Vismia Guianensis Research Articles

Do the edge effects influence epicuticular wax production in Vismia guianensis (Aubl.) Choisy (Hypericaceae)?

Forest fragmentation leads to various environmental problems. It causes edge effects that can decrease biodiversity, promote the growth of lianas, and affect the production of epicuticular wax. This study focuses on examining the secondary metabolites found in the epicuticular wax of Vismia guianensis leaves and investigating the impact of the edge effect on their production. We extracted and quantified the epicuticular wax and analyzed its constituents using gas chromatography coupled with a mass spectrometer. The amount of cuticular wax extracted from V. guianensis leaves ranged from 33.69 to 631.57 μg/cm². Individuals at the forest edge had the lowest wax content, averaging 250.96 μg/cm². On the other hand, individuals located in the interior of the forest had the highest values, with an average of 340.67 μg/cm² per surface unit. The analysis of the samples identified and quantified nine long-chain alkanes (C27 to C35) in the composition of the cuticular wax. The predominant compound in the wax of all individuals was nonacosane alkane (C29). Interestingly, the individuals within the forest fragment exhibited less diversity of compounds compared to those at the forest edge.

Prenylated Benzophenones from Vismia Guianensis Reduced Nematode Growth and Chemotaxis.

Biopesticides are generally considered a safer and more environmentally friendly alternative to conventional pesticides. Plant metabolites display a range of pest specific activity ranging from antimicrobial to larvicidal and nematocidal. We herein describe the evaluation of a Guyanese collection of Vismia guianensis (Clusiaceae) for anthelmintic activity. The bioassay-guided evaluation of the hexane extract yielded the new prenylated benzophenone 8,9-epoxyvismiaphenone F (1). The final structures were elucidated based on spectral analysis and comparison to the known metabolite. To evaluate the anthelmintic efficacy of these compounds, Caenorhabditis elegans were exposed to the compounds via a ring assay model. Post-exposure, the numbers of live C. elegans in the compound (middle), bacteria ring were recorded for 3 d, as well as the total number of live worms for each plate. Compound 1 reduced C. elegans' overall growth and reproduction, suggesting that these prenylated benzophenones may hold some promise as natural pesticides.

The Anti-Virulence Effect of Vismia guianensis against Candida albicans and Candida glabrata.

In folk medicine, Vismia guianensis is used to treat skin diseases and mycoses in the Amazon region. We evaluated the anti-Candida activity of the hydroalcoholic extract from the leaves of Vismia guianensis (EHVG). HPLC-PDA and FIA-ESI-IT-MSn were used to chemically characterize EHVG. The anti-Candida activity was determined in vitro by the minimum inhibitory concentrations (MIC) against Candida glabrata (ATCC-2001); Candida albicans (ATCC-90028, ATCC-14053, and ATCC-SC5314), and C. albicans clinical isolates. EHVG effects on adhesion, growth, and biofilm formation were also determined. Molecular docking was used to predict targets for EHVG compounds. The main compounds identified included anthraquinone, vismione D, kaempferol, quercetin, and vitexin. EHVG was fungicidal against all tested strains. C. albicans ATCC 14053 and C. glabrata ATCC 2001 were the most sensitive strains, as the extract inhibited their virulence factors. In silico analysis indicated that vismione D presented the best antifungal activity, since it was the most effective in inhibiting CaCYP51, and may act as anti-inflammatory and antioxidant agent, according to the online PASS prediction. Overall, the data demonstrate that EHVG has an anti-Candida effect by inhibiting virulence factors of the fungi. This activity may be related to its vismione D content, indicating this compound may represent a new perspective for treating diseases caused by Candida sp.

Host-tree selection by the ant garden-initiating arboreal ponerine Neoponera goeldii.

Host-tree selection by the ant garden-initiating arboreal ponerine Neoponera goeldii.

