Search Results (397)

Simian foamy virus (SFV) is a retrovirus that infects primates. However, epidemiological studies of SFV are often limited to captive populations. The southeastern Brazilian Atlantic Forest is home to both an endemic, endangered species, Leontopithecus rosalia, and an introduced species, Leontopithecus chrysomelas, to which no data on SFV exist. In this study, we assessed the molecular prevalence of SFV, their viral load, and their phylogenetic relationship in these two species of primates. Genomic DNA was extracted from 48 oral swab samples of L. chrysomelas and 102 of L. rosalia. Quantitative PCR (qPCR) was performed to diagnose SFV infection and quantify viral load. SFV prevalence was found to be 23% in L. chrysomelas and 33% in L. rosalia. No age-related differences in prevalence were observed; however, L. rosalia showed a higher mean viral load (3.27 log10/10⁶ cells) compared to L. chrysomelas (3.03 log10/10⁶ cells). The polymerase gene sequence (213 pb) of L. rosalia (SFVlro) was clustered within a distinct SFV lineage found in L. chrysomelas. The estimated origin of SFVlro dated back approximately 0.0836 million years ago. Our study provides the first molecular prevalence data for SFV in free-living Leontopithecus populations while offering insights into the complex evolutionary history of SFV in American primates. Full article

Small rodents are known hosts of various pathogens, including Hepatozoon, but until now, in Brazil, only Hepatozoon milleri has been described in these animals. In this study, liver samples and blood smears were obtained from 289 rodents belonging to 14 Cricetidae and two Muridae species that had been captured in municipalities of the states of Paraná and Rio de Janeiro. Smears were stained with Giemsa, and gametocytes were detected via microscopy in 10.72% (n = 31/289) of samples, with these individuals representing three rodent species. Significant morphometric differences were observed in gametocyte measurements in Akodon rodents. Using conventional PCR, Hepatozoon spp. 18S rDNA fragments were amplified in 24.91% (n = 72/289) of samples, with those individuals representing seven rodent species. Phylogenetic analyses clustered 41 sequences from this study into a subclade with other sequences from small mammals in Brazil, identifying four distinct haplotypes, and, for the first time, a relationship between Hepatozoon haplotype and gametocyte length was observed. Based on phylogenetic analysis, this study reinforces the trophic relationship between rodents and reptiles as a possible link in the Hepatozoon transmission cycle in South America. Furthermore, our findings expand knowledge on Hepatozoon spp. hosts, describing Oxymycterus nasutus and Oxymycterus quaestor as new host species and identifying two novel circulating haplotypes in rodents from Paraná State, southern Brazil. Full article

The arboreal rodent Oecomys catherinae, which has a wide geographic distribution across Brazilian biomes, provides a model for investigating environmental influences on morphological variation. We assessed craniodental differences between the Atlantic Forest and Cerrado biomes, as well as along latitudinal gradients, using 45 specimens from 18 localities. Linear morphometric analyses (21 measurements) revealed no significant sexual dimorphism, allowing for pooled analyses. Principal Component Discriminant Analysis (DAPC) confirmed significant morphological divergence between biomes (72% accuracy, p < 0.01). We identified bony palate length (BPL) as the most discriminating variable, with higher values in the Atlantic Forest, suggesting a possible dietary adaptation in response to ecological pressures. Latitudinal effects were modest (adjusted R² = 0.05) although significant (F_1,43 = 3.63; p = 0.03), with southern populations exhibiting larger cranial dimensions than northern ones. We conclude that biome type and latitude played important roles in shaping cranial morphology in O. catherinae populations. Full article

