Atlantic Forest Region Research Articles

Prediction of land use/land cover and environmental estimation of carbon stocks in the Atlantic forest: A study in the state of Sergipe, Brazil

The forest ecosystems of the Atlantic Forest biome in Brazil are experiencing intense deforestation, contributing to climate change. Valuing the ecosystem service of CO2 sequestration can help in environmental policies to reduce deforestation and promote ecological restoration in this region. In this study, we sought to understand the dynamics of land use and land cover in the Atlantic Forest region of the state of Sergipe between 1985 and 2021 and to simulate land use and land cover for 2031 and 2051, assuming the current business as usual (BAU) trend was used as a reference scenario. The results showed that the agriculture-pasture mosaic class obtained the greatest percentage (5.27 %) and net (around 514.00 km²) increase among the land use and cover classes evaluated in the study area between 1985 and 2021. In the BAU scenario, total emissions reach 1,137,942.07 Mg CO2 in 2031 and 692,815.16 Mg CO2 in 2051, imposing an opportunity cost for society of US$ 7.94 million and US$ 4.35 million, respectively.

Endemic and threatened birds as surrogates for identifying conservation priority areas and ecological corridors in the America’s most endangered habitat

Investigating multi-taxa macroecological patterns can provide critical insights for spatial conservation planning and landscape management across biodiversity hotspots. The Pernambuco Endemism Center (PEC) is a biogeographic region of the Brazilian Atlantic Forest known to harbor the most threatened habitats in the Americas and a considerable number of recent bird extinctions. Here, we modeled the distribution of 30 threatened forest-dependent birds, 29 of which endemic to the PEC, to reveal key habitats/resources for their survival, identify conservation priority areas, and design ecological corridors. We found variations in the responses of the taxa to landscape characteristics when we addressed these organisms separately and when we grouped them by conservation status. Overall, the environmental variables related to forest quality (e.g., distance to large fragments, distance to the forest edge, percentage of tree cover, percentage of older forests) were important predictors of habitat suitability for the regional threatened avifauna. Additionally, we revealed forest fragments of high ecological importance for the PEC’s threatened birds, and we propose the creation of the Pernambuco Endemism Center Restoration Arc (PEC-ARC) that may maximize the investments in conservation and guarantee the connectivity of crucial areas for long-term species survival.

A trip of a bamboo lifetime: tracing the origin and evolution of Chusquea (Poaceae, Bambusoideae, Bambuseae) in Patagonia, southernmost South America

Abstract We performed a phylogenetic analysis with estimated clade ages and an ancestral-range estimation focused on the Patagonian species of Chusquea, i.e. the Chusquea culeou clade, to unravel their biogeographical history. Phylogenetic analyses were conducted with sequence data from four plastid markers, using maximum parsimony and Bayesian inference approaches. The complete sampling and addition of the Patagonian Chusquea species into a phylogenetic framework revealed the most likely origin and evolutionary history of the Chusquea culeou clade. The Patagonian Chusquea originated roughly 11.35 Mya, most likely from a common ancestor from the Atlantic Forest region, when this lineage underwent in situ diversification and its species evolved sympatrically. All the extant species have arisen in the last 8 Myr. Moreover, according to the present sampling, the most recent common ancestor of subtribe Chusqueinae originated in the Northern Andes, which is also the most common source area of the estimated dispersal events. Some other preliminary insights on the biogeographic history of the genus are included.

Isolation and In Vitro Biological Evaluation of Triterpenes from Salacia grandifolia Leaves.