Weed Dynamics and Yield of Cowpea Inoculated in Mulching (Crushed Capoeira)

Mulching (crushing capoeira) is an alternative system for the use of fire for cultivation in the Northern region of Brazil. Cowpea is considered an important food crop in this region; however, weeds might limit its productivity. This study aimed to evaluate the population dynamics of weeds and the productivity of cowpea with different habit of growth inoculated with Bradyrhizobium sp in mulching. The experiment was carried out in randomized blocks with the cultivars BRS Guariba and BR 17 Gurgueia, with and without inoculation of Bradyrhizobium sp and nitrogen fertilization as a control. Twenty-seven species and three genera of weeds were identified, distributed into 12 botanical families in the BRS Guariba cultivar and 25 species in ten families in BR 17 Gurgueia cultivar. The results revealed that the significative species were Vismia guianensis (Aubl.) Pers, Cyperus sp, Scleria melaleuca Rchb. ex Schltdl. & Cham, and Spermacoce verticillata L. Inoculation with Bradyrhizobium sp reduced the infestation of the most important species and presented higher productivity (1965.09 kg ha-1) than the treatment without inoculation (987.14 kg ha-1). The growth habit of cowpea cultivars in mulching (crushing capoeira) system did not affect crop yield, but longer studies are needed to validate the information obtained.

Flora of Ceará State, Brazil: Caryocaraceae, Hypericaceae, and Rhizophoraceae

Abstract We examined the diversity and distribution of Caryocaraceae, Hypericaceae, and Rhizophoraceae in Ceará State, Brazil. Floristic treatments were carried out based on comparative analyses of the morphological characters of specimens from several Brazilian herbaria (ALCB, EAC, HCDAL, HST, HUEFS, HVASF, IAN, MBM, MOSS, SP, UEC and UFMT), the scientific literature, and photographs of type collections. Each family is represented here by a single species. Caryocar coriaceum occurs predominantly in the southern portion of Ceará State in typical open (cerrado) and forested savannas (cerradão). Vismia guianensis is widely distributed and occurs in several vegetation types, but mainly ombrophilous forests and savannas. Rhizophora mangle has a narrow distribution range, being recorded in coastal vegetation with fluvial and/or lacustrine influences (mangrove swamps). All three species were recorded in designated Conservation Areas. An identification key for the species, morphological descriptions, commentaries on their conservation, habitats and phenologies, as well as photographs and illustrations are provided.

Calcium and Magnesium Dynamics in Litter in a Successional Forest Ecosystem, Under Hydroperiod

This study was part of the Manipulation of Moisture and Nutrient Availability in Young Regrowth Forests in Eastern Amazonia Project (MANFLORA). The experiment was designed in completely randomized blocks containing control and irrigated treatments during the dry period (5 mm of water/day), with four repetitions each. The monthly mean litter values ranged from 316.10 to 997.90 kg ha-1 month-1. The magnitude of this phenomenon can be explained by the functional role of the floristic structure, represented by the species Myrcia sylvatica (G. mey) DC., Myrcia bracteata (Rich) DC., Miconia ciliata (Rich) DC., Lacistema pubescens Mart., Lacistema aggregatum (Berg.) Rusby, Vismia guianensis (Aubl.) Choisy, Cupania scrobiculata Rich. and Ocotea guianensis Aubl., which constituted the determinant factors, associated with the hydroperiodic effect and ecosystem manipulation. The monthly mean of the analytical results of mass treatments were significant (P < 0.05), however, when compared annually there was no significance, which indicates seasonal influence, since the period of greatest deposition is the dry one, regardless of the water manipulation along the period studied. Only in time the mass values of Ca and Mg were not significant for treatment (P < 0.05). The amount of Ca was significantly (P < 0.05) higher than that of Mg.

