Resumo em Inglês:

Abstract This study aimed to evaluate litterfall and nutrient dynamics in an experimental plantation of peach palm (Bactris gasipaes Kunth) in Taubaté, São Paulo, Brazil. Litterfall was collected monthly between March 2010 and May 2011, and the plant material was separated into leaflets and rachises. During the 15-month study period, the plantation produced 9.2 Mg ha−1 of litter (4.8 Mg ha−1 of leaflets and 4.4 Mg ha−1 of rachises). Seasonal variations were observed in litter production and nutrient concentration. Litter deposition was the highest at the end of the dry season and at the beginning of the rainy season, that is, in months with low rainfall and lower minimum temperatures. Macronutrient return to the soil was estimated at 141.5 kg N ha−1, 24.8 kg P ha−1, 78.2 kg K ha−1, 55.1 kg Ca ha−1, and 37.8 kg Mg ha−1.

Resumo em Inglês:

Abstract Cadmium (Cd) is one of the most toxic elements to plants, so Cd-tolerant trees should be used in reforestation or remediation systems. In this study the effects of Cd on seed germination and early seedling growth were evaluated in Schinus molle plants. Seeds of S. molle were treated with Cd at concentrations of 0 (control), 0.01, 0.02, 0.05, and 0.125 mM using Cd(NO3)2. Seed germination parameters and seedling growth traits were evaluated 33 days after the experiment started. Seeds and roots were sampled for anatomical evaluation and processed with plant microtechniques. No effects of Cd were found on the germination percentage of S. molle seeds. However, seedlings’ shoot and root fresh masses and lengths increased with Cd treatment. Cadmium increased root cortex and endodermis thickness and reduced the percentage of vascular tissues in seedlings. Schinus molle seeds and seedlings thus showed tolerance to Cd related to anatomical adaptations.

Resumo em Inglês:

Abstract This article sought to assess the genetic diversity within and between natural populations of Astrocaryum acaule by means of AFLP markers. Ninety individuals were sampled in three populations located in Manaus (state of Amazonas) across regions with different intensities of anthropogenic activity. Two clusters were differentiated by means of dendrograms and Bayesian cluster analysis, the first consisting of individuals from the Tarumã-Açu population in an intensely agricultural region, and the second, of populations from UFAM and Tupé conservation areas. The physical isolation of A. acaule populations has resulted in good conservation of its genetic identity, since anthropogenic activity is an important modifier of the genetic diversity of natural populations. Genetic diversity was higher within populations (74.58%) than between them (25.42%), which means that we have to collect representative samples from each of the genetically distinct groups for genetic conservation of the species. Therefore, in situ conservation is recommended.

Resumo em Inglês:

Abstract In forest nurseries, one of the factors that change the growth and quality of seedlings is water supply, which has a direct influence on metabolic processes such as stomatal conductance and photochemical efficiency of photosystem II. This study aims to identify the influence of different watering regimes as well as the use of a water-retaining polymer on the initial growth and metabolic processes of Enterolobium contortisiliquum seedlings. The experimental design was in random blocks with a factorial scheme. Morphological attributes, as well as physiological and biochemical attributes were investigated. We verified that the performance of E. contortisiliquum seedlings depends on the watering regime provided to the plants; furthermore, up to 60 days after the application of the treatments, both the height and diameter of the collection and the leaf water potential were similar in the water regimes of 8 mm day-1 and 12 mm day-1.

Resumo em Inglês:

Abstract Ecological restoration through conventional plantation techniques can create forests with low biodiversity. As such, one way to overcome possible shortcomings of the restoration process is to use nucleation techniques, such as artificial perches. These structures attract the avifauna and increase the deposition of seeds associated with feces or bird regurgitation. Seed rain and seedlings regeneration were monitored under artificial perches and control areas in a degraded area of Rio de Janeiro, RJ, Brazil. In this study, 46 morphospecies of seeds were identified. Under the perches, greater abundance and richness of seeds were found with certain ecological and functional traits that support the role of artificial perches as a biological diversity core. Seedling establishment was low under the perches and control areas. This suggests that integrated actions to improve soil conditions should be applied to enhance seedling establishment.