Rare earth elements (REEs) are emerging soil contaminants due to increasing fertilizer use, mining activities, and technological applications. However, few studies have assessed their concentrations in soils or associated environmental risks. Here, we evaluate the influence of land cover types (Eucalyptus plantation, forest, and pasture), parent material, and soil physicochemical properties (predictor variables) on REE content in the Brazilian Atlantic Forest and measure pseudo-total REE content using inductively coupled plasma mass spectrometry (ICP-MS). Differences in REE content across land cover types, parent materials, and soil properties were assessed using similarity and variance analyses (ANOSIM, ANOVA, and Kruskal–Wallis) followed by post hoc tests (Tukey HSD and Dunn’s). We used model selection based on the Akaike criterion (ΔAICc < 2) to determine the influence of predictor variables on REE content. Our results showed that parent materials (igneous and metamorphic rocks) were the best predictors, yielding plausible models (Adj R² ≥ 0.3) for Y, δEu, and La_N/Sa_N. In contrast, Ca:Mg alone provided a plausible model (Adj R² = 0.15) for δCe anomalies, while clay content (Adj R² = 0.11) influenced the Sa_N/Yb_N ratio, though soil properties had weaker effects than parent materials. However, we found no evidence that Eucalyptus plantations or pastures under non-intensive management increase REE content in Brazilian Atlantic Forest soils. Full article

Inselbergs are rocky outcrops with specialized vegetation, including woody species growing in poorly developed soils. We investigated whether populations of the lithophytic tree Pseudobombax petropolitanum A. Robyns (Malvaceae), a key species endemic to Atlantic Forest inselbergs, have convergent or divergent patterns of functional traits related to leaf chemistry. This study was carried out on three inselbergs located in southeastern Brazil. Green and senescent leaves from nine healthy trees and soil samples were collected in each inselberg. The carbon, nitrogen, phosphorus, potassium, calcium, and magnesium concentrations, and the natural abundances of δ¹³C and δ¹⁵N, were measured in leaves and soil, and the C/N, C/P, and N/P ratios were calculated. The specific leaf area (SLA) was measured, and the nutrient retranslocation rate between green and senescent leaves was estimated. Divergences between populations were observed in the concentrations of potassium and magnesium in the green and senescent leaves, as well as in the C/P and N/P ratios in senescent leaves. Our results suggest that nutrient and water dynamics may differ in some inselbergs due to specific nutrients or their relationships, even though there were convergences in most functional traits related to leaf chemistry among the Pseudobombax populations. The divergences among the populations could have important implications for species selection in the ecological restoration context. Full article

The Brazilian Araucaria Forest (AF) now covers only 1% of its original extent due to significant degradation, making conservation a challenge. The AF occurs in a mosaic alongside grassland and Atlantic Forest ecosystems, influencing bird species’ distribution through ecological processes. We compared the composition and functional diversity of the bird community along a gradient of AF cover in a protected area (Pró-Mata Private Natural Heritage Reserve) in southern Brazil. Bird sampling was conducted using MacKinnon lists along five trails with different histories of vegetation suppression, based on forest cover estimates from landscape imagery. Birds were functionally classified based on morphological and ecological traits. We recorded 191 bird species in total. We found higher bird richness in trails with less forest cover, while functional diversity responded inversely to vegetation cover. Bird species composition shifted from more open-habitat specialists to more forest specialists with the increasing forest cover and vegetation structural complexity. These findings highlight the ecological importance of maintaining vegetation heterogeneity, as vegetation mosaics enhance avian species richness and support a broader range of functional traits and ecosystem processes. We recommend the conservation of Araucaria Forest–grassland mosaics as a strategic approach to support multidimensional biodiversity and sustain key ecological functions in southern Brazil. Full article

Tropical forests face increasing threats and are often replaced by secondary forests that regenerate after disturbances. In the Atlantic Forest, this creates fragments of different successional stages. The aim of this study is to understand how soil nutrients and light availability gradients influence the species composition and structure of trees and regenerating strata in remnants of lowland rainforest. We sampled 15 plots for the tree stratum (DBH ≥ 5 cm) and 45 units for the regenerating stratum (height ≥ 50 cm, DBH < 5 cm), obtaining phytosociological, entropy and equitability data for both strata. Canopy openness was assessed with hemispherical photos and soil samples were homogenized. To analyze the interactions between the vegetation of the tree layer and the environmental variables, we carried out three principal component analyses and two redundancy analyses and applied a linear model. The young fragments showed good recovery, significant species diversity, and positive successional changes, while the older ones had higher species richness and were in an advanced stage of succession. In addition, younger forests are associated with sandy, nutrient-poor soils and greater exposure to light, while mature forests have more fertile soils, display a greater diversity of dispersal strategies, are rich in soil clay, and have less light availability. Mature forests support biodiversity and regeneration better than secondary forests, highlighting the importance of preserving mature fragments and monitoring secondary ones to sustain tropical biodiversity. Full article