Chemical Composition and Biological Activities of Essential Oils from Fresh Vismia guianensis (Aubl.) Choisy and Vismia cayennensis (Jacq.) Pers. Leaves

The Vismia Vand. genus encompasses many species indigenous to the Amazon rain forest where they are popularly known as “Lacre” bark and leaves are widely employed by locals to treat dermatophytoses. The aim of this study was to investigate the chemical composition of essential oils (EOs) extracted from the aerial parts of the species Vismia guianensis (Aubl.) Choisy and Vismia cayennensis (Jacq.) Pers. and to assess their antimicrobial activity against the bacteria Staphylococcus aureus Rosenbach 1884 and Escherichia coli (Migula 1895) Castellani and Chalmers 1919 as well as the fungi Candida albicans (C.P. Robin) Berkhout 1923 and Candida parapsilosis (Ashford) Langeron & Talice 1932. The analysis of the chemical composition of the essential oil extracted from V. guianensis leaves (EOVg) indicated 46 components, of which three sesquiterpenes predominated, namely: (E)-caryophyllene (10.40%), α-copaene (29.45%), and (E)-nerolidol (24.06%). As to the essential oil from V. cayennensis leaves (EOVc), 61 components were identified, of which two oxygenated sesquiterpenes stood out as the main components, namely, germacrone (25.42%) and curzerene (25.29%). EOVg exhibited Minimum Inhibitory Concentration (MIC) of 1.56 µg/mL against the yeast C. parapsilosis whereas EOVc was active against the bacteria E. coli and S. aureus as well as the yeast C. parapsilosis. The results obtained in this study strongly recommend further research on the essential oils in question with a view to isolating and identifying the components responsible for their observed antimicrobial activities.

Densidade e composição do banco de sementes do solo em ecossistema sucessional de floresta na Amazônia Oriental, Brasil

Na Amazônia, a agricultura itinerante garante a subsistência das comunidades tradicionais, porém, ocasiona intensos impactos ambientais. A restauração florestal com o monitoramento de indicadores, como o banco de sementes é indispensável, pois, fornece informações sobre as espécies viáveis para germinação em cenários de distúrbios ecossistêmicos. Objetivou-se, portanto, avaliar a composição e a densidade do banco de semente de uma floresta sucessional na Amazônia, submetida à manipulação de água e nutrientes há 12 anos. As coletas foram realizadas de maneira aleatória, com o auxílio de um amostrador vazado, em um fragmento florestal com três tratamentos (controle - CTL, remoção de serapilheira - REM e irrigação periódica- IRR). Encontramos 684 indivíduos e 32 espécies. A densidade de indivíduos variou de 820 ± 112 a 972 ± 394 ind m-2 para REM e CTL, enquanto a de espécies variou de 188 ± 48 a 216 ± 9,24 spp m-2 para CTL e REM, respectivamente. Os arbustos apresentaram a maior quantidade de indivíduos emergentes, e os cipós, a menor. Os maiores índices de Shannon-Weanver e Pielou foram observados no CTL. As espécies Vismia guianensis, Cecropia obtusa e Cyperus rotundus foram as mais frequentes em todos os tratamentos e as espécies pioneiras predominaram. A velocidade de emergência do tratamento REM foi inferior ao CTL, enquanto o tempo médio de emergência foi semelhante entre os tratamentos. A composição e densidade do banco de sementes não foram afetadas pelo efeito residual da manipulação de serapilheira. Apesar disso, os resultados foram ligeiramente superiores para o tratamento CTL.

Ecosystem restoration after bauxite mining: favorable indicators for Technosols construction and soil management using liming and subsoiling

