ICB - Artigos publicados em periódicos

URI Permanente para esta coleçãohttp://200.137.215.59//handle/ri/1399

Navegar

Agora exibindo 1 - 20 de 1587

Broad geographic dispersal is not a diversification driver for Emberizoidea
(2025-01-22) Pinto Ledezma, Jesus Nazareno; Arango Garcia, Axel; Villalobos Camacho, Crisóforo Fabricio; Rojas Soto, Octavio Rafael
The movement of species to new geographical areas has been proposed to be crucial for speciation. As such, dispersal has been regarded as a likely explanation for the variation in species richness among clades. The Emberizoidea are a highly diverse Oscine bird clade native to the New World that has been characterized for their ubiquitous distribution both ecologically and geographically, making this group ideal to test how biogeographical dispersal could promote speciation. To do so, we relate dispersal rates with speciation rates of Emberizoidea families using a combination of bioregionalization analysis, ancestral area reconstruction and speciation rate estimation methods. We found that the Emberizoidea superfamily likely arose from a widespread ancestor distributed over the New World, with its range evolution being primarily driven by range contraction and the main cladogenetic events for the clade occurring within bioregions. Moreover, we demonstrate that dispersal rates between bioregions showed no relationship with speciation rates, suggesting that the movement to new geographical spaces is not a driver of speciation in this group. Instead, cladogenetic events within individual bioregions promoted by range stability prove to be an important driver for speciation at broad spatial scales for Emberizoidea families.
Gall responses to drying habitats: insights from the communityof galling herbivores associated with the superhost Caryocar brasiliense Cambess. (Caryocaraceae)
(2025-02-02) Fernandes, Ivonette dos Santos; Araújo, Walter Santos de; Carneiro, Renê Gonçalves da Silva
Galls are new plant organs formed in response to the stimuli of gall-inducing organ-isms, but may also be inﬂuenced by environmental conditions.• This study evaluated the richness, abundance, and co-occurrence in the gall commu-nity associated with Caryocar brasiliense Cambess. (Caryocaraceae) areas with varyingdegrees of environmental stress due to the drying of palm swamps, called Veredas.Additionally, structural and metabolic attributes related to nutrition and protectionwere evaluated as possible stress markers. The research was conducted in two Cerradoareas with different water availability: the Parque Estadual Veredas do Peruacßu (lowerwater availability; more stressful) and the Area de Protecß~ao Ambiental do Rio Pandeiros(higher water availability; less stressful).• A total of 51,336 galls from ﬁve morphospecies were sampled: intralaminar globoid gall(IGG), extralaminar globoid gall (EGG), globoid petiolar gall (GPG), lenticular gall(LG) and clavate gall (CG). Gall richness was similar in both environments, but abun-dance was higher in the less stressful area, challenging the hypothesis that environmen-tal stress increases gall formation. Random co-occurrence patterns suggested that gallinducers occupy distinct spatial niches to reduce competition. Structurally and meta-bolically, galls exhibited similarities, including nutritive tissues and nutritious sub-stances in their internal compartments. However, in the more stressful environment,some galls had smaller internal and larger external compartments, with increased lig-nin and phenolic compounds in the outer tissue layers.• Lignin deposition and phenolic accumulation are evidenced as stress markers whichindicate that galls display phenotypic plasticity and adaptive strategies, enhancing pro-tection and survival under the stressful conditions of drying environments.
