169 research outputs found

    Floristic composition and phytophysiognomies of Cerrado disjunct remnants in Campos Gerais, PR, Brazil - Southern boundary of the biome

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    O cerrado possui seu limite austral de ocorrência nos Campos Gerais do Paraná onde, na forma de pequenos fragmentos disjuntos, tem grande afinidade com as formações savânicas de São Paulo e do Planalto Central do Brasil. Encontra-se, na sua maior parte, em propriedades particulares, sob forte pressão da agropecuária, tendo sido até então pouco estudado. Foram realizadas análises florísticas e fitofisionômicas de 30 remanescentes de cerrado em seis municípios, com determinação de um total de 1.782 táxons. Asteraceae foi a família com maior riqueza de espécies (256), seguida por Fabaceae (207), Poaceae (183), Myrtaceae (72) e Melastomataceae (54). Encontrou-se um gradiente latitudinal e geomorfológico na distribuição das fisionomias: cerrado stricto sensu (50%) e cerradão (13%) distribuem-se nos planaltos areníticos ao norte da região; enquanto cerrado rupestre (17%) e campo sujo com fácies de cerrado (20%) estão mais representados nas porções meridionais, nos relevos escarpados dos vales dos rios. Os remanescentes mostraram similaridade florística com áreas core do Bioma e podem ser consideradas áreas marginais da amplitude geográfica de muitos táxons, compartilhando espécies típicas, características da Província Sulina. Portanto, estas áreas campestres seriam melhor classificadas como savanas do que como estepes. A fitocenose mais austral em Ponta Grossa, com alta riqueza de espécies, encontra-se isolada biogeograficamente dos demais elementos do Bioma, constituindo um possível centro de endemismo.The cerrado (Brazilian savannah) has its Southern limits of occurrence in the Campos Gerais region in the State of Paraná, through small disjunction patches with great affinities with the Northern savannah formations of São Paulo and the Central Plateau of Brazil. They are mostly on private lands, under strong pressure from agribusiness and have been hitherto little studied. A floristic and phytophysiognomical analysis of 30 remnants in different municipalities was carried out, reaching a total of 1,782 determined taxa, being Asteraceae the richest family (256), followed by Fabaceae (207), Poaceae (183), Myrtaceae (72) and Melastomataceae (54). There is a geomorphological and latitudinal gradient on the distribution of physiognomies: cerrado stricto sensu (50%) and cerradão (13%) are distributed mainly in the sandstone plateaus in the north region, while cerrado rupestre (17%) and grassland with cerrado facies (20%) are most frequent in the river valleys cliffs in the South. These remnants present floristic similarity with the core area of the Biome, and could be considered marginal areas of the geographical range of several taxa, sharing typical species of the Southern Province. Thus the whole area would be more correctly named savannah instead of steppe. The austral phytocoenosis of Ponta Grossa, a possible endemism centre with great richness, is biogeographically isolated from the other cerrado patches

    Altitude and temperature drive anuran community assembly in a Neotropical mountain region

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    Understanding the spatial variation in species richness and the mechanisms that limit species range sizes along geographical gradients belong to the central research issues in macroecology. Here, we aim to test the topographic and climatic effects on anuran species richness and community composition in mountainous regions in the Brazilian Atlantic Forest biome. We used Individual-Based Rarefaction Curve (interpolation and extrapolation), Generalized Additive Model (GAM), Midpoint method and Principal Coordinates Analysis (PCoA) to analyze the topographic and climatic effects on anuran community composition, richness, and range sizes in a global biodiversity hotspot. Our results showed that altitude and annual mean temperature and temperature seasonality were the main drivers of species altitudinal range sizes and community assembly in mountainous regions. In conclusion, Anuran community richness peaked at intermediate altitudes following thus a hump-shaped pattern and corroborated the Rapoport's altitudinal rule as range sizes increased with altitude in mountainous regions from the Atlantic Forest biome. This study revealed new insights into the patterns and drivers of Neotropical anuran communities. Abstract in Portuguese is available with online material.Peer reviewe

    Habitat suitability of Anopheles vector species and association with human malaria in the Atlantic Forest in south-eastern Brazil

