Southern Brazilian Atlantic Forest Research Articles

Local heterogenisation and regional homogenisation linked to habitat loss induced by dams in riparian forests of the Brazilian Atlantic Forest

Riparian forests are crucial for biodiversity, but dam construction for hydroelectric power disrupts these ecosystems, causing habitat loss and altering river dynamics. Our study investigates the impacts of dams on tree diversity in the southern Brazilian Atlantic Forest. We sampled trees along riverbanks and uplands across 15 dam-affected fragments, analysing the relationship between habitat loss (i.e. loss of riparian zones by permanent flooding due to dam filling), elevation difference, fragment size, and dam implementation time with alpha and beta diversity using mixed models and redundancy analyses. Habitat loss had a more significant impact on beta diversity, leading to shifts in species composition and reduced uniqueness of communities as the impact’s intensity, spatial extent, and duration increased. Alpha diversity only increased in response to local elevation differences between plots located on uplands and riverbanks. Our sampling design can be applied to other inadequately monitored systems to provide insights into beta diversity, a component often neglected in dam licensing and mitigation processes. Our findings reveal a transient local heterogenisation, transitioning into regional homogenisation due to dam-induced habitat loss in riparian forests of the Brazilian Atlantic Forest.

Ecological inferences in Orchidaceae species from the Brazilian subtropical Atlantic Forest based on morphological and functional anatomical traits

Ecological anatomy studies seek to link structural aspects to environmental pressures, improving knowledge about the occurrence and distribution of species. Orchidaceae is a group with high species richness and ecological diversity, well represented in the Brazilian Atlantic Forest, a biodiversity hotspot. The Iguaçu National Park (ParNa Iguaçu) is an important remnant of the southern Brazilian Atlantic Forest with a high richness of Orchidaceae. Given the family's diversity and the relevance of ecological anatomy studies for interpreting traits associated with the survival of plants in certain environments, we studied 38 species of Orchidaceae from ParNa Iguaçu, seeking to identify possible functional groups. For this, we surveyed 57 leaf morpho-anatomical characters and conducted histochemical and statistical tests. The morpho-anatomical traits group the species into two functional groups, with Cyclopogon congestus emerging isolated. In group A, xeromorphic morphoanatomical characters predominate, and group B combines members with meso/hygromorphic characteristics. We advocate the importance of understanding the ecological behavior of species, especially Orchidaceae, due to their important ecological role, in conservation actions in protected areas. Furthermore, our results highlight the morphological and anatomical diversity of the Orchidaceae found in ParNa Iguaçu, as well contributing to the development of better management practices for these plants, considering the threats posed by the opening of clearings and climate change.

Native peccaries activity patterns and temporal overlap with wild boar in the southern Brazilian Atlantic Forest

ABSTRACT We analyzed long-term camera-trap data from Protected Areas in the Brazilian Atlantic Forest to study activity patterns of coexisting peccary species (Tayassu pecari and Dicotyles tajacu) and the exotic wild boar (Sus scrofa). The highest pattern overlap was between D. tajacu and S. scrofa (Δ1 = 0.78), followed by T. pecari and S. scrofa (Δ1 = 0.64), and the lowest between D. tajacu and T. pecari (Δ1 = 0.61). In the presence of feral pigs, collared peccary activity exhibited two distinct peaks, occurring in the late evening and early morning. When coexisting with white-lipped peccaries, their activity peaks early in the evening and again in the mid-morning, potentially enabling them to avoid overlapping with the activity peaks of white-lipped peccaries, which are distributed throughout the day. Our findings suggest a potential interference of wild boars in the temporal niche dynamics of native peccaries across various areas within the Brazilian Atlantic Forest biome. Nonetheless, we emphasize the imperative for more focused investigations at both regional micro and macro scales throughout the Atlantic Forest, specifically delving into other dimensions of the niche, such as food and habitat utilization among the three species.

