Search Results (124)

Forest plantations represent an alternative to reduce timber extraction pressure in the Amazonian forests. In order to tolerate the hostile field conditions of deforested areas, high-quality seedlings are required. This study aimed to find the optimal dose of a native microbial consortium (NMC), which enhances seedling quality indicators, in three forest species at nursery phase. A completely randomized design (3 × 5) was used. Factor 1: Bolaina blanca (Guazuma crinita Mart.), Capirona (Calycophyllum spruceanum Benth. Hook. f.), and Marupa (Simarouba amara Aubl.). Factor 2: Incremental doses of 0, 160, 320, 480, and 640 mL NMC per plant. The nursery survival (%), robustness index, root height/length ratio, shoot–root index, Dickson Quality Index (DQI), Nitrogen (%), Phosphorus (%), and Potassium (%) content in tissues were analyzed. Statistical analyses consisted of two-way ANOVA per variable and correlation analysis. The results indicated that increasing doses of NMC did not improve nursery survival for any species; did not decrease the robustness index, plant height/root length ratio, or the shoot–root index for any species; and did not increase the DQI, P%, or K% for any species; however, they did increase the N% for all species. In conclusion, the incremental dose of 160 mL was chosen for increasing the N% without affecting nursery survival. Full article

Anthropized areas in the Brazilian Amazon require detailed mapping to identify zones for sustainable use. This study developed a topoclimatic zoning framework to evaluate the conservation and agroforestry potential of three native species: Carapa guianensis (Andiroba), Dipteryx odorata (Cumaru), and Bertholletia excelsa (Amazon Nut). The hypothesis was that integrating topographic and climatic data can effectively identify high-potential areas for these species to support forest restoration and sustainable management. This study applied ecological modeling and Geographic Information System (GIS) tools to classify zones into high, medium, and low potential for each species. Results showed Carapa guianensis has high potential in 64% of anthropized areas, Dipteryx odorata in 72% of the Legal Amazon, and Bertholletia excelsa in 58%, highlighting their adaptability and strategic value for restoration efforts. The findings emphasize the importance of topoclimatic zoning as a tool for conservation and sustainable use strategies. By aligning with Brazil’s Payment for Environmental Services (PES) Law, this approach can foster agroforestry practices, enhance biodiversity conservation, and strengthen the Amazon bioeconomy, ensuring ecological resilience and sustainable development. Full article

Conservation strategies that use sustainable use of natural resources through green-labelled markets generally do not recognize the legal sale of wild meat as appropriate due to potential overexploitation and zoonotic disease risks. Wildlife hunting is important to the livelihoods of rural communities living in tropical forests for protein and income. Wildlife management plans in the Peruvian Amazon permit hunting of wild meat species for subsistence and sale at sustainable levels, that include peccaries, deer, and large rodents. These species have fast reproduction making them less vulnerable to overhunting than other species. This study assessed the sustainability of a wildlife management plan. Populations of species were estimated using camera traps and distance transect surveys, and sustainability analysis used hunting pressure from community hunting registers. Interviews were conducted to understand hunters, perceptions of the management plan. Long-term time-series showed increases in collared peccary (3.0 individual/km² to 5.41 individual/km²) and white-lipped peccary (3.50 individual/km² to 7.00 individual/km²) populations and short-term time series showed a decline in paca populations from 8.5 individual/km² to 3.01 individual/km². The unified harvest analysis showed permitted species populations were greater than 60% of their carrying capacities and hunted at less than 40% of their production, which shows sustainable hunting. The wildlife management plan achieved its general objective of sustainable hunting and improving livelihoods. The broader question is whether sustainable wildlife use plans that allow Amazonian communities to sell limited amounts of wild meat can be a way to change illegal wild meat trade to a legal, green labelled trade with added value. Full article