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    Every year, autochthonous cases of Plasmodium vivax malaria occur in low-endemicity areas of Vale do Ribeira in the south-eastern part of the Atlantic Forest, state of São Paulo, where Anopheles cruzii and Anopheles bellator are considered the primary vectors. However, other species in the subgenus Nyssorhynchus of Anopheles (e.g., Anopheles marajoara) are abundant and may participate in the dynamics of malarial transmission in that region. The objectives of the present study were to assess the spatial distribution of An. cruzii, An. bellator and An. marajoara and to associate the presence of these species with malaria cases in the municipalities of the Vale do Ribeira. Potential habitat suitability modelling was applied to determine both the spatial distribution of An. cruzii, An. bellator and An. marajoara and to establish the density of each species. Poisson regression was utilized to associate malaria cases with estimated vector densities. As a result, An. cruzii was correlated with the forested slopes of the Serra do Mar, An. bellator with the coastal plain and An. marajoara with the deforested areas. Moreover, both An. marajoara and An. cruzii were positively associated with malaria cases. Considering that An. marajoara was demonstrated to be a primary vector of human Plasmodium in the rural areas of the state of Amapá, more attention should be given to the species in the deforested areas of the Atlantic Forest, where it might be a secondary vector.FAPESPCNP

    Forest and connectivity loss drive changes in movement behavior of bird species

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    In a rapidly changing world, it is important to understand how environmental modifications by humans affect species behavior. This is not a simple task, since we need to deal with a multitude of species and the different external contexts that affect their behavior. Here, we investigate how interpatch short-distance movements of 73 common forest bird species can be predicted by forest cover and forest isolation. We modeled bird movement as a function of environmental covariates, species traits - body mass and feeding habit - and phylogenetic relationships using Joint Species Movement Models. We used field data collected in forest edges and open pastures of six 600 x 600 m plots in the Atlantic Forest biodiversity hotspot. We found that birds fly larger distances and visit more forest patches and remnant trees with decreasing forest cover. Increasing landscape isolation results in larger flight distances, and it increases the use of trees as stepping-stones for most species. Our results show that birds can adjust their behavior as a response to spatial modification in resource distribution and landscape connectivity. These adjusted behaviors can potentially contribute to ecosystem responses to habitat modification.Peer reviewe

    Visualization and categorization of ecological acoustic events based on discriminant features

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    Although sound classification in soundscape studies are generally performed by experts, the large growth of acoustic data presents a major challenge for performing such task. At the same time, the identification of more discriminating features becomes crucial when analyzing soundscapes, and this occurs because natural and anthropogenic sounds are very complex, particularly in Neotropical regions, where the biodiversity level is very high. In this scenario, the need for research addressing the discriminatory capability of acoustic features is of utmost importance to work towards automating these processes. In this study we present a method to identify the most discriminant features for categorizing sound events in soundscapes. Such identification is key to classification of sound events. Our experimental findings validate our method, showing high discriminatory capability of certain extracted features from sound data, reaching an accuracy of 89.91% for classification of frogs, birds and insects simultaneously. An extension of these experiments to simulate binary classification reached accuracy of 82.64%,100.0% and 99.40% for the classification between combinations of frogs-birds, frogs-insects and birds-insects, respectively

    Natural forest regeneration on anthropized landscapes could overcome climate change effects on the endangered maned sloth (Bradypus torquatus, Illiger 1811)