Resumo em Inglês:

Abstract Forest harvest residues are usable; however, studies on their quality are incipient. Thus, our study sought to perform physico-mechanical characterization of wood from the branches of Astronium lecointei and Manilkara huberi, as well as to compare its properties with trunk material found in the literature. The material was collected in the Tapajós National Forest (Flona - Tapajós) and cut for the trials performed at the Universidade Federal do Oeste do Pará (Ufopa). Descriptive statistics were used for data analysis and the averages were compared with values found in the literature for the trunk of the studied species and other commercial wood of the region. The physical properties of Astronium lecointei and Manilkara huberi showed approximate averages to those of trunk, while the mechanical properties presented lower averages. Therefore, regarding the mechanical properties, the residues may be substituents for the trunks of other species for having similar properties.

Resumo em Inglês:

Abstract Exposing timber to temperatures approaching 200 °C causes thermal modification and changes its characteristics. This study evaluates the effect of various levels of thermal treatment on the physical properties of juvenile and mature wood from rubber tree (Hevea brasiliensis). Boards taken from 53-year-old rubber trees were thermally modified at up to 220 °C. Thermal treatment caused decreases on the oven-dried density, equilibrium moisture content, and swellings on juvenile and mature woods of H. brasiliensis. Influence of thermal modification at 180-200 °C in juvenile wood was lower than in mature wood, whereas the treatment at 220 °C caused a greater variation in properties of juvenile wood. The thermally modified wood is a suitable product for use in environments with high levels of relative humidity.

Resumo em Inglês:

Abstract The comparison of vegetation at two different moments allows for recognizing the stability of plant communities. The structure and floristic composition of a Caatinga fragment in the municipality of Poço Verde, state of Sergipe, were evaluated after four years (2011-2015). Sampling was performed through 30 plots of 20 m × 20 m, considering individuals with circumference at breast height ≥ 6 cm. Despite the increase in density (0.79%) and basal area (4.82%), changes in floristic composition, in Shannon-Wiener diversity (from 3.33 nats.ind-1 to 3.30 nats.ind-1) and in Pielou equability (from 0.78 to 0.80) were small. None of the structural parameters evaluated (richness, density, basal area, importance value and Shannon-Wiener diversity) significantly differed between evaluation periods. The vegetation remained stable over time, tolerating current anthropization levels and enabling the use of its natural resources through planned management.

Resumo em Inglês:

Abstract Tropical forests include remnants that should be characterized and monitored for long-term conservation. With this in mind, we performed a survey of the floristic composition and structure of the Mata Santa Elisa (Campinas, SP), and compared it to other fragments of semi-deciduous seasonal forest in the municipality. In Mata Santa Elisa, 506 living arboreal specimens were found, belonging to 100 species, 75 genera and 32 families. At the time of this work, the fragment was well-preserved and contained exclusive species and those of economic interest or potential, highlighting its importance in the region.

Resumo em Inglês:

Abstract Our study aims to determine the energetic quality of residues from the manufacturing of jatropha and eucalyptus, as well as to evaluate the physical properties of the briquettes made with different proportions of these biomasses. The following proportions were used for this study: 100% eucalyptus; 75% eucalyptus; 50% jatropha and 50% eucalyptus; 75% jatropha; and 100% jatropha. The apparent density of the residues, the immediate chemical product, the highest calorific value (HCV), the apparent density, the energy density, the usable calorific value (UCV), the lowest calorific value (LCV), the breaking strength of the briquettes (FR) and the hydroscopic moisture balance (HMB) were verified. Although the energetic characteristics of the jatropha residues are not superior to those of eucalyptus, this biomass adds favorable mechanical characteristics to the briquettes comprised of greater proportions of jatropha to eucalyptus, guaranteeing the energetic properties of the briquette, as well as reducing the production cost.

Resumo em Inglês:

Abstract Pecan cultivation in Brazil has gained increasingly economic importance in the southern part of the country. The objective of this work was to identify the pathogen that causes root rot in Carya illinoinensis seedlings in the nursery, through morphological, molecular and pathogenicity tests. Fungi from the genus Fusarium found in symptomatic roots of pecan seedlings were isolated in potato dextrose agar (PDA) culture medium and purified. Morphological characterization was performed in PDA and carnation leaf agar (CLA) media. For the molecular characterization, the genomic segments ITS (internal transcribed spaces), β-tub (beta-tubulin), and tef1-α (elongation fact 1-alpha) were sequenced. The pathogenicity test was performed on healthy seedlings in the greenhouse. The combination of morphological and molecular characters was fundamental for identification of the species, showing that the most suitable genes for identification were ITS and tef1-α. The causative agent of root rot in C. illinoinensis seedlings in the nursery was identified as Fusarium oxysporum.

