Search Results (31)

Euterpe oleracea Martius is the main palm tree species that contributes to the Amazonian economy and its pulp is a widely sought-after product in the market due to its nutritional and health benefits. However, high market demand has stimulated changes in land use practices of native stands, including management models that increase fruit productivity. Thus, we aimed to evaluate the socioeconomic aspects involved in the extractivism/local management practices of this species in a community in the Brazilian Amazon. We interviewed 10 families from the 15 ones that participate in the productive chain of this species in the community, with questions related to the socioeconomic aspects, management practices, and commercialization of E. oleracea. Its fruit collection in the community is an important activity that provides family income, with the majority of production being for pulp. Family labor is of fundamental importance for the maintenance of production and is presented in all steps of the production chain. The main advantage in Santa Luzia is its location near the main consumer markets, so community members should take advantage of this more effectively and stimulate the strengthening of the community’s local processing unit, mainly for the commercialization of the pulp, which constitutes the greatest contribution. Full article

Ocotea quixos (Lam.) Kosterm, known as Ishpingo, is a tree endemic to the Amazonian rainforests of Colombia, Ecuador, and Peru. In Ecuador, the Ishpingo tree faces significant threats due to overexploitation for its valuable spices and essential oils, as well as extensive deforestation and land-use changes. Understanding and preserving the genetic diversity of Ishpingo is vital for ensuring the species’ survival and continued contribution to the ecological and cultural richness of the Amazonian rainforest. Nevertheless, we currently lack comprehensive genetic diversity data. Within this scenario, we developed nuclear microsatellites to analyze the genetic diversity in ten known Ecuadorian populations of Ishpingo. Results show low levels of genetic diversity, especially when compared with other Ocotea trees. The mean number of alleles ranged from 2.20 to 4.47, the observed heterozygosity from 0.33 to 0.62, while the expected heterozygosity (He) was notably higher, ranging from 0.61 to 0.79. The inbreeding coefficient (Fis) was consistently positive, with some values close to zero. Despite these results, some populations such as the northern populations of Ishpingo still harbor moderate levels of genetic diversity, key for the preservation of this species. Full article

Two Amazonian species of açaí palm trees (Euterpe oleracea and Euterpe precatoria) are exploited in the commercial production of açaí pulp or juice. While E. oleracea benefits from developed cultivation technologies, E. precatoria lacks such advancements. Studies on the morphology and development of açaí palms under cultivation conditions can contribute to increasing the productivity of the species. The aim of this study was to carry out morphological characterization, assess growth and development in the juvenile phase of the plants, and obtain allometric models for E. precatoria and E. oleracea. Evaluations were conducted between 44 and 48 months post-planting. Allometric equations were formulated to accurately estimate leaf area. The results showed that E. oleracea begins reproduction earlier and exhibits greater growth in stem dimensions and leaf areas compared to E. precatoria, indicating that E. precatoria can be cultivated at higher planting densities. Allometric models, based on leaf length and width, effectively predicted individual leaf areas for both species, demonstrating their utility in optimizing cultivation strategies. Full article

The presence of green areas in urbanized cities is crucial to reduce the negative impacts of urbanization. However, these areas can influence the signal quality of IoT devices that use wireless communication, such as LoRa technology. Vegetation attenuates electromagnetic waves, interfering with the data transmission between IoT devices, resulting in the need for signal propagation modeling, which considers the effect of vegetation on its propagation. In this context, this research was conducted at the Federal University of Pará, using measurements in a wooded environment composed of the Pau-Mulato species, typical of the Amazon. Two machine learning-based propagation models, GRNN and MLPNN, were developed to consider the effect of Amazonian trees on propagation, analyzing different factors, such as the transmitter’s height relative to the trunk, the beginning of foliage, and the middle of the tree canopy, as well as the LoRa spreading factor (SF) 12, and the co-polarization of the transmitter and receiver antennas. The proposed models demonstrated higher accuracy, achieving values of root mean square error (RMSE) of $3.86$ dB and standard deviation (SD) of $3.8614$ dB, respectively, compared to existing empirical models like CI, FI, Early ITU-R, COST235, Weissberger, and FITU-R. The significance of this study lies in its potential to boost wireless communications in wooded environments. Furthermore, this research contributes to enhancing more efficient and robust LoRa networks for applications in agriculture, environmental monitoring, and smart urban infrastructure. Full article