Although its economic importance, bauxite mining causes the loss of natural ecosystems. In this sense, the Technosols building from materials made or modified by man, such as mine tailings, is necessary for recovering degraded areas. Additionally, the Technosols management, such as subsoiling and liming, increases chances of plants establishment and growth. In this study, a degraded area by bauxite mining with constructed Technosol in the Eastern Amazon, Brazil, was tested under three different soil management treatments: Technosol-1 (Tech-1), Liming only; Technosol-2 (Tech-2), Subsoiling + 200 g of NPK in the pit; Technosol-3 (Tech-3), Scarification + liming + all Tech-2 procedures. In every treatment and in a reference forest (R-forest), 8 years after the initial seedling planting, three types of indicators were assessed: structural (horizontal vegetation structure, density of natural regeneration, and soil cover), compositional (species diversity, ecological groups, and dispersal syndromes), and functional (chemical properties of Technosols and dry matter and nutrients from the litter stock). The most representative species in all treatments were Croton matourensis and Vismia guianensis, both coming from the natural regeneration and common in early successional stages. Coverage rates in all treatments showed less than 5% of exposed Technosol and the diversity, ecological group, and dispersal syndrome indexes followed a successful trajectory along 8 years. Tech-2 and Tech-3 presented the best chemical attributes and nutrients in the litter stock, but they would probably last several decades to reach the R-forest attributes. Thus, subsoiling alone or with liming provided the best chemical results for soil, litter, and vegetation performance, being recommended to speed up restoration of degrades areas by bauxite mining in the Amazon.

Recovering ecosystem functions through the management of regenerating community in agroforestry and plantations with Khaya spp. in the Atlantic Forest, Brazil

Our aims were to describe the role of the selective management of regenerating community (RC) on the recovery of ecosystem functions in production areas of African mahoganies under mixed stands and agroforestry systems, established on abandoned farmland. A randomized block experiment was set up with the following treatments: (T1) mixed-plantation of African mahogany under conventional system (including herbicide application); (T2) mixed-plantation of African mahogany with selective conduction of RC; (T3) agroforestry system with African mahogany; (T4) agroforestry system with African mahogany with selective conduction of RC. The parameters of horizontal structure, diversity and ecological attributes of species of the regenerating community were studied. In addition, the production of aboveground biomass and nutrient stocks, soil fertility, and soil microbial activity were assessed. In T1, herbicide application (glyphosate) affected the floristic composition of the regenerating community by reducing the dominance of monocots and Pteridium arachnoideum, allowing the regeneration of other taxonomic groups of herbaceous species. In response, there was a reduction in the litter biomass stock comparing to the other treatments. The treatments with selective management of the RC (T2 and T4) produced more biomass and accumulated higher amounts of C and nutrients than the conventional treatments (T1 and T3). These treatments also allowed other shrub and tree species to overcome the ecological filter imposed by grasses and colonize the experimental area. Baccharis dracunculifolia, Vismia guianensis, Cecropia pachystachya and Inga sp. were the most important regenerating species that contributed most to the stocks of all nutrients in living aboveground biomass. Pruning and selective management in T4 increased the soil effective cation exchange, while in the T1 treatment there was a lower activity of the β-glucosidase enzyme. The selective management of RC in agroforestry systems through the manipulation of competitive relationships allowed the colonization of native tree and shrubby species that provide several additional ecosystem services, including pollination, fauna attraction, food production, pest control and environmental regulation for the agroecosystem.

Stimulation of isoprene emissions and electron transport rates as key mechanisms of thermal tolerance in the tropical species Vismia guianensis.

Tropical forests absorb large amounts of atmospheric CO2 through photosynthesis, but high surface temperatures suppress this absorption while promoting isoprene emissions. While mechanistic isoprene emission models predict a tight coupling to photosynthetic electron transport (ETR) as a function of temperature, direct field observations of this phenomenon are lacking in the tropics and are necessary to assess the impact of a warming climate on global isoprene emissions. Here we demonstrate that in the early successional species Vismia guianensis in the central Amazon, ETR rates increased with temperature in concert with isoprene emissions, even as stomatal conductance (gs ) and net photosynthetic carbon fixation (Pn ) declined. We observed the highest temperatures of continually increasing isoprene emissions yet reported (50°C). While Pn showed an optimum value of 32.6±0.4°C, isoprene emissions, ETR, and the oxidation state of PSII reaction centers (qL ) increased with leaf temperature with strong linear correlations for ETR (ƿ=0.98) and qL (ƿ=0.99) with leaf isoprene emissions. In contrast, other photoprotective mechanisms, such as non-photochemical quenching, were not activated at elevated temperatures. Inhibition of isoprenoid biosynthesis repressed Pn at high temperatures through a mechanism that was independent of stomatal closure. While extreme warming will decrease gs and Pn in tropical species, our observations support a thermal tolerance mechanism where the maintenance of high photosynthetic capacity under extreme warming is assisted by the simultaneous stimulation of ETR and metabolic pathways that consume the direct products of ETR including photorespiration and the biosynthesis of thermoprotective isoprenoids. Our results confirm that models which link isoprene emissions to the rate of ETR hold true in tropical species and provide necessary "ground-truthing" for simulations of the large predicted increases in tropical isoprene emissions with climate warming.

