RCAAP Repository

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.

The combustion with fluidized bed reactors has as main advantages the best energy utilization of combustible materials and a lower generation of pollutants. The fluidization success depends on the characteristics of the particles that compose the bed. This research aimed to perform a preliminary evaluation and characterization of the energy potential and the fluidization curves in fluidized beds formed by binary mixtures of eucalyptus chips + sand and mineral coal + sand. We tested: 1) physical characterization of solid fuels; 2) chemical characterization of combustible materials; 3) thermogravimetric analysis of fuels; 4) determination of the fluidization curves and minimum fluidization velocity for a polydisperse bed. We observed 19.15 MJ kg-1 of lower calorific value for eucalyptus chips and 10.1 MJ kg-1 for coal. The increase in biomass percentage in mixture caused a pressure drop in bed, indicating the formation of preferred paths and a necessity to increase fluid velocity. The fluidization of coal and Eucalyptus chips can be viable in a bubbling fluid bed process, motivating future theoretical and experimental studies involving the application of this methodology in the development of clean and sustainable technologies.

The fragmentation of habitats has several ecosystem impacts. The high response of vegetation to environmental changes makes it a good indicator of biodiversity conservation condition. This work evaluated the conservation of a Cerradão fragment in the Cáceres municipality, Mato Grosso State, by analyzing the horizontal structure and diversity of species of the tree-shrub layer. The survey was based on two randomized conglomerates, totaling 8 plots and 0.8 ha. The criterion included was the diameter at 1.30 m above ground level ≥ 10 cm. A total of 411 individuals, 44 species and 21 botanical families were sampled. The families Fabaceae and Bignoniaceae presented the greatest species richness. The values of the Shannon-Weaver diversity and the Pielou Equability indices were considered high (3.18 and 0.84, respectively). The floristic similarity between the conglomerates was high, (Sørensen Index = 74.63%), indicating that the fragment is homogeneous. We observed inverted-J shape diametric distribution. The community presented an aggregate tendency, with an average Payandeh Aggregation index equal to 1.40. The richness and phytosociology indicated good conservation of the tree-shrub layer, as there were no floristic-structural changes in the fragment due to the anthropic activities surrounding the area.

This study aimed to verify the influence of the size of the diaspores and scarification treatments on the emergence rate and initial growth of Pterodon emarginatus Vog. (Fabaceae) after one year of storage. Diaspores of the species were collected, measured, weighed and separated into three size classes, with amplitude determined by the width of the fruit. Subsequently, they were submitted to thermal and mechanical scarification. A randomized experimental design was used, with 10 replicates of 10 units / each. We performed a survival analysis, besides analysis of variance and Tukey post-hoc test to verify significant differences in the percentage of diaspores emergence. We used generalized linear models to verify the variation in the initial growth of the seedlings. Our results indicated that treatments intercropped with the largest diaspore sizes positively influenced the percentage of emergence. Larger diaspores also resulted in larger diameter seedlings and stem length. Mechanical scarification led to a higher biomass allocation in the roots. We suggest that P. emarginatus diaspores should be submitted to pre-germination treatments to potentiate seedling emergence and development. We also recommend choosing the largest diaspores.

Moringa oleifera Lam (Moringaceae) is a species tolerant to arid and semi-arid environments, such as the Brazilian Northeast. In this region climatic conditions make water a scarce resource. Water limitation affects plant growth and development where its impact will depend on its duration, intensity and the plant’s development stage. During the reproductive period water deficit can be critical since there is high water demand in this phase. The present study had as  objective to verify how M. oleifera reproductive attributes respond to the Brazilian semiarid (Brazilian tropical dry forest)  seasonality. We hypothesize attributes such as fruit size, seed number and physiological quality are different between dry and rainy seasons, with lower values for the dry season. The biometric characteristics of the fruits and M. oleifera seed germination produced in the two seasons were analyzed. It was observed differences in fruit weight, length and seed number, as well as for speed and germination percentage, with greater values during the rainy season. Seasonality affected important reproductive aspects for the successful recruitment and establishment of the specie, showing that, even tolerating drought, water deficit may limit M. oleifera reproductive success.

This study aimed to evaluate the efficiency of salvinia proportions in the substrate composition to grow Jamaican nettletree seedlings. The chemical characteristics of the substrate were improved as the dosage increased, resulting in Al reduction and increased pH, CTC, base saturation, K, Ca, Mg, P and organic matter contents. Growth of Jamaican nettletree  seedlings was influenced by the fertility levels of the substrate. The highest plant height, stem diameter, dry mass, and macronutrient accumulation were verified in treatments with 75% and 100% of the organic compound.

