RCAAP Repository

The present study aimed to determine the static bending and the apparent specific gravity of Inga marginata wood in different humidity conditions. Three individuals were cut at an approximate age of six years. For determination of the studied properties, we followed the recommendations of ASTM D143-94 norm. We observed reduction of more than 1.2 times the modulus of elasticity, modulus of rupture, tension at the proportional limit and maximum force in the static bending as a function of fiber saturation. In general, the samples presented smaller apparent specific gravity values and higher mechanical resistance according to the desorption until the equilibrium moisture of 12%. The wood, in this condition, was classified as moderately heavy.

This study aimed to evaluate the growth of species Senna multijuga, Myrsine coriaceae, Schizolobium parahyba var. parahyba, Inga edulis, I. marginata and Citharexylum myrianthum, in the recovery of an area degraded by livestock. The experiment was conducted in the Natural Reserve of Guaricica in Antonina, PR. Four treatments were tested with different densities of individuals of each species, each with three replications in 3.000 m² blocks. The evaluation was based on the variables: total height (h), diameter at 1.30 m above ground level, crown cover area, basal area and mortality. Except for the mortality that was compared by the Kruskal-Wallis test, the other variables were compared by the Tukey test at 5% significance level. I. edulis presented the best growth and I. marginata the worse, while M. coriacea presented the lowest mortality and S. multijuga the highest. Treatments expressed similar results, since higher density of I. edulis generated higher average h and higher density of S. multijuga generated higher mortality. Higher density of I. edulis tend to increase the efficiency of restoration projects, while C. myrianthum and M. coriacea also presented potential for plantings in the study region.

The studies of landscape ecology from metrics using geoprocessing and remote sensing are important technologies to evaluate the conditions of native forest remnants, especially in biomes fragmented and with a high rate of deforestation as the Caatinga. This study aimed to describe the structure of the forest landscape in the municipality of Ribeira do Pombal, Bahia State, Brazil, using a landscape metric index. The use of soil and forest fragments was characterized using an image of the Landsat-8 OLI satellite. We used the software Fragstats 4.2® to calculate the landscape metrics. Even in a matrix with high percentage of pastures, fragments of the open and dense caatinga of medium and large size predominate in the landscape, with great proximity and connectivity. Reforestation and enrichment of the small fragments of open Caatinga may contribute to form ecological corridors. The great percentage of fragments larger than 100 ha ensures floristic diversity and resilience of the dense caatinga in the municipality of Ribeira do Pombal, BA.

The aim of this research was to evaluate the influence of pre-germination treatments on germination and initial seedling growth of Libidibia ferrea. We tested 5 treatments: control; sulfuric acid; water for 24 h; hot water and scarification. We evaluated the percentage of initial growth (%E), speed index (IVE) and mean emergence time (TME). For germination we evaluated the height and stem diameter of the seedlings, number of leaves, leaves, stem and roots dry matter and root/shoot ratio. Sulfuric acid treatment presented higher %E and IVE and lower TME, and it was the treatment that showed the better growth of the plants.

The objective of this work was to evaluate the floristic and phytosociological composition of a Cerrado lato sensu fragment. A census was carried out in the study area, of 6.7 ha, with inclusion limit of 15 cm of circumference at 1.30 m above ground level. We registered 15,434 individuals, from 78 species, 72 genera and 33 families. Density, dominance and cover value were analyzed, with a total density of 2,303.58 ind ha-1 and a basal area of 94.303 m² ha-1. The species with the highest cover values, in descending order, were Myrcia splendens, Astronium fraxinifolium, Magonia pubescens, Qualea parviflora, Protium heptaphyllum, Curatella americana, Vatairea macrocarpa, Tachigali aurea, Byrsonima stipulacea and Machaerium brasiliense, which represented 53% of all individuals of the area. Species of the genus Qualea presented dominance, representing 11% of the total of individuals. The distribution pattern of the individuals was inverted “J” format, but Astronium fraxinifolium, Magonia pubescens and Tachigali aurea presented lower number of individuals in the initial classes. The Shannon diversity index and the Pielou equability indicated the existence of high species richness and diversity when comparing the studied area with Cerrado fragments nearby.