Habitat loss and land-use intensification are major threats to biodiversity in the Brazilian Atlantic Forest, particularly for bat assemblages that provide key ecosystem services. In this study, we examined how landscape composition (forest and pasture cover) and local forest structure influence the richness and abundance of phyllostomid bats across 20 forest fragments in southern Bahia. Bat sampling was conducted using mist nets, and forest structure was quantified using tree measurements and vertical foliage stratification. We applied structural equation modeling to test the direct and indirect effects of landscape and local variables. Our results show that forest cover has both direct and indirect positive effects on bat diversity, mediated by improved forest structure. In contrast, increased pasture cover negatively affected forest structure and was weakly associated with bat diversity. The most abundant species were generalist frugivores, such as Carollia perspicillata and Rhinophylla pumilio. These findings highlight the importance of maintaining forest cover and structural complexity to support bat diversity in agroforestry-dominated landscapes. Conservation strategies that integrate habitat protection with sustainable land-use practices are crucial to maintaining biodiversity and the ecological functions provided by bats in this globally threatened biome. Full article

Monitoring forest structure, diversity, and biomass in restoration areas is both expensive and time-consuming. Metrics derived from digital aerial photogrammetry (DAP) may offer a cost-effective and efficient alternative for monitoring forest restoration. The main objective of this study was to use metrics derived from digital aerial photogrammetry (DAP) point clouds obtained by remotely piloted aircraft (RPA) to estimate aboveground biomass (AGB), species diversity, and structural variables for monitoring restored secondary tropical forest areas. The study was conducted in three active and one passive forest restoration systems located in a secondary forest in Sergipe state, Brazil. A total of 2507 tree individuals from 36 plots (0.0625 ha each) were identified, and their total height (ht) and diameter at breast height (dbh) were measured in the field. Concomitantly with the field inventory, the plots were mapped using an RPA, and traditional height-based point cloud metrics and Fourier transform-derived metrics were extracted for each plot. Regression models were developed to calculate AGB, Shannon diversity index (H′), ht, dbh, and basal area (ba). Furthermore, multivariate statistical analyses were used to characterize AGB and H′ in the different restoration systems. All fitted models selected Fourier transform-based metrics. The AGB estimates showed satisfactory accuracy (R² = 0.88; RMSE = 31.2%). The models for H′ and ba also performed well, with R² values of 0.90 and 0.67 and RMSEs of 24.8% and 20.1%, respectively. Estimates of structural variables (dbh and ht) showed high accuracy, with RMSE values close to 10%. Metrics derived from the Fourier transform were essential for estimating AGB, species diversity, and forest structure. The DAP-RPA-derived metrics used in this study demonstrate potential for monitoring and characterizing AGB and species richness in restored tropical forest systems. Full article

