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Highlights: [•] Leaves of Caesalpinia platyloba provided cassane diterpenes. [•] Vibrational circular dichroism assigned their absolute configurations. [•] A chemical correlation with a vouacapane from Dipteryx lacunifera was carried out. [Copyright &y& Elsevier]

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Dipteryx odorata and Dipteryx punctata are species native to the Amazonian, traded by extractivists to obtain coumarin. We aimed to analyze the presence of coumarin in the ethanolic extracts of leaves, branches and fruits of D. odorata and D. punctata and to evaluate the antimicrobial activity of these extracts against phytopathogenic fungi and bacteria of clinical interest. Chemical analyses were performed by thin layer chromatography (TLC) and by gas chromatography coupled to mass spectrometry (GC-MS). For the antifungal assays, the fungi used were Cercospora longissima , Colletotrichum gloeosporioides , two isolates of Fusarium spp. and Sclerotium rolfsii , and the antibacterial assay was performed using the minimum inhibitory concentration (MIC) test with Burkholderia cepacia , Escherichia coli , Pseudomonas aeruginosa and Staphylococcus aureus bacteria. In D. odorata seed extracts and in D. punctata husks, endocarps, and seeds, we identified 1,2-benzopyrone. D. odorata endocarp extracts and D. punctata seeds provided the greatest decrease in mycelial growth of the evaluated phytopathogens, showing promise as an alternative control. The husk and endocarp extracts of both species had a weak effect on E. coli . This research is the first to compare the different parts of species of the genus Dipteryx and to evaluate the use of husks and endocarps of D. punctata fruits to obtain coumarin. Chemical analyses used to quantify the compounds existing in the extracts, and tests with phytopathogens in vitro and in vivo are currently being carried out.

Water deficit to causes serious problems in the growth and development of plants, impairing their metabolism. Thus, it is necessary to use agents that can mitigate plant damage. This study assesses the potential of silicon to mitigate water deficit stress in Dipteryx alata Vogel seedlings and to help in their recovery after the resumption of irrigation. The study analyzed four water regimes: (I) Continuous irrigation; (II) Water deficit without Si; (III) Water deficit + 0.75 mL Si; and (IV) Water deficit + 1.50 mL Si. Seedlings were evaluated in four periods: (1) (T0 - time zero) at the beginning of the experiment, before irrigation suspension; (2) (P0) when the photosynthetic rates (A) of seedlings under irrigation suspension reached values close to zero, period in which irrigation was resumed; (3) (REC) when A reached values ​​close to those of seedlings under continuous irrigation, characterizing the recovery period; and (4) (END) 45 days after REC, when seedlings were kept under continuous irrigation, similar to the control. Application of 0.75 mL Si alleviates damage to the photosynthetic apparatus of D. alata seedlings that remain longer under water deficit, and contributes to faster physiological recovery after the resumption of irrigation. D. alata seedlings have recovery potential after the stress period, regardless of Si application.

Genetic effects of habitat fragmentation may be undetectable because they are generally a recent event in evolutionary time or because of confounding effects such as historical bottlenecks and historical changes in species' distribution. To assess the effects of demographic history on the genetic diversity and population structure in the Neotropical tree Dipteryx alata (Fabaceae), we used coalescence analyses coupled with ecological niche modeling to hindcast its distribution over the last 21 000 years. Twenty-five populations (644 individuals) were sampled and all individuals were genotyped using eight microsatellite loci. All populations presented low allelic richness and genetic diversity. The estimated effective population size was small in all populations and gene flow was negligible among most. We also found a significant signal of demographic reduction in most cases. Genetic differentiation among populations was significantly correlated with geographical distance. Allelic richness showed a spatial cline pattern in relation to the species' paleodistribution 21 kyr BP (thousand years before present), as expected under a range expansion model. Our results show strong evidences that genetic diversity in D. alata is the outcome of the historical changes in species distribution during the late Pleistocene. Because of this historically low effective population size and the low genetic diversity, recent fragmentation of the Cerrado biome may increase population differentiation, causing population decline and compromising long-term persistence. [ABSTRACT FROM AUTHOR]