Habitat fragmentation explains the occupancy probability of the largest herbivore in the Neotropical forests
(2025-08-03) Regolin, André Luis; Collevatti, Rosane Garcia; Bailey, Larissa Lynn; Boscolo, Danilo; Rodrigues, Laís Lautenschlager; Beca, Gabrielle Cristina; Rodrigues, Mauro Galetti; Dias, Viviane Brito
Large mammals play an important role in ecosystem functioning, yet the loss of natural vegetation cover due to conversion to agriculture and other land uses has pushed wildlife into small and impoverished habitats. Thus, it is paramount to understand how landscape structure enables large mammals to thrive in tropical rainforests. We surveyed 42 forest landscapes in the Brazilian Atlantic forest for lowland tapir (Tapirus terrestris) using camera traps, analyzed landscape structure based on thematic maps, and assessed the matrix vegetation heterogeneity using satellite image texture. To evaluate the multiscale effects of the predictive variables on the species’ occurrence probability, we used a single-season occupancy approach. Beyond advancing the understanding of the species’ habitat requirements in human-modified landscapes, we used the species as a model to test theo retical predictions about the scale of effect (SoE), which have yet to be empirically evaluated. Habitat loss and fragmentation per se reduced the lowland tapir’s occurrence, as did matrix vegetation heterogeneity. Different landscape metrics influenced species occupancy at distinct spatial scales, and the SoE of fragmentation metrics was not smaller than habitat amount. Habitat fragmentation at a wide scale was the main predictor of species occupancy probability. Our findings highlight the critical role of habitat spatial structure in shaping the distri bution of the lowland tapir in human-modified landscapes. Beyond protecting large forest remnants, it is rec ommended to increase landscape connectivity at a broad scale through ecosystem restoration efforts to safeguard the species’ persistence in the Brazilian Atlantic Forest.
Advances and shortfalls in knowledge of Antarctic terrestrial and freshwater biodiversity
(2025-02-06) Pertierra, Luis R.; Convey, Peter; Barbosa, Andres; Biersma, Elisabeth Machteld; Cowan, Donald; Diniz Filho, Jose Alexandre Felizola; Ríos Murillo, Asunción; Escribano-Álvarez, Pablo; Fraser, Ceridwen; Fontaneto, Diego
Antarctica harbors many distinctive features of life, yet much about the diversity and functioning of Antarctica’s life remains unknown. Evolutionary histories and functional ecology are well understood only for vertebrates, whereas research on invertebrates is largely limited to species descriptions and some studies on environmental tolerances. Knowledge on Antarctic vegetation cover showcases the challenges of characterizing population trends for most groups. Recent community-level microbial studies have provided insights into the functioning of life at its limits. Overall, biotic interactions remain largely unknown across all groups, restricted to basic information on trophic level placement. Insufficient knowledge of many groups limits the understanding of ecological processes on the continent. Remedies for the current situation rely on identifying the caveats of each ecological discipline and finding targeted solutions. Such precise delimitation of knowledge gaps will enable a more aware, representative, and strategic systematic conservation planning of Antarctica.
Environmental factors trigger the spermatogenesis cycle of the toad Rhinella schneideri (anura: bufonidae)
(2025-04-30) Sousa, Gessica Coelho de; Costa, Matheus Santos; Lima, Phâmella Neres de; Marco Junior, Paulo De; Benetti, Édson José; Simões, Karina; Maciel, Natan Medeiros
This study investigated the correlation between environmental factors and spermatogenetic activity in Rhinella schneideri males from the Cerrado biome. Over 12 months, we examined the reproductive cycle using biometric, histological, morphometric, and stereological analyses. Morphometric and stereological parameters, along with the Gonadosomatic Index (GSI), varied significantly throughout the year. These variations were related to environmental conditions from the month prior to specimen collection, with a notably negative correlation between peak breeding activity and rainfall. Despite exhibiting a continuous reproductive cycle, R. schneideri males showed seasonal morphological changes in testicular tissue. A delayed response in the spermatogenesis cycle to environmental fluctuations was also observed, suggesting that environmental factors act as biological triggers. Our findings indicate that R. schneideri is well adapted to the challenging environmental conditions of the Cerrado, which are typically unfavorable for most frog species in other biomes.