Technological evolution of wood harvesting machines has allowed the expansion of selective thinning areas in forest stands, with gains in productivity, but with risks to affect the work quality. In this context, the aim of this study was to evaluate the quality of harvesting operation in Pinus taeda stands under two thinning models: (1) systematic cutting of the fifth line and selective in adjacent lines, and (2) systematic cutting of the seventh line and selective in adjacent lines. Quality was evaluated by measuring stump height and logs length in assortments saw log, veneer log, and pulpwood. The values were analyzed by means of histograms and the averages were compared by pre-established dimensions through Wilcoxon’s test (α ≤ 0.05). It was verified that 90% of stump heights were above pre-established value, with means of 12.5 and 12.9 cm, resulting in wasted wood volume of 0.50 and 0.62 m3 ha-1 in thinning models 1 and 2, respectively. Length of saw log and veneer log in both thinning models were higher than expected, while values for pulpwood showed significant lower values when compared to the pre-established.

In the paper " New country, Brazilian states and host records of the eucalypt shoot psyllid Blastopsylla occidentalis", DOI: 10.4336/2018.pfb.38e201701533, published in Pesquisa Florestal Brasileira, v. 38, 2018, on the page footer, where it reads:“DOI: 10.4336/2018.pfb.e201701533”,it should read:“DOI: 10.4336/2018.pfb.38e201701533”.

This study aimed to evaluated physical and mechanical properties of particleboard manufactured with Ligustrum lucidum wood, pure or with Pinus taeda, and to compare these panels properties with the normative requirements and those panels produced only with Pinus taeda. Panels were produced with urea-formaldehyde and tannin-formaldehyde resins, in 10% of proportion based on solid mass of dried particles. For the panels preparation, it was established nominal specific mass of 0.75 g.cm-3, specific pressure of 3.92 MPa, temperature of 160 °C and pressing time of 8 min for urea-formaldehyde resin and 10 min for tannin-formaldehyde. After the air conditioning period, samples for physical and mechanical tests were prepared. The use of only Ligustrum lucidum wood and tannin-formaldehyde, as well as the use of mixture woods and urea-formaldehyde provided panels better performance in relation to physical and mechanical properties. These panels reached mechanical properties requirements of normative codes and demonstrated the potential of L. lucidum for particleboard production.

Research on natural regeneration and its relationship with adult vegetation are important to subsidize the understanding of succession of secondary forests. The aims of this study was to characterize the ecological and floristic structure of the regenerative community (DHB < 5 cm) and its similarity to adult strata (DHB ≥ 5 cm), in a forest secondary Araucaria Forest fragment. Regeneration was sampled in 24 plots in three height classes and total natural regeneration (TNR) was calculated. We sampled 433 plants, belonging to 66 species and 29 botanical families, with emphasis on Myrtaceae. The floristic similarity between regeneration and the adult strata was high (68.3%). Regeneration and adult strata presented high diversity and equitability and low dominance. Allophylus edulis (9.5%), Mollinedia clavigera (8.5%) and Myrciaria tenella (8.3%) were the species which showed the highest TNR. They are typical of understory and they are not important in the adult strata. However, other important species in the regeneration, among them key species such as Ocotea porosa (Brazilian-walnut) should continue in the future structure of the forest. Most regeneration species are zoocoric and heliophilous, but the proportion of late stage species is higher in the larger size class, indicating that the forest is in full succession and evolving to its climax.

The present study had as objective to analyze the spatial pattern of the anemocoric and zoocoric species in environments with different individuals densities. The study was conducted in two fragments of Highland Araucaria Forest: one under silvipastoril system and another in a forest under secondary succession, in the municipality of Turvo, Paraná State, Brazil. The coordinates (x, y) of each point was registered. The spatial pattern was analyzed through the function K of Ripley, in the univariate form, using the package Splancs. In the area under silvipastoril system, anemochory syndrome is aggregated, while individuals with zoochory dispersion syndrome showed aggregated pattern up to 15 m and random pattern in the upper classes. Anemocoric species showed aggregated pattern in the area under secondary succession regardless the distance. Probably, more complex factors, such as dispersers’ ecology, interspecific relationships and environmental features may define the spatial distribution of some species.

