Introduction: Pentaclethra macroloba is a hyperdominant tree in the Amazon estuary of great socioeconomic importance for the region because the oil from its seeds is a powerful herbal medicine. Objective: We aimed to characterize the morphological structure, the morphological adaptations in response to the daily flooding of the Amazon estuary and the biogeographic area of P. macroloba. Methods: Detailed description of the external morphology, from germination to the adult tree, was obtained from individuals located in floodplain forest, Northeast Amazonia. The occupation area and the geographical extension of P. macroloba were determined from point of geographical coordinates of botanical samples deposited in the digital collections of Mobot and SpeciesLink. Results: Adult individuals have adapted structures in response to daily flooding, such as: adventitious roots to increase respiratory efficiency and lenticels in the trunk, serving as a connection point for oxygen transport between the root and the aerial part. Dried fruit favours the activation of the explosive dehiscence mechanism, allowing the seed to be expelled long distance. Deltoid shape of the seed allows water fluctuation and more efficient dispersal. Seedling is phanerocotylar hypogeal and with one pair of reserve cotyledons that provide the seedling an extra source of energy to escape the flood. Germination rate was 78 % and the speed was 0.2 seeds.day-1. Circular buffer method revealed the presence of 123 subpopulations of P. macroloba distributed in a radius of 5 699 943 km² across the Neotropical region. Conclusions: Much of the morphological structures of P. macroloba are adaptive and evolutionary responses to the periodically flooded environment of the Amazon estuary, showing that these environments select the trees, best adapted, to inhabit the flood. P. macroloba has a wide geographical area denotes the plasticity of adapting to different environments, which may justify its monodominance in some regions.

Significant gaps remain in understanding the response of plant reproduction to environmental change. This is partly because measuring reproduction in long‐lived plants requires direct observation over many years and such datasets have rarely been made publicly available. Here we introduce MASTREE+, a data set that collates reproductive time‐series data from across the globe and makes these data freely available to the community. MASTREE+ includes 73,828 georeferenced observations of annual reproduction (e.g. seed and fruit counts) in perennial plant populations worldwide. These observations consist of 5971 population‐level time‐series from 974 species in 66 countries. The mean and median time‐series length is 12.4 and 10 years respectively, and the data set includes 1122 series that extend over at least two decades (≥20 years of observations). For a subset of well‐studied species, MASTREE+ includes extensive replication of time‐series across geographical and climatic gradients. Here we describe the open‐access data set, available as a.csv file, and we introduce an associated web‐based app for data exploration. MASTREE+ will provide the basis for improved understanding of the response of long‐lived plant reproduction to environmental change. Additionally, MASTREE+ will enable investigation of the ecology and evolution of reproductive strategies in perennial plants, and the role of plant reproduction as a driver of ecosystem dynamics.

Andiroba (Carapa guianensis) seeds are the source of an oil with a wide range of biological activities and ethnopharmacological uses. However, few studies have devoted attention to innovative formulations, including nanoemulsions. The present study aimed to obtain a colloidal system with the andiroba oil using a low‐energy and organic‐solvent‐free method. Moreover, the preliminary residual larvicidal activity of the nanoemulsion against Aedes aegypti was evaluated. Oleic and palmitic acids were the major fatty acids, in addition to the phytosterol β‐sitosterol and limonoids (tetranortriterpenoids). The required hydrophile‐lipophile was around 11.0 and the optimal nanoemulsion was obtained using polysorbate 85. The particle size distribution suggested the presence of small droplets (mean diameter around 150 nm) and low polydispersity index (around 0.150). The effect of temperature on particle size distribution revealed that no major droplet size increase occurred. The preliminary residual larvicidal assay suggested that the mortality increased as a function of time. The present study allowed achievement of a potential bioactive oil in water nanoemulsion that may be a promising controlled release system. Moreover, the ecofriendly approach involved in the preparation associated with the great bioactive potential of C. guianensis makes this nanoemulsion very promising for valorization of this Amazon raw material.