Ten relevant questions for applying biodiversity offsettingin the Pantanal wetland
(2025-07-01) Lourival, Reinaldo Francisco Ferreira; Loyola, Rafael Dias; Roque, Fabio de Oliveira; Bolzan, Fábio Padilha; Guerra, Angélica; Nunes, Alessandro Pacheco; Lacerda, Ana Cristyna Reis; Nunes, André Valle; Gomes, Amanda Alves; Paranhos Filho, Antonio Conceição
In Brazil, biodiversity offsetting operates in an ad hoc manner while biodiversity equivalence has mainly been overlooked by public policies. Despite being mandatory since 1965s Forest Code (Law 4.771), we fail to have a robust offsetting framework. The revision of the forest code in 2012 (i.e., Native Vegetation Protection Law—NVPL—Law n° 12,651/2012), maintained the obligation for landowners to set aside a biome-specific percentage of their native vegetation for preservation. Known as Legal Reserves, these set-asides are a precondition for compliance with NVPL's regularization procedure called CAR (Rural Environmental Cadaster). Despite enthusiasm about biodiversity offsetting opportunities following the NVPL enactment in 2012, uncertainties around its implementation remains. Here, we formulated 10 questions that discuss and illustrate how offsetting can be applied to maintain wetland integrity, economic fairness and biodiversity conservation in the Pantanal and Upper Paraguay River basin (UPRB). The aim is to stimulate robust public policies and stimulate wetland offsetting research opportunities. We provided examples of implementation opportunities of the NVPL in integrating the floodplain and highland in Pantanal at UPRB, analyze spatial compliance deficits, and illustrate opportunities that require harmonized legislation and policies between Mato Grosso and Mato Grosso do Sul states in Brazil.
Rethinking global hotspots for threatened terrestrial vertebrates
(2025-01-08) Yair Huais, Pablo; Osorio-Olvera, Luis; Maximiliano Cordier, Javier; Nerea Tomba, Ana; Soberón Mainero, Jorge Luciano; Nori, Javier; Loyola, Rafael Dias
Aim We aimed to delimit hotspots for terrestrial threatened vertebrate species (HTV) through novel macroecological and statistical approaches. Location Global. Time Period Present day (1979–2024). Major Taxa Studied Terrestrial threatened vertebrate species (n = 7188). Methods In comparison with previous delimitations of hotspots, we: (i) considered richness and degree of endemism together through a robust statistical framework; (ii) focused on a priority set of species extremely important in terms of conservation, based on IUCN threat status; and (iii) used a fine spatial scale which allowed us to define key sub-areas within classic hotspots. We also assessed the degree of protection and human impact within the proposed HTV. Results We propose 20 global hotspots for threatened terrestrial vertebrates. In comparison with classic hotspots, proposed HTV have a significantly more limited distribution, covering ~27% of classic hotspots' area. In addition, a large proportion of HTV (~27%) does not match with classic hotspots. The overlap between HTV and protected areas (PAs) is low (< 11%), and extremely low when only strict protected areas are considered (< 1.5%). Also, a great degree of HTV exhibits high to extreme levels of human modification. On average, the velocity of climate change within HTV has been low, but attention must be given to notable areas presenting medium to high velocities. Interestingly, the geographical locations of highly endemic and rich areas considerably varied across individual vertebrate taxa. Yet, a high proportion of these priority areas for individual taxa are covered by the proposed HTV (74%–89%). Main Conclusions Our findings present key areas of the world for threatened terrestrial vertebrate species, many of these at high risk due to an interplay among low levels of protection, extreme levels of human modification and climate change. The proposed HTV are highly relevant in terms of decision-making, serving as a guide for allocating the limited conservation resources.