Resumo em Inglês:

Abstract Dipteryx alata is an arboreal species found in the Brazilian Savannah (BS), that has potential human and animal uses, including nutrition, medicine, and revegetation. This study aimed to evaluate the nutritional status and growth of D. alata seedlings used to recover degraded soils to which residues had been added compared to seedlings grown in the BS. The degraded soil was treated with organic and agroindustrial residues. Twelve months after seedlings were introduced, they were evaluated for height, stem diameter, chlorophyll index, and concentration of foliar macro and micronutrients. The foliar concentration was determined for D. alata seedlings grown in the degraded area and BS. The addition of residues increased foliar concentration of seedlings grown in the degraded area; however, concentrations did not reach similar levels to seedlings grown in BS. D. alata accumulated Mn in plants. The height and stem diameter of seedlings responded positively to residue application.

Resumo em Inglês:

Abstract This study aimed to carry out a phytosociological survey in a riparian area of an intermittent stream in the semi-arid region of Paraíba, Brazil. Fifty-one contiguous plots of 10 × 20 m (1.02 ha) were distributed along the watercourse. Living and dead shrub-tree individuals, still standing, with stem diameter at ground level (DGL) ≥ 3 cm and total height ≥ 1 m were sampled. Fifty-one species distributed in 22 families were sampled. Fabaceae, Euphorbiaceae, and Anacardiaceae had the highest species richness. Aspidosperma pyrifolium Mart. & Zucc., Combretum monetaria Mart., and Cenostigma pyramidale (Tul.) E. Gagnon & G.P. Lewis had the highest importance values. Shannon index was 2.61 nats.ind.−1 and the total basal area was 25.4 m2. Height and diameter mean values were 5.4 m and 12.4 cm, respectively. Phytosociological parameters recorded for the studied riparian vegetation have higher values in comparison with those obtained in other areas of the caatinga.

Resumo em Inglês:

Abstract Litterfall and nutrient cycling are essential processes for the forest diversity and productivity maintenance. This study aims to characterize the litterfall and evaluate if it has correlations with climatic variables in the Semideciduous Seasonal Forest on advanced succession stage, in Southern Brazil. During the 2007-2010 period, the litterfall was collected every month, sorted into leaves, twigs, and miscellaneous fractions. The litterfall amount average was 7.75 Mg ha-1 year-1 and leaves constituted the highest litterfall percentage (75.0%), followed by twigs (14.7%), and miscellaneous (10.3%). Higher leaf amounts were recorded in August and September. The minimum air temperature was negatively correlated with the leaves and twigs production, that is, the litterfall amount increases when the air temperature decreases. The litterfall amount corresponds to values expected to advanced successional stage of the forest typology studied. In Semideciduous Seasonal Forest in Southern Brazil, the thermal stress exerts influence on the litterfall amount.

Resumo em Inglês:

Abstract This study aimed to assess the potential of artificial neural networks (ANN) as a tool to estimate deforestation rates in the municipality of São Félix do Xingu, PA, Brazil. The following input variables were used: deforestation rate until 2014, slope, altitude, Euclidean distance to roads and rivers, permanent preservation area (PPA), and property area. A total of 2,800 properties were used, of which 2,000 were used for training and 800 for validation of the networks. The input layer included nine neurons: six as quantitative variables and three as categorical variables. The output layer included a single neuron - the deforestation rate. The training results indicated high correlation (r = 0.92) and root mean square error (RMSE) of 12.4%. Validation of the model estimated RMSE = 12.9% and r = 0.91. The study results evidenced the high potential of ANN as a tool to estimate farm deforestation rates.

Resumo em Inglês:

Abstract In this study, we assessed the gas exchange in Caryocar brasiliense seedlings in water deficit conditions and their capacity to recover after rehydration. We assessed plant photosynthetic rates, internal carbon concentrations, stomatal conductance, transpiration rates, water-use efficiency, instantaneous carboxylation efficiency, chlorophyll index, and photosystem II quantum efficiency. All gas exchange parameters were reduced after the suspension of irrigation. Seedling photosynthetic rates approached zero after 12 days. The equilibrium was reestablished in all variables 11 days after re-initiating irrigation, with the exception of internal CO2 concentration and stomatal conductance. Exposure of seedlings to water stress resulted in drastically reduced photosynthetic processes. This reduction occurred due to the limitation of stomatal conductance and low rubisco carboxylation efficiency but not to irreversible damage photosystem II. All of these parameters demonstrated recuperation with rehydration, but only the photosynthetic rates reached initial control values.