Baru, a Brazilian Cerrado native fruit, stands out for its high nutritional value. Considering that reports about its technological potential are scant, this study aimed to add value to the processing chain. For that, ethanol and isopropanol were evaluated in terms of their suitability to solubilize baru nut oil (BNO), extract baru nut cake oil (BNCO), and obtain a protein-rich defatted flour. The BNO solubility in alcohols was adequately described by nonrandom two-liquid (NRTL) parameters, and the highest solubilization capacity was achieved with absolute isopropanol. Alcoholic extraction did not affect the BNCO tocopherol content (80-112 mg/kg oil) or its fatty acid composition. Both protein solubility and thermal stability were negatively affected by solvent hydration, temperature, and contact stages. However, the materials exhibited adequate water and oil absorption capacities (3.5 and 1 g/g sample), as well as improved foaming capacity and stability, confirming their potential for use in several food formulations., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: This study assessed the effects of Baru (Dipteryx alata Vog.) almond oil supplementation on vascular function, platelet aggregation, and thrombus formation in aorta arteries of Wistar rats. Methods: Male Wistar rats were allocated into three groups. The control group (n = 6), a Baru group receiving Baru almond oil at 7.2 mL/kg/day (BG 7.2 mL/kg, n = 6), and (iii) a Baru group receiving Baru almond oil at 14.4 mL/kg/day (BG 14.4 mL/kg, n = 6). Baru oil was administered for ten days. Platelet aggregation, thrombus formation, vascular function, and reactive oxygen species production were evaluated at the end of treatment. Results: Baru oil supplementation reduced platelet aggregation (p < 0.05) and the production of the superoxide anion radical in platelets (p < 0.05). Additionally, Baru oil supplementation exerted an antithrombotic effect (p < 0.05) and improved the vascular function of aorta arteries (p < 0.05). Conclusion: The findings showed that Baru oil reduced platelet aggregation, reactive oxygen species production, and improved vascular function, suggesting it to be a functional oil with great potential to act as a novel product for preventing and treating cardiovascular disease.

Abstract: The effect of roasting on phenolic compounds and antioxidant activities in baru nuts (Dipteryx alata Vog) with and without peels were investigated. Approximately 50% of the total phenolic content (Folin Ciocalteu assay) and 90% of the free radical-scavenging activity (DPPH) were present in the peel of the baru nut. Among the eight phenolics identified: p-coumaric acid, ellagic acid, caffeic acid, hydroxybenzoic, catechin, ferulic acid, epicatechin and gallic acid, the last was predominant in all nut samples with values that ranged from 224.0 to 66.7mg/100g. The roasting process did not reduce the total phenolic content significantly compared to the raw nut (p >0.05). However, roasting reduced the DPPH activity by approximately 50% in the nuts with peels. With the exception of gallic acid, the content of the other seven phenolic compounds significantly decreased after the roasting process in baru nuts with peels, suggesting that a phenolic other than gallic acid is the main compound responsible for the antioxidant potential of this nut. [Copyright &y& Elsevier]

Abstract: This article analyses the density, spatial distribution, and diameter structure of two neotropical tree species, Dipteryx odorata (Aubl.) Willd. and Copaifera reticulata Ducke, in undisturbed forests, logged forests, and forests used for the extraction of Non-Timber Forest Products (NTFPs). Both species are commercially harvested for timber and non-timber products which can fetch high prices on national and international markets. In undisturbed forests, both species display a low tree density, a random adult tree distribution pattern and a flat diameter structure, or one biased towards larger trees. The random spatial distribution pattern did not vary in the three types of forests analysed, whereas individual density and diameter structure did. The NTFP extraction areas exhibited the highest population densities for both species. In the logged forests, there was a lower density of very large D. odorata trees, while the areas used for D. odorata seed extraction showed a drastic reduction in the frequency of young trees. The results of this study seem to suggest that oil extraction from C. reticulata does not have any effect on the regeneration of that species, whereas D. odorata seed collection could affect the viability of populations. [Copyright &y& Elsevier]