The aim of this work was to analyze the level of workers exposure to noise and vibration of semi-mechanized logging operations. The research was carried out in harvesting operations in the southern region of Espírito Santo State, Brazil. Data were collected in a Pinus elliottii stand with 40 years old. Noise and vibration were analyzed in different logging activities and timber extraction. The noise exposure levels were measured using a dosimeter and the vibration with an accelerometer, according to NHO-01 and ISO 5349-1 standards. Logging and timber extraction exceeded the level of noise exposure limit, presenting 100.8 dB (A) and 91.3 dB (A), respectively. The vibration analysis showed fatigue levels in both axes, highlighting the delimitation with greater exposure (0.265 m s-2). Fatigue levels were observed in the axes XY of the upper limbs of the workers during logs transportation, with emphasis to load and unload activities (0.174 m s-²). We observed the necessity to adopt measures to reduce worker’s exposition to unhealthy conditions, as they are essential to the performance of those activities.

The quantification of fuel material in the Cerrado area is limited by the difficulty in obtaining data, the high costs and the high time spent in the field. In search of alternatives that facilitate the data acquisition, the use of RGB sensors stands out being able to be a useful and effective tool in quantifying the combustible material. In this context, the objective of this work was to evaluate the feasibility of using images from an airborne RGB sensor by a multirotor to estimate the combustible material by means of regression analysis. The fuel material was sampled from the area that was weighed in the field and dried in an oven. With the digital images processing, the height (htMDA) and the vegetation index (NGRDI) of the pixels covering the sample units were obtained, followed by a correlation analysis between the digital processing data and the combustible material. Subsequently, three regression models were adjusted, in which adjusted coefficient of determination (R²aj) was obtained from 0.39 to 0.80. The use of RGB sensors has potential for estimation of combustible material. When the htMDA and NGRDI variables are combined, values closer to the mid-range are obtained.

The objective of this reserach was to evaluate and compare data on floristic and natural regeneration diversity in seven clearing areas formed by the selective management of araucaria in remnants of Araucaria Forest. The indices of Shannon and Jaccard were used, respectively, to analyze the floristic diversity and to relate the similarities in each clearing area. The classification of the species into ecological groups was based on literature review. The families Myrtaceae and Salicaceae presented the biggest frequency of species. Araucariaceae did not present a significant number of individuals. The similarity analysis according to Jaccard index with cut line at 50% showed low similarity between the studied clearing areas, indicating high species variability. When using the cut line of 40%, three distinct groups were formed. The ecological group of the initial secondary species was the most representative, as expected due to the natural regeneration in newly formed clearings, indicating an initial successional stage in the new stage of forest evolution.

The objective of the research was to verify changes in vegetation cover of part of the Upper Rio Guamá Reserve in Paragominas, Para State, Brazil, through vegetation indexes, aiming at a multitemporal overview of environmental degradation. The images were obtained from INPE databases and the vector bases acquisition from IBGE. Image processing was performed using ENVI 4.7 software, where the bands R5, G4 and B3 were used for the images of 1991 and 2010 and the bands 6R, 5G and 4B for the image of 2016. We also performed re-projection, mask cutting and geometric rectification by control points. The classification of normalized difference vegetation index (NDVI) was made for water, no vegetation, grass, capoeira (early forest regeneration after the abandonment of agricultural practices), secondary forest and dense forest classes, to generate the area indices (ha). . In 25 years there were considerable changes in forest cover, probably due to agriculture expansion and timber extraction activities.

The presence of weeds in stands aiming at forest restoration can cause harn, as they can compromise the growth of tree species. The objective of this work was to evaluate the efficiency of crowning with cardboard disks to control Urochloa spp. at forest restoration. The survival and growth of eight native tree species and the maintenance costs of manual crowning (T1) and the use of cardboard disks (T2) were evaluated. There was no effect of the cardboard disks when considering the survival and growth of the tree species 9 months after planting. At this age, only 23% of the original cardboard disks mass remained. Costs of cardboard treatment was 65% higher than manual crowning.

