Dimas Agostinho da Silva

Effects of region, soil, land use, and terrain type on fuelwood properties of five tree/shrub species in the Sahelian and Sudanian ecozones of Mali.

Abstract• ContextThere is little information about inter- and intra-specific variation in fuelwood properties of trees/shrubs in West Africa.• AimsWe studied variation in fuelwood properties of Balanites aegyptiaca, Combretum glutinosum, Guiera senegalensis, Piliostigma reticulatum, and Zizyphus mauritiana in the Sahelian and Sudanian ecozones of Mali.• MethodsTrees were sampled on different soil (sandy, sandy/loam, or rocky), land use (parkland agroforest or woodland), and terrain (flat, temporarily flooded, or hill slope) types in five regions extending from the drier eastern to the more humid western parts of Mali. Basic density, volatile matter, fixed carbon, ash content, moisture content, gross calorific value, and fuel value index were measured for each tree and adjusted for tree age.• ResultsAll fuelwood properties differed significantly among species, but there were significant species by region interactions. Most fuelwood properties of four species differed significantly among regions. Soil and/or land use type had significant effects on a few fuelwood properties of four species.• ConclusionIn general, fuelwood production is recommended in all regions for G. senegalensis, in drier regions for B. aegyptiaca and C. glutinosum, in more humid regions for Z. mauritiana, and on rocky soils for all species. Fuelwood production of P. reticulatum is not recommended.

Influência do espaçamento nas características energéticas de espécies arbóreas em plantios de curta rotação

This study aimed to determine the higher heating value (PCS) of trees and basic density weighted (ρb pond) of wood of Acacia mearnsii De Wild, Eucalyptus grandis W. Hill ex Maiden, Mimosa scabrella Benth and Ateleia glazioviana Baill distributed in different spacings in planting: 2.0 x 1.0 m, 2.0 x 1.5 m, 3.0 x 1.0 m and 3.0 x 1.5 m, at ages of 1 and 3 years. The study was conducted in an experiment in the city of Frederico Westphalen, State of RS, in experimental design of randomized complete block design with three replications in a split plots. The determination of the PCS of the trees was made from the weighting of the values obtained in each compartment (wood, bark, twig and leaf) using calorimeter bomb. The determination of ρb pond was performed from the weighting of the values recorded on discs collected at different positions along the stem, using the method of hydrostatic balance and dry mass. The PCS of all species in the first year after planting was higher than the third year, highlighting the Acacia mearnsii with the highest averages. The ρb pond had no systematic trend of increase or decrease over time, and the species Acacia mearnsii and Ateleia glazioviana showed the highest values. The different planting spacings did not induce the change in PCS and ρb pond in the species studied and it was not verified a positive or negative systematic trend in relation to the living space provided by the spacing.

Ponto de amostragem ao longo do fuste para estimativa do poder calorífico da madeira

This research had the objective of studing the variation of the calorific power along the shaft of the species forest Acacia mearnsii de Wild, Eucalyptus grandis W. Hill, Mimosa scabrella Benth. and Ateleia glazioveana Baill and also to evaluate the number and the positions of the samples along the shaft for the estimate of calorific power of these species. For so much, they were solitary disks of approximately two centimeters of thickness, along 0%, 25%, 50% and 75% of the total height of trees, with a year of age, for determination of the power calorific superior in calorimeter (C5000, IKA WORKS). For the Eucalyptus grandis and the Ateleia glazioveana it is possible to esteem the power calorific superior starting from a disk, respectively in the positions 50% and 0%, and for the Mimosa scabrella with two disks, in the positions 0+75% and for the Acacia mearnsii, three disks, in the positions 0+25+75%.