Combining protection and restoration strategies enables cost-effective compensation with ecological equivalence in Brazil
(2025-07-08) Matos, Clarice Borges; Carvalho, Francisco D'Albertas Gomes de; Mendes, Mariana Eiko; Loyola, Rafael Dias; Metzger, Jean Paul Walter
Ecological compensation and offsets have been used worldwide to repair the residual impacts caused by human activities. Achieving ecological equivalence in them has been challenging, and conflicts between development and environmental sectors commonly arise. We addressed this issue by testing an approach that is cost-effective and includes equivalence in compensation. We used the Brazilian Native Vegetation Protection Law's Legal Reserve (a native vegetation percentage of every rural property that must be conserved) compensation scheme as a study case. We created scenarios to test the law's three main compensation strategies (vegetation protection, restoration, and regularization of private lands inside public protected areas) separately and combined. We used a recently developed framework to assess ecological equivalence, including biodiversity, landscape, and ecosystem attributes measured and exchanged in a disaggregated manner. Cost-effectiveness was evaluated regarding deficit resolution (deficit in Legal Reserve needing compensation), economic costs, and native vegetation gained (additionality). The most effective strategy for deficit resolution was restoration (98.99 % of resolution), followed by protection (40.22 %) and regularization (0.15 %). Restoration was the most expensive strategy, but it also had the highest additionality. Combined scenarios resulted in balanced cost-effectiveness. The combination of protection followed by restoration was the best strategy, since its deficit resolution was high (99.47 %), with an intermediate cost and additionality. It is thus possible to make cost-effective compensation exchanges accounting for ecological equivalence adequately. We also used simple calculations in a new spatial optimization automated deficit and compensation prioritization path to generate spatially explicit results. Considering ecological equivalence guarantees additionality and more equitable spatial distribution of ecological benefits. These findings underscore the importance of incorporating equivalence in compensation, offering a promising avenue for bolstering efforts in compensation and offset schemes to address the ongoing climate and environmental global crisis by proposing a new approach to achieve this.
Planning for the restoration of functional connectivity in Brazil
(2025-01-20) Moreira, Stella Manes da Silva; Rocha, Diogo Souza Bezerra; Oliveira, Luiz; Liévano Latorre, Luisa Fernanda; Rocha, Juliana Monteiro de Almeida; Capellão, Renata de Toledo; Cordeiro, Carlos Leandro de Oliveira; Silva, Viviane Dib da; Loyola, Rafael Dias; Oliveira, Luiz Eduardo Lacerda de
Aim Land use and land cover (LULC) change is the main driver of biodiversity loss, causing habitat loss and fragmentation that hinders species movement and negatively impacts populations. While habitat fragments are structurally disconnected, functional connectivity can still occur depending on the species' dispersal abilities. Incorporating landscape connectivity into restoration planning helps identify strategic areas significantly enhancing connectivity. Here, we present an unprecedented, nationwide continuous spatial layer representing each restorable pixel's contribution to functional connectivity, using Brazil as a case study.
Proximity to research centers, fluvial accessibility, and dams presence drive sampling efforts for phytoplankton, zooplankton, and macrophytes in freshwater ecosystems
(2025-03-24) Nabout, João Carlos; Andrade, Ariany Tavares de; Oliveira, Israel Bernardes de; Silva, Larissa Araújo da; Terribile, Levi Carina; Porto, Lucas Jardim; Almeida, Marcela Fernandes de; Carvalho, Priscila Magalhães de Oliveira; Oliveira, Roniel Freitas; Vieira, Ludgero Cardoso Galli
Understanding biodiversity and monitoring ecosystems require robust sampling eforts for important bioindicators like phytoplankton, zooplankton, and aquatic macrophytes. This study quantifed sampling eforts for these aquatic groups across the Tocantins-Araguaia Basin in Central Brazil, evaluating the infuence of geographic and environmental factors such as human development, fuvial and terrestrial accessibility, elevation variation, and proximity to protected areas and research centers. These variables align with the appeal and accessibility hypotheses, which help explain sampling patterns observed across regions. A systematic review compiled 2,307 unique feld collection records, allowing analysis of spatial and temporal sampling patterns. The sampling efort was quantifed based on geographic coordinates per grid cell, with predictors analyzed using generalized linear mixed models. Results showed sampling was concentrated in the centralsouthern region, with phytoplankton covering 28.83% of the area, macrophytes 16.13%, and zooplankton 11.9%. Key drivers of sampling efort included proximity to research centers, dam presence, and fuvial accessibility. Additionally, protected areas and human development infuenced sampling efort for specifc biological groups. Despite these eforts, vast regions, especially in the northern Araguaia River, remain under-sampled, highlighting the need for comprehensive long-term sampling strategies to address critical biodiversity knowledge gaps.