Novo Índice Integrado de Qualidade da Água (IWQI) e sua aplicação com poluentes emergentes na bacia do bioma Mata Atlântica no sul do Brasil

ABSTRACT The presence of emerging contaminants in surface water is a growing concern, as these substances are not typically monitored by environmental quality systems, potentially leading to the consumption of contaminated water. In this study, the presence of caffeine, an emerging contaminant that is ingested solely by humans and is present in surface water due to its chemical characteristics, was investigated as a potential indicator of anthropogenic contamination in the Itajaí-Açu River in the southern Brazilian Atlantic Forest biome. Additionally, twelve other emerging pollutants were examined in the Itajaí-Açu River, including estrone (E1), estradiol (E2), ethinylestradiol (EE2), estriol (E3), prednisone (PD), hexestrol (HEX), acetaminophen (ACM), Oxytetracicline (OC). Surface water samples were collected over five months and analyzed using high-performance liquid chromatography. The results revealed that caffeine was present in 84% of the analyzed samples, and emerging pollutants were present in all monitored municipalities. The study also investigated the relationship between an integrated water quality index, the magnitudes and occurrences of caffeine, and land use. The emerging pollutants Estrone, Ethinylestradiol, Hexestrol, Naproxen and Oxytetracycline were not detected in the analyzed samples. However, Ibuprofen, Tetracycline, Prednisone, and Acetaminophen were present in 44% and 36% of the samples, respectively, with Estriol, Ketoprofen, and Estradiol having a lower occurrence. The mean concentrations of Estradiol, Estriol, Ketoprofen, Acetaminophen, and Ibuprofen were 0.08 µg L-1, 0.23 µg L-1, 0.15 µg L-1, 0.42 µg L-1, and 0.44 µg L-1, respectively, and were higher than previously reported. The concentration range of caffeine during the study was <0.10 to 1.48 µg L-1, with the mean concentration being 0.30 µg L-1. These findings highlight the presence of emerging pollutants in the Itajaí-Açu River and the need for continued monitoring and regulatory legislation to protect surface water quality in Brazil.

Structural Differences in Herbaceous Communities on Edge and Interior Atlantic Forest in South Brazil

The Atlantic Forest is recognized worldwide as hotspots due to its megadiversity. This study aimed to evaluate whether there are differences between the floristic and structural diversity of the herbaceous component in an edge and interior region of the southern Brazilian Atlantic Forest. The study was developed in a forest fragment located in the state of Santa Catarina, south Brazil. The edge of the fragment is characterized by an area up to 10-15m wide, covered massively by herbaceous-subshrub vegetation and rare arboreal individuals. The interior is discontinuously shaded by the arboreal and shrub component contained in the upper strata of the forest. The phytosociological survey used the plot method. 100 plots of 1 m² were established, 50 on the edge of the forest fragment and 50 plots inside it. The phytosociological parameters studied for both areas were absolute frequency (AF), relative frequency (RF), absolute coverage (AC) and relative coverage (RC). Through the treatment and analysis of these data, the importance value index (IVI) of each species was obtained. At the edge of the forest fragment, 18 families and 34 species were identified. Of the 34 species found, 31 are angiosperms (24 dicots and 7 monocots) and 3 are monilophytes. All species are native to the Brazilian flora, with the exception of Centella asiatica and 2 lycophytes. In the interior, 14 species were found, being represented by 10 families. All species in the interior were angiosperms (4 dicots and 8 monocots) and 2 monilophytes. All species are native to the Brazilian flora and have herbaceous habit. The herbaceous community in the interior is different from the herbaceous community at the forest edge. The initial hypothesis of the work was confirmed, since none of the species present at the edge of the forest occurs in the interior of the forest.

Predominant prevalence of Ranavirus in southern Brazil, a region with widespread occurrence of the amphibian chytrid

AbstractEmerging infectious diseases are a major cause of amphibian declines worldwide. Two of these diseases are amphibian chytridiomycosis caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd) and a viral disease caused by different ranaviruses (Rv). Whereas Bd is known to be widespread in Brazil, Rv was only recently detected in natural habitats. We therefore investigated the co‐occurrence of Bd and Rv in wild tadpoles in the southern Brazilian Atlantic Forest from 21 ponds. Because infection by Bd might cause immune suppression in the host, we hypothesized that tadpoles infected with Bd would be more prone to infection with Rv than Bd‐free individuals, hence presenting higher Rv loads. Surprisingly, co‐infection was rare (less than 6% of the sampled specimens), and we did not find evidence that Bd would facilitate Rv infection. On the other hand, we detected Rv in 38% of tadpoles (125 out of 324), representing twice the prevalence of Bd in the same populations. We tested the influence of biotic and abiotic factors on infection by each pathogen on tadpoles, and we detected a positive relationship between forest cover and infection by Rv, whereas no relationship was found for Bd infection. Based on the putatively low rate of co‐infection and high prevalence of Rv in wild anuran populations, we advocate for the inclusion of Rv screening and monitoring in addition to Bd in conservation‐oriented amphibian surveys. Only surveying both diseases will provide a complete picture of amphibian disease‐related declines.

