia reticulata (Leguminosae) is a Brazilian tree that occurs in two biomes: Cerrado, a woody savanna vegetation, and the Atlantic Forest, a tropical forest. In this study, phenological patterns and their variability within and among populations located in these biomes and in transitional zones between them were assessed. METHODS: During a 15-month period, individuals from two populations in Cerrado, two in the Atlantic Forest, and six in transitional zones (three in a cerrado-like environment and three in forest fragments) were evaluated in Minas Gerais State, Brazil. The individuals were evaluated monthly according to the proportion of the canopy in each vegetative phenophase (leaf fall, leaf flush and mature leaves) and each reproductive phenophase (floral buds, flowers, immature fruits and mature fruit/seed dispersal). In order to assess the phenological variability within and among populations, habitats and biomes, the Shannon-Wiener diversity index, the Morisita-Horn similarity index and genetic population approach of partitioning diversity were used. KEY RESULTS: Populations of P. reticulata, in general, showed similar phenology; the main differences were related to leaf fall, a process that starts months earlier in the Cerrado than in transitional sites, and even later in forest areas. Considerable synchrony was observed for reproductive phenology among populations and between biomes. Most phenological diversity was due to differences among individuals within populations. CONCLUSION: In spite of environmental differences, P. reticulata from the Atlantic Forest and Cerrado showed similar phenological behavior with only about 10% of the total diversity being attributed to differences between biomes.     

Variability in fruit and seed morphology among and within populations of Plathymenia (Leguminosae-Mimosoideae) in areas of the Cerrado, the Atlantic forest, and transitional sites

Plathymenia reticulata is a tree species that occurs in two different Brazilian biomes, the Cerrado (a savannah environment), and the Atlantic Forest. In the present study, we evaluated morphological variation within and among five populations located in these vegetation types and in transitional sites in order to test the hypothesis that habitat selective pressures, being different in the Cerrado and the Atlantic Forest, would cause adaptive differences in morphological traits in individuals occurring under these different circumstances. Thirteen morphological traits of fruits, seeds, and of the membranous endocarp were obtained from 30 fruits and 20 seeds from each of nine to 10 individuals per population. Significant variation was found for all traits while comparing individuals within populations, and most traits varied significantly among populations as well. Some traits differed significantly between forest and Cerrado populations, while transition sites showed intermediate patterns and higher within-population variation. Contrary to our hypothesis, variation in seed size and mass among populations from different habitats was not significant. However, as predicted, the membranous endocarp was shorter for the seeds from Cerrado populations than from the Atlantic Forest. These data suggest the existence of P. reticulata ecotypes from Cerrado and Atlantic Forest; the relevance to Plathymenia evolution and to its wide ecological distribution is discussed.     

Effectiveness of Mosquito Magnet? trap in rural areas in the southeastern tropical Atlantic Forest

Traps are widely employed for sampling and monitoring mosquito populations for surveillance, ecological and fauna studies. Considering the importance of assessing other technologies for sampling mosquitoes, we addressed the effectiveness of Mosquito Magnet^® Independence (MMI) in comparison with those of the CDC trap with CO2 and Lurex3^® (CDC-A) and the CDC light trap (CDC-LT). Field collections were performed in a rural area within the Atlantic Forest biome, southeastern state of São Paulo, Brazil. The MMI sampled 53.84% of the total number of mosquitoes, the CDC-A (26.43%) and CDC-LT (19.73%). Results of the Pearson chi-squared test (χ2) showed a positive association between CDC-LT and species of Culicini and Uranotaeniini tribes. Additionally, our results suggested a positive association between CDC-A and representatives of the Culicini and Aedini tribes, whereas the MMI was positively associated with the Mansoniini and Sabethini as well as with Anophelinae species. The MMI sampled a greater proportion (78.27%) of individuals of Anopheles than either the CDC-LT (0.82%) or the CDC-A traps (20.91%). Results of the present study showed that MMI performed better than CDC-LT or CDC-A in sampling mosquitoes in large numbers, medically important species and assessing diversity parameters in rural southeastern Atlantic Forest.     

Compliance to Brazil's Forest Code will not protect biodiversity and ecosystem services

In striking contrast to heartening events in the adjacent Amazon, Brazil's Cerrado biome has seen continued deforestation over the past decade. Though approved in 2012, no study evaluated the impacts of new Brazilian Forest Code (FC) revision on biodiversity and ecosystem services. Here, we report the first assessment of the likely loss and gain in biodiversity and ecosystem services expected if the FC is properly enforced across 200 million hectares of the Cerrado. We also discuss the challenges associated to compliance with the law and present opportunities for conservation. Establishing restoration programmes in private properties with currently less native vegetation than required by the FC could create habitat for 25% more threatened species than now found in these places and could also increase water security and carbon stock in 56.6 MtC. More important, trading environmental reserve quotas coupled with the strategic expansion of protected areas on private and public land could definitely rescue the Cerrado from the brink.     