Addressing the urgent climate and biodiversity crisis through strategic ecosystem restoration in Brazil
(2025-02-08) Liévano Latorre, Luisa Fernanda; Rocha, Juliana Monteiro de Almeida; Akama, Alberto; Almeida, Hernani Alves; Loyola, Rafael Dias; Andrade, Ricardo Teixeira Gregório de; Anjos, Marcelo Rodrigues dos; Itabaiana, Yasmine Antonini; Bahia, Thaíse de Oliveira; Barbosa, Flavia Rodrigues
Ecosystem restoration is crucial worldwide to address environmental challenges. Many countries, including Brazil, have committed to restoring degraded landscapes at national and international levels. Brazil aims to restore twelve million hectares of degraded areas by 2030, which requires strategic decision-making to allocate resources effectively and balance biodiversity gains with societal benefits. Our modeling approach uses extensive biodiversity field data to identify priority areas for restoration across Brazil's diverse phytogeographic domains. By focusing on expanding native species habitats and enhancing connectivity, we aim to maximize ecological returns. Precisely, we pinpoint areas within each Brazilian phytogeographic domain with the greatest potential for habitat enhancement, including the Amazon's arc of deforestation, central Cerrado, the limits of Caatinga, Pampa, and Pantanal, and the coastal areas of the Atlantic Forest. Restoring 30 % of these areas—approximately 76 million hectares—could significantly benefit 11,028 species by increasing available habitat by up to 10 % and improving landscape functional connectivity by 60 %. Moreover, this restoration effort would capture up to 9.8 million tons of atmospheric carbon, contributing to global climate goals. As Brazil strives to meet national and international targets, we also advocate for economic incentives to support restoration practices within each phytogeographic domain. Integrating prioritization modeling into decision-making ensures optimal biodiversity and carbon stock outcomes to guide more effective restoration efforts. This comprehensive strategy helps advance restoration goals and underscores the vital role of science-based planning in safeguarding our planet's natural heritage.
A run-of-river mega-dam in the largest Amazon tributary changed the diversity pattern of planktonic communities and caused the loss of species
(2025-04-01) Barbosa, Alfonso Pineda; Peláez, Óscar; Velho, Luiz Felipe Machado; Gurgel, Priscila Cabral Silveira; Rodrigues, Luzia Cleide
Run-of-river dams (RORs) are often considered less environmentally damaging than storage dams, but information on their impact on regional biodiversity is scarce. In particular, the effects of RORs on species commonness are largely unknown. In this study, we assessed the impacts of ROR on the biodiversity of phytoplankton and zooplankton in the largest tributary of the Amazon River. We investigated the effects of the ROR on changes in environmental heterogeneity, species richness and beta diversity and examined whether these changes varied with species commonness. We examined the shift in species composition and environmental heterogeneity between damming phases and assessed changes in species richness for the whole community (q0), more abundant species (q2) and typical species (q1—a community without rare and more abundant species). We also decomposed the total diversity (γ) registered at each phase into its local diversity (α) and its spatial (β1—variation among sites) and temporal (β2—variation between samplings and β3—variation between seasons) components. We then evaluated whether the contributions of these components varied with damming for q0, q1 and q2. After damming, the environmental heterogeneity and the richness of both communities decreased (considering the whole community). Beta diversity decreased for phytoplankton and increased for zooplankton. Changes in the contribution of γ components after damming were more evident for typical and more abundant species. For phytoplankton, β1 and β3 decreased while the importance of α increased. For zooplankton, while β1 and β3 increased, α decreased. We showed that analysing the commonness of species could be useful for understanding the impact of ROR. On the one hand, if the interest is in evaluating the response of communities in terms of species number, researchers could consider the whole community. On the other hand, if the interest is in evaluating changes in spatial and temporal patterns, typical and more abundant species appear to be more sensitive than the whole community. Our findings showed changes in diversity patterns and species loss after damming, suggesting that RORs are not as friendly as expected, at least for plankton. Our findings contribute to the evaluation and monitoring strategies for existing dams and those that will be built in the Amazon region in coming years.