Abstract: The protective effect of plant-based foods in human health has been attributed to the presence of bioactive compounds in all parts of the plants. A previous study found a high level of minerals, tannins and phytic acid in the baru nut (Dipteryx alata Vog.), which is a native fruit of the Brazilian savanna. This study investigated the antioxidant activity (AA) of the aqueous and ethyl acetate extracts of the baru nut and the effect of the consumption of this nut on the oxidative status of rats supplemented orally with iron. The AA was evaluated in vitro using the ferric reducing antioxidant power (FRAP), β-carotene/linoleic acid system and free-radical scavenging (DPPH) assays. The total polyphenol concentration was determined spectrophotometrically using the Folin–Ciocalteu reagent. The in vivo study was conducted in male Wistar rats that were fed an AIN-93M diet with or without 10% baru nut or 1% phytic acid and supplemented daily with iron or saline by gavages for 17days. The liver, heart and spleen were collected for the determination of the malondialdehyde (MDA), carbonyl protein and iron concentrations. The specific activities of catalase, glutathione reductase, glutathione peroxidase and glutathione S-transferase were also determined in these tissues. A T test was used to compare the results among the rats groups and between the different baru nut extracts (p<0.05). The aqueous extract of the baru nut contained a higher level of phenolic compounds and a higher antioxidant activity, as measured by FRAP and the β-carotene/linoleic system, relative to the EtOAc extract. The iron supplementation reduced the body weight gain, increased the levels of iron and MDA in the liver and the spleen and increased the carbonyl levels in all three tissues. Consumption of the baru nut reduced the carbonyl levels in the liver, heart and spleen of the iron-supplemented rats (p=0.002, 0.012 and 0.036, respectively) relative to the heart carbonyl level of rats that were fed the control diet (p=0.000); it also marginally reduced the iron-induced lipid oxidation in the liver (p=0.117) and the spleen (p=0.074). Phytic acid reduced the carbonyl level in the spleen (p=0.020) and marginally reduced the carbonyl level in the liver (p=0.098) of iron-supplemented rats. These results demonstrated that the consumption of the baru nut protects tissues against iron-induced oxidative stress, and the phytic acid from the baru nut may be partially responsible for this protective effect; however, other compounds such as phenols may also be involved. [Copyright &y& Elsevier]

Methods of seed germination and suitable substrates for seedling growth of gurguéia nut (Dipteryx lacunifera) were studied in the present work. The following methods of seed germination i.e. I and II) Room temperature water soak for 24 and 48 hours; Ill, IV, V and VI) hot water soak, for 5, 10, 15 and 20 minutes, respectively; and VII) mechanical scarification, were studied. The studied substrates were: S1) red Oxisol:sand:bovine manure ( 1 : 1 : 1 ); S2) red Oxisol:sand:goat manure ( 1 : 1 : 1 ); S3) red Oxisol:decomposed buriti stem:bovine manure (I: I: I); S4) red Oxisol:decomposed buriti stem:goat manure (I: 1: I); and S5) washed sand. No seed germination was recorded for methods IV, V and VI, whereas for the other methods, values ranged from 70% to 85%, with the highest average being registered for room temperature water soak for 24 hours. Excluding S3, emergence parameters were better as S1 shifted to S5 with the latter one was found to be best. Substrate affects seedling formation of gurgueia nut, indicating that washed sand may be used in this process. [ABSTRACT FROM AUTHOR]

Abstract: Over the past decade, shihuahuaco timber – comprising several species of Dipteryx (Fabaceae) traded internationally as “cumarú” or “Brazilian teak” – has become one of the most highly demanded types of hardwood from Peruvian Amazonia, particularly in the Chinese market. Dipteryx is an ecologically important canopy-emergent genus with widespread distribution in neotropical forests. To assess the response of Dipteryx to logging, we conducted inventories in three logging areas in the Regions of Ucayali and Loreto, Peru. The size-class distributions of Dipteryx populations in recently logged sites showed that initial post-logging conditions enhance recruitment of residual seedlings. These conditions are created by a combination of logging gaps and the activities of farmers migrating into logged lands. Through protection and liberation of shihuahuaco seedlings in post-logged forest as well as within and around agricultural fields, local residents and timber companies could favor the recovery of this valued resource. However, as logged land is increasingly converted to agriculture and pastureland, the reestablishment of mature seed trees is not assured. [Copyright &y& Elsevier]