Resumo em Inglês:

Abstract This work aimed to assess the virulence of Beauveria bassiana isolates in different concentrations on Thaumastocoris peregrinus (Hemiptera, Thaumastocoridae) and select them to control this insect pest. Suspensions of IBCB35, IBCB66, IBCB18, IBCB01 and JAB06 isolates were tested in the concentrations of zero, 1 × 104, 1 × 106, 1 × 108 conidia/ml, applied on the eucalyptus leaves used to feed the insects. Dead insects were disinfested daily and placed in a humid chamber to confirm the death by fungus. Mortality at the end of the experiment ranged from 12% for IBCB66 to 48% for IBCB18 at a concentration of 1 × 104 conidia/ml, between 32% for IBCB66 and 68% for JAB06 at a concentration of 1 × 106 conidia/ml, and between 60% for IBCB01 and 84% for JAB06 at the concentration 1 × 108 conidia/ml. The assessed isolates were efficient in controlling the insect, especially JAB06.

Resumo em Inglês:

Abstract This work aimed to evaluate the influence of the substrate composition on the emergence, vigor, and growth of Tabernaemontana catharinensis seedlings in a greenhouse. Seeds were placed to germinate by testing the following substrates: pure Mecplant and combined with fine texture vermiculite (V) or charcoal rice husk (CRH) in different proportions. Variables of emergence percentage, emergence speed index, height, collection diameter, root length, leaf area, dry mass (shoot, root, and total), Dickson quality index, and photosynthetic pigment contents were evaluated. Germinated plants on pure Mecplant substrate presented lower emergence values and morphophysiological parameters. This commercial substrate associated with vermiculite at 1:1 and 1:3 proportions provided higher seed vigor and higher seedling growth, proving to be more adequate for the seedling formation of the species. The formulated substrates did not show a significant influence on the photosynthetic pigment contents.

Resumo em Inglês:

Abstract This study aimed to perform a comparative analysis between models of mechanical maintenance in forestry machines, subsidizing operational planning in order to reduce production costs. The work was conducted in a forestry company with feller bunchers, skidders and harvester machines. The comparative analysis included the Traditional Maintenance and the World Class Maintenance (WCM) models in the judgment of mechanical availability, hydraulic oil consumption and maintenance costs. Using the WCM maintenance model, the results showed a 5% increase in mechanical availability and a 60% reduction in hydraulic oil consumption. The maintenance cost increased by 3% in the WCM model due to an investment in infrastructure and the training of mechanics, but with the potential for better maintenance of forest machines, along with improvements in operational safety, production capacity and longer machine life.

Resumo em Inglês:

Abstract This study evaluated color and reflectance spectra during industrial process of yerba mate leaves and tested the potential of these parameters to predict moisture and tannin content, to be applied as an auxiliary tool in quality control in industry. Two groups of yerba mate samples were evaluated: one grown under organic and another under conventional conditions. The results indicate an increase in lightness, loss of the green color, although less marked in the organic samples, an increase of yellow in both types of samples along processing due to moisture removal at high temperatures. For moisture content, reflectance curve can be applied with R2 ≥ 0.9, and for tannin content the sum of b* parameter and spectra in region 590-700 nm are recommended. Color parameters and reflectance spectra can be applied for a preliminary evaluation of moisture and tannin content in the yerba mate industry, contributing for the quality control of samples.

Resumo em Inglês:

Abstract This study aimed to identify priority areas for the passive restoration of the Arauaí river basin, municipality of Moju, Pará, using a multicriteria model. This basin is located in a region with intense land use dynamics and expansion of oil palm cultivation, and with high forest loss and fragmentation. The Weighted Linear Combination method was used, with the aggregation of five criteria (Natural Erosion Vulnerability, Potential Land Use and Cover to Passive Restoration, Proximity to the Primary Forest, Forest cover deficit in PPAs, and Distance from Roads and Highways). This analysis allowed to evaluate different biophysical classes and types of land use that affect the selection of areas for restoration. A total of 207.82 km2 of priority areas for passive restoration were identified in the studied basin, with about 80% of its priority areas having medium to very high priority. The final map generated proved to be a useful instrument in the environmental management of restoration plans in the Amazon watershed.