Salacia grandifolia is naturally found in the Atlantic Forest regions of Brazil. Despite the pharmacological potential of plants from the Salacia genus, phytochemical studies on this species have not been reported in literature. A new triterpene, 28-hydroxyfriedelane-3,15-dione (1), and seven known compounds (friedelan-3-one (2), friedelan-3β-ol (3), friedelane-3,15-dione (4), 15α-hydroxyfriedelan-3-one (5), 28-hydroxyfriedelan-3-one (6), 30-hydroxyfriedelan-3-one (7), and 29-hydroxyfriedelan-3-one (8)) were obtained from the hexane extract of Salacia grandifolia leaves. These isolated compounds and three extracts, hexane (EH), chloroform (EC), and ethyl acetate (EAE), were assessed for their potential biological activities, which consisted in the evaluation of antiviral activity against a murine coronavirus, mouse hepatitis virus 3 (MHV-3), antibacterial activity against the susceptible and methicillin-resistant Staphylococcus aureus (MRSA), and antileukemia activity against the THP-1 and K-562 cell lines. The extracts EH and EAE along with the triterpenes 1 and 6 exhibited moderate to high antiviral activity, with emphasis on 6, which presented an EC50 value of 2.9 ± 0.3 μM. None of the compounds presented antibacterial activity against the tested strains. The evaluated compounds 1, 4, 6 and 7 exhibited low cytotoxic activity against the tested leukemia cell lines. Taken together, this study comprises an overview for the potential of the Salacia grandifolia biological activities, including a new isolated triterpene.

Reproductive behavior of Phyllomedusa tetraploidea (Anura: Hylidae) Pombal & Haddad, 1992 in the Brazilian Atlantic Forest

The reproductive potential of an individual is crucial for ensuring the production of offspring. However, knowledge about polyandry in anurans is limited. In this report, we present the first documented case of polyandrous reproduction or multiple reproduction in Phyllomedusa tetraploidea (Anura: Hylidae) Pombal & Haddad, 1992. This observation occurred during a rainy night in the Atlantic Forest region of northwest Paraná, Brazil. The multiple reproduction event involved four males (three of which were identified as satellites) and one female. Notable behaviors were recorded, including a vocalizing male assisting the female in folding leaves with his feet before depositing the eggs. The entire multiple reproduction event lasted about 40 minutes. Additionally, we observed a pair of P. tetraploidea engaging in axillary amplexus, where the male and female positioned their bellies toward each other. This amplexus lasted approximately 80 minutes, from their initial meeting until the eggs were deposited and they separated. This study contributes to our understanding of P. tetraploidea's reproductive mode, detailing behaviors from vocalization to egg deposition. It also adds to our knowledge of the evolution of reproductive strategies.

Minor loss or huge threat? Assessment of potential infrastructure projects reveals drastic landscape degradation in the Atlantic forest

Projects demanding deforestation to expand urban infrastructure and road networks put pressure on the Atlantic Forest − a hyper-fragmented global conservation hotspot known for its high biodiversity and endemism. To support decision-making, we applied a scientific approach to analyse the immediate and long-term impacts of two major planned projects in the most threatened Atlantic Forest region – the Pernambuco Endemism Center, a crucial area for the survival of many endemic species. A Metropolitan Road Arch and a Training School for Career Sergeants are expected in the Environmental Protection Area Aldeia-Beberibe (31,634 ha) in the next few years. The area has 198 protected forest remnants, including one larger than 10,000 ha. Our analysis shows that the projects’ implementation may deforest 189 ha, increase fragment number by 3.5 % and decrease the average patch area by 4 %. The largest fragment will be divided into two. We may lose 335,307 trees and 44,655.59 Mg of carbon. Approximately 112.67 ha of watershed protection will be damaged. Thus, in the medium to long term, habitat quality will worsen, and the probability of connectivity will decrease, restricting forest-dependent species’ mobility considerably. To date, alternative areas have been proposed in meetings, working groups, and environmental advisory bodies for the analysed projects.We strongly oppose further deforestation and suggest that science-based approaches must be immediately considered for any project that requires forest suppression in highly fragmented landscapes. This is crucial to mitigate the alarming scenarios of extreme climate and biodiversity loss that we are currently witnessing in Brazil and worldwide.

DNA barcoding reveals a new population of the threatened Atlantic Forest frog Sphaenorhynchus canga

Species identification plays a significant role in biodiversity conservation. As many species remain unrecognized, particularly in neotropical hotspots like the Brazilian Atlantic Forest (AF), novel molecular techniques are being widely employed to bridge this gap. In this study, we used DNA barcoding and phylogenetic tools to identify a new population of Sphaenorynchus canga in the central region of the Brazilian AF. Our results extend the species’ known distribution by approximately 200 km to the south, encompassing a different mountain range than its type locality (Serra do Espinhaço). This disjunct distribution, while not uncommon among amphibians, suggests a historical connection between these two mountain complexes as a biogeographic explanation. Despite the discovery of a new S. canga population, the species continues to face numerous anthropogenic threats such as mining, land use, and cattle ranching. Urgent conservation and research efforts are warranted to ensure the survival of S. canga populations across these habitats.