The effect of four sub-extracts prepared from the lyophilized hydroalcoholic bark of Dipteryx alata (Leguminosae-Papilionoideae) dissolved in a methanol-water (80:20) mixture through a liquid-liquid partition procedure has been investigated against the neuromuscular blockade of the venom of the snake Bothrops jararacussu. The active CH2Cl2 sub-extract has been extensively analyzed for its chemical constituents, resulting in the isolation of four lupane-type triterpenoids: lupeol (1), lupenone (2), 28-hydroxylup-20(29)-en-3-one (3), betulin (4), nine isoflavonoids: 8-O-methylretusin (5), 7-hydroxy- 5,6,4′-trimethoxyisoflavone (6), afrormosin (8), 7-hydroxy-8,3′,4′-trimethoxyisoflavone (9), 7,3′-dihydroxy-8,4′-dimethoxyisoflavone (10), odoratin (11), 7,8,3′-trihydroxy-4′-methoxyisoflavone (13), 7,8,3′-trihydroxy-6,4′-dimethoxyisoflavone (15), dipteryxin (17), one chalcone: isoliquiritigenin (7), one aurone: sulfuretin (14) and three phenolic compounds: vanillic acid (12), vanillin (16), and protocatechuic acid (18). Their chemical structures were elucidated on the basis of spectroscopic analysis, including HRMS, 1Dand 2D-NMR techniques. [ABSTRACT FROM AUTHOR]

Extracts from Dipteryx alata bark obtained with different solvents (hexane, dichloromethane, ethyl acetate and methanol) were mixed in vitro with Bothrops jararacussu (Bjssu, 40 μg/mL) and Crotalus durissus terrificus (Cdt, 15 μg/mL) snake venoms, and applied to a mouse phrenic nerve-diaphragm preparation to evaluate the possible neutralization of venom effects. Cdt venom neurotoxic effect was not inhibited by any of the extracts, while the neurotoxic and myotoxic actions of Bjssu venom were decreased by the methanolic extract. This inhibition appears to be augmented by tannins. Dichloromethane bark extract inhibited ∼40% of Bjssu venom effects and delayed blockade induced by Cdt. The methodology used to determine which extract was active allows inferring that: (i) phenolic acids and flavonoids contained in the methanolic extract plus tannins were responsible mostly for neutralization of Bjssu effects; (ii) terpenoids from the dichloromethane extract may participate in the anti-Cdt and anti-Bjssu venom effects; (iii) a given extract could not inhibit venoms from different species even if those belong to the same family, so it is improper to generalize a certain plant as antiophidian; (iv) different polarity extracts do not present the same inhibitory capability, thus demonstrating the need for characterizing both venom pharmacology and the phytochemistry of medicinal plant compounds. [ABSTRACT FROM AUTHOR]

Abstract: In the Neotropics, there is a growing interest in establishing plantations of native tree species for commerce, local consumption, and to replant on abandoned agricultural lands. Although numerous trial plantations have been established, comparative information on the performance of native trees under different regional environments is generally lacking. In this study, we evaluated the accumulation and partitioning of above-ground biomass in 16 native and two exotic tree species growing in replicated species selection trials in Panama under humid and dry regional environments. Seven of the 18 species accumulated greater total biomass at the humid site than at the dry site over a two-year period. Species-specific biomass partitioning among leaves, branches and trunks was observed. However, a wide range of total biomass found among species (from 1.06kg for Dipteryx panamensis to 29.84kg for Acacia mangium at Soberania) justified the used of an Aitchison log ratio transformation to adjust for size. When biomass partitioning was adjusted for size, a majority of these differences proved to be a result of the ability of the tree to support biomass components rather than the result of differences in the regional environments at the two sites. These findings were confirmed by comparative ANCOVAs on Aitchison-transformed and non-Aitchison-transformed variables. In these comparisons, basal diameter, height and diameter at breast height were robust predictors of biomass for the pooled data from both sites, but Aitchison-transformed variables had little predictive power. [Copyright &y& Elsevier]