Resumo em Inglês:

Abstract This study aimed to assess the effectiveness of four weed control strategies in forest setting stands linked by a set of Atlantic Forest tree species. Four treatments were employed: mechanical – manual hoeing and mowing; chemical – glyphosate herbicide application in the total area; chemical – cultural – herbicide spraying and herbaceous legume intercropping; chemical-mechanical – herbicide planting in rows and mowing in the interrows. Diameter, crown area and soil cover percentage of the eight tree species were assessed at 18 months. Herbicide spraying in total area promoted the greatest reduction in weed populations, as well as superior growth in height, diameter, crown area and soil cover of the tree species. More interventions were necessary in the treatment of mechanical weed control that has also shown the least growth of the tree species. The chemical method was the most effective in weed control and promoted the greatest growth of the tree species.

Resumo em Inglês:

Abstract This research aimed to evaluate the relationship between Vessel-Ray Pits (VRP) and Intervessel Pits (IVP) and water flows in the different axes of Eucalyptus urophylla wood. Samples of E. urophylla wood were used to correlate the VRP and IVP dimensions with free, adsorbed and total water flow rates. Correlations were conducted for the three axes of the wood. Results indicated that overall, it could be observed that the greater VRP and IVP in the axial axis of wood increased free water and absorbed water flows. On the one hand, the greater VRP in the radial and tangential directions reduced the free water flow and increased the absorbed water flow. On the other hand, the greater IVP in the radial and tangential directions of the wood accelerated the free water outlet and reduced the absorbed water flow. The VRP and IVP of E. urophylla wood influenced water flow according to its physical state and wood axis.

Resumo em Inglês:

Abstract This study aimed to characterize the floristic composition and community structure of vascular epiphytes in 13 green areas of Juiz de Fora, in the State of Minas Gerais, Brazil. The calculated parameters were relative and absolute frequencies, Shannon diversity (H') and Pielou evenness (J) indices. 56 species belonging to 22 families were recorded, with the richest species being Bromeliaceae (eight spp.). Tillandsia tricholepis, T. recurvata, Microgramma squamulosa, and Rhipsalis lindbergiana were dominant (comprising 79.5% of relative frequency). Most species were accidental epiphytes (26 spp.), probably due to an effect of the disturbed environment. The richest and most diverse area was the Parque Halfeld (26 species and H’=2.2), which is also the oldest sampled area. There was a higher concentration of epiphytes in the tree crowns, possibly representing a response to anthropic actions. The results highlighted the importance of thorough studies to achieve a better understanding of this ecologically relevant synusia in such disturbed environments.

Resumo em Inglês:

Abstract Although the conservation of tropical biodiversity depends on protected areas, there is still a very large ‘gap’ of knowledge on the flora of Brazilian reserves, especially in the Northeast region of Brazil. Field and herbarium surveys of the phanerogamic flora of the Ubajara National Park, located on the Brazilian Northeast, were made and analyses on phenology and dispersal syndromes were performed. 418 taxa (213 trees and shrubs, 100 terrestrial herbs, 68 climbing plants, 33 sub-shrubs, two epiphytes, one hemiparasite and one aquatic herb) were recorded. The most representative families were: Fabaceae, Malvaceae, Asteraceae, Rubiaceae and Euphorbiaceae. The annual flowering / fruiting peak hypothesis was not fully confirmed, therefore, the forest may be an important food resource for the fauna all year long (especially in the moister region). Zoochory was the predominant dispersal syndrome in the moister area, whereas, autochory and anemochory together, predominated in the drier area.

Resumo em Inglês:

Abstract The main objectives of the study were to determine which was the best implantation of forest method between direct seeding and planting of seedlings, the use of Slow Release Fertilizer (SRF) and hydrogel in the pioneer species Schizolobium parahyba var. amazonicum and Senegalia polyphylla, and the use of morphometric indices, such as slenderness of trunk and canopy, to assist in growth evaluation. Generalized Linear Model (GLM) and Principal Component Analysis (PCA) were used as the main methods. The morphometric indices, plus the variables height, trunk and canopy diameter, provided complementary information on the morphological growth pattern of the plant. For both species, both direct seeding and planting of seedlings promoted good results in the growth variables, with the planting of seedlings showing better results in Senegalia, however, not enough statistical clarity for Schizolobium. Regarding inputs, the SRF promoted the best results and therefore this fertilizer was recommended for a complementary input in forest implantation.