Future at risk? Specialized flagship herbivores threatened by climate change in the Atlantic Rainforest
(2025-07-19) Ribeiro, Matheus de Souza Lima; Bellaver, Juliane Maria Fernandes; Hoffmann, Diego; Ribeiro, Matheus de Souza Lima; Pires, Ana Carolina Teixeira; Bordignon, Leandra; Fernandes, Geraldo Wilson; Romanowski, Helena Piccoli
Predictive niche modeling studies suggest significant biodiversity loss under climate change scenarios, indicating that species currently classified as least concern may face extinction risks. Here, we assessed two flagship butterfly species endemic to the Atlantic Forest: Arcas ducalis and Cyanophrys bertha. Both species have previously been listed as regionally threatened, and C. bertha is considered ’Vulnerable’ (VU) by the International Union for Conservation of Nature (IUCN), although both are now classified as ’Least Concern’ (LC) by Brazilian government. It remains unclear whether these species are naturally rare or difficult to detect. Assessing the effects of climate change on their conservation status and dispersal potential may help establish more accurate threat categories. This study aimed to evaluate the effects of climate change under two scenarios (SSP245, optimistic; SSP585, pessimistic) for two future periods. The results indicate that A. ducalis may experience a range reduction of over 46%, with a decline of more than 40% in interaction with one of its host plants under the pessimistic scenario. Conversely, C. bertha could be classified as ’Near Threatened’ (NT) due to a range reduction of over 66% and a decrease of more than 89% in interaction with one of its host plants in the same scenario. Representation within Conservation Units (CUs) suggests that both species will maintain adequate range coverage only under current conditions, with significantly reduced coverage in future scenarios. Given these findings, stronger measures, such as incentives for establishing and maintaining protected areas, are essential for conservation of these flagship species.
Leaf traits mediate galling insect frequency on woody plants in a Neotropical savanna
(2025-07-07) Santos, Leandro Maracahipes dos; Bergamini, Leonardo Lima; Sobral, Fernando Landa; Almeida Neto, Mário; Cianciaruso, Marcus Vinicius; Araújo, Walter Santos de
Galling insects are highly specialized herbivores that exhibit intimate interactions with their host plants. How ever, the role of interspecific variation in plant traits on galling species occurrence has been little explored. Here, we assessed the roles of nutritional (P:N ratio) and defensive (latex, specific leaf area, leaf toughness and extrafloral nectaries) leaf traits in determining galling insect frequency and richness across 50 woody plant species in a Brazilian savanna. Specifically, we tested the hypotheses that nutritional leaf traits attract galling insects, thus increasing their frequency and species richness, while defensive leaf traits reduce galling frequency and richness. Sampling was conducted during the rainy season, resulting in the identification of 82 galling insect species distributed among 42 plant species. We found no relationship between leaf traits and galling species richness. However, latex reduced the frequency of galling insects, whereas the presence of extrafloral nectaries, tougher leaves and higher leaf P:N ratio were positively associated with galling frequency. Our findings indicate that latex plays an important role on the occurrence of galling insects, presumably by hindering oviposition and reducing egg survival and larval hatching. Additionally, the presence of extrafloral nectaries may offer protection against natural enemies, tough leaves can increase leaf longevity and enhance defense against herbivory, and galling species prefer plant with better nutritional quality. In contrast to previous studies, we demonstrate that defensive and nutritional leaf traits do not affect galling species richness; rather, defensive traits influence the frequency of galling insects among savanna plant species.