Flow-through amperometric methods for detection of the bioactive compound quercetin: performance of glassy carbon and screen-printed carbon electrodes

Rapid methods using batch injection analysis (BIA) with amperometric detection were developed for the determination of quercetin extracted from the Brazilian plants Brunfelsia uniflora (BU), Vismia guianensis (VG), and Arrabidaea brachypoda (AB). One method was based on a glassy carbon electrode (GCE) and pulsed amperometry (BIA-PA), while the other employed a screen-printed carbon electrode (SPCE) and conventional amperometry (BIA-CA). Both proposed methods required minimal sample manipulation (only dilution in the carrier electrolyte), and the determination was performed with a single injection of 100 μL of sample solution. The BIA-PA method was highly accurate (RSD = 0.7%, n = 30), fast (120 injections h−1), and presented low limits of detection (0.004 μmol L−1) and quantification (0.015 μmol L−1). The BIA-CA method was also accurate (RSD = 1.1%, n = 30), fast (120 injections h−1), and presented low limits of detection (0.027 μmol L−1) and quantification (0.091 μmol L−1). The application of the proposed methods for the determination of quercetin in the plant extracts provided results similar to those obtained by high-performance liquid chromatography (HPLC) at a confidence level of 95%.

Soil seed banks in successional stages of forest ecosystems in the Belém, Pará, Brazil, metropolitan region

The seed bank is essential for the initiation of natural forest regeneration, especially in ecosystems in
 the early stages of development, where there have been anthropogenic or natural disturbances. The objective
 of the current study was to evaluate seed bank dynamics in three forest ecosystems, two in Utinga State Park
 (PEUt) and one on the Federal Rural University of Amazonia (UFRA) campus, both in Belém, Pará, Amazonian
 Brazil. The ecosystems were: primary forest (PF), early successional forest (ESF), and late successional forest
 (LSF). For seed bank evaluation, five plots were installed in each forest ecosystem, and in each plot 5 soil
 samples were removed at a depth of 0-0.05 m. In the three ecosystems, the most abundant species in the
 seed bank were Cecropia obtusa, Phyllanthus tenellus and Vismia guianensis. Zoochoria was the dominant
 dispersion syndrome with 1,041 (67.8%) individuals. In the PF and LST ecosystems the predominant life form
 was tree, followed by shrub, whereas in the ESF the shrub life form predominated, followed by tree. Thirtyone
 species were recorded in PF, 26 in ISF, and 32 in LSF. In general, pioneers were most frequent ecological
 group, with 289 individuals (93.2%) in PF, 288 individuals (88.7%) in LSF, and 188 (75.06%) in ESF. Thus, all
 ecosystems possessed a high potential for resilience in case of possible forest disturbances, and the PF seed
 bank was considered the most diverse in terms of arboreal species.