Resumo em Inglês:

Abstract South American cities have been expanding extremely fast and with reduced urban planning, which can lead to significant biodiversity loss. In this study, it was assessed the potential consequences of unplanned urban growth on bird species inhabiting an area comprising a mosaic of forest and natural grasslands in the city of Belo Horizonte in Brazil. Considering the lower aboveground biomass, it would be expected grassland patches to be more occupied by humans than forest patches. The bird community inhabiting the area in 2012 was recorded and it was also provided a visual interpretation of satellite imagery for 2012 and 2018. The urban area increased 192.73%, which occurred to the detriment of forest and, especially, grasslands, with a reduction of 10.78% and 22.12%, respectively. In this area, it was recorded a total of 126 bird species, of which 65% were classified as of open habitat. It was also discussed the need for better urban planning by incorporating potential impacts on biodiversity and preservation of habitat mosaics within urban landscapes.

Resumo em Inglês:

Abstract Market demands lead companies to improve their processes by implementing quality management. Quality management is inserted to support decision-making in quality control assessments to allow variability reduction, achieving homogeneity when added to the standardization of methodologies, which is the main characteristic desired by the industry. Our study seek to analyze if quality control of silvicultural operations in a forest-based company showed an increased compliance index between 2012 and 2016; and to analyze the efficiency of quality control evaluation through comparative analyzes with the methodology proposed by Shewhart for the most outlier operation. The evaluations have shown that quality assessments did not present a regular evolutionary pattern in the period evaluated. The herbicide application activity was the most outlier operation, since it did not show a trend for constant improvement.

Resumo em Inglês:

Abstract Diaspore dispersal is an essential function of plant species, with effects on plant populations and natural forest dynamics. This study examines how traits of the mother plant (height, crown spread and distance from the diaspores) and the wind (wind speed) affect the spatial distribution of anemochorous diaspores of Apuleia leiocarpa, Peltophorum dubium, and Jacaranda micrantha in Southern Brazil. The number of diaspores from A. leiocarpa, P. dubium, and J. micrantha decrease with the increase in distance from the mother plant and there was no influence of wind direction on the spatial distribution of diaspores. Diaspore sizes of these plants were not related to their dispersal distances. Diaspore dispersal for A. leiocarpa was negatively correlated to the plant height and the crown spread. The dispersal of Peltophorum dubium and Jacaranda micrantha were not influenced by the diaspores and plants traits considered in this study.

Resumo em Inglês:

Abstract This study sought to assess the variation in species composition and community structure considering soil characteristics. Based on physical and chemical analyses of soil, we selected four sites for vegetation sampling: Haplic Cambisol (P1), Regolithic Neosol (P2), Latosol Bruno (P3) and Humic Cambisol (P4). In each site, we sampled all arboreal individuals with DBH ≥ 4.8 cm. Sites were distinguished by species with different values of importance and indicator index (indVal). Sites were clearly separated in biplots generated by canonical ordination (RDA), which indicated that the distribution of species correlates with acidity, Al+, C and P concentrations, CEC, pH, base saturation, drainage, and pedological unit. Our results show that local scale variation in soil attributes influences tree species composition and community structure, and, thus, should be considered for understanding the distribution, occupation, and response of tree species in remnants of Mixed Ombrophilous Forest.

Resumo em Inglês:

Abstract This study quantify the total organic carbon content, light fraction organic matter (LFOM), and soil organic matter fractions (from chemical and physical fractionations) in four different cultivation areas: 1 and 2) rubber tree clonal plantations (FX 3864 and IAN 873); 3) a pasture; and 4) a secondary forest. The research was carried out using soil samples from clonal plantations of eight-year-old rubber trees, located in the coastal plain (Tabuleiros Costeiros) of the state of Rio de Janeiro. The difference in the management of the rubber tree clone area promoted improvements in the soil quality, as it increased the carbon contents of the granulometric fractions, LFOM, and humic substances from the IAN 873 clone area. Both rubber tree areas evaluated presented higher mineral-associated organic carbon levels and humic substances than did the pasture area, reinforcing the reforestation potential of areas with degraded pastures through hevea culture.