Effects of geographical origin and post-harvesting processing on the bioactive compounds and sensory quality of Brazilian specialty coffee beans

Specialty coffee beans are those produced, processed, and characterized following the highest quality standards, toward delivering a superior final product. Environmental, climatic, genetic, and processing factors greatly influence the green beans’ chemical profile, which reflects on the quality and pricing. The present study focuses on the assessment of eight major health-beneficial bioactive compounds in green coffee beans aiming to underscore the influence of the geographical origin and post-harvesting processing on the quality of the final beverage. For that, we examined the non-volatile chemical profile of specialty Coffea arabica beans from Minas Gerais state, Brazil. It included samples from Cerrado (Savannah), and Matas de Minas and Sul de Minas (Atlantic Forest) regions, produced by two post-harvesting processing practices. Trigonelline, theobromine, theophylline, chlorogenic acid derivatives, caffeine, caffeic acid, ferulic acid, and p-coumaric acid were quantified in the green beans by high-performance liquid chromatography with diode array detection. Additionally, all samples were roasted and subjected to sensory analysis for coffee grading. Principal component analysis suggested that Cerrado samples tended to set apart from the other geographical locations. Those samples also exhibited higher levels of trigonelline as confirmed by two-way ANOVA analysis. Samples subjected to de-pulping processing showed improved chemical composition and sensory score. Those pulped coffees displayed 5.8% more chlorogenic acid derivatives, with an enhancement of 1.5% in the sensory score compared to unprocessed counterparts. Multivariate logistic regression analysis pointed out altitude, ferulic acid, p-coumaric acid, sweetness, and acidity as predictors distinguishing specialty coffee beans obtained by the two post-harvest processing. These findings demonstrate the influence of regional growth conditions and post-harvest treatments on the chemical and sensory quality of coffee. In summary, the present study underscores the value of integrating target metabolite analysis with statistical tools to augment the characterization of specialty coffee beans, offering novel insights for quality assessment with a focus on their bioactive compounds.

Status and distribution of Paraguayan Procyonidae and Mephitidae (Mammalia: Carnivora)

Two species of procyonid (Nasua nasua and Procyon cancrivorus) and one species of mephitid (Conepatus chinga) have long been documented to occur in Paraguay, but very little has been published about their ecology in the country since the early 19th Century works of Azara and Rengger. Data on the distribution and status of these species in the country is collated from museum specimens, published literature and reliable observations to provide a basis for future research. A hierarchical approach is taken towards types of record and maps are provided that distinguish these for all species. All three species remain common in the Chaco region west of the Paraguay River, and all are considered of Least Concern. However, this region is experiencing high levels of deforestation and data to assess the potential declines of the species is unavailable. The two species of procyonid are also widespread in the Oriental region, but the status of Conepatus chinga there is unclear. There are multiple reports from the Atlantic Forest region but documentation is limited to fecal molecular samples. Clarifying the distribution of that species in the Oriental region is a priority for research.

Genomic data identify genetic structure in Enoploctenus cyclothorax (Araneae: Ctenidae), revealing two distinct taxonomic units in the southern region of the Brazilian Atlantic Forest

Genomic data identify genetic structure in Enoploctenus cyclothorax (Araneae: Ctenidae), revealing two distinct taxonomic units in the southern region of the Brazilian Atlantic Forest

Cytotoxic and Phytotoxic Activities of Native Brazilian Forest Gabiroba (Campomanesia xanthocarpa Berg.), Fruits, and Flour against Shrimp (Artemia salina L.) and Lettuce (Lactuca sativa L.).