How do distinct facets of tree diversity and community assembly respond to environmental variables in the subtropical Atlantic Forest?

This study assessed the impact of altitude, precipitation, and soil conditions on species richness (SR), phylogenetic diversity (PD), and functional diversity (FD) standardized effect sizes in subtropical Brazilian Atlantic Forest tree communities. We considered specific trait information (FDs) for FD, reflecting recent adaptive evolution, contrasting with deeper phylogenetic constraints in FD. Three functional traits (leaf area-LA, wood density-WD, and seed mass-SM) were examined for their response to these gradients. Generalized least squares models with environmental variables as predictors and diversity metrics as response variables were used, and a fourth-corner correlation test explored trait-environmental relationships. SR decreased with altitude, while PD increased, indicating niche convergence at higher altitudes. Leaf area and seed mass diversity also decreased with altitude. For LA, both FD and FDs were significant, reflecting filtering processes influenced by phylogenetic inheritance and recent trait evolution. For SM, only the specific trait structure responded to altitude. LA and SM showed significant trait-environmental relationships, with smaller-leaved and lighter-seeded species dominant at higher altitudes. Soil gradients affect diversity. Fertile soils have a wider range of LA, indicating coexistence of species with different nutrient acquisition strategies. WD variation is lower for FDs. SM diversity has different relationships with soil fertility for FDs and FD, suggesting phylogeny influences trait variation. Soil pH influences WD and LA under acidic soils, with deeper phylogenetic constraints (FD). Environmental factors impact tree communities, with evidence of trait variation constraints driven by conditions and resources. Subtropical Atlantic forests' tree assemblies are mainly influenced by altitude, pH, and soil fertility, selecting fewer species and narrower trait spectra under specific conditions (e.g., higher altitudes, pH). Functional diversity patterns reflect both phylogenetic and recent evolution constraints, with varying strength across traits and conditions. These findings highlight the intricate processes shaping long-lived species assembly across diverse environments in the Southern Brazilian Atlantic Forest.

Leaf-Level Field Spectroscopy to Discriminate Invasive Species (Psidium guajava L. and Hovenia dulcis Thunb.) from Native Tree Species in the Southern Brazilian Atlantic Forest

Invasive species are known to have potential advantages over the native community and can be expressed in their leaf functional traits. Thus, leaf-level traits with spectral reflectance can provide valuable insights for distinguishing invasive trees from native trees in complex forest environments. We conducted field spectroscopy measurements in a subtropical area, where we also collected trait data for 12 functional traits of invasive (Psidium guajava and Hovenia dulcis), and native species (Psidium cattleianum and Luehea divaricata). We found that photosynthetic pigments were responsible for the greatest interspecific variability, especially in the green region of the spectrum at 550 nm, therefore contributing to detection of invasive species. In addition, according to LDA and stepwise procedures, the most informative reflectance spectra were concentrated in the visible range that is closely related to pigment absorption features. Furthermore, we aimed to understand the leaf optical properties of the target invasive species by using a combination of narrow bands and linear regression models. P. guajava showed high correlations with specific leaf area, Car/Chl and relative water content. H. dulcis had a strong correlation with water content, specific leaf area and Chla/Chlb. Overall, this methodology proved to be appropriate for discriminating invasive trees, although parameterization by species is necessary.