Evaluating the development process of mosquito species under the influence of temperature is essential for understanding their ecology and geographical distribution, as well as assessing their potential as vectors of pathogens. Aedes (Protomacleaya) terrens, a species recognized for its susceptibility and competence in transmitting the chikungunya virus, serves as a relevant model for research in this context. This study aimed to analyze the influence of temperature on egg hatching and the development cycle of this species to expand knowledge on its biology and implications for public health. During the experiment, 800 eggs were used, collected through 10 ovitraps in a forest remnant located in Uruaçu, Goiás, Brazil. The total number of eggs was divided into four groups, exposed to constant temperatures of 15 ± 2 °C, 20 ± 2 °C, 25 ± 2 °C, and 30 ± 2 °C. After hatching, first-instar larvae were individually separated and monitored daily under controlled conditions until adult emergence. The highest hatching rate occurred at 25 °C, showing an optimal point around 27 °C. Throughout development, temperature significantly reduced the duration of each stage, with the fastest complete cycle at 30 °C, a difference of approximately 10–12 days when compared to 20 °C and approximately 47 days when compared to 25 °C. These results offer valuable insights into the temperature sensitivity of Ae. terrens across its developmental stages, suggesting that each stage has its own optimal temperature. Thus, small variations in responses to environmental conditions and differentiation between sexes may become more pronounced throughout development. In this sense, temperature can affect not only the development and survival of dipterans but also the capacity for virus transmission, as the pathogen influences the reproduction rate and longevity of the vectors. Full article

The Mixed Ombrophyllous Forest (MOF), inserted in the Atlantic Forest biome, is of great ecological value, with deficient management strategies. In this context, sustainable management helps to promote the regeneration and growth of individual trees and control others, while maintaining the natural forest structure. This study therefore aimed to discuss opportunities and limitations of biochar, produced from two species from the MOF, which are currently only utilized to a limited extent in the study area in southern Brazil. A slow pyrolysis process at a lab scale was designed, biochar was produced, and key properties were analyzed from Hovenia dulcis Thunb. (chosen as an invasive species) and Mimosa scabrella Benth. (chosen as a native, fast-growing species), including branches and stems. The results showed that branches of Mimosa scabrella (BMS) had the highest biochar yield (30.32 ± 0.3%) and the highest electrical conductivity (415.08 ± 24.75 mS cm⁻¹). Stems of Mimosa scabrella (SMS) showed the highest higher heating value (HHV—31.76 ± 0.01 MJ kg⁻¹), lower heating value (LHV—31.03 ± 0.01 MJ kg⁻¹), and energy yield (49.1%), while the branches of Hovenia dulcis (BHD) showed the lowest values. For the elemental analysis, SMS showed the best results, with the highest amount of fixed carbon (78.62 ± 0.22%) and carbon content (85.87 ± 0.083%), and consequently the lowest amount of ash (3.52 ± 0.08%). BHD showed a better water-holding capacity (303.26 ± 15.21%) and higher pH value (7.65 ± 0.14). The investigations conducted on the biochar from both species indicate a strong suitability of these woods for producing high-quality biochar. Full article

Assessing the ranging and dispersal behavior of apex predators and its consequences for landscape connectivity is of paramount importance for understanding population and ecosystem effects of anthropogenic land use change. Here, we synthesize ranging and dispersal ecological information on pumas (Puma concolor) and present estimates of how different land uses affect the space use and dispersal of pumas on fragmented landscapes in an ecotone between biodiversity hotspots in southeastern Brazil. Additionally, we evaluate the effect of animal translocations on dispersal and movement patterns. Using location data for 14 GPS-collared pumas and land use data, we assessed when, how long, and how far individuals dispersed; how forest loss and infrastructure influenced puma home range size; and how movement patterns changed according to land use and proximity to infrastructure, during ranging and dispersal, for residents, natural dispersers, and translocated individuals. We present the first detailed record on the dispersal of pumas in Brazil and in the tropics, including long-distance dispersals, and show that pumas moved faster and more linearly during dispersal than during ranging. Their movement was slower and their home ranges were smaller in more forested areas, underscoring the importance of forest as habitat. In contrast, movement rates were higher in open pastures, mainly during dispersal. Our study underscores the scarcity of research on puma space use and dispersal in South America and reveals partial divergences in dispersal behaviors compared to North America and temperate regions, especially concerning dispersal ages. Furthermore, we give the first steps in presenting how land cover and human infrastructure affect the movement of this apex predator in a tropical ecosystem, an important subsidy for land use management. We call for more comprehensive studies on the movement ecology of carnivores combined with long-term population monitoring, to allow linking individual behavior with metapopulation dynamics and landscape connectivity and drawing more effective measures to sustain their populations. Full article

