Helga Correa Wiederhecker

Amazonia is highly sensitive to climate extremes, yet we lack an Amazon-wide assessment that examines the spatial-temporal changes in these extreme conditions. We address this within seasons and across the hydrological year, using a quantiles approach that integrates the frequency and magnitude of climate extremes and by linking changes in temperature with evapotranspiration. We show that high temperature extremes and temperature-linked measures of water deficit are both changing at a much faster rate than central trends. The 95 ^th percentile of maximum temperatures in the driest period increased by 0.49 °C per decade (dec ^-1 ) compared to 0.21°C dec ^-1 for the central trend of mean temperatures for the year. Crucially, over 700,000 square kilometres in central-north Amazonia have experienced increases in extreme dry season temperatures ≥ 0.75 °C dec ^-1 ( ≥ 3.22 °C over 43 years). Adaptation measures for these rapid changes in climate extremes must include preventing the deforestation and disturbances that amplify risks.

Urbanisation is a powerful environmental force, negatively impacting the few organisms that persist in urban areas. Fluctuating asymmetry (FA), a recognised bioindicator of ontogenetic and environmental stress, may reflect such impacts, though its role in assessing urban intensification remains unclear. We investigated the relationship between urbanisation intensity and FA in birds, analysing 10 locally abundant species in Brasília city, Brazil. Our hypothesis posited that birds in more urbanised areas would exhibit higher FA. We measured bird tarsus and wing to assess asymmetry and also examined whether FA differed between traits. Neither wing nor tarsus FA increased with urban intensity. However, tarsus FA was consistently higher than wing FA. Notably, our FA values for both traits are comparable to or, in the case of tarsus, exceed those reported for birds in fragmented forests. These findings suggest that urbanisation (even at lower intensities) may impose stronger genetic and/or environmental stress on developmental stability than previously recognised.

The Amazon wetlands are the largest and most diverse freshwater ecosystem globally, characterized by various flooded vegetation and the Amazon River’s estuary. This critical ecosystem is vulnerable to land use changes, dam construction, mining, and climate change. While several studies have utilized remote sensing to map wetlands in this region, significant uncertainty remains, which limits the assessment of impacts and the conservation priorities for Amazon wetlands. This study aims to enhance wetland mapping by integrating existing maps, remote sensing data, expert knowledge, and cloud computing via Earth Engine. We developed a harmonized regional wetland classification system adaptable to individual countries, enabling us to train and build a random forest model to classify wetlands using a robust remote sensing dataset. In 2020, wetlands spanned 151.7 million hectares (Mha) or 22.0% of the study area, plus an additional 7.4 Mha in deforested zones. The four dominant wetland classes accounted for 98.5% of the total area: Forest Floodplain (89.0 Mha; 58.6%), Lowland Herbaceous Floodplain (29.6 Mha; 19.6%), Shrub Floodplain (16.7 Mha; 11.0%), and Open Water (14.1 Mha; 9.3%). The overall mapping accuracy was 82.2%. Of the total wetlands in 2020, 52.6% (i.e., 79.8 Mha) were protected in Indigenous Territories, Conservation Units, and Ramsar Sites. Threats to the mapped wetlands included 7.4 Mha of loss due to fires and deforestation, with an additional 800,000 ha lost from 2021 to 2024 due to agriculture, urban expansion, and gold mining. Notably, 21 Mha of wetlands were directly affected by both reduced precipitation and surface water in 2020. Our mapping efforts will help identify priorities for wetland protection and support informed decision-making by local governments and ancestral communities to implement conservation and management plans. As 47.4% of the mapped wetlands are unprotected and have some level of threats and pressure, there are also opportunities to expand protected areas and implement effective management and conservation practices.

Este estudo investiga a aplicação dos mosaicos mensais da Planet/NICFI para o mapeamento da superfície de água e demais áreas úmidas na Bacia Hidrográfica do Alto Paraguai (BAP) para o período de janeiro de 2021 a abril de 2024. O mapeamento foi realizado por meio de técnicas de classificação de imagens, baseada em aprendizado de máquina e processamento com computação em nuvem. O estudo demonstrou a capacidade dessas imagens em fornecer informações detalhadas sobre a superfície de água na BAP, especialmente na região de planalto, para a identificação de novos corpos d'água. Além disso, o mapeamento de superfície de água foi satisfatório para monitorar a variação mensal do pulso de inundação na planície. No entanto, o estudo identificou limitações espectrais do sensor Planet, resultando em menor sensibilidade para o mapeamento de áreas úmidas para além da superfície de água. Os resultados indicam que os mosaicos mensais da Planet/NICFI são uma ferramenta promissora para o monitoramento da superfície de água na BAP, especialmente como forma de adicionar detalhes em escala local quando comparados aos mapeamentos existentes com outras imagens orbitais. A análise temporal dos dados ainda revelou que 2023 foi o ano com maior volume de água no período estudado, enquanto os primeiros meses de 2024 indicam uma forte tendência de seca, mostrando o potencial do fluxo de processamento adotado como ferramenta para detecção precoce de tendências de seca e inundações.