The rain forest canopy hosts a large percentage of the world's plant biodiversity, which is maintained, in large part, by internal nutrient cycling. This is the first study to examine the effects of site (canopy, forest floor) and tree species ( Dipteryx panamensis, Lecythis ampla, Hyeronima alchorneoides) on decay rates of a common substrate and in situ leaf litter in a tropical forest in Costa Rica. Decay rates were slower for both substrates within the canopy than on the forest floor. The slower rate of mass loss of the common substrate in the canopy was due to differences in microclimate between sites. Canopy litter decay rates were negatively correlated with litter lignin:P ratios, while forest floor decay rates were negatively correlated with lignin concentrations, indicating that the control of litter decay rates in the canopy is P availability while that of the forest floor is carbon quality. The slower cycling rates within the canopy are consistent with lower foliar nutrient concentrations of epiphytes compared with forest floor-rooted plants. Litter decay rates, but not common substrate decay rates, varied among tree species. The lack of variation in common substrate decay among tree species eliminated microclimatic variation as a possible cause for differences in litter decay and points to variation in litter quality, nutrient availability and decomposer community of tree species as the causal factors. The host tree contribution to canopy nutrient cycling via litter quality and inputs may influence the quality and quantity of canopy soil resources. Abstract in Spanish is available at [ABSTRACT FROM AUTHOR]

The knowledge of polysaccharides obtained from fruit seed and its chemical characteristics are important to evaluate their final properties, as well as their uses and benefits. Solid state nuclear magnetic resonance (NMR) has been used to evaluate the behavior of the samples, since NMR permits to evaluate both chemical and dynamic molecular behavior of polysaccharides, because they are amorphous and heterogeneous. The NMR analyzes were carried out using high and low field NMR techniques. The results obtained from high field showed the main chemical constituents present in the seeds and seed flour. Through low field NMR different domains with their own molecular mobility and interactions were observed; due to the measurements of proton spin-lattice relaxation time (T1H). According to the results obtained for Cumbaru seed, solid state NMR showed to be a powerful source to characterize fruit seed flour. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [ABSTRACT FROM AUTHOR]

Seed production, seed dispersal and recruitment are critical processes in population dynamics, because they are almost never completely successful. We recorded the recruitment dynamics for the population of Dipteryx oleifera in a tropical rainforest in eastern Nicaragua (12°05' N., 83°55' W.) from March 2002 to August 2006. Seeds and seedlings had highly clumped distributions, while sapling distributions appeared to be random. Seedling survival increased away from the nearest conspecifc adult tree, where seedling density is lower. Since relative growth rates of seedlings are not correlated with the distance to the nearest conspecific adult, seedling survival appears to be independent of seedling growth. Seedling density is inversely correlated with seedling insect herbivory damage. Seedling survival correlated negatively with the number of saplings per sub-plot (10x10m), suggesting that insect herbivore may also cue in on saplings rather than only on adult D. oleifera trees in order to locate seedlings. Seedling establishment is significantly clumped with respect to the nearest adult tree. Larger clumps of seedlings seems more ephemeral than isolated smaller clumps located away from the nearest D. oleifera tree. These results support current empirical evidence presented earlier for the Janzen-Connell hypothesis for Dipteryx oleifera at seed and seedling stages and, the Recruitment Limitation hypothesis at the sapling stage, because sapling individuals might have recruited after random light-gap formation. [ABSTRACT FROM AUTHOR]

The fruits of Dipteryx lacunifera, known as ‘fava de morcego’ and ‘garampara’, comprise pleasant tasting kernels that contain high amounts of fatty acids mainly oleic acid and are commonly consumed by inhabitants of the northeast of Brazil. In the present study, the crude EtOH extract of the fruit kernels was separated into hexane, Et2O, AcOEt, and H2Osoluble fractions. The Et2O fraction was found to exhibit the highest 1,1diphenyl2picrylhydrazyl DPPH radicalscavenging activity in vitro, and was subjected to further fractionation. Column chromatography over silica gel and Sephadex LH20, followed by preparative HPLCC18, afforded ?eriodictyol 1, ?butin 2, luteolin 3, 3?,4?,7trihydroxyflavone 4, butein 5, and sulfuretin 6. The antiradical activities of compounds 1, 2, 4, and 6, together with the positive controls rutin, butylated hydroxy toluene BHT, and tertbutylhydroquinone TBHQ, were evaluated with the DPPH assay and were found to decrease in the order rutin>4>1>6>2>TBHQ>BHT. [ABSTRACT FROM AUTHOR]