A call for flexpert ecologists
(2025-07-09) Cianciaruso, Marcus Vinicius; Almeida Neto, Mário; Bini, Luis Mauricio
Can the morphological variation of Amazonian bufonidae (Amphibia, Anura) be predicted by their habits and habitats?
(2025) Oliveira, Andressa Sasha Quevedo Alves; Alexandre, Rafaela Jemely Rodrigues; Pena, Simone Almeida; Correia, Letícia Lima; Souza, Thais Santos; Dias, Samantha Valente; Vieira, Thiago Bernardi
The species of the Bufonidae family exhibit a great diversity of habitats, diurnal or nocturnal habits, a complex evolutionary history, and a wide distribution, which makes this group suitable for morphological studies. In this work, we aimed to identify the existence of morphological patterns related to the habitat use and diurnal or nocturnal habits of Bufonidae in the Brazilian Amazon. To achieve this, we studied the morphological measurements of 210 specimens from three zoological collections and characterized the type of habitat and diurnality/ nocturnality of the species. The morphological patterns and habitat use were investigated through principal component analysis (PCA) and multiple correspondence analysis (MCA), respectively. The evaluation of the relationships between morphological variation, habitat use, and diurnality/nocturnality was performed via redundancy analysis (RDA). Accordingly, Amazonian bufonids were divided into three morphological groups associated with different vegetation types and environments, demonstrating that body size is closely linked to diurnal or nocturnal life habits and habitat. Species with large body sizes are associated to anthropized areas, while intermediate and smaller species are associated with primary forests.
Nitrate, water temperature, conductivity, and transparency drive littoral phytoplankton species composition and biovolume in two reservoirs in the Xingu river
(2025) Souza, Dilailson Araújo de; Nunes, Daniela Santana; Bomfim, Francieli de Fátima; Vieira, Thiago Bernardi; Felizzola, Juliana Feitosa; Silva, Karina Dias da
Ecological interactions in the littoral zone maintain water quality, biodiversity, and ecological services in freshwater ecosystems. Phytoplankton occupy a central position in the ecosystem due to their sensitivity to environmental changes and ecological importance for ecosystem functioning. Here, we aimed to evaluate dissimilarity in physicochemical characteristics and phytoplankton composition of the littoral zone in two reservoirs of the Belo Monte Hydroelectric Complex. We also investigated the physicochemical factors determining spatial variation in the composition, richness, and biovolume of littoral phytoplankton in the environments studied. The physical and chemical characteristics of the water displayed distinct patterns in the Xingu and Intermediate reservoirs, which drove phytoplankton biovolume and species composition. However, the richness of phytoplankton species was similar in the two reservoirs. More specifically, phytoplankton biovolume and species composition were influenced by nitrate, temperature, conductivity, and transparency. Our study increases understanding of the environmental factors determining spatial variation of littoral phytoplankton communities in reservoirs. This data improves understanding of littoral zones in reservoirs and highlights the importance of littoral phytoplankton in maintaining water quality and ecosystem services in these waterbodies.