This study analyzes tree diversity and its ecological importance value in silvopastoral systems in the Sumaco Biosphere Reserve (SBR), Ecuador, along an altitudinal gradient of 400–2000 masl. Twenty-six plots distributed into low (400–700 masl), medium (701–1600 masl) and high (1601–2000 masl) zones were used. The Shannon index and the importance value index (IVI), based on abundance, dominance and relative frequency, were estimated. The results highlight that in pastures with dispersed trees, the richness of trees decreases with increasing altitude in the elevational gradient; they also show a higher tree density at lower altitudes in contrast to the Andean–Amazonian primary forests. The lower and middle zones showed higher diversity, linked to regeneration and the presence of nearby forests. Species of high commercial value, such as Cedrela odorata and Jacaranda copaia, were common, reflecting knowledge of the local timber market. In the lower and middle zones, the 10 most important species accounted for more than 70% of the trees, with up to 96% in the upper zone. A total of 51 taxa (including 42 species and nine taxa at the rank of genus) were identified, which were mostly native; 64.7% are classified by the IUCN as least-concern (LC) species, 31.4% as not evaluated (NE) species and 3.9% as vulnerable (VU) species, specifically highlighting Cedrela odorata and Cedrela montana. The study concludes with policy recommendations related to the importance of trees in silvopastoral systems for the conservation of species and the livelihoods of local communities, highlighting the need for responsible management of Amazonian pasturelands. Full article

The Amazonian native tree species Parkia multijuga has potential silvicultural characteristics that can be utilized to productive plantations. Understanding its mating system is necessary to delineate the methods for the breeding of the species, the collection of seeds for conservation, and the use of seedlings for production plantations. The aim of this study is to evaluate the mating system and population genetic diversity of P. multijuga, using molecular markers. The DNA of 221 plants was extracted and genotyped with nine microsatellite loci using capillary electrophoresis in an automated DNA sequencer. The estimates for single and multilocus crossing rates were 0.998 and 1.0, respectively. The paternity correlation was low (${\widehat{r}}_{p\left(m\right)}$ = 0.307). The fixation index (f) showed values below zero, indicating an excess of heterozygotes. The cluster number K = 2 shows a better grouping among families for genetic structure. P. multijuga families consist mainly of half-sibs, and the reproductive strategy of the species is allogamy. Full article

The Amazonian rainforest is a hyper-diverse ecosystem in the number of species and the myriad of intertaxon relationships that are mostly understudied. In order to characterize a dominant and economically important Amazonian species, the Brazil nut tree (Bertholletia excelsa Bonpl.), at the genome level, wegenerated high-coverage long-read sequencing data from the leaves of a single individual. The genome assembly revealed an unexpected discovery: two circular contigs that could be assigned to the chromosome and a plasmid of a Pantoea stewartii strain. Comparative genomics revealed that this strain belongs to the indologenes subspecies and displays high synteny with other strains isolated from diseased leaves of the neotropical palm Bactris gasipaes Kunth. Investigation of pathogenicity-related genes revealed the absence of the entire type III secretion system gene cluster in the plasmid, which was otherwise highly similar to a plasmid from an isolate known to cause disease in Dracaena sanderiana Mast. In contrast, several genes associated with plant-growth promoting traits were detected, including genes involved in indole-3-acetic acid (IAA) production, phosphate solubilization, and biosynthesis of siderophores. In summary, we report the genome of an uncultivated P. stewartii subsp. indologenes strain associated with the Brazil nut tree and potentially a plant growth-promoting bacteria. Full article

Amazonian biodiversity has been used for generations by human populations, especially by Indigenous peoples and traditional communities in their cultural, social and economic practices. However, forest degradation, driven by forest fires, has threatened the maintenance of these resources. This study examined the effects of recent forest fires on species with timber, non-timber and multiple-use potential in Brazil’s state of Acre. Forest inventories in five forest types were analyzed, identifying species with timber, non-timber and multiple-use potential based on a review of existing scientific articles, books and studies in the technical literature. The indicators of the effect of forest fires on species density were based on the mean and standard deviation of tree density and absolute abundance. We found that 25% of the tree individuals have potential for use by humans, 12.6% for timber, 10.7% non-timber and 1.4% have multiple-use potential. With the negative impact of fire, the reduction in timber, non-timber and multiple-use potential can range from 2 to 100%, depending on the vegetation type and especially on the recurrence of fire. However, even in forests that are degraded by fire, species that are useful to humans can be maintained to a certain degree and contribute to other environmental services, thus they must be preserved. Full article