Avaliação do processo produtivo de uma indústria de manufatura de painéis por meio do balanço de material e do rendimento da matéria-prima

The present study aimed at evaluating the productive process of panels, using the principles of material balance and the yield of wood raw material, in order to establish a methodology to be applied in other wood industries. This work was carried out in the panel-manufacturing sector of Battistella Industria e Comercio Ltda, State of Santa Catarina. Data were obtained by means of visits, questionnaire application and office data. In order to represent the material balance some equations and a flowchart were produced. Based on these data, it was possible to conclude that the industry is integrated, fact that represents a competitive advantage. The material balance indicated that the activity with the highest potential to produce waste was wood lath preparation (55,71% from all the waste); the activities with the highest yield were pressing (97,44%) followed by sectioning (93,92%); boarding (93,51%); sandpapering (90,97%) and lath preparation (54,51%). The overall yield of manufacturing was 63,16%. These values were similar to those found in the literature. The methodology developed in this study is simple and may be applied to any other industry of the wood sector.

Evaluation of the energy-related properties of tropical wood waste using NIR spectroscopy

The aim of this study was to evaluate the energy-related potential of wood residues of four Amazonian species and calibrate the properties of wood and charcoal using the Near Infrared Spectrometry (NIRS) technique. Residue slabs of cardeiro (Scleronema micranthum Ducke), cedrinho (Scleronema sp.), louro (Ocotea sp.), and piquiarana (Caryocar villosum Pers.) wood were used. The following properties were determined: density, chemical composition, immediate chemical analysis, and superior calorific value of wood; and yield, immediate chemical analysis, calorific value, and friability of charcoal. NIR spectra were obtained and calibration models were generated for each energy property. The results indicate that residues of these forest species can be used as a renewable energy source. NIR spectroscopy has proved to be a possible tool for calibrating energy properties of wood.

Variation in growth, wood density and carbon concentration in five tree and shrub species in Niger

There is little information about variation in growth, wood density and carbon concentration in native tree and shrub species in Africa. This information is needed to make realistic projections about carbon sequestration of different species in different environments. Farmers manage natural regeneration of many native species in the drylands of Niger, so there is interest in carbon sequestration potential of the species. The objectives of this study were to determine: (1) if tree height, stem diameter, mean ring width, wood density and carbon concentration differ among five tree and shrub species (Combretum glutinosum, Combretum micranthum, Combretum nigricans, Guiera senegalensis, Piliostigma reticulatum) in Niger; (2) if variation within species is affected by land use type (parkland agroforests, woodlands), soil type (sandy, rocky), terrain type (temporarily flooded, flat, hill slope) and mean annual rainfall; and (3) if growth variables, wood density and carbon concentration are correlated in the five species. Environmental variables did not have strong effects on growth and wood variables of the species, and some effects differed among species. Height across species increased with mean annual rainfall. Stem diameter and mean ring width across species were greater in parkland agroforests than in woodlands. Carbon concentration was positively correlated with growth variables of four species, but was not correlated with wood density in most species. Correlations between wood density and growth differed in sign among some species. We conclude that above-ground carbon sequestration per tree probably increases with mean annual rainfall and is greater in parkland agroforests than in woodlands.

Variation in growth, wood stiffness and density, and correlations between growth and wood stiffness and density in five tree and shrub species in the Sahelian and Sudanian ecozones of Mali

Key messageMost effects of environmental variables on growth, wood stiffness, specific stiffness and density, and correlations between growth and wood stiffness, specific stiffness and density were not consistent among species.AbstractWood stiffness is a key functional trait of woody plants, but variation in wood stiffness has not been studied in native tree and shrub species in Africa. We investigated variation in growth (height, stem diameter, height/diameter ratio, ring width), wood stiffness (dynamic modulus of elasticity in longitudinal and tangential axes), specific wood stiffness (dynamic modulus of elasticity divided by air-dry density) and air-dry density of Balanites aegyptiaca, Combretum glutinosum, Guiera senegalensis, Piliostigma reticulatum and Ziziphus mauritiana related to region, land use type, soil type, terrain type, latitude, longitude, elevation and mean annual rainfall, and correlations of growth with wood stiffness, specific wood stiffness and wood density in the Sahelian and Sudanian ecozones of Mali. Growth variables, wood stiffness and wood density differed significantly among some of the species, but specific wood stiffness did not differ significantly among any of the species. There were few consistent effects of the environmental variables on growth and wood variables of the five species. Geographical coordinates generally had stronger effects than mean annual rainfall on growth and wood variables of the species. Positive correlations between growth and wood density were significant in three of the species. Correlations between height and wood stiffness and/or specific wood stiffness differed in sign among some of the species. Results illustrate that different species may respond differently to environmental factors in the Sahelian and Sudanian ecozones of West Africa.