Landscape conservation as a strategy for recovering biodiversity: Lessons from a long‐term program of pasture restoration in the southern Atlantic Forest

Abstract Although ecological restoration has entered the global agenda to reverse different anthropogenic disturbances, we still know little about how this solution interacts with other conservation strategies, to avoid the progressive loss of species and ecosystem services. Here we evaluate one of the pioneering restoration programs in the southern Brazilian Atlantic Forest, where the combination of conservation and restoration efforts has been carried out for 20 years. Specifically, we tested how landscape characteristics, restoration strategies and environmental characteristics affect the results of the restoration of pastures. We established 65 circular plots (total 4.0 ha) along restoration areas (3–10 years) and sampled trees and shrubs composing the canopy (DBH ≥ 5 cm) and understorey (DBH < 5 cm, height > 1.3 m). We analysed the landscape metrics (proportion of old‐growth forests in 200, 500 and 1,000 m buffers around each plot; and area and distance of the nearest‐neighbouring old‐growth forests). We explored the multiple effects of landscape, restoration strategy (reforestation, natural regeneration) and environmental variables (soil, pasture grass types) on the species composition and multiple diversity metrics of restoration areas. The species composition was very similar among restoration ages and restoration strategies. We found positive and strong effects of old‐growth forest (200 m buffer) proportion on the species richness and Shannon diversity (canopy and understorey), above‐ground biomass (canopy) and functional diversity (understorey) of restoration areas. The restoration strategies affected forest structure, and, in general, the reforestation strategy increased above‐ground biomass, Shannon, functional and phylogenetic diversities (in canopy), and percentage of endemic species and biomass (understorey), when compared to natural regeneration. The 20‐year experience in the southern Atlantic Forest showed that programs focused on landscape conservation associated with a mixture of restoration strategies (i.e. natural regeneration in larger areas and active restoration in more disturbed sites), can be an efficient strategy to ensure biodiversity and ecosystem services in tropical landscapes. Synthesis and applications. To manage degraded tropical lands and achieve global targets for biodiversity and ecosystem services, it is necessary to first ensure the conservation of natural remnants and then use multiple restoration strategies in less resilient areas.

New species of tree cricket Oecanthus Serville, 1831 (Orthoptera: Grylloidea) from Southern Brazilian Atlantic Forest, with bioacoustics.

Tree Crickets, Oecanthus Serville, 1831 have a worldwide distribution, and are known as Tree Crickets because they are common in the treetops, even though many species occur in different strata of forest, and also in open fields. In this work we describe a new species of Oecanthus from Southern Brazil, based on the most significant diagnostic structures in the ocanthine taxonomy, such as the phallic sclerites and metanotal gland morphology, as well as calling song. The new species herein described has a distinct faint red spot between the eyes, a metanotal gland with a triangular posterior median lobe with the apex curved up and forward, the median lophi of pseudepiphallus slightly elongate with an U-shaped invagination, and the ectophallic distal arc prolongation with the posterior apex U-bifurcated. The calling song stands out among the local stridulating crickets for alternate a regular and an irregular train of chirps. Illustrations of the external morphology, information about type specimens, material examined, measurements, and spectrogram of the calling and courtship songs is provided.

Influence of environmental factors on the tropical peatlands diazotrophic communities from the Southern Brazilian Atlantic Rain Forest.

The tropical peatlands of southern Brazil are essential for the maintenance of the Atlantic Rain Forest, one of the 25 hotspots of biodiversity in the world. Although diazotrophic micro-organisms are essential for the maintenance of this nitrogen limited ecosystem, so far studies have focused only on micro-organisms involved in the carbon cycle. In this work, peat samples were collected from three tropical peatland regions during dry and rainy seasons and their chemical and microbial characteristics were evaluated. Our results showed that the structure of the diazotrophic communities in the Brazilian tropical peatlands differs in the evaluated seasons. The abundance of the genus Bradyrhizobium showed to be affected by rainfall and peat pH. Despite the shifts of the nitrogen-fixing population in the tropical peatland caused by seasonality it showed to be constantly dominated by α-Proteobacteria followed by Cyanobacteria. In addition, more than 50% of nifH gene sequences have not been classified, indicating the necessity for more studies in tropical peatland, since the reduction of N supply in the peatlands stimulates the recalcitrant organic matter decomposition performed by peatland micro-organisms, influencing the C stock.

Systematics and phylogeography of the Brazilian Atlantic Forest endemic harvestmen Neosadocus Mello-Leitão, 1926 (Arachnida: Opiliones: Gonyleptidae).