In the face of widespread deforestation, the conservation of rainforest trees relies increasingly on their ability to maintain reproductive processes in fragmented landscapes. Here, we analysed nine microsatellite loci for 218 adults and 325 progeny of the tree Dipteryx panamensis in Costa Rica. Pollen dispersal distances, genetic diversity, genetic structure and spatial autocorrelation were determined for populations in four habitats: continuous forest, forest fragments, pastures adjacent to fragments and isolated pastures. We predicted longer but less frequent pollen movements among increasingly isolated trees. This pattern would lead to lower outcrossing rates for pasture trees, as well as lower genetic diversity and increased structure and spatial autocorrelation among their progeny. Results generally followed these expectations, with the shortest pollen dispersal among continuous forest trees (240 m), moderate distances for fragment (343 m) and adjacent pasture (317 m) populations, and distances of up to 2.3 km in isolated pastures (mean: 557 m). Variance around pollen dispersal estimates also increased with fragmentation, suggesting altered pollination conditions. Outcrossing rates were lower for pasture trees and we found greater spatial autocorrelation and genetic structure among their progeny, as well as a trend towards lower heterozygosity. Paternal reproductive dominance, the pollen contributions from individual fathers, did not vary among habitats, but we did document asymmetric pollen flow between pasture and adjacent fragment populations. We conclude that long-distance pollen dispersal helps maintain gene flow for D. panamensis in this fragmented landscape, but pasture and isolated pasture populations are still at risk of long-term genetic erosion. [ABSTRACT FROM AUTHOR]

We studied the effect of seed density on seed predation by following the fate of bat-dispersed Dipteryx micrantha (Leguminosae) seeds deposited under bat feeding roosts. The study was conducted in Cocha Cashu biological station, Amazonian Peru, during the fruiting period of Dipteryx. Predation of Dipteryx seeds in the area is mainly by large to medium-sized rodents. Seed deposits beneath bat feeding roosts were monitored for a 13-week period in an 18-ha study area. A total of 210 seed deposits were found, and on average, seed predators encountered 22% of them during any one week. About one-third of the seed deposits escaped predation, and those deposits that had relatively few seeds were more likely to go unnoticed by rodents than were deposits with many seeds. The mean seed destruction rate was 8% per week; deposits with many seeds tended to lose a smaller proportion of their seeds to seed predators than did deposits with few seeds. Regression tests for the weekly data showed that, at the beginning of the observation period, seed predation was not density-dependent. Later, when the total seed crop beneath roosts was high, the number of seeds predated per deposit was positively density-dependent, while the proportion of seeds predated was negatively density-dependent, indicating predator satiation. Seed deposits that had been visited by seed predators once had a higher probability of being revisited the week after, especially if they contained many seeds when first encountered. This indicates that the foraging behavior of rodents may be affected by their remembering the location of seed-rich patches. [ABSTRACT FROM AUTHOR]