Gabiroba, a native fruit in Brazil's Atlantic Forest region, has significant nutritional and therapeutic properties. However, due to its seasonality, consumption by the population is limited. Thus, the development of gabiroba byproducts would add significant value to the food and therapeutic industries. Therefore, it is essential to study and support the lack of toxicity of gabiroba fruit extracts. In the present study, physicochemical analyses of fresh fruits (GF) and dehydrated whole gabiroba flour (WGF) and preliminary toxicity analyses of WGF were performed. The toxicity results showed a microcrustacean LC50 of >1000 mg/mL when exposed to WGF extracts at various concentrations (10-1000 μg/mL; p = 0.062) using the Artemia salina method, with no evidence observed of proliferative activity or toxic metabolic compounds in the WGF extract. The phytotoxicity of WGF using Lactuca sativa L. allowed germination and root growth at various concentrations of WGF extract, with the lowest (100 μg/mL) and highest (1000 μg/mL) concentrations exhibiting 98.3% and 100% seed germination, respectively. In conclusion, these results indicate that the WGF preparation preserved the nutritional and antioxidant potential of gabiroba fruits and that WGF is safe for use as a raw material in the food industry and for therapeutic purposes.

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.

Documenting birds over two centuries of deforestation in an Atlantic Forest region of Brazil

ABSTRACT The first ornithological record from Paraná State, Southern Brazil, dates from 1820, when forests covered 83% of the area. There is a lack of studies evaluating how knowledge on species richness increased over time, together with a massive deforestation process. We aimed to describe the changes, by decade, in forest species richness since that time, and to determine how field effort hours were distributed. We reviewed published studies using online databases. We compared forest bird communities between decades with Jaccard Dissimilarity Indices and compared communities’ composition among decades with Analysis of Similarity. In 200 years, 421 forest bird species were mentioned. Most of the species were detected until 1980, a likely subset of the avifauna before habitat loss; fewer species (108) were recorded afterward. An increasing number of species (8–20) stopped being recorded by decade from the 1980s. Field effort hours were mentioned in 1984, remaining temporally and spatially uneven. More than 1,000 localities have been inventoried, but most species reports are from Eastern municipalities. Areas within Serra do Mar, Curitiba, and Londrina stand out as protected forests and well-known academic centers. Cerrado endemics corroborated the relevance of exploring different regions, but further studies in this domain are strongly recommended.

Ecological and molecular associations between neotropical wild felids and Taenia (Cestoda: Taeniidae) in the Atlantic Forest: a new report for Taenia omissa.

Ecological associations between wild felids and parasites from the Taeniidae family are related to predator-prey interactions, where felids act as definitive hosts while their prey, herbivores and/or omnivores, act as intermediate hosts. In the Atlantic Forest, six neotropical felid species coexist in sympatry, but the ecological parasite-host interactions remain poorly studied. Taenia omissa is a tapeworm that parasitizes cougars (Puma concolor) as its only definitive host and their ungulate prey as intermediate hosts. The aim of this study was to identify tapeworms present in road-killed fauna using both molecular and morphological characteristics and their predator-prey relationship. Adult tapeworms found in a cougar, a jaguarundi (Herpailurus yagouaroundi), and two ocelots (Leopardus pardalis); and metacestodes found in a red brocket deer (Mazama americana) and a wild guinea pig (Cavia aperea) were analyzed. Through morphological analysis of rostellar hooks and molecular analysis of the mitochondrial genetic marker cox1, Taenia omissa adult individuals were identified in the cougar, and metacestodes in the red brocket deer, proving the existence of a full host-parasite life cycle in the Atlantic Forest region. This new report reveals the southernmost record of T. omissa and broadens its geographic distribution. In addition, isolates of the Taenia genus divergent from those described so far in molecular databases were reported and suggested a wild cycle that involves the jaguarundi and agouti (Dasyprocta asarae) as definitive and intermediate hosts, respectively. These results highlight the complexity of the tapeworm population in the region and the need to study it with both morphological and molecular approaches.

Revisiting Metternichia (Solanaceae) Through an Integrative Approach: A Monotypic Genus?