Caracterización florística del bosque subandino y algunas áreas disturbadas en San Bernardo (Cundinamarca), Colombia

A characterization of the vegetation in forest relicts, Eucalyptus globulus plantations, and grasslands in the municipality of San Bernardo was made with a preferential sampling. Plots were created according to type of land cover and stratum according to Moreno (2001) and Villareal et al . (2004). 31 species were recorded for the forest relict, seven in the E. globulus plantations, and 25 in the grassland areas. Greatest values of Shannon diversity were obtained for the forest relicts (2.97), followed by grasslands (2.40), and lastly the E. globulus plantations (1.15). In terms of Simpson dominance, the same pattern was found, since forest relicts had the highest value (0.93), followed by grasslands (0.83) and E. globulus plantations (0.56). Species with the highest values of IVI and IPF included Hedyosmum bonplandianum , Miconia theaezans , and Vismia guianensis in the forest relicts and E. globulus in its plantations. Similarly, some plant attributes that favor colonization and establishment were identified due to their possible implications on the restoration of the ecosystem. Anthropic activities such as agriculture, livestock, forest plantations, and fires, among others, have caused the loss of native vegetation and fragmented the ecosystem.

Essential Oils from Leaves of Medicinal Plants of Brazilian Flora: Chemical Composition and Activity against Candida Species

Background: The biotechnological potential of medicinal plants from Brazilian Caatinga and the Atlantic Forest has not been extensively studied. Thus, screening programs are important in prospecting for compounds for developing new drugs. The purpose of this study was to determine the chemical composition and to evaluate the anti-Candida activity of essential oils from leaves of Hymenaea courbaril var. courbaril, Myroxylon peruiferum, and Vismia guianensis. Methods: The oils were extracted through hydrodistillation and their chemical compositions were analyzed by gas chromatography coupled with mass spectrometry. Antifungal activity against C. albicans, C. tropicalis, C. parapsilosis, C. glabrata, and C. krusei was evaluated by determining the minimal inhibitory (MIC) and fungicidal (MFC) concentrations. Results: The major compounds of the oils were caryophyllene oxide and trans-caryophyllene for H. courbaril; spathulenol, α-pinene, and caryophyllene oxide for M. peruiferum; and caryophyllene oxide and humulene epoxide II for V. guianensis oil. The oils showed antifungal activity against all the strains tested, and the MIC values ranged between 0.625 and 1.25 μL/mL and MFC from 0.625 to 2.5 μL/mL. Conclusion: The essential oils from the species studied have the potential to be evaluated as clinical applications in the treatment of candidiasis.

Natural regeneration in a fragment of semideciduous forest in Sinop, MT

This study aimed to evaluate the physiognomy structure, composition and diversity of tree species in a semideciduous forest fragment on the site Clotilde located in the municipality of Sinop, Mato Grosso. For floristic and phytosociological analysis were installed 7 plots of 100m2 systematically distant 25 meters of each other, sampled all the arboreal component with height greater than 5 cm. For the diametric analysis they were measured the circumferences of the individuals who had diameter less than 30 cm from the ground. Subjects were classified into four classes of natural regeneration size. They identified 18 species belonging to 18 genera and 15 families with a total of 250 individuals in an area of 0.07 hectares. The trees presented Shannon Diversity Index estimated 2.13 for the height class I, 1.98 for class II, 0.99 for class III and 0.89 for class IV, and the species the highest values of importance measured by the IVI, were Vismia guianensis and Trattinickia rhoifolia excelling in all studied phytosociology. It was concluded that the analyzed fragment has low floristic diversity

Anti-inflammatory activity of Vismia guianensis (Aubl.) Pers. extracts and antifungal activity against Sporothrix schenckii