Variation and correlations in traits of Prosopis africana and Balanites aegyptiaca in the West African Sahel: implications for tree domestication programs.

ABSTRACT Rural communities in the West African Sahel use Prosopis africana and Balanites aegyptiaca for construction wood, fuel and other needs. Provenance/progeny tests were established at one site in Niger, and evaluated after 11 (growth, survival) and 13 years (wood basic density, calorific value). Based on analysis of variance, growth and wood density varied significantly among provenances and families of P. africana only. For both species, linear regressions demonstrated that provenances from drier zones of the Sahel grew faster than those from more humid zones. P. africana provenances from drier zones also had denser wood and higher survival. In contrast, wood calorific value of both species was generally higher in provenances from more humid zones. Larger trees of both species tended to have denser wood and higher calorific value, but density and calorific value were not significantly correlated. Results suggest that selecting faster growing trees could indirectly increase both wood density and calorific value.

EFFECT OF PLANTING AGE AND SPACING ON ENERGY PROPERTIES OF Eucalyptus grandis W. Hill EX Maiden

This study aimed to determine the effect of planting age and spacing on energy properties of different compartments of the biomass of Eucalyptus grandis W. Hill ex Maiden, disseminated in different spacings: 2.0 x 1.0 m, 2.0 x 1.5 m, 3.0 x 1.0 m e 3.0 x 1.5 m, in the 1st, 3rd and 5th year after the planting. The present study was carried out as an experiment installed in an experimental design of randomized complete blocks in three replications. Variables determined were Biomass (BIO), Gross Calorific Value (GCV), Basic Density (BD), Energy Productivity (EP), Energy Density (ED), Fixed Carbon Content (FCC), Volatile Material Content (VMC), and Ash Content (AC). Ages have an effect on all studied variables, and in the 5th year after planting, the largest BIO, EP, BD, ED and FCC values are checked. The planting spacings induce different productions of BIO and EP, with a trend towards lower values with increasing planting spacing in all assessed periods. The compartments of trees influence BIO, GCV, FCC, VMC and AC variables. Regarding to energy, the higher the age and lower the planting spacing, the better the energy properties of biomass.

Compósito para a construção civil a partir de resíduos industriais

Os estudos que visam a utilizacao dos residuos industriais vem se intensificando diante da pressao das organizacoes ambientais, escassez de recursos naturais, busca de certificacoes para ganho de mercado e minimizacao de impacto ambiental. O presente trabalho desenvolveu um novo composito a base de residuos industriais como cinzas de madeira, lodo de estacao de tratamento de agua (ETA) e residuos de producao de cal com propriedades mecânicas que atendem as exigencias da ASSOCIACAO BRASILEIRA DE NORMAS TECNICAS - NBR 15270-1/2005, NBR 15270-2/2005 e NBR 5739/2007, objetivando a sua utilizacao na construcao civil sem o acrescimo de cimento Portland. As resistencias a compressao variaram de 2,35 a 16,48 MPa. O indice de absorcao de agua das amostras testadas tambem atendeu as normas aplicadas, demonstrando que ao longo do tempo de cura houve diminuicao da porosidade com possivel hidratacao da cal. Os resultados do ensaio de resistencia a compressao apresentaram variacoes durante o tempo de cura que podem ser justificadas pela presenca de material orgânico no lodo de ETA e pelo tamanho das particulas de cinza de madeira que durante a homogeneizacao nao foram destruidas completamente. Apesar das variacoes observadas nos resultados, as resistencias dos compositos se enquadram na classificacao para blocos cilindricos de concreto e blocos cerâmicos para alvenaria.