Abstract— Improving species delimitation and knowledge on species complexes is crucial for many areas of study in Biology, especially conservation. Integrative taxonomy contributes to this topic by using different approaches to better delineate taxonomic boundaries. Metternichia (Solanaceae), historically a monospecific genus, has a geographic range that comprises contrasting environments. Metternichia principis was described as having two varieties: the typical variety, found in the humid forests of eastern Brazil (Atlantic Forest region), and M. principis var. macrocalyx, which presents a larger calyx and inhabits mostly semi-arid areas (Caatinga region). In this study, we tested the validity of such groups by integrating environmental, phenological, morphometric, and palynological data; applying uni- and multivariate tests; and evaluating the conservation status of each taxon. Our results support the recognition of two morphological groups within Metternichia, largely in agreement with the original circumscription of the varieties. Multivariate analyses clearly indicate different ecological niches, with each taxon inhabiting environments with distinct mean annual precipitation and temperature. Phenological data show some differences between the varieties regarding months with the highest number of flowering and fruiting records. In general, M. principis var. macrocalyx presents larger flower and pollen characters, and smaller fruit characters compared to the typical variety. Based on these findings, we elevate the variety to the status of species, as the new combination Metternichia macrocalyx. Following IUCN guidelines, both taxa are here preliminarily considered endangered (EN).

Spatiotemporal dynamics reveals forest rejuvenation, fragmentation, and edge effects in an Atlantic Forest hotspot, the Pernambuco Endemism Center, northeastern Brazil.

Large forested tracts are increasingly rare in the tropics, where conservation managers are often presented with the challenge of preserving biodiversity in small and isolated fragments. The Atlantic Forest is one of the world's most important biodiversity hotspots, jeopardized by habitat loss and fragmentation. The Pernambuco Endemism Center (PEC) is the most degraded of the Atlantic Forest regions and because of the dramatic levels of deforestation, fragmentation, and ongoing species losses, studies on the distribution and configuration of the PEC's forest cover are necessary. However, across dynamic tropical landscapes, investigating changes over time is essential because it may reveal trends in forest quality attributes. Here, we used Google Earth Engine to assess land use and land cover data from MapBiomas ranging from 1985 to 2020 to calculate current landscape metrics and to reveal for the first time the spatiotemporal dynamics of the PEC's forests. We identified a forest cover area that ranged from 571,661 ha in 1985 to 539,877 ha in 2020, and about 90% of the fragments were smaller than 10 ha. The average fragment size was about 11 ha, and only four fragments had more than 5,000 ha. Deforestation was mostly concentrated in northern Alagoas, southern Pernambuco, and non-coastal Paraíba and Rio Grande do Norte. On average, borders represented 53.6% of the forests from 1985 to 2020, and younger forests covered 52.3% of the area in 2017, revealing a vegetation rejuvenation process 2.5 times higher than in total Atlantic Forest. In 2017, older forest cores in fragments larger than 1000 ha (i.e., higher-quality habitats) represented only 12% of the remaining forests. We recommend that the amount of forest cover alone may poorly assist conservation managers, and our results indicate that ensuring legal protection and increasing surveillance of the PEC's few last higher-quality habitats is urgently needed.

Transformation of Brazil's biomes: The dynamics and fate of agriculture and pasture expansion into native vegetation

Land use and cover change (LUCC) in Brazil encompass a complex interplay of diverse factors across different biomes. Understanding these dynamics is crucial for informed decision-making and sustainable land management. In this study, we comprehensively analyzed LUCC patterns and drivers using 30 m resolution MapBiomas Collection 6.0 data (1985–2020). By mapping deforestation of primary and secondary natural vegetation, natural vegetation regeneration, and transitions between pasture, soybean, agriculture, and irrigation, we shed light on the intricate nature of LUCC in Brazil. Our findings highlight significant and increasing trends of deforestation in primary vegetation in the country. Simultaneously, the Atlantic Forest, Caatinga, Pampa, and other regions of the Cerrado have experienced intensification processes. Notably, the pasture area in Brazil reached its peak in 2006 and has since witnessed a gradual replacement by soybean and other crops. While pasture-driven deforestation persists in most biomes, the net pasture area has only increased in the Amazon and Pantanal, decreasing in other biomes due to the conversion of pasturelands to intensive cropping in other regions. Our analysis further reveals that primary and secondary vegetation deforestation accounts for a substantial portion of overall forest loss, with 72 % and 17 %, respectively. Of the cleared areas, 48 % were in pasture, 9 % in soybean cultivation, and 16 % in other agricultural uses in 2020. Additionally, we observed a lower rate of deforestation in the Atlantic Forest, a biome that has been significantly influenced by anthropogenic activities since 1986. This holistic quantification of LUCC dynamics provides a solid foundation for understanding the impacts of these changes on local to continental-scale land-atmosphere interactions. By unraveling the complex nature of LUCC in Brazil, this study aims to contribute to the development of effective strategies for sustainable land management and decision-making processes.