Understanding how regional and local climate variability drive radial growth in trees is necessary to assess the climate-warming mitigation potential of forests. However, tree species occurring in the same region differently respond to climate variability, including climate extremes such as droughts, depending on soil–moisture gradients (hydrological niche). We analyzed a tree-ring network built in a mountainous area (Sierra de Gredos, central Spain) to compare climate–growth responses between species and sites located along soil–moisture gradients. Tree-ring methods were applied to six tree species, and sampled in twelve sites, including conifers (Pinus pinaster) and broadleaves (Quercus pyrenaica, Quercus robur, Quercus ilex, Celtis australis, and Prunus lusitanica). Series of growth indices were correlated with climate variables and climate indices (NAO, North Atlantic Oscillation). The radial growth of most species was enhanced by high growing-season precipitation, linked to negative NAO phases. The influence of precipitation on growth variability strengthened as site elevation decreased, particularly in the case of C. australis and oak species. The topographical modulation of climate–growth couplings indicates that the hydrological niche drives species responses to water shortage. Tree-ring data could be used to refine time-dependent hydrological niches. Full article

Forest–atmosphere interactions through mass and energy fluxes significantly influence climate processes. However, due to anthropogenic actions, native Araucaria forests in southern Brazil, part of the Atlantic Forest biome, have been drastically reduced. This study quantifies CO₂ and energy flux contributions from each forest stratum to improve understanding of surface–atmosphere interactions. Eddy covariance data from November 2009 to April 2012 were used to assess fluxes in an Araucaria forest in Paraná, Brazil, across the ecosystem, understory, and overstory strata. On average, the ecosystem acts as a carbon sink of −298.96 g C m⁻² yr⁻¹, with absorption doubling in spring–summer compared to autumn–winter. The understory primarily acts as a source, while the overstory functions as a CO₂ sink, driving carbon absorption. The overstory contributes 63% of the gross primary production (GPP) and 75% of the latent heat flux, while the understory accounts for 94% of the ecosystem respiration (RE). The energy fluxes exhibited marked seasonality, with higher latent and sensible heat fluxes in summer, with sensible heat predominantly originating from the overstory. Annual ecosystem evapotranspiration reaches 1010 mm yr⁻¹: 60% of annual precipitation. Water-use efficiency is 2.85 g C kgH₂O⁻¹, with higher values in autumn–winter and in the understory. The influence of meteorological variables on the fluxes was analyzed across different scales and forest strata, showing that solar radiation is the main driver of daily fluxes, while air temperature and vapor pressure deficit are more relevant at monthly scales. This study highlights the overstory’s dominant role in carbon absorption and energy fluxes, reinforcing the need to preserve these ecosystems for their crucial contributions to climate regulation and water-use efficiency. Full article

Kempnyia Klapálek, 1914 (Plecoptera: Perlidae) is the only genus within its family endemic to Brazil, being present in the Atlantic Forest and sections of the Cerrado. Taxonomic knowledge of the genus is incomplete, especially for nymphs. An integrative approach to the description of species and semaphoronts is essential for further studies. We describe a new species of Kempnyia based on morphological and molecular data, associate and describe the nymphs of both the new species and Kempnyia umbrina Froehlich, 1988, as well as expand its distribution and correct past mistakes in identification of K. umbrina. Specimens were identified morphologically and sequenced for the barcode region of the cytochrome oxidase subunit I (COI) mitochondrial gene, resulting in eight new sequences for three species of the genus. Both morphological and molecular analyses revealed a new species, Kempnyia krenaki sp. nov. Its nymph and that of K. umbrina are also described. With our additions, the number of known Kempnyia species rises to 41, of which 26 have COI sequences available in GenBank. Although only 11 nymphs have been associated and described for the genus so far, as the Kempnyia sequence database continues to grow, studies associating and describing nymphs will become more common, gradually reducing the Haeckelian deficit. Full article