The major diversity centre for Neotropical Turneraceae

The Neotropical country where the Turneraceae are best represented is Brazil; 82% of the American species are native, and 73% of them are endemic to this country. The most diverse states are Bahia, Minas Gerais and Goiás. Within this area the diversity – in terms of number of species – was analysed at a level of one degree square, taking into account the phytogeographic domains (biomes) recognized in Brazil. The distribution of endemic and rare species was also explored. The major centre of diversity is located in the Chapada Diamantina, Bahia, inside the biome ‘Caatinga’, but there are hotspots in Minas Gerais and Goiás, within the biome ‘Cerrado’. The biome with highest number of endemic species is the ‘Cerrado’, followed by the ‘Caatinga’.     

Phylogeographical structure of the neotropical forest tree Hymenaea courbaril (Leguminosae: Caesalpinioideae) and its relationship with the Vicariant Hymenaea stigonocarpa from Cerrado

The phylogeography of Hymenaea courbaril var. stilbocarpa from Atlantic Forest and riverine forests of the Cerrado biome in central and southeastern Brazil was investigated. The data were compared with those of its congeneric Hymenaea stigonocarpa, a typical tree from savanna. In the Cerrado, H. courbaril var. stilbocarpa is found in sites contiguous with those of H. stigonocarpa, and they share common life-history attributes. The psbC/trnS3 region of the chloroplast DNA was sequenced in 149 individuals of H. courbaril var. stilbocarpa. High genetic variation was found in this species, with the identification of 18 haplotypes, similarly to what was found in H. stigonocarpa with 23 haplotypes in the same geographic region. Populations of H. courbaril var. stilbocarpa could be structured in 3 phylogeographic groups. Spatial analysis of molecular variation indicated that 46.4% of the genetic variation was due to differences among these groups. Three haplotypes were shared by H. courbaril var. stilbocarpa and H. stigonocarpa, and only 10.5% of the total genetic variation could be attributed to between-species difference. We surmise that during the glacial times, H. courbaril var. stilbocarpa populations must have gone extinct in most parts of the southern of its present-day occurrence area. After climate amelioration, these areas were probably recolonized from northern and eastern. The relatively similar phylogeographic structure of vicariant Hymenaea species suggests that they were subjected to the same impacts during the Quaternary climatic fluctuations. The sharing of haplotypes and the genetic similarity between the 2 Hymenaea species suggest the existence of ancestral polymorphism and/or hybridization.     

Climatic stability in the Brazilian Cerrado: implications for biogeographical connections of South American savannas,species richness and conservation in a biodiversity hotspot

Aim To investigate the historical distribution of the Cerrado across Quaternary climatic fluctuations and to generate historical stability maps to test: (1) whether the ‘historical climate’ stability hypothesis explains squamate reptile richness in the Cerrado; and (2) the hypothesis of Pleistocene connections between savannas located north and south of Amazonia. Location The Cerrado, a savanna biome and a global biodiversity hotspot distributed mainly in central Brazil. Methods We generated occurrence datasets from 1000 presence points randomly selected from the entire distribution of the Cerrado, as determined by two spatial definitions. We modelled the potential Cerrado distribution by implementing a maximum‐entropy machine‐learning algorithm across four time projections: current, mid‐Holocene (6 ka), Last Glacial Maximum (LGM, 21 ka) and Last Interglacial (LIG, 120 ka). We generated historical stability maps (refugial areas) by overlapping presence/absence projections of all scenarios, and checked consistencies with qualitative comparisons with available fossil pollen records. We built a spatially explicit simultaneous autoregressive model to explore the relationship between current climate, climatic stability, and squamate species richness. Results Models predicted the LGM and LIG as the periods of narrowest and widest Cerrado distributions, respectively, and were largely corroborated by palynological evidence. We found evidence for two savanna corridors (eastern coastal during the LIG, and Andean during the LGM) and predicted a large refugial area in the north‐eastern Cerrado (Serra Geral de Goiás refugium). Variables related to climatic stability predicted squamate richness better than present climatic variables did. Main conclusions Our results indicate that Bolivian savannas should be included within the Cerrado range and that the Cerrado’s biogeographical counterparts are not Chaco and Caatinga but rather the disjunct savannas of the Guyana shield plateaus. Climatic stability is a good predictor of Cerrado squamate richness, and our stability maps could be used in future studies to test diversity patterns and genetic signatures of different taxonomic groups and as a higher‐order landscape biodiversity surrogate for conservation planning.     