Ethnopharmacological relevanceVismia guianensis (Aubl.) Pers. is traditionally used in North and Northeast of Brazil for the treatment of dermatomycoses. Since the strategy associating immunomodulators with antifungal drugs seems to be promissory to improve the treatment efficacy in fungal infections, we aimed to investigate the antifungal activity of V. guianensis ethanolic extract of leaves (VGL) and bark (VGB) against Sporothrix schenckii ATCC 16345 and their antinflammatory activities. Material and methodsThe extracts were analyzed by HPLC-DAD-IT MS/MS for in situ identification of major compounds. Antifungal activity was evaluated in vitro (microdilution test) and in vivo using a murine model of S. schenckii infection. The production of TNF-α, IFN-γ, IL-4, IL-10 and IL-12 by measured by ELISA, as well as measured the production and inhibition of the NO after treatment with the plant extracts or itraconazole (ITR). ResultsTwo O-glucosyl-flavonoids and 16 prenylated benzophenone derivatives already described for Vismia were detected. Both VGL and VGB showed significant antifungal activity either in in vitro assay of microdilution (MIC=3.9µg/mL) and in vivo model of infection with reduction of S. schenckii load in spleen. It was also observed a predominance of reduction in the production of NO and the proinflammatory cytokines evaluated except TNFα, but with stimulation of IL-10, as evidence of a potential anti-inflammatory effect associated. ConclusionThe results showed that both VGL and VGB have a significant antifungal against S. schenckii and an anti-inflammatory activity. These results can support the use of these extracts for alternative treatment of sporotrichosis.

Communities of saprobic fungi on leaf litter of Vismia guianensis in remnants of the Brazilian Atlantic Forest

We examined the mycobiota associated with Vismia guianensis leaf litter in three Atlantic Forest remnants of Brazil’s semiarid region. Among the study sites, two remnants were protected forest reserves, whereas the third was influenced by major anthropogenic activities. Eighteen litter samples were collected in wet and dry seasons and were processed by particle filtration technique. A total of 4750 fungal isolates of 142 taxa were identified. Species richness was higher in litter samples collected during wet season. Nonmetric multidimensional scaling multivariate analysis showed differences in the composition of fungal communities among the sampling sites and the seasons. Analysis of similarity showed that the differences were statistically significant (R = 0.85; P = 0.0001). Our findings revealed that spatial and temporal heterogeneity, and human activities had significant impacts on the saprobic fungi of V. guianensis leaf litter.

Fast natural regeneration in abandoned pastures in southern Amazonia

Abandoned pastureland provides a prime opportunity for forest recovery of these degraded areas in the Amazon. Many factors impact forest regeneration, including time and intensity of pasture use before abandonment, and proximity of a source of propagules. Given these conditions, it is necessary to better investigate the effect of such factors on the natural regeneration of abandoned pastureland. Here we employed chronosequences to study secondary forest succession in abandoned pastures along the Madeira River, Rondônia, Brazil. We installed 314m2 plots in 36 abandoned pastures previously subjected to long-term use (average of 9years), but now at different stages of natural regeneration. All tree species stems ⩾30cm in height were identified, and their diameter was measured at ground level. Using a historical series of Landsat satellite images, time of pasture encroachment (“encapoeiramento”), time of pasture use, and time since last use were all calculated. The percentage of forest cover adjacent to each plot was calculated using a circular buffer (120m radius) overlaid on a land-cover classification. Model selection procedure was used to access the importance of four predictors on natural regeneration variables (species density, basal area, stem density). We sampled 6380 stems belonging to 202 morphospecies grouped into 138 genera and 51 families. The two most important species were Vismia guianensis and Vismia gracilis that together represented 40% of abundance, 70% of frequency, and 101% of IVI (Importance Value Index) of the plants sampled. Most species (164) were recorded in a maximum of four out of 36 plots sampled. Species density increased by ca. five species per year after pasture encroachment. Occurrence of rare species increased with time following encroachment, while relative abundance and basal area of the main pioneer species decreased with the advance of forest succession. Time of pasture encroachment, time of pasture use, and time since last use had significant effect on natural regeneration, whereas cover of surrounding forest had limited influence. Although constrained by long-term use, natural regeneration in abandoned pastures occurred relatively rapidly based on the high occurrence of resprouting pioneer species, which formed secondary sites during the first years of succession. Afterwards, regeneration was incremented by the establishment of a number of late succession species. We conclude that forest restoration of abandoned pastures in the Amazon should use the natural potential of forest regeneration, considering both the speed and intensity of the process.