We analyzed the spatial distribution pattern of Pentaclethra macroloba to assist in the development of management plans and conservation of this species in estuarine floodplain forests. The study was conducted in an area of floodplain forest of 55.94 ha, in Mazagão, Amapá, Brazil. A census was performed and all individuals of ≥ 30 cm circumference at breast height (CBH), living and dead, were georeferenced. Ripley’s K function was used to analyze the spatial distribution of the population, including mortality and diameter classes. The relationships between distance to the edge of inundation and density and basal area of the population were analyzed using linear regression. We recorded 993 live individuals and 22 dead. The distribution of the population was found to vary with the topographic gradient associated with the distance to the edge of the inundation. Diameter classes 1 (≤ 13.2 cm) and 2 (≤ 18.6 cm) were spatially aggregated close to the water and randomly distributed far from the water. Classes 3 (≤ 24.0 cm) and 4 (≤ 29.5 cm) were aggregated at all distances, and classes 5 (≤ 34.9 cm), 6 (≤ 40.3 cm), 7 (≤ 45.7 cm) and 8 (≤ 51.2 cm), were randomly distributed at all distances. Mortality was randomly distributed. The population density was 18 trees h^-1 with a basal area of 49 m² h^-1, and both density (r²=0.51; p=0.0195) and basal area (r²=0.67; p=0.0039) increased with the distance from the edge of the inundation. We conclude that the spatial distribution and successful establishment of this species in floodplain forest are related to the dynamics of flooding and the resultant impacts on dispersal processes.

A castanha-da-amazônia é um alimento naturalmente orgânico, considerado funcional por promover boa nutrição e saúde do organismo. Seu consumo regular já foi associado com a redução de várias doenças, graças à elevada atividade antioxidante e anti-inflamatória de alguns fitoquímicos, principalmente do Selênio (Se). Os objetivos deste estudo foram: 1) avaliar se matrizes superiores de castanheiras, que apresentam maior produção de frutos, também possuem maior teor de Se; 2) analisar se castanhas (safra 2021) sementes são alteradas após um ano armazenamento em diferentes condições controladas; 3) verificar se a composição centesimal das castanhas (safra 2022) é alterada após pré-secagem e armazenamento no campo. O teor médio de Se foi 143 mg kg-1, variando de 33 a 544 mg kg-1, com maiores valores nas amêndoas de castanhas coletadas em matrizes com menor produção de frutos. As amêndoas armazenadas nos próprios frutos durante um ano apresentaram teor de umidade (21%) e atividade de água (0,91) superiores aos daquelas armazenadas na câmara fria e na sala do laboratório, além de mais carboidratos e menos lipídeos. Isso comprovou a eficiência do armazenamento das sementes nos ouriços para manter sua viabilidade germinativa. De modo geral, não houve alterações significativas na composição centesimal e nutricional de castanhas que passaram pelos paióis de pré-secagem e pelo armazém do comprador local, comprovando que nessas condições é possível manter a qualidade da castanha fresca. Esses resultados podem subsidiar ações de comercialização, melhoramento e valorização da cadeia produtiva da castanha que favoreçam sua qualidade enquanto alimento funcional e nutracêutico.

This work augments research on masting for the economically important tropical tree Carapa guianensis Aublet, specifically on whether determinants of mast years vary regionally, spatially, and due to longer term ENSO climate patterns. Longer term measurements (an 11-year period in Acre and Roraima; 4 years and 8 months in Amapá) from three regions of the Brazilian Amazon allowed for the analysis of whether climate cues were regionally consistent for this species. We used generalized linear mixed models, to determine which factors were significant in predicting whether trees would produce in a given year and to model the seed production quantity. We found a positive effect of increasing the diameter at breast height (dbh) on the quantity and likelihood of seed production. Our results also suggested that ecosystems and climate cues may jointly affect seed production. In flooded forests, increases in dry season rainfall had a negative impact on the likelihood of seed production whilst none of the precipitation variables investigated influenced the quantity of seeds produced. In drier terra firme forests in Acre with extended dry seasons, increases in dry season precipitation had significant and positive impacts on both the likelihood and the quantity of seed production. Our results illustrate the importance of considering plant habitat and climate to better understand individual and regional differences in seed production and their responses to inter-annual climate variation.