The objectives of this research were: a) to test several traditional and generic hypsometric models; and b) to analyse their adjustments and performances according to age and number of thinnings. The data set came from measurements of diameter and height of 1099 trees distributed equitatively over 11 treatments with age ranging from 5 to 25 years, and number of thinnings varying from 0 (zero) to 6. Each treatment considered consists on the combination of different ages with different number of thinnings. The Pinus oocarpa stands belongs to Duraflora S/A, located in Agudos, State of São Paulo, Brazil. The selection of the best hypsometric model was based on adjusted coefficient of determination (R²adj), standard error of estimate and graphic analysis of residuals. Due to the small variation of model statistics for each treatment, a ranking of the models was performed. In a general way, the Curtis traditional model provided the best fit to the data. The models number 6, 7 and 8 had the best performance among the generic ones. The hypothesis that selective thinnings dissociat the hypsometric relationship was confirmed by the gradative reduction of the R² as the number of thinnings increased. As the stands became older, and the number of thinnings increased, the estimation of heights for these cases was obtained by using the equation hˆ = b0, b0, being equal to the average height.

The chemical characteristics of earthworm casts and a soil sample from a commercial plantation of Eucalyptus grandis aged 3 years old near the city of Mogi-Guaçu in the State of São Paulo, Brazil, were compared. The casts were collected at the surface of the mineral soil, while the soil was collected at depths of 0 - 5; 5 - 10; 10 - 20 and 20 - 30 cm. The Ca+2 and Mg+2 contents of casts, in comparison to the 0 to 5 cm soil depth, were 11 times higher,while the K+ contents were 3 times higher. In addition, the cation exchange capacity (CEC) and C contents were 4.41 and 2.83 more concentrated in the casts, respectively. It was observed a decrease in Aluminum saturation (m%) from 73%, in the depth of the 0-5 cm, to 45% in the casts. While the chemical characteristics of the native earthworm casts represent a distinct improvement over the soil, it remains to be seen what influence, if any, this has on the growth and nutrition of E. grandis.

The relationship between meteorological variables and the diameter increment of Zanthoxylum rhoifolia (mamica-de-cadela) and Zanthoxylum hyemale (coentrilho) was studied. It was taken data of two trees for each species in Santa Maria - Rio Grande do Sul, Brazil. The observation period included years from 1974 to 1996 for mamica-de-cadela and from 1977 to 1996 for coentrilho. The stem analysis was used to restore the tree’s diameter increment. Discs were taken at 1,30m, 2,70m and 3,80m high of each tree.The 4 radii on perpendicular cross sections were measured on each disc. To identify the short-term variation in radial increment, the synchronization and standardization of disc’s sequence were performed for each tree. Temperature and precipitation data from Santa Maria Meteorological Station were used to calculate the evapotranspiration and the potential water balance. The correlation analysis between tree’s annual increment and potential water balance showed significant statistical results for both species.

This work had as objective to select mathematical models to predict the height of trees in function of DBH and age, in black wattle stands, Acacia mearnsii De Wild., in Southeastern region of the State of Rio Grande do Sul, Brazil. For the adjustment of the height data 19 mathematical equations were tested, being used arithmetic and logarithmic linear equations and one no-linear equation (Chapman-Richards). The following statistical criteria were used in order to select the best equations: a) adjusted determination coefficient (Raj), b) standard error of estimate (Syx), c) variation coefficient in percentage (CV%),d) Furnival index in percentage (IF%) and e) F statistic. The analysis of residues graphic was accomplished for the five better ranked mathematical models. The equation 16, represented by log h = b0 + b1 * 1/d + b2 * 1/I + b3 * 1/D * I resulted as the most efficient model, estimated as function of DBH and age of trees, to adjust the heights in stands with ages of 2, 4, 6 and 8 years old.

The senescence and fall of the leaves and branches are mechanisms where thetrees can recycle the nutrients by biochemical cycling and by biogeochemical cycling. The objective of this paper was to evaluate the nutrients retranslocation in the non-deciduous leaves and branches and also in the deciduous leaves and branches. The leaves and branches for analysis were collected in the subplots of Acacia mearnsii stand at the age of three years old.The stand is located in the Rio Grande do Sul State – Brazil – in low fertility soil. The nutrients analysis results showed that the N was the element which had highest concentration for both, leaves and branches. The most retranslocated nutrients were P, K and Mg respectively. The elements N and Ca showed the lowest retranslocation in the leaves and branches.

This paper analyzes Eucalyptus badjensis Beuzev. & Welch half sib progenies planted in two areas of Southern Brazil. The species is considered potential for plantation in frost prone areas and for oil production (1,8 cineol). Height and DBH growth were fast on both areas, Vargem Bonita (SC) and Ponta Grossa(PR). In the colder area the species showed higher survival rate and no signal of frost damage. Heritabilities were different between locals varying from low to medium magnitude. It is recommended introduction of more genetic material with a higher number of progenies.