We assessed the species composition and community structure of herbaceous and tree/shrub strata in two agroforestry systems (AGP and SILV), traditional cropping system (TRAD0), areas under fallow for six (TRAD6) and nine (TRAD9) years and preserved Caatinga vegetation (MATA). We determined the absolute density and frequency of species, using plots. Individual trees/shrubs were separated into size classes of diameter. In the herbaceous stratum, the most frequent and abundant species were Alternanthera ficoidea in AGP, Amaranthus in SILV and TRAD0 and Commelina virginica in AGP, TRAD6, TRAD9 and MATA. The most frequent and abundant species in the tree/shrub stratum of AGP, MATA and SILV was Cordia oncocalyx. Mimosa caesalpiniifolia and Croton blachetianus occured at the greatest densities in TRAD6 and TRAD9, respectively. After fallow periods of six and nine years vegetation recovered floristic composition, although there was more individuals with smaller diameters when compared to MATA.

This study aimed the automatic identification of trees in circular sample units of 200, 300 and 400 m² in stands of Eucalyptus spp., using TLS (Terrestrial Laser Scanning) in Mato Grosso do Sul State, Brazil. Three planting ages were tested: 2 years-old-plantation, considering trees with natural pruning (E. urophylla -200 m²) and without natural pruning (E. grandis - 300 m²), and trees with 4.5 and with 5.5 years-old without pruning (hibrid E. urophylla x E. grandis - 400  m²). Field laser scanning was performed with Trimble TX5 equipment. This approach was based on a cut of point-cloud at 1.3 m above ground level (DBH) and the developing the algorithm 2D slice. It was possible to detect 98.3, 98 and 93.9% of trees for samples units of 200, 300 and 400 m², respectively. These identifications were influenced by the spatial distribution of trees because of the shading of trees further from the equipment. This simple scan should be applied only for small sample units. The error detections in areas greater than 200 m², may influence negatively the dendrometric estimations.

The objective of this work was to analyze seeds germination of Senegalia polyphylla (DC.) Britton & Rose (Fabaceae) attacked by bruchid beetles (Coleoptera: Chrysomelidae: Bruchinae). Fruits of this species were collected in São Gonçalo do Rio Preto, Minas Gerais State. The indene and bruchid-damaged seeds were submitted to germination tests in five treatments, with 100 seeds each. The best percentage of germination was obtained in healthy and sanded seeds. Healthy seeds imbibed in water had a low percentage of germination. Bruquids attack provided a reduction in germination rate, however they did not prevent this process from occurring in damaged seeds.

The objective of this study was to analyze the temporal behavior of seedlings survival from seeds without and with the application of treatment to overcome dormancy. We used native forest species, in a riparian forest area of the Piauitinga River, at the municipality of Lagarto, Sergipe State, Brazil. In the field, the design of the direct sowing was in randomized blocks, testing 5 native species (2 pioneer: Guazuma ulmifolia Lam. e Cecropia pachystachya Trécul. and 3 climax species, that are demanding of light: Cassia grandis L.f., Enterolobium contortisiliquum (Vell.) and Libidibia ferrea var. leiostachya L. P. Queiroz). We used 2 treatments (without and with the application of treatment to overcome dormancy) in four replicate samples. Seedlings of Enterolobium contortisiliquum from seeds without treatment to overcome dormancy presented the highest survival among the species and treatments used. Libidibia ferrea var. leiostachya presented late emergence. The initial survival of the species seedlings used in the riparian forest sections of the Piauitinga River showed a decrease over time until stabilization was achieved after sowing, regardless treatment to overcome dormancy.

Forestry activities in the Amazon generate large amounts of waste, from logging process, with carbonization being a potential alternative to mitigate this liability. However, the diversity of species and the lack of information on ideal carbonization parameters make the operation of the ovens difficult. In this research, the effects of the species and carbonization parameters on energy quality in the conversion of wood industry residues into charcoal are evaluated. The study material came from the municipality of Paragominas, Pará, collecting samples of the three most commercialized species, Handroanthus serratifolius (Vahl) S.O., Hymenolobium petraeum Ducke and Enterolobium schomburgkii (Benth.) Benth. The carbonizations were carried out in a muffle furnace, with temperatures of 500 °C and 600 °C and a final level of 30 min and 60 min. The species and temperature parameters were those that had a significant effect, exerting the greatest influence on the production and quality of charcoal. The time at the final level of carbonization did not show any influence on the variables. The increase in temperature caused a reduction in gravimetric yield. The wood residues of the three species showed high quality characteristics for the production of charcoal.