This study investigates the application of Planet/NICFI mosaics for the monthly mapping of surface water and other wetlands in the Upper Paraguay River Basin (BAP) from January 2021 to April 2024. Mapping was made using image classification techniques, based on machine learning and cloud computing processing. The study demonstrated the potential of these images to provide detailed information on the water surface in the BAP, especially in the plateau region, for the identification of new water bodies. Furthermore, the surface water mapping was satisfactory to monitor the monthly variation of the flood pulse in the floodplain. However, the study identified spectral limitations of the Planet sensor, with lower sensitivity for mapping wetlands beyond the water surface. The results indicate that the Planet/NICFI monthly mosaics are a promising tool for monitoring the water surface in the BAP, especially to add detail at the local scale when compared to existing mappings with other orbital images. The temporal analysis of the data also revealed that 2023 was the year with the highest volume of water in the period studied, while the first months of 2024 indicate a strong drought trend, showing the potential of the adopted processing flow as a tool for early detection of drought and flood trends.

As ações humanas que levam à redução e à transformação de ambientes naturais são uma das principais causas da crescente perda global de biodiversidade. O aumento nas taxas de extinção de espécies e a redução das populações naturais são alguns indicadores dessa perda. No contexto brasileiro, o Programa Monitora do ICMBio é uma importante fonte de dados para o monitoramento da biodiversidade. Assim, uma parceria entre WWF e ICMBio foi feita em 2023 para buscar estratégias analíticas que impulsionassem a análise dos dados das espécies monitoradas. A partir dessa parceria, desenvolvemos o pacote distanceMonitoraflorestal, criado para aplicar os modelos de análise por distância para estimar densidades populacionais para espécies de aves e mamíferos monitoradas pelo módulo Florestal Global. Neste artigo, apresentamos as funcionalidades do pacote a partir dos dados da população de Sapajus apella (macaco-prego) monitorada na REBIO do Uatumã e comentamos detalhes do método de análise de dados de amostragem por distância.

The capybara is the largest living rodent, attracting attention due to its large size, its formation of large herds, and because it is commonly seen in urban environments. Thus, understanding the dynamics of capybara populations living in urban environments is relevant, especially given the conflicts observed between the species and humans in these environments. Here, we investigated the hypothesis of overpopulation of the capybara in Lago Paranoá, a lake in a large neotropical city, Brasília, Brazil. To do this, we investigated their spatial distribution at the site and estimated the capybara population using a variation of the mark‐recapture method and compared it to known population estimates for the species. We found that the capybaras in our study area mainly form small flocks of 1 to 9 animals and occupy almost the entire shore of Lake Paranoá. We estimated the occurrence of 0.30 to 0.52 ind./ha (average = 0.41 ind./ha), demonstrating that the number of capybaras in our region is small when compared to capybara counts in other regions (range 0.075–6.44 ind./ha). Furthermore, we found that although the capybara population fluctuates throughout the year, it appears to be stable, not supporting our initial hypothesis. Urban areas can provide habitat for some species, which may help offset negative effects of losses of unmanaged habitats; however, this raises the possibility of wildlife–human conflicts.

Understanding how the urbanization process affects the lives of animals that live in these environments is relevant to conservation and management. In fact, the urbanization process has a direct impact on animals and can influence their health state. Thus, our objective was to investigate the immunological response of birds to the urbanization process. We recorded the H/L ratio of 723 birds of 10 species captured in Brasília (a large city in central Brazil), as a measure of chronic stress in birds. The H/L ratio was positively associated with the intensity of urbanization and negatively associated with body condition. However, body condition was not associated with intensity of urbanization. We confirmed our hypothesis that birds living in areas with greater urban intensity are more stressed. In addition, we demonstrated that the H/L ratio is negatively associated with body condition, and that this variable should be considered in studies that aim to assess the health of animals. These findings are relevant because they confirm that the urbanization process, along with all its environmental changes (increased artificial light, increased noise, suppression of vegetation, increased built-up areas, etc.), has a negative direct impact on wild populations, which have to deal with major urban changes.

The objective of this work was to estimate the population density of five Brazilian Cerrado species and to evaluate their productive potential under two scenarios, one with vegetation conservation and the other with deforestation. The studied species were: Annona crassiflora, Caryocar brasiliense, Eugenia dysenterica, Hancornia speciosa, and Tachigali subvelutina. For this, nine species distribution models were used, each one encompassing 23 bioclimatic and geomorphological environmental variables. Population density was quantified and spatialized with exponential regression models using forest inventory data. The models indicated a moderate to strong proportional relationship between habitat suitability and population density, with a root mean square error ranging from 35.8 to 55.7%. Estimated productivity varied from 1,325 to 254,844 Mg per year, with E. dysenterica showing the highest productive potential. The modeling of species distribution allows for the estimation of population density and productive potential. Its accuracy depends on the used species, environment, and scale of data. Climate pressures and Cerrado degradation intensify the challenges faced by local communities, highlighting the urgency of conservation strategies, sustainable management, and climate adaptation to strengthen sociobioeconomy.