Neosadocus harvestmen are endemic to the Southern Brazilian Atlantic Forest. Although they are conspicuous and display great morphological variation, their evolutionary history and the biogeographical events underlying their diversification and distribution are still unknown. This contribution about Neosadocus includes the following: a taxonomic revision; a molecular phylogenetic analysis using mitochondrial and nuclear markers; an investigation of the genetic structure and species’ diversity in a phylogeographical framework. Our results show that Neosadocus is a monophyletic group and comprises four species: N. bufo, N. maximus, N. robustus and N. misandrus (which we did not find on fieldwork and only studied the female holotype). There is astonishing male polymorphism in N. robustus, mostly related to reproductive strategies. The following synonymies have resulted from this work: “Bunoweyhia” variabilis Mello-Leitão, 1935 = Neosadocus bufo (Mello-Leitão, 1926); and “Bunoweyhia” minor Mello-Leitão, 1935 = Neosadocus maximus (Giltay, 1928). Most divergences occurred during the Miocene, a geological epoch marked by intense orogenic and climatic events in the Brazilian Atlantic Forest. Intraspecific analyses indicate strong population structure, a pattern congruent with the general behavior and physiological constraints of Neotropical harvestmen.

Dynamics of Natural Regeneration: Implications for Landscape Restoration in the Atlantic Forest, Brazil

This study aimed to understand post-agricultural natural forest regeneration in the Southern Brazilian Atlantic Forest and its possible role as a cost-effective, passive approach to forest restoration. The study characterized vegetation structure, floristic composition, and the dynamics of secondary forest chronosequences. Data were collected from 159 plots (10 × 10 m each) across forest remnants in Santa Catarina State, covering forest ages that ranged from 2 to 60 years of regeneration after swidden agriculture. Only areas with no signs of degradation were sampled in order to provide a description of vegetation characteristics that could be used to identify and monitor natural regeneration. A total of 11,455 woody plants were identified and classified into 334 species representing 71 families. As the succession process unfolds, the continuous turnover of species makes forests more diverse and structurally complex. Floristic similarity among forest types is observed during the early stages of succession, but decreases over time. Pioneer species dominate young secondary forests, representing about 40% of the basal area up to 10 years of regeneration. Shade-tolerant species start colonizing the sites at early ages; however, they become more important structural elements only after 30 years of succession. The observed patterns of forest structure and species diversity largely conform to the post-agricultural succession seen in many tropical forests. The high species diversity found in this study highlights the importance of natural regeneration as a strategy to restore ecosystems. Floristic data can be used as a reference for choosing suitable species for active restoration, as well as contributing to the design of integrated restoration strategies. We herein reinforce the potential of natural regeneration as part of large-scale restoration programs, which would be particularly attractive to family farmers by the low cost of supplies and labor.

Filling distribution gaps: Two new species of the catfish genus Cambeva from southern Brazilian Atlantic Forest (Siluriformes, Trichomycteridae)

The fauna and flora of the Brazilian Atlantic Forest have been intensively inventoried since the 19thcentury, but some components of this rich biota are still poorly known, and some areas have been poorly sampled. Recent studies on a rich collection of mountain catfishes of the genusCambevahave revealed a high diversity of species still undescribed in the region. Here we provide formal descriptions for two of these species, found in areas inserted in a broad gap of the presently known genus distribution. The first one is endemic to small coastal river basins of Santa Catarina state, southern Brazil; it is tentatively placed in an intrageneric clade, also includingC. castroi,C. davisi,C. guareiensisandC. zonata, by all sharing the presence of a flat small process on the dorsal margin of the quadrate, laterally overlapping metapterygoid and situated just posterior to the syncondrial joint between the metapterygoid and the quadrate. Phylogenetic relationships of the second new species, endemic to the Rio Itajaí-Mirim basin, are still obscure, but it shares a derived morphology of the mesethmoid with some species of theC. baliosgroup. Although species ofCambevahave little external morphological variation when compared to other trichomycterine groups, the present study once more shows the importance of recording and using osteological characters to diagnose externally similar trichomycterine species.

