Leandro de Oliveira Salles

The palm swamp landscapes, particularly the Vereda wetlands and their associated swamp gallery forests (VED.SGF), comprise essential yet threatened ecosystems within the Brazilian Cerrado. In addition to supporting significant portions of biodiversity, they provide critical ecosystem services such as storing and filtering excess rainwater and serving as major carbon reservoirs in organic soils. These wetlands are directly linked to the drainage systems of the headwaters of the main Cerrado river basins, which together account for about two-thirds of Brazil’s hydrographic basins. Mapping and managing VED.SGF ecosystems through remote sensing present major challenges addressed in this first study. Their narrow, dendritic, and complex tabular spatial pattern, often elongated along watersheds on scales of hundreds of kilometers, suffering distortions due to human impact, and the limited amount of annotated data make segmentation particularly challenging. Existing deep learning (DL) methods, typically pre-trained on natural images, struggle to capture the spectral and spatial intricacies of these ecosystems. This study introduces a trained-from-scratch U-Net model supported by field-based experimental procedures to ensure high-quality wetland annotations. The resulting dataset covers approximately 7300 km² in western Bahia and provides domain-specific weights tailored to remote sensing applications. Using high-resolution (4.6 m) RGB mosaics, the model was trained, validated, and tested to establish a reproducible and scalable pipeline. The proposed method achieved robust results in an independent test area of 8040 km², with a mean IoU of 0.728, F1-score of 0.843, and Cohen’s Kappa of 0.837. These results demonstrate consistent performance and strong generalization to new areas, establishing a scientifically reliable baseline that situates the model competitively within the current state of the art. By releasing both the model weights and annotated dataset, this study provides valuable resources to advance future research on mapping and monitoring these unique and strategic wetland ecosystems.

The concept of biodiversity combines the two fundamental dynamics of life on Earth–the flow of energy and the flow of genes across space and time, which are linked, respectively, to four billion ye...

This is a posthumous tribute to the late pteridologist Paulo Günter Windisch from fellow researchers.

Over the lifetime of an animal, metabolic processes in the body maintain bone tissues in a dynamic state of equilibrium. After the death of the organism, bone tissues undergo diagenesis, an intense transformation that affects its physicochemical constitution. Although many recent works have greatly contributed to the understanding of the processes surrounding diagenesis, there is still much yet to be understood about this multifaceted phenomena. In this work, XRF and microCT were used to characterize the specimen elemental configuration and investigate the fossilization process of a recovered Puma concolor (cranium, mandible and teeth elements), found submerged in a lake in the Impossível‐Ioiô Cave System (Bahia, Brazil). MicroCT enabled the identification of the density distribution throughout the specimens, which were used as reference to XRF analyses. The XRF spectra of the analyzed specimen showed the presence of 11 elements: P, Cl, Ca, Mn, Fe, Cu, Zn, Br, Sr, Y and Hg. Yttrium counts proved to be regular throughout the specimen surface and decreased in the interface between bone surface and interior, evidencing their correspondence to sample environmental exposure. Furthermore, a correlation between fossil surface coloration, element configuration and density is presented. The relatively low presence of Fe and Y in the enamel elicits its elementary and structural preservation. The combined results contribute to the understanding of the physicochemical process of paleomastozoological fossilization, further enriching the comprehension of the process of fossilization in a submerged environment.

Rodents of the genus Akodon comprise 41 extant species, and are considered the most diverse genus of the tribe Akodontini. The most recently described extant species is Akodon kadiweu, known exclusively from Serra da Bodoquena, a karstic region located in Mato Grosso do Sul state, Brazil. Some sub -fossil and fossil specimens of Akodon have been reported in recent years for Brazil, but most remain unidentified at the species level. Here we examine the identity of Quaternary specimens of Akodon sp. from the limestone cave Nossa Senhora Aparecida, located in Serra da Bodoquena. Quantitative characters allowed the distinction of Akodon sp. specimens from smaller and larger congeners, and skull qualitative characters of nasal, interorbital region, supraorbital margins, zygomatic notches, zygomatic plate, incisive foramina, mesopterygoid fossa, mandible and molars allowed to identify these individuals as A. kadiweu. Our results revealed the first known past representatives of Akodon to be recorded in Mato Grosso do Sul, as well as western Brazil.

The Brazilian Cerrado is a global biodiversity hotspot with notoriously high rates of native vegetation suppression and wildfires over the past three decades. As a result, climate change can already be detected at both local and regional scales. In this study, we used three different approaches based on independent datasets to investigate possible changes in the daytime and nighttime temperature and air humidity between the peak of the dry season and the beginning of the rainy season in the Brazilian Cerrado. Additionally, we evaluated the tendency of dew point depression, considering it as a proxy to assess impacts on biodiversity. Monthly increases of 2.2−4.0℃ in the maximum temperatures and 2.4−2.8℃ in the minimum temperatures between 1961 and 2019 were recorded, supported by all analyzed datasets which included direct observations, remote sensing, and modeling data. The warming raised the vapor pressure deficit, and although we recorded an upward trend in absolute humidity, relative humidity has reduced by ~15%. If these tendencies are maintained, gradual air warming will make nightly cooling insufficient to reach the dew point in the early hours of the night. Therefore, it will progressively reduce both the amount and duration of nocturnal dewfall, which is the main source of water for numerous plants and animal species of the Brazilian Cerrado during the dry season. Through several examples, we hypothesize that these climate changes can have a high impact on biodiversity and potentially cause ecosystems to collapse. We emphasize that the effects of temperature and humidity on Cerrado ecosystems cannot be neglected and should be further explored from a land use perspective.