Astrocaryum aculeatum, a palm tree incipiently domesticated from upland ecosystems in the Brazilian Amazon, is especially adapted to anthropized areas. The pulp of the fruit, obtained by extractivism, is consumed fresh by the Amazonian population. The objective of the study is to evaluate the diversity and genetic structure of the natural populations of A. aculeatum, exploited by extractive farmers in Amazonas, Brazil, seeking to suggest conservation and management strategies for this species. A total of 218 plants were sampled in 15 populations in 14 municipalities in the state of Amazonas, evaluated by 12 microsatellite loci. A total of 101 alleles were observed. The means of the observed heterozygosities (H_O = 0.6390) were higher than expected (H_E = 0.557), with high levels of heterozygotes in the populations. The fixation index in the loci and populations was negative. The F_ST (0.07) and AMOVA showed moderate population structure. Bayesian analysis indicated the grouping k = 4 as the most adequate. There is a high genetic diversity in populations, with a moderate genetic structure due to possible historical events, which could be related to the process of subpopulation formation, possibly presenting three historical moments: before and after the beginning of deforestation and today. The conservation and management policies of this species must be carried out at a watershed level. Full article

Amazonian floodplain forests along large rivers consist of two distinct floras that are traced to their differentiated sediment- and nutrient-rich (várzea) or sediment- and nutrient-poor (igapó) environments. While tree species in both ecosystems have adapted to seasonal floods that may last up to 270–300 days year⁻¹, ecosystem fertility, hydrogeomorphic disturbance regimes, water shortage and drought, fire, and even specific microclimates are distinct between both ecosystems and largely explain the differences in forest productivity and taxonomic composition and diversity. Here, we review existing knowledge about the influence of these environmental factors on the tree flora of both ecosystems, compare species composition and diversity between central Amazonian várzeas and igapós, and show that both ecosystems track distinct species life-history traits. The ecosystem-level and taxonomic differences also largely explain the biogeographic connections of várzeas and igapós to other Amazonian and extra-Amazonian ecosystems. We highlight the major evolutionary force of large-river wetlands for Amazonian tree diversity and explore the scenarios by which the large number of Amazonian floodplain specialist tree species might even contribute to the gamma diversity of the Amazon by generating new species. Finally, we call attention to the urgent need of an improved conservation of Amazonian várzea and igapó ecosystems and their tree species. Full article

The rubber tree, Hevea brasiliensis, is a neotropical Amazonian species. Despite its high economic value and fungi associated with native individuals, in its original area in Brazil, it has been scarcely investigated and only using culture-dependent methods. Herein, we integrated in silico approaches with novel field/experimental approaches and a case study of shotgun metagenomics and small RNA metatranscriptomics of an adult individual. Scientific literature, host fungus, and DNA databases are biased to fungal taxa, and are mainly related to rubber tree diseases and in non-native ecosystems. Metabarcoding retrieved specific phyllospheric core fungal communities of all individuals, adults, plantlets, and leaves of the same plant, unravelling hierarchical structured core mycobiomes. Basidiomycotan yeast-like fungi that display the potential to produce antifungal compounds and a complex of non-invasive ectophytic parasites (Sooty Blotch and Flyspeck fungi) co-occurred in all samples, encompassing the strictest core mycobiome. The case study of the same adult tree (previously studied using culture-dependent approach) analyzed by amplicon, shotgun metagenomics, and small RNA transcriptomics revealed a high relative abundance of insect parasite-pathogens, anaerobic fungi and a high expression of Trichoderma (a fungal genus long reported as dominant in healthy wild rubber trees), respectively. Altogether, our study unravels new and intriguing information/hypotheses of the foliar mycobiome of native H. brasiliensis, which may also occur in other native Amazonian trees. Full article

Tapirira guianensis (Anacardiaceae) is a natural resource from the Amazonian Forest and is locally known in French Guiana as “loussé” (creole), “tata pilili” (wayãpi), or “ara” (palikur). The tree is used by indigenous populations for medicinal purposes. To increase the potential of this tree for cosmetic, agro-food, or pharmaceutical uses, extracts were obtained through ultrasound-assisted extraction (UAE) from T. guianensis leaves using various extraction solvents such as water, methanol, and methanol–water (85/15; v/v). Chemical (DPPH, TEAC, ORAC) tests were applied to assess the anti-radical potential of these extracts. The polyphenol contents were determined by spectrophotometric (UV/Visible) and by means of chromatographic (UPLC-DAD-ESI-IT-MSⁿ) methods. Tapirira guianensis leaf hydromethanolic extract produced the highest polyphenol content and exhibited antiradical activities in chemical assays (DPPH, TEAC, and ORAC) similar to (or higher than) those of a well-known antiradical plant, green tea. In T. guianensis, two classes of polyphenols were evidenced: (1) galloylquinic acids (identified for the first time in the studied species) and (2) flavonols and flavanols (present in small amounts). Flavonols seemed to play a major role in the antioxidant activity of DPPH. These findings provide a rationale for the use of T. guianensis in traditional medicine and to pave the way for seeking new biological properties involving this Amazonian tree. Full article