First record of microplastic contamination in adult endemic amazonian anuran species
(2025) Ferreira, Maria Luiza Cunha e Souza; Reis, Adrian José Oliveira dos; Ferreira, Erikson Bruno Loseiro; Dipold, Jessica; Freitas, Anderson Zanardi de; Wetter, Niklaus Ursus; Oliveira-Bahia, Veronica Regina Lobato de; Vieira, Thiago Bernardi
in various animal groups, such as anuran amphibians during both larval and adult stages. However, current studies on adult anuran amphibians focus on assessing only one exposure route, the digestive system, while other routes remain underestimated. Therefore, this present study aimed to evaluate the degree of contamination in the digestive, respiratory, and integumentary systems, in situ, of two endemic Amazonian adult anuran species (Physalaemus ephippifer and Boana multifasciata). From this, we identified and characterized microplastic particles for each exposure route, assessed the effects of morphometric measures on the total MP contamination level and in the gastrointestinal tract (GIT). Additionally, we determined different contamination indices and how they vary according to species and systems. Based on our data, the digestive and integumentary exposure routes showed the highest contamination levels for both species. Additionally, variations in MP contamination levels indicated that P. ephippifer had a higher level of MP contamination. Thus, this study provides the first evidence of microplastic exposure through respiratory and integumentary routes in adult anurans in situ, and it is the first to identify MP contamination in terrestrial biomonitors in the Amazon.
Assessing site and species associations with beta diversity of fish assemblages in Amazonian streams
(2025) Lucena, Maria Dayanne Lima de; Martins, André Ribeiro; Casatti, Lilian; Vieira, Thiago Bernardi; Brejão, Gabriel Lourenço; Carvalho, Fernando Rogério de; Michelan, Thaísa Sala; Juen, Leandro; Montag, Luciano Fogaça de Assis de
The increasing environmental changes threatening the fish fauna of streams are driving a growing interest in understanding how sites and species contribute to diversity, as this is important information for decision-making related to the management and conservation of priority areas and species. The objective of this study was to understand how environmental factors, spatial distance between streams, land use, and land cover (landscape) may be associated with the uniqueness of fish assemblages in Amazonian streams. We sampled fish assemblages and characterised environmental conditions in 29 streams within and around the Tapajós River basin, near the Amazon National Park in Brazil. Each stream was studied along a 150-m stretch. The variables associated with the local contribution to beta diversity (LCBD) were vegetation cover and the presence of refuges. Streams inside and outside the park showed similar contributions to beta diversity. Species richness and abundance showed a negative relationship with LCBD, suggesting that unique sites tended to have few species and low abundance. The species that contributed most to beta diversity (SCBD) had intermediate occurrence, high abundance, and non-marginal niches. We did not observe an effect of niche breadth on SCBD, as both generalist and specialist species contributed equally to beta diversity. Our findings underscore the role of environmental variables in ecological uniqueness. Sites unique in species composition may also exhibit low species richness and abundance. Our study demonstrates the importance of environmental variables in conserving biodiversity in Amazonian streams in the face of environmental changes. By examining the contributions of sites and species, we highlight the importance of considering habitat quality and uniqueness in protecting these ecosystems against the challenges of global change.
A simple way to quantify plastic in bats (Mammalia: Chiroptera) using an ultraviolet flashlight
(2025) Correia, Letícia Lima; Vieira, Thiago Bernardi; Brasil, Ariane de Sousa; Garcia, Magali Gonçalves; Silva, Daniela de Melo e; Santos, Ana Beatriz Alencastre dos; Brasil, Danielle Regina Gomes Ribeiro
Bats, as key ecological players, interact with a diverse array of organisms and perform essential roles in ecosystems, including pollination, pest control, and seed dispersal. However, their populations face significant threats from habitat contamination, particularly from microplastics (MPs). This study introduces a novel, efficient, and cost-effective method for visualizing transparent microplastics using ultraviolet (UV) light. By employing handheld UV flashlights with a wavelength range of 312 to 400 nm, we enhance the detection of MPs that may otherwise go unnoticed due to color overlap with filtration membranes. All necessary precautions were taken during sampling and analysis to minimize the risk of contamination and ensure the reliability of the results. Our findings demonstrate that the application of UV light significantly improves the visualization and identification of MPs, particularly transparent fibers. This innovative approach contributes to our understanding of plastic contamination in bat habitats and underscores the importance of monitoring environmental pollutants to protect bat populations and maintain ecosystem health.

Navegar

Submissões Recentes