Endemic birds of the Atlantic Forest: traits,conservation status,and patterns of biodiversity

The bird fauna of the Brazilian Atlantic Forest is exceptionally diverse and threatened, with high levels of endemism. Available lists of the endemic birds of the Atlantic Forest were generated before recent taxonomic revisions lumped or split species and before the recent increase in species occurrence records. Our objective, therefore, was to compile a new list of the endemic birds of the Atlantic Forest, characterize these species in terms of conservation status and natural history traits, and map remaining vegetation and protected areas. We combined GIS analysis with a literature search to compile a list of endemic species and, based on the phylogeny and distribution of these species, characterized areas in terms of species richness, phylogenetic diversity, and endemism. We identified 223 species of birds endemic to the Atlantic Forest, including 12 species not included in previous lists. In addition, 14 species included in previous lists were not considered endemic, either because they occur outside the Atlantic Forest biome or because they are not considered valid species. The typical Atlantic Forest endemic bird is a small forest‐dependent invertivore. Of the species on our list, 31% are considered threatened or extinct. Only ~ 34% of the spatial analysis units had > 10% forest cover, and protected area coverage was consistently low (< 1%). In addition, we found spatial incongruity among the different measures of biodiversity (species richness, relative phylogenetic diversity, restricted‐range species, and irreplaceability). Each of these measures provides information concerning different aspects of biological diversity. However, regardless of which aspect(s) of biodiversity might be considered most important, preservation of the remaining areas of remnant vegetation and further expansion of protected areas are essential if we are to conserve the many endemic species of birds in the Atlantic Forest.     

Effect of rain on trap building by Myrmeleon brasiliensis in a riparian woodland from the Cerrado biome in Brazil

In areas of the Cerrado biome (Brazilian savanna) with well‐defined rainy and dry seasons, changes in climate and landscape affect the abundance and seasonality of insects. Larvae of the antlion Myrmeleon brasiliensis (Návas) (Neuroptera: Myrmeleontidae) are predators that build traps in dry sandy soil to capture prey. Here we determined the effect of rain on trap building by M. brasiliensis larvae in a riparian forest in the Cerrado biome. Differences in population size and developmental stage were found between the rainy and dry seasons. In the laboratory, the effect of rain‐soaked soil on trap building was evaluated. Fewer antlion larvae were found in the rainy season. Moreover, a greater abundance of larvae in the final stage of development (third instar) was found in the dry season, whereas more first instars were found in the rainy season. The latter revealed that wet soil affects the trap building of the larvae, as smaller traps were built in the treatment with soaked soil (simulated rain), whereas the larvae in the control treatment (no rain) continued building traps with no change in size. The findings indicate that seasonality in the Cerrado biome exerts a short‐term influence on M. brasiliensis larvae (larvae build fewer traps) as well as a long‐term influence (association with life cycle).     

Association of Constrictotermes cyphergaster Silvestri (Isoptera: Termitidae) with trees in the Brazilian Cerrado

Termites usually build nests differently shaped and characterized according to each species, to protect and keep society cohesion. Some species build nests in the ground, some prefer tree thunks or branches as support, whereas other dig galleries in the wood. The purpose of this study is to analyze the relationship between the occurrence of arboreal termites Constrictotermes cyphergaster Silvestri and tree species that support the nest of this species, in a Cerrado sensu strictu of the Serra de Caldas Novas, GO. Data suggest a association relationship between C. Cyphergaster and the tree species Qualea grandiflora Mart., Annona crassiflora Mart., Caryocar brasiliense Camb. and Plathymenia reticulata Benth., shown by high Qui-squared values (chi2 = 214.986, gl. = 20, P < 0.001). This relationship may be found among other termites and tree species, including Cerrado biome, and may be due to several factors, such as natural competitors and predators, toxin production by other tree species or benefits between associated species (facultative mutualism or facilitation).     

Isolation and characterization of microsatellite loci for Hymenaea courbaril and transferability to Hymenaea stigonocarpa, two tropical timber species

Hymenaea courbaril is a tropical timber species, intensely exploited and found in the Amazon, Atlantic Forest and Brazilian Cerrado biome. Nine highly polymorphic microsatellite loci were developed from a genomic library enriched for AG/TC repeats. In a total of 41 individuals, from two natural populations, seven to 13 alleles per locus were detected and expected heterozygosity ranged from 0.75 to 0.90. Seven loci were effectively transferred to Hymenaea stigonocarpa. High levels of polymorphism make the present primers useful for population genetic studies and are a powerful tool to investigate mating system, gene flow and spatial genetic structure.