Habitat amount and ambient temperature dictate patterns of anuran diversity along a subtropical elevational gradient

AbstractAimPatterns of diversity along elevational gradients are driven by species characteristics but remain poorly understood. Filling this gap is imperative given the deteriorating conservation status of anurans worldwide. Here, we examine frog diversity and species composition along a sharp subtropical elevational gradient and assess the degree to which these are determined by environmental and spatial predictors.LocationAn extensive southern Brazilian Atlantic Forest elevational gradient ranging from 300 to 1,800 m above sea level.MethodsWe sampled 38 ponds and used structural equation modelling to examine the direct and indirect effects of area, climate, habitat amount, habitat complexity and productivity on frog species richness and abundance. We also applied joint species distribution models to investigate the importance of these predictors on frog species composition using species distribution and co‐occurrence along the elevational gradient.ResultsWe recorded 12,636 individuals of 41 frog species. Frog species richness was highest at intermediate elevations, showing a hump‐shaped pattern. Frog abundance was highest at lowlands and decreased towards higher elevations. We found support for only the habitat amount hypothesis in explaining overall species richness. Although temperature had a positive influence on productivity and frog abundance, neither predictors were related to species richness. Species composition diverged markedly between lowland and highland frog assemblages, which was mainly attributed to differences in ambient temperature.Main conclusionElevations containing more extensive natural habitat areas retained the most species‐rich frog assemblages. The mid‐elevational peak is likely attributed to lowland habitat (<800 masl) heterogeneity and extreme climatic conditions in highland areas (>1,400 masl). The entire elevational gradient is, however, critical in maintaining anuran species diversity as lowland assemblages are distinct from those at mid‐ to high elevations. Our study also shows that anthropogenic habitat loss has a decisive effect on montane frog diversity, reinforcing the need to effectively protect these areas.

Thraulodes marianoi sp. nov., a remarkable new species of mayfly (Ephemeroptera: Leptophlebiidae) with dark wings from the southern Brazilian Atlantic Forest.

Thraulodes marianoi sp. nov. is described, illustrated and diagnosed based on a single male imago from a subtropical forest at Pico do Marumbi State Park, in the protected area of Mananciais da Serra, state of Paraná, Brazil. Based on the dark coloration of legs and the large dark spot at base of forewing, T. marianoi sp. nov. is similar to species of the niger-group (Peruvian Amazonia) and to T. basimaculatus Giordano Domínguez, 2005, a species endemic to Bolivia. The new species can be distinguished from all other species in the genus Thraulodes Ulmer, by the combination of following characteristics: (1) four cross-veins basal to bulla in forewing; (2) brown area covering about of proximal half of the forewing; (3) pleura violet; (4) middle and posterior femora yellowish washed with dark brown; (5) terga and sterna I-IV white washed with dark brown on posterior and lateral margin terga and sterna V-X dark brown; (6) penes short and wide with distolateral area, "ear-like" and poorly developed lateral pouch; (7) styliger plate triangular, median projection short and rounded on the apex. This new species represents the first record of the genus from the state of Paraná, Brazil.

<p class="Body"><strong>Stochastic and deterministic processes differently affect the community st</strong><strong>ructure of edaphic mites (Acari: Mesostigmata) in the southern Brazilian Atlantic Forest</strong></p>

Most mesostigmatid mites (Arachnida: Parasitiformes) are soil-dwelling predators, feeding predominantly on detritivorous and fungivorous invertebrates. Little is known about the role of environmental and spatial parameters in driving the structure of their local communities. The aim of this study is to assess the relative importance of environmental/spatial parameters in different scales and microhabitats on the community structure of edaphic mesostigmatid mites in the southern Brazilian Atlantic Forest. Soil and litter samples were collected in 20 sites (six subsamples per microhabitat per site; N = 240 samples) distant from each other over ranges varying from 100 m to seven km. Geographic distances between sampling sites and spatial eigenfunctions were used as proxies of stochastic processes to assess the influence of spatial parameters on mite community structure. Environmental parameters included soil grain size, moisture and organic matter, vegetation structure, litter depth and percentage of leaves, branches, and thin roots in plant litter. We collected 1135 Mesostigmata individuals from 77 species/morphospecies. Mite composition strongly differed between soil and litter microhabitats. Mite communities geographically closer were more similar to each other in terms of Mesostigmata composition than expected if there is no spatial structure. Litter depth, soil organic matter and soil moisture significantly contributed to edaphic mite community structure. Deterministic processes predominated in explaining the composition of the litter fauna, while the composition of the soil fauna was more sensitive to stochastic processes. Our results provide evidence that the composition of Mesostigmata communities not only differ between microhabitats, but they are differently structured by environmental and spatial parameters depending on the scale. This provides new insight into the processes affecting of mite diversity within soil ecosystem at fine and broad scales, and highlights the importance of the spatial proximity and microhabitat in driving the composition of mite communities.