Study of co-occurrence of mycotoxins in cocoa beans in Brazil by liquid chromatography-tandem mass spectrometry (LC-MS/MS)

In this study, 135 samples of cocoa beans collected in the Amazon and Atlantic Forest regions of Brazil were analysed to evaluate the possible co-occurrence of 34 mycotoxins. The results indicate that 42% of the cocoa samples exhibited quantifiable levels for 11 mycotoxins: aflatoxins (AFs) B1, B2 and G1; ochratoxin A; citrinin; cyclopiazonic acid; tenuazonic acid; paxilline; sterigmatocystin; zearalenone and fumonisin B2. Of the samples, 18% exhibited the co-occurrence of up to six mycotoxins. No toxins belonging to the groups of trichothecenes or ergot alkaloids were detected. Contingency analysis of the incidence of mycotoxins did not show significant differences between the two regions evaluated. Seven samples were contaminated with AFs, while only one contained ochratoxin A above 10 μg kg−1. The accuracy of the method was evaluated by proficiency testing for ochratoxin A, where satisfactory Z-scores were obtained.

Evolution of passive restoration in abandoned banana plantations: an ecological and spatial analysis

The present paper analyzes the evolution of natural regeneration in two areas with abandoned banana groves, located in the Atlantic Forest region Vale do Ribeira - São Paulo. With 7ha each, the areas have abandoned banana plantations of different periods: 8 years (Area 1) and 4 years (Area 2). The regenerating individuals were inventoried and identified, the species classified according to the dispersion syndrome and the successional group, and the Shannon, Pielou and Simpson's Equalibility indexes were calculated. Geostatistics was applied to characterize the spatial behavior of the floristic attributes studied. In total, 4361 individuals were inventoried, belonging to 32 families and 81 species. The most abundant family was Fabaceae (20% of the total inventoried). In Area 1, 2455 regenerating individuals (4721 ind.ha-1) distributed in 81 species and 32 botanical families were registered. In Area 2, 1906 regenerating individuals (3592 ind. ha-1), 23 botanical families and 52 species. The Shannon H' index of Area 1 (H= 3.326 nat.ind-1) and Area 2 (H=2.72 nat.ind-1). The results show that natural regeneration is taking place in both areas, and that abandoned banana groves can, over time, become forests.

Environmental drivers of tropical forest snake phenology: Insights from citizen science.

Museum specimens and citizen science initiatives are valuable sources of information on how anthropogenic activities affect biodiversity and how species respond to rapid global change. Although tropical regions harbor most of the planet's biodiversity, investigations on species' phenological changes are heavily biased toward temperate regions. Such unevenness in phenological research is also taxonomically biased, with reptiles being the least studied group among tetrapod species regarding animal phenology. Herein, we used long-term time-series data to investigate environmentally driven changes in the activity pattern of tropical forest snakes. We gathered natural history collection and citizen science data for 25 snake species (five venomous and 20 non-venomous) from an Atlantic Forest region in southeastern Brazil. Using circular mixed-effects models, we investigate whether snake activity patterns followed the variation in environmental variables over a decade. Our results show that the activity pattern of Atlantic Forest snakes was seasonal and largely driven by average temperature and relative humidity. Since snakes are ectothermic animals, they are particularly sensitive to temperature variations, especially at small scales. Moreover, relative humidity can affect snake's seasonal activities through physiological constraints and/or prey availability. Most specimens were registered during the rainy season, with highly venomous snakes (lanceheads and coral snakes) emerging as the most abundant taxa. We highlight the importance of citizen science and natural history collections in better understanding biodiversity. Furthermore, our data obtained from local collectors underscore the need for environmental education programs and collaboration between researchers and local decision-makers to raise awareness and reduce conflicts between people and snakes in the region.