Based on statistical analyses applied to official data from the Digital Atlas of Disasters in Brazil over the last 25 years, we evidenced a consistent intensification in the annual occurrence of natural disasters in the state of Pará, located in the eastern Brazilian Amazon. The quantitative comparison between the averages of the most intense period of disasters (2017 to 2023) and the earlier years (1999 to 2016) revealed a remarkable percentage increase of 473%. Approximately 81% of the state’s municipalities were affected, as indicated by disaster mapping. A clear seasonal pattern was observed, with Hydrological disasters (Inundations, Flash floods, and Heavy rainfall) peaking between February and May, while Climatological disasters (Droughts and Forest fires) were most frequent from August to October. The catastrophic impacts on people and the economy were documented, showing a significant rise in the number of homeless individuals and those directly affected, alongside considerable material damage and economic losses for both the public and private sectors. Furthermore, we conducted a comprehensive composite analysis on the tropical ocean–atmosphere dynamic structure that elucidated the various triggering mechanisms of disasters arising from Inundations, Droughts, and Forest fires (on seasonal scale), and Flash floods and Heavy rainfall (on sub-monthly scale) in Pará. The detailed characterization of disasters on a municipal scale is relevant in terms of the scientific contribution applied to the strategic decision-making, planning, and implementation of public policies aimed at early risk management (rather than post-disaster response), which is critical for safeguarding human well-being and strengthening the resilience of Amazonian communities vulnerable to climate change. Full article

Amid increasing deforestation, surface fires reaching the forest understory are one of the primary threats to Amazonian ecosystems. Despite extensive research on post-fire mortality in woody species, the literature on palm resilience to fire is scant. This study investigates post-fire mortality in four understory palms, namely Bactris maraja Mart., Chamaedorea pauciflora Mart., Geonoma deversa (Poit.) Kunth, Hyospathe elegans Mart., and juvenile individuals of Euterpe precatoria Mart. (açaí palm). The objectives included (a) comparing post-fire responses; (b) developing mortality models based on severity variables; and (c) evaluating if diameter protects bud stems from heat flux. Conducted at the edge of an Ombrophylous Forest in Alto Juruá Acre, Brazil (7°45′ S, 72°22′ W), the experiment subjected 85 individuals to controlled burning in a 1 m² area near the palm stem, with temperature sampling using K thermocouples. The results showed varying mortality rates among species, with a larger palm stem diameter correlating to reduced mortality. Crown burning patterns significantly influenced mortality, especially for Euterpe precatoria. The species exhibited diverse regrowth capacities, with B. maraja showing the highest number and tallest basal resprouts. The variation in morphology among species appeared to be more important than the amount of heat flux applied to each individual involved in the experiment, as no significant difference was observed in the time–temperature history measured. This study underscores post-fire plant mortality as a critical indicator of fire severity, essential for understanding its ecological impacts. Full article

Wildfire represents a significant threat to ecosystems and communities in the Department of Amazonas, Peru, causing losses in biodiversity and land degradation and affecting socioeconomic security. The objective of this study was to analyze the spatial and temporal distribution of burned areas (BAs) from 1986 to 2023 to identify recurrence patterns and their impact on different types of land use and land cover (LULC). Landsat 5, 7, and 8 satellite images, processed by Google Earth Engine (GEE) using a decision tree approach, were used to map and quantify the affected areas. The results showed that the BAs were mainly concentrated in the provinces of Utcubamba, Luya, and Rodríguez de Mendoza, with a total of 1208.85 km² burned in 38 years. The most affected land covers were pasture/grassland (38.25%), natural cover (forest, dry forest, and shrubland) (29.55%) and agricultural areas (14.74%). Fires were most frequent between June and November, with the highest peaks in September and August. This study provides crucial evidence for the implementation of sustainable management strategies, fire prevention, and restoration of degraded areas, contributing to the protection and resilience of Amazonian ecosystems against future wildfire threats. Full article