Insights from a large-scale inventory in the southern Brazilian Atlantic Forest

A key issue in large-area inventories is defining a suitable sampling design and the effort required to obtain reliable estimates of species richness and forest attributes, especially in species-diverse forests. To address this issue, data from 418 systematically distributed 0.4 ha plots were collected. Estimators of nonparametric species richness were employed to assess the floristic representativeness of data collected in three forest types in the Brazilian Atlantic Forest. The sampling sufficiency of forest attributes was evaluated as a function of sample size. Altogether, 831 tree/shrub species were recorded. The data acquired through the systematic sampling design were representative of both species richness and basal area. The confidence intervals’ length would not substantially decrease by using more than 70 % of the reference sample (n = 364), thereby reaching a length of ~5 % of the sample mean. Nevertheless, reliable estimates of species richness for diverse forests demand a thorough sampling approach far more exacting so as to achieve acceptable population estimates of forest attributes. Though the study area is regarded as a biodiversity hotspot, the forest stands showed diminished species richness, basal area, stem volume and biomass when compared to old-growth stands. As regards species richness, the data provided evidence of contrasting great γ-diversity (at the forest type level) and small α-diversity (at the forest stand level). Amongst anthropic impacts, illegal logging and extensive cattle grazing within stands are undoubtedly key factors that threaten forest conservation in the study area.

Effects of crowding due to habitat loss on species assemblage patterns.

Terrestrial animals are negatively affected by habitat loss, which is assessed on a landscape scale, whereas secondary effects of habitat loss, such as crowding, are usually disregarded. Such impacts are inherently hard to address and poorly understood, and there is a growing concern that they could have dire consequences. We sampled birds throughout a deforestation process to assess crowding stress in an adjacent habitat remnant in the southern Brazilian Atlantic Forest. Crowding is expected of highly mobile taxa, especially given the microhabitat heterogeneity of Neotropical forests, and we hypothesized that the arrival of new individuals or species in refuges shifts assemblage patterns. We used point counts to obtain bird abundances in a before-after-control-impact design sampling of a deforestation event. Temporal changes in taxonomic and functional diversity were examined with metrics used to assess alpha and beta diversity, turnover of taxonomic and functional similarity, and taxonomic and functional composition. Over time increased abundance of some species altered the Simpson index and affected the abundance-distribution of traits in the habitat remnant. Taxonomic composition and functional composition changed in the remnant, and thus bird assemblages changed over time. Taxonomic and functional metrics indicated that fugitives affected resident assemblages in refuges, and effects endured >2 years after the deforestation processes had ceased. Dissimilarity of taxonomic composition between pre- and postdeforestation assemblages increased, whereas functional composition reverted to preimpact conditions. We found that ecological disruptions resulted from crowding and escalated into disruptions of species' assemblages and potentially compromising ecosystem functioning. It is important to consider crowding effects of highly mobile taxa during impact assessments, especially in large-scale infrastructure projects that may affect larger areas than is assumed.

Phylogenomic species delimitation in microendemic frogs of the Brazilian Atlantic Forest

The advent of next-generation sequencing allows researchers to use large-scale datasets for species delimitation analyses, yet one can envision an inflection point where the added accuracy of including more loci does not offset the increased computational burden. One alternative to including all loci could be to prioritize the analysis of loci for which there is an expectation of high informativeness. Here, we explore the issue of species delimitation and locus selection with montane species from two anuran genera that have been isolated in sky islands across the southern Brazilian Atlantic Forest: Melanophryniscus (Bufonidae) and Brachycephalus (Brachycephalidae). To delimit species, we obtained genetic data using target enrichment of ultraconserved elements from 32 populations (13 for Melanophryniscus and 19 for Brachycephalus), and we were able to create datasets that included over 800 loci with no missing data. We ranked loci according to their number of parsimony-informative sites, and we performed species delimitation analyses using BPP with the most informative 10, 20, 40, 80, 160, 320, and 640 loci. We identified three types of phylogenetic node: nodes with either consistently high or low support regardless of the number of loci or their informativeness and nodes that were initially poorly supported where support became stronger as we included more data. When viewed across all sensitivity analyses, our results suggest that the current species richness in both genera is likely underestimated. In addition, our results show the effects of different sampling strategies on species delimitation using phylogenomic datasets.