Experimental mixture design was drawn to evaluated the effects of the interactions between water, methanol and ethyl acetate mixtures on the extraction efficiency of coumarin (1,2-benzopyrone) from Dipteryx odorata seeds. Solvents were defined considering those preferred as green solvents for natural products extraction. Ultrasonic-assisted extraction method developed was simple, fast, low cost and highly selective. Analyses were performed by reversed-phase liquid chromatography using acetonitrile/water (40:60 v/v) as mobile phase, a C18 column, and a diode-array detector at 274 nm. Results were evaluated in linear, quadratic, special cubic, and full cubic models. The Full cubic model showed the best extraction results with a total error of 3.67%. The optimal extraction point was obtained using 15% water, 20% methanol, and 65% ethyl acetate (v/v). Based on the Guide for the Expression of Uncertainty in Measurements and Monte Carlo simulations, the uncertainty expression presented deviations of 1.18 and 1.64, respectively, showing the reliability of the analytical method. D. odorata seeds are popularly used in the pharmaceutical, food, and cosmetic applications due to high content of coumarins. However, the yield of coumarins extraction depends on the proper choice of the extraction method and solvents. The ternary mixture was optimized and resulted in 3.82% coumarin (weight/seed), which, compared to literature, showed a good increase over that obtained using common solvents, without considering the mathematical modeling., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Baru (Dipteryx alata Vogel) is a native tree plant, widely distributed in Brazil, and has a growth and development in acidic soils like Cerrado, indicating a probable tolerance to adverse soil conditions, such as the high concentration of metals and the acidic pH. Due to the lack of information about the tolerance of this species to metals and the possibility of being used in the recovery of degraded areas and/or in phytoremediation, this work was developed with the objective of evaluating the in vitro germination and growth capacity of baru in medium supplemented with different concentrations of aluminum, iron, and manganese, as well as through chemical analysis, to determine the concentration of metals accumulated in cultivated plants in these conditions. The treatments consisted in different concentrations of metals: aluminum, Al 3+ (0, 3.5, 7.0, 10.5, 21.0, or 42.0 mg L -1 ); iron, Fe 3+ (0, 2.5, 4.9, 7.4, 14.7, or 29.4 mg L -1 ); and manganese, Mn 2+ (0, 0.4, 0.8, 1.2, 2.4, or 4.8 mg L -1 ) added to the medium WPM. The tested values were based on using the lower concentration as the limit value, calculated based on risk to human health in accordance with CONAMA resolution 420/2009 for groundwater. At 60 days of cultivation, the percentage of germination, the average number of leaves, the length of the main root and the aerial part, the fresh and dry mass of the aerial part and the root system and the cations concentration Al 3+ , Fe 3+ and Mn 2+ in the plant biomass, were evaluated. The results showed that under the conditions in which the experiment was conducted, germination and in vitro growth of baru were not affected by the presence in high concentrations of any of the evaluated metals, with no differences in the percentage of germination and plant growth, as well as typical toxicity characteristics were not observed, such as changes in root morphology, chlorosis, or tissue oxidation. The absence of toxicity symptoms in baru plants, in the presence of Al 3+ , Fe 3+ , and Mn 2+ , indicate that the species is tolerant to these metals. The accumulation of Al 3+ and Fe 3+ in the plant biomass at the beginning of growth, simultaneously with the increase in the concentrations of these elements in the culture medium, indicates that this species can be used for phytoremediation, because it is a probable accumulator of these elements throughout its development, given the presence in significant concentrations of these elements also in the seeds., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Field experiments and survival analysis were used to test whether the Janzen-Connell model operated for two common Amazonian tree species in Peru: the midstorey palm, Astrocaryum murumuru, and the canopy-emergent legume, Dipteryx micrantha. Seed and seedling survival patterns of these species partially supported the model, depending on tree species, type of predator, spatial scale and the particular year. At a small scale of a 2.5-ha plot, Astrocaryum seed predation by insects and mammals was density-dependent. At a larger scale of 100 ha, Dipteryx seed survival increased with distance from conspecific adults, but for Astrocaryum seeds there was no distance dependence. At the scale of 200–400 ha Dipteryx seed survival was negatively related to the number of individuals present in groups of conspecific adult trees. In 1992 a higher proportion of Astrocaryum seedlings survived far from, compared with close to, conspecific adult trees, whilst in 1993 more Dipteryx seedlings survived beneath conspecific adult trees than farther away. [ABSTRACT FROM PUBLISHER]

The role of regeneration strategies in structuring tropical tree communities has been a recent focus of attention of tropical ecologists. Canopy discontinuities created by tree-falls are considered to be critical to many rain forest trees for establishing and completing their life cycles. It was investigated whether it is advantageous for two common large-seeded and shadetolerant Amazonian tree species, the palm Astrocaryum murumuru and the legume, Dipteryx micrantha, to have their seeds dispersed to gaps. The dispersal process was simulated by placing experimental seeds and seedlings in gaps and in the shaded understorey, and then following their performance. Seeds and seedlings from the two species were used. The Cox proportional hazard model was used to estimate the survival functions and compare survivorship curves. Survival of Astrocaryum seeds, and of Dipteryx seeds and seedlings, was higher in two gap zones (crown and bole) than in the shaded understorey (both near and far away from a conspecific adult). A higher proportion of seedlings of both plant species survived within gaps than in the shaded understorey over an 18-wk period. One year after the seedlings had been transplanted into gaps these patterns still held. Naturally occurring Astrocaryum seeds survived better beneath conspecific adult trees located within 30 m of gaps than beneath trees located 100 m from gaps. Variation in gap size was significant for Dipteryx seeds, but not for Dipteryx seedlings and Astrocaryum seeds and seedlings. Dipteryx seeds survived longer in smaller than in larger gaps. By colonizing tree-fall gaps, these two species improved their chances of completing their life cycles. [ABSTRACT FROM PUBLISHER]