With few measurement sites and a great need to validate satellite data to characterize the exchange of energy and carbon fluxes in tropical forest areas, quantified by the Net Ecosystem Exchange (NEE) and associated with phenological measurements, there is an increasing need for studies aimed at characterizing the Amazonian environment in its biosphere–atmosphere interaction, considering the accelerated deforestation in recent years. Using data from a flux measurement tower in the Caxiuanã-PA forest (2005–2008), climatic data, CO₂ exchange estimated by eddy covariance, as well as Gross Primary Productivity (GPP) data and satellite vegetation indices (from MODIS), this work aimed to describe the site’s energy, climatic and carbon cycle flux patterns, correlating its gross primary productivity with satellite vegetation indices. The results found were: (1) marked seasonality of climatic variables and energy flows, with evapotranspiration and air temperature on the site following the annual march of solar radiation and precipitation; (2) energy fluxes in phase and dependent on available energy; (3) the site as a carbon sink (−569.7 ± 444.9 gC m⁻² year⁻¹), with intensity varying according to the site’s annual water availability; (4) low correlation between productivity data and vegetation indices, corroborating data in the literature on these variables in this type of ecosystem. The results show the importance of preserving this type of environment for the mitigation of global warming and the need to improve satellite estimates for this region. NDVI and EVI patterns follow radiative availability, as does LAI, but without direct capture related to GPP data, which correlates better with satellite data only in the months with the highest LAI. The results show the significant difference at a point measurement to a satellite interpolation, presenting how important preserving any type of environment is, even related to its size, for the global climate balance, and also the need to improve satellite estimates for smaller areas. Full article

The starting point of this proposal is a collection of decorated cuias, preserved in Portugal and produced by Indigenous women in Grão-Pará in the 18th century. The objects in question are an exemplary case of the global art history of the Amazonian communities. In order to investigate them, it is necessary to consider the procurement and ritual use of cuias (fruits of the cuieira tree-Crescentia cuyete), the sophisticated techniques used to produce a durable, glossy, black varnish from cumatê (or cumaté, cumati), a natural dark red pigment extracted from the skins of the cumatezeiro or axuazeiro tree (Myrcia atramentifera), as well as the incorporation of fauna and flora motifs from Asian or Asian-inspired textiles and embroidery, which circulated worldwide. Their history brings together the nature of the forest, the myths of creation, and the knowledge and practices of Indigenous and riverine women, mainly from the lower Amazon. Studying these objects produced by Indigenous female painters in a colonial context of appropriation, in addition to contributing to their knowledge, can stimulate dialogues on the knowledge of the Brazilian Amazon rainforest with other locations in America, sharing their ancestry and resistance. Full article

Here, we examine the effects of wildfires on the soil seed bank of a terra firme forest in the eastern Amazon. This seed bank is described via community-level attributes across forest stands exposed to wildfires once or twice, as well as across unburned, old-growth forest stands. A total of 2345 seeds germinated (837.5 seeds/m²). Across all three forest habitats, the soil seed bank was dominated by a small set of light-demanding species, with two to three species accounting for over 80% of all seeds. On the other hand, the seed bank of all habitats completely lacked seeds from the old-growth flora. Wildfires posed no effects relative to seed density and species richness. However, fire (1) reduced beta diversity, (2) caused an 8% increase in herb abundance and a 4% increase in the number of seeds produced by short-lived pioneers, and (3) resulted in a slight impact on taxonomic species composition. Our results suggest that the soil seed bank, while exhibiting high seed densities, is naturally species poor and, thus, relatively resistant to the first fire events. This implies that the recovery of fire-degraded forests will rely on vertebrate-dispersed seeds coming from any remaining well-preserved old-growth forest stands that are present in the landscape and are highly vulnerable to fire. Full article

The Ecuadorian Amazon holds more biodiversity than most other places on Earth. Palms are a particularly dominant component of the vegetation; however, it remains unknown to what degree the pattern has persisted through time. Here, we investigate the persistence of palm dominance through time and the degree to which past human activities (e.g., fire, cultivation, and forest opening) have affected changes in palm abundances across five regions of the Ecuadorian Amazon. We analyzed soil cores (40–80 cm depth) from each region for charcoal (evidence of past fire) and phytoliths (evidence of past vegetation change). The timings of fires (based on ¹⁴C radiocarbon dates), the occurrence, recurrence, and number of fires (based on charcoal presence and abundance in samples), and the amount of change in palm abundances (based on phytoliths) varied within and between the studied regions. The charcoal and phytolith results indicate the presence of low levels of past human activity at all sites. Our results show that patterns of modern palm hyperdominance found in Amazonian forests have not been persistent through time, and that even low levels of past human activities can affect palm abundance. Full article