The vast Amazonian biome still poses challenges for botanists seeking to know and recognize its plant diversity. Brazilian northern cities are expanding fast, without considering the regional biodiversity, and urban plantings of almost exclusively exotic species are taking place. It is paramount that the correct identity of such trees is ascertained before procurement of the seeds and young plants, as the use of popular names may lead to importation of plant material from elsewhere, with potential introduction of invasive species. The abundant local diversity also leads to the need to score the most suitable species within a given region. Following the preparation of authoritatively named floristic lists in Southeastern Pará state, we proceeded to score and rank the most suitable trees for urban planning using different characteristics such as size, ornamental value, ecologic role, resilience and known methods of propagation. From an initial 375 species list, 263 species were ranked according to their suitability for street and urban area plantings and visualized using a Venn diagram. A final list with the 49 of the highest-ranking species was further analysed regarding their pollination and phenology period and two types of dissimilarity analyses were provided to aid practitioners in matching and choosing groups of species. Different local vegetation types mean that similar floristic lists must be used to extract cohorts of suitable plants to increase the urban richness in the eight Brazilian states that are included in the Amazonian biome. Full article

Copaifera reticulata Ducke is a popularly known species known as copaíba that is widely spread throughout the Amazon region. The tree yields an oleoresin which is extensively used in local traditional medicine mainly as an anti-inflammatory and antinociceptive agent. The aim of the present study was to assess the anti-inflammatory potential of this oleoresin obtained from a national forest in the central Amazon which presented an unusual chemical composition. The chemical composition of volatile compounds of oleoresin was analyzed by gas chromatography-mass spectrometry. The acute toxicity assay was performed with a single dose of 2000 mg/kg. The anti-inflammatory potential was evaluated by carrageenan-induced paw edema and air pouch assays using four different C. reticulata oleoresin concentrations (10, 100, and 400 mg/kg). The exudate was evaluated for nitrite concentration through the colorimetric method and for TNF-α, IL-1β, and PGE₂ by ELISA. C. reticulata oleoresin collected in the Amazonian summer contained six major sesquiterpene compounds (β-bisabolene, cis-eudesma-6,11-diene, trans-α-bergamotene, β-selinene, α-selinene, and β-elemene) and was nontoxic at a dose of 2000 mg/kg, showing low acute toxicity. Different from oleoresin obtained from other sites of the Brazilian Amazon, the major volatile compound found was β-Bisabolene with 25.15%. This β-Bisabolene-rich oleoresin reduced the formation of paw edema induced by carrageenan and reduced the global number of cells in the air pouch assay, as well as exudate volume and nitrite, TNF-α, IL-1β, and prostaglandin E₂ levels (p < 0.05). C. reticulata oleoresin with a high β-Bisabolene concentration showed anti-inflammatory activity, reducing vascular permeability and consequently edema formation, and thus reducing cell migration and the production of inflammatory cytokine, confirming its traditional use by local Amazonian communities. Full article

Studies of dynamics and biomass accumulation are essential for understanding forest functioning and productivity. They are also valuable when planning strategies for the conservation and sustainable use of natural resources. This study was conducted in five one-hectare plots of gallery forest in the Orinoco basin (three in terra firme and two in igapó floodplains), located in the Tomogrande Reserve, Santa Rosalía municipality, Vichada, Colombia. The differences between these forest types were determined and quantified considering diversity, floristic composition, aboveground biomass, forest dynamics and the influence of soils’ physicochemical composition. Terra firme forests were more diverse (Fisher’s α = 30.4) and had higher mortality and recruitment rates than igapó forests but there were no significant differences in stem turnover rates between forest types. Relative tree growth rate was also higher in terra firme than in igapó, but the opposite was found for biomass change (1.47 t/ha/year in igapó), resulting in an average carbon accumulation rate of 0.33 t/ha/year in terra firme and 0.66 t/ha/year in igapó. Igapó forest has high carbon accumulation potential given the high wood density of certain dominant species. Igapó soils contained a higher concentration of sand, silt, phosphorus and potassium ions, while terra firme soils had a higher clay content with lower pH. In general, the demographic and growth rates were consistent with those described for Amazonian forests. This study highlights the potential of igapó forest in the Orinoco basin as important carbon sinks, which should be included in the management and conservation strategies for this region. Full article