Resumo em Inglês:

Abstract This research aims to evaluate the physico-mechanical properties of wood-plastic composites produced with recycled polyethylene terephthalate, high-density polyethylene, low-density polyethylene and polypropylene, and sawdust from the following species: Pinus caribaea, Pinus cubensis, Cedrela odorata, Talipariti elatum and Eucalyptus sp. Composites were obtained by extrusion with dimension of 1,000 × 250 × 16 mm (length × width × thickness), through six treatments. The following physico-mechanical properties were evaluated: density, moisture content, water absorption and thickness swelling, compression, static bending and traction. Treatment 6 obtained the best results, with 1,060 kg m-3 density, 5.23% moisture content, 0.32% water absorption, and 0.18% thickness swelling. Compressive strength was 138.10 MPa, static bending 18.53 MPa, and traction 29.4 MPa. The technology developed has prospects for large-scale production.

Resumo em Inglês:

Abstract This study evaluated the quality of the particleboard produced with particles generated from mobile discharges with mixture of equal parts of industrial particles of Pinus. The material was collected and processed in the form of chips by a company specialized in waste recycling. The experimental plan consisted in producing panels with nominal density 0.55, 0.70 and 0.85 g/cm3, and urea-formaldehyde resin of 8, 10 and 12%. The increased density and resin content contributed to improve the physical and mechanical properties of the panels. The panels produced with nominal density of 0.70 and 0.85 g/cm3, and 10% resin content, showed better feasibility of using mobile discharges particles in a proportion of 50% mixture with particles of Pinus industrial production of particleboards.

Resumo em Inglês:

Abstract It is essential to know the ecological tolerance of Anadenanthera peregrina (L.) Speg seedlings regarding the light and edaphic conditions. The aim of this study was to evaluate the effect of substrates and shading levels on the emergence and quality of A. peregrina seedlings. The seeding was done in two substrates: 100% Dystroferric Red Latosol (DRL) and DRL + commercial substrate (1:1, v/v). The species were kept under four shading levels: 0% (direct sunlight), 30%, 50% and 70%. The highest speed and shortest emergence time of A. peregrina occurred in DRL. The highest growth characteristics of aerial part, xylopodium and roots occurred under direct sunlight and DRL. The productions of fresh and dried masses of different vegetative organs, physiological and Dickson quality index were higher in DRL and direct sunlight. The A. peregrina seedlings in 100% of DRL and direct sunlight showed more viable morphophysiological and quality indicators for their production.

Resumo em Inglês:

Abstract Extractivism of pequi (Caryocar brasiliense) fruit represents an economic opportunity for rural communities of Brazil despite the lack of research on its production chain. This study aims to characterize the commercialization of pequi fruit in municipalities of the state of Minas Gerais and identify public policies that strengthen its production chain in order to support its use for generating income within rural communities. Information was obtained through searches on official sites, published literature and other documents, and through semi-structured and open interviews held in 39 commercial establishments and in five restaurants. Between 2003 and 2011, the national production and the price of one tonne of pequi has risen from 42% to 209%. Sales of pequi by the Centrais de Abastecimento de Minas Gerais S.A. (CeasaMinas) of Greater Belo Horizonte, Brazil, has risen 113% between 2010 and 2014. The results indicate the feasibility of pequi extractivism for a quilombola community.

Resumo em Inglês:

Abstract The objective of this study was to assess the efficiency of a mixed arbuscular mycorrhizal fungi (AMF) inoculum versus a single isolate to promote the seedling development of native Caatinga species: baraúna (Schinopsis brasiliensis Engl.) and juazeiro (Zizyphus joazeiro Mart.). The experiment was conducted in a greenhouse, presenting a completely randomized design with four treatments (Control - not inoculated, inoculated with Claroideoglomus etunicatum, Acaulospora longula or a mix of C. etunicatum and A. longula) and seven replicates. The AMF inoculation promoted an increase in all growth variables of the two plant species, with increments above 100% in all inoculation treatments, and a significant reduction in the transplanting time of the seedlings to the field. We concluded that the AMF use under study in the mixed form is as beneficial as in the isolated form for Z. joazeiro and S. brasiliensis seedling production.