Full-waveform LiDAR (FWF) offers a promising advantage over other technologies to represent the vertical canopy structure of secondary successions in the Amazon region, as the waveform encapsulates the properties of all elements intercepting the emitted beam. In this study, we investigated modifications in the vertical structure of the Amazonian secondary successions across the vegetation gradient from early to advanced stages of vegetation regrowth. The analysis was performed over two distinct climatic regions (Drier and Wetter), designated using the Maximum Cumulative Water Deficit (MCWD). The study area was covered by 309 sample plots distributed along 25 LiDAR transects. The plots were grouped into three successional stages (early—SS1; intermediate—SS2; advanced—SS3). Mature Forest (MF) was used as a reference of comparison. A total of 14 FWF LiDAR metrics from four categories of analysis (Height, Peaks, Understory and Gaussian Decomposition) were extracted using the Waveform LiDAR for Forestry eXtraction (WoLFeX) software (v1.1.1). In addition to examining the variation in these metrics across different successional stages, we calculated their Relative Recovery (RR) with vegetation regrowth, and evaluated their ability to discriminate successional stages using Random Forest (RF). The results showed significant differences in FWF metrics across the successional stages, and within and between sample plots and regions. The Drier region generally exhibited more pronounced differences between successional stages and lower FWF metric values compared to the Wetter region, mainly in the category of height, peaks, and Gaussian decomposition. Furthermore, the Drier region displayed a lower relative recovery of metrics in the early years of succession, compared to the areas of MF, eventually reaching rates akin to those of the Wetter region as succession progressed. Canopy height metrics such as Waveform distance (WD), and Gaussian Decomposition metrics such as Bottom of canopy (BC), Bottom of canopy distance (BCD) and Canopy distance (CD), related to the height of the lower forest stratum, were the most important attributes in discriminating successional stages in both analyzed regions. However, the Drier region exhibited superior discrimination between successional stages, achieving a weighted F1-score of 0.80 compared to 0.73 in the Wetter region. When comparing the metrics from SS in different stages to MF, our findings underscore that secondary forests achieve substantial relative recovery of FWF metrics within the initial 10 years after land abandonment. Regions with potentially slower relative recovery (e.g., Drier regions) may require longer-term planning to ensure success in providing full potential ecosystem services in the Amazon. Full article

This paper offers paradigmatic insights from an international workshop on Ecological Legacies: Bridge Between Science and Community, in Ecuador, in the summer of 2023. The conference brought together foreign and local scholars, tour operators, village community, and Indigenous leaders in the upper Amazonia region of Ecuador with the goal of developing a vision for a sustainable and regenerative future of the upper Amazon. The conference offered three epistemological contributions to the existing literature in the emergent field of Montology, including addressing issues of (a) understanding the existing linguistic hegemony in describing tropical environments, (b) the redress of mistaken notions on pristine jungle environments, and (c) the inclusion of traditional knowledge and transdisciplinary approaches to understand the junglescape from different perspectives and scientific traditions. Methodologically, the conference bridged the fields of palaeoecological and ethnobotanical knowledge (as part of a wider conversation between science and local communities). Results show that local knowledge should be incorporated into the study of the junglescape and its conservation, with decolonial approaches for tourism, sharing language, methodology, tradition, and dissemination of the forest’s attributes. Our research helped co-create and formulate the “Coca Declaration” calling for a philosophical turn in research, bridging science and ethnotourism in ways that are local, emancipatory, and transdisciplinary. We conclude that facilitating new vocabulary by decolonial heightening of Indigenous perspectives of the junglescape helps to incorporate the notion of different Amazons, including the mountainscape of the Andean–Amazonian flanks. We also conclude that we can no consider Ecuador the country of “pure nature” since we helped demystify pristine nature for foreign tourists and highlighted local views with ancestral practices. Finally, we conclude that ethnotourism is a viable alternative to manage heritagization of the junglescape as a hybrid territory with the ecological legacies of the past and present inhabitants of upper Amazonia. Full article

