ABSTRACT Soil properties and classes can influence the occurrence of plants and the production of Brazil nut fruits and may have a different distribution between sites. This study aimed to evaluate the relationship of plants’ occurrence, production of Brazil nut fruits, and spatial variability of the properties in different soil classes in two Brazil nut stand in the state of Acre, Brazil. The study was conducted in two plots in two native Brazil nut stand, Cachoeira (CP01 and CP02 - plots 1 and 2) and Filipinas (FP01 and FP02 - plots 1 and 2). The soil profiles were described morphologically. Sixty soil samples were collected in each plot. The chemical properties, granulometry, soil density, particle density, and estimated total porosity were determined. The average fruit production was calculated by counting the fruits in a sample of Brazil nut trees. Subsequently, the trees were divided into three classes of production: low (≤1.5 can; the can unit has 18-L, which is able to hold 59 and 77 fruits, respectively, for Cachoeira and Filipinas), medium (1.6 to 3.9 cans), and high (≥4.0 cans). The can unit is the traditional measure of volume in the region and varies according to the locality. Cluster analysis was performed to determine whether there was a difference between Brazil nut stands and soil profiles, and geostatistics was used to evaluate the spatial dependence of soil properties. The highest occurrence of Brazil nut trees with high fruit production (≥4.0 cans) was found in the Latossolo Vermelho Distrófico argissólico (Oxisol) and Argissolo Vermelho-Amarelo Distrófico típico (Ultisol). However, the Argisol also hosted the plants with the lowest productions (≤1.5 can). The pH, total organic carbon, sum of bases, P, N, granulometry, and porosity showed a greater spatial variability, and FP02 showed a greater number of properties with high spatial variability compared to the other areas. Although the occurrence of plants and the production of Brazil nut fruits ( Bertholletia excelsa ) were associated with the classes and the physical and chemical properties of the soil, pyxidium production differed between areas. In general, soil physical properties were limiting factors for Brazil nut production and/or higher tree occurrence. Filipinas environment showed a low fruit production and a greater spatial variability of soil properties compared to Cachoeira.

Abstract This study aimed to evaluate the physicochemical composition, color and sensory acceptance of low-fat açaí and cupuaçu nectar, as well as changes in these parameters during storage. Nectars were prepared with açaí pulp previously defatted by centrifugation on a pilot scale. The study consisted of two steps. In the first step, the physicochemical characteristics, instrumental color, and sensory acceptance of the nectar prepared with low-fat açaí pulp were evaluated and compared with those of nectar prepared with full-fat açaí pulp. In the second step, titratable acidity, pH, soluble solids, anthocyanin content, instrumental color, and sensory acceptance of the low-fat açaí and cupuaçu nectar were evaluated for 6 months of storage at 25°C in the absence of light. The use of low-fat açaí pulp resulted in nectars with good overall acceptance, but with lower scores for color acceptance than those of the full-fat nectar. The low-fat nectar remained stable with respect to acidity, pH, and soluble solid content during storage for up to 180 days. However, there was degradation of anthocyanins, which had a negative impact on the product color and sensory acceptance over time. Under the conditions evaluated, the estimated product shelf life is up to 120 days.

RESUMO A perda de diversidade em regiões tropicais tem sido pauta em diversas discussões governamentais e não governamentais, com foco principalmente na fragmentação e destruição de ecossistemas naturais. No entanto, tomadas de decisões sobre a conservação de recursos genéticos precisam ser pautadas em parâmetros genéticos populacionais, especialmente para as espécies com interesse econômico que são alvo de maior interferência humana. Este trabalho teve como objetivo definir e avaliar parâmetros genéticos para a conservação de populações de jatobá (Hymenaea courbaril) na região sul-ocidental da Amazônia brasileira. A espécie é uma das que possuem madeira mais valiosa e é uma das mais intensamente exploradas na Amazônia brasileira. O estudo foi realizado em três áreas de florestas preparadas para a exploração madeireira, segundo plano de manejo sustentável. Calculou-se, com uso de oito locos de marcadores microssatélites, a diversidade genética, os estimadores para a conservação da espécie e a divergência entre as populações. As populações com menor densidade populacional (< 0,08 ind.ha-1) apresentaram maior diversidade genética e índice de fixação elevado. A população com maior densidade populacional (0,25 ind.ha-1) foi a que apresentou menor diversidade genética e ausência de endogamia. A Área Mínima Viável para conservação da espécie foi compatível com a realidade do local de estudo, com uma ressalva de uma das populações onde há necessidade de uma área muito maior em relação às demais. A divergência genética foi elevada (G'st = 0,344) e as populações foram classificadas como Unidades Independentes para o Manejo.

ABSTRACT The loss of diversity in tropical regions has been focus on several governmental and non-governmental discussions, focusing mainly on the fragmentation and destruction of natural ecosystems. However, decisions about the conservation of genetic resources must be guided by population genetic parameters, especially for species with economic interests that are subject to greater human interference. This study aimed to define and evaluate genetic parameters for the conservation of populations of Hymenaea courbaril in southwestern Amazon. This species is one of the most valuable and intensively exploited wood species in the Brazilian Amazon. We studied three forest areas prepared for logging in the background of sustainable management. It was calculated with eight microsatellite loci, genetic diversity, intra-population conservation estimators and genetic divergence among populations. Genetic diversity and fixation index were higher in the low density populations (< 0.08 ind.ha-1). The most density population (0.25 ind.ha-1) showed the lowest genetic diversity and no inbreeding. The Minimum Viable Area for species conservation was consistent with the reality of the studied areas, with a proviso for one of the populations where there is a need for a much larger area than the other to conserve populations. The genetic divergence was high (G'st = 0344) and the populations were considered Independent Management Units.