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    Climate change and habitat loss have been identified as the main causes of species extinction. Forest regeneration and protected areas are essential to buffer climate change impacts and to ensure quality habitats for threatened species. We assessed the current and future environmental suitability for the maned sloth, Bradypus torquatus, under both future climate and forest restoration scenarios, using ecological niche modeling. We compared environmental suitability for two Evolutionarily Significant Units (ESUnorth and ESUsouth) using two climate change scenarios for 2070, and three potential forest regeneration scenarios. Likewise, we evaluated the protection degree of the suitable areas resulting from the models, according to Brazilian law: PA—Protected Areas; PPA—Permanent Protection Areas (environmentally sensitive areas in private properties); and LR—Legal Reserves (natural vegetation areas in private properties). Finally, we calculated the deficit of PPA and LR in each ESU, considering the current forest cover. Forest regeneration might mitigate the deleterious effects of climate change by maintaining and increasing environmental suitability in future scenarios. The ESUnorth contains more suitable areas (21,570 km²) than the ESUsouth (12,386 km²), with an increase in all future scenarios (up to 45,648 km² of new suitable areas), while ESUsouth might have a significant decrease (up to 7,546 km² less). Suitable areas are mostly unprotected (ESUnorth—65.5% and ESUsouth—58.3%). Therefore, PPA and PA can maintain only a small portion of current and future suitable areas. Both ESUs present a high deficit of PPA and LR, highlighting the necessity to act in the recovery of these areas to accomplish a large-scale restoration, mitigate climate change effects, and achieve, at least, a minimum forested area to safeguard the species. Notwithstanding, a long-term conservation of B. torquatus will benefit from forest regeneration besides those minimum requirements, allied to the protection of forest areas. Atlantic Forest, climate change, conservation, forest regeneration, landscape ecology, Pilosa, XenarthraNatural forest regeneration on anthropogenic landscapes could overcome climate change effects on the endangered maned sloth (Bradypus torquatus, Illiger 1811)acceptedVersio

    Setting priority conservation management regions to reverse rapid range decline of a key neotropical forest ungulate

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    Mammals are important components of biodiversity that have been drastically and rapidly impacted by climate change, habitat loss, and anthropogenic pressure. Understanding key species distribution to optimize conservation targets is both urgent and necessary to reverse the current biodiversity crisis. Herein, we applied habitat suitability models for a key Neotropical forest ungulate, the white-lipped peccary (WLP Tayassu pecari), to investigate the effects of climate and landscape modifications on its distribution, which has been drastically reduced in Brazil. We used 318 primary records of WLP to derive habitat suitability maps across Brazil. Our models included bioclimatic, topographic, landscape, and human influence predictors in two modelling approaches. Models including all categories of predictors obtained the highest predictive ability and showed prevalence of suitable areas in forested regions of the country, covering 49% of the Brazilian territory. Filtering out small forest fragments (<2050 ha) reduced the suitable area by 5%, with a further reduction of 4% that was caused by deforestation until 2020, therefore until 2020, the species has suffered a reduction of ~60% from its historical range in Brazil. Of the 40% of the Brazilian territory suitable to WLP, only 12% are protected. In the Atlantic Forest, only half of all protected areas have suitable habitat for WLP and even less in Pantanal (44%), Cerrado (14%) and Caatinga (7%). In a second modelling approach, mapping the areas with suitable climate and those with suitable landscapes separately, allowed us to identify four categories of conservation values, and showed that only 17% of the Brazilian territory has both high landscape and climatic suitability for WLP. Our models can help with complementary conservation management strategies and actions that could be essential in slowing down and possibly reversing current trends of population and geographic range reductions for te species, thereby averting a possible future collapse of forest ecosystem functioning in the Neotropical region

    Movement syndromes of a Neotropical frugivorous bat inhabiting heterogeneous landscapes in Brazil

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    Background There is growing evidence that individuals within populations can vary in both habitat use and movement behavior, but it is still not clear how these two relate to each other. The aim of this study was to test if and how individual bats in a Stunira lilium population differ in their movement activity and preferences for landscape features in a correlated manner. Methods We collected data on movements of 27 individuals using radio telemetry. We fitted a heterogeneous-space diffusion model to the movement data in order to evaluate signals of movement variation among individuals. Results S. lilium individuals generally preferred open habitat with Solanum fruits, regularly switched between forest and open areas, and showed high site fidelity. Movement variation among individuals could be summarized in four movement syndromes: (1) average individuals, (2) forest specialists, (3) explorers which prefer Piper, and (4) open area specialists which prefer Solanum and Cecropia. Conclusions Individual preferences for landscape features plus food resource and movement activity were correlated, resulting in different movement syndromes. Individual variation in preferences for landscape elements and food resources highlight the importance of incorporating explicitly the interaction between landscape structure and individual heterogeneity in descriptions of animal movement.Peer reviewe
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