The characteristics of South American biomass burning (BB) aerosols transported over northern and central Argentina were investigated from July to December 2019. This period was chosen due to the high aerosol optical depth values found in the region and because simultaneously intensive biomass burning took place over the Amazon. More specifically, a combination of remote sensing observations with simulated air parcel back trajectories was used to link the optical and physical properties of three BB aerosol events that affected Pilar Observatory (PO, Argentina, 31°41′S, 63°53′W, 338 m above sea level), with low-level atmospheric circulation patterns and with types of vegetation burned in specific fire regions. The lidar observations at the PO site were used for the first time to characterize the vertical extent and structure of BB aerosol plumes as well as their connection with the planetary boundary layer, and dust particles. Based mainly on the air-parcel trajectories, a local transport regime and a long transport regime were identified. We found that in all the BB aerosol event cases studied in this paper, light-absorbing fine-mode aerosols were detected, resulting mainly from a mixture of aging smoke and dust particles. In the remote transport regime, the main sources of the BB aerosols reaching PO were associated with Amazonian rainforest wildfires. These aerosols were transported into northern and central Argentina within a strong low-level jet circulation. During the local transport regime, the BB aerosols were linked with closer fires related to tropical forests, cropland, grassland, and scrub/shrubland vegetation types in southeastern South America. Moreover, aerosols carried by the remote transport regime were associated with a high aerosol loading and enhanced aging and relatively smaller particle sizes, while aerosols associated with the local transport pattern were consistently less affected by the aging effect and showed larger sizes and low aerosol loading. Full article

French Guiana, located in the Guiana Shield, is a natural reservoir for many zoonotic pathogens that are of considerable medical or veterinary importance. Until now, there has been limited data available on the description of parasites circulating in this area, especially on protozoan belonging to the phylum Apicomplexa; conversely, the neighbouring countries describe a high parasitic prevalence in animals and humans. Epidemiological surveillance is necessary, as new potentially virulent strains may emerge from these forest ecosystems, such as Amazonian toxoplasmosis. However, there is no standard tool for detecting protozoa in wildlife. In this study, we developed Meat-Borne-Parasite, a high-throughput meta-barcoding workflow for detecting Apicomplexa based on the Oxford Nanopore Technologies sequencing platform using the 18S gene of 14 Apicomplexa positive samples collected in French Guiana. Sequencing reads were then analysed with MetONTIIME pipeline. Thanks to a scoring rule, we were able to classify 10 samples out of 14 as Apicomplexa positive and reveal the presence of co-carriages. The same samples were also sequenced with the Illumina platform for validation purposes. For samples identified as Apicomplexa positive by both platforms, a strong positive correlation at up to the genus level was reported. Overall, the presented workflow represents a reliable method for Apicomplexa detection, which may pave the way for more comprehensive biomonitoring of zoonotic pathogens. Full article

The processes of occupation and exploitation in the Amazon have been increasing, and as a consequence, forest areas are being replaced by agroecosystems. As a consequence of this change, changes have been occurring in the soil attributes, and consequently, in the stability of aggregates in these environments. Thus, this work had two objectives: the first was to evaluate the impacts generated by the conversion of forests into agroecosystems on the soil attributes that are related to aggregates, in the southwestern region of the Amazon; the second objective was to evaluate the roles of pedophysical and pedochemical parameters on the stability of soil aggregates. The study was carried out on rural properties located in the southern part of Amazonas State, Brazil. Eight areas under different agroecosystems were selected: in the municipality of Canutama: (i) annatto, (ii) guarana, and (iii) cupuassu; in the municipality of Humaitá: (iv) cassava, (v) agroforestry, and (vi) sugarcane; and in the municipality of Manicoré: (vii) pasture and (viii) native forest. Unformed soil samples were collected from the 0.00–0.10 m layer and analyzed for aggregate stability, bulk density, soil organic carbon, and soil organic carbon stock. Univariate, bivariate, and multivariate analyses were performed. The largest soil aggregations occurred in the annatto, guarana, sugarcane, and pasture agroecosystems. We associate the greater aggregation capacity of soils with factors that are inherent to the cultivated species and soil properties. The first factor corresponds to the adaptability of the Amazonian and grass species and their ability to produce biomass. The second factor is related to the physical and chemical properties of Amazonian soils, largely influenced by the sand fraction, soil organic carbon, soil acidity, and availability of exchangeable Ca and Mg. Full article