Soil chemical attributes in native and exotic forest cover in source of Batatais State Forest, São Paulo, Brazil / Atributos químicos do solo em coberturas florestais nativas e exóticas no manancial da Floresta Estadual de Batatais, São Paulo, Brasil

Este trabalho tem por objetivo analisar a homogeneidade das amostras de solo das árvores nativas plantadas há 20 anos na Floresta Estadual de Batatais em comparação com outros usos/ocupação. Ao longo da projeção da copa de oito espécies nativas foram coletadas amostras compostas de solo na profundidade 0-0,20 m, que foram avaliadas junto com o solo de outros estudos com árvores de progênies de Eucalyptus pellita, de E. tereticornis e do plantio comercial de Pinus caribaea hondurensis e P. c. bahamensis. A análise multivariada dos atributos do solo das espécies nativas restou não significativa, indicando a homogeneidade do solo na área de estudo, restando a expressão genética das espécies para outras variáveis dendrométricas e de qualidade da madeira a serem estudadas. Por outro lado, a análise multivariada das espécies nativas com as de Eucalyptus e Pinus resultaram altamente significativas, mostrando que existe diferença dos atributos do solo em relação aos diferentes usos/ocupações. Os Eucalyptus apresentam maior teor de bases que o Pinus e o Florestamento, em áreas com menor acidez potencial e maior capacidade de troca de cátions (CTC), restando à área com Florestamento maior acidez potencial e menor CTC

Wood quality of 10 clonal progenies of rubber tree as raw material for bioenergy

The use of wood as a bioenergetic source requires knowledge of its technical properties. The rubber tree Hevea brasiliensis has an economic life cycle of 25 to 30 years in Brazil. It is used for extracting rubber and generating residual wood for fuel. Our goal was to characterize the wood quality of 10 clonal progenies as a source of raw material for bioenergy. Ten clonal progenies of 12-year-old Hevea brasiliensis from an experimental planting in Selvíria municipality were evaluated. Three trees per clone were evaluated for individual properties of Higher Heating Value, immediate chemical analysis, chemical composition, fiber dimensions, thermogravimetric analysis of wood under nitrogen atmosphere and Fourier Transform Infrared Spectrosocopy analysis. We highlight clone IAC 311 for fuel because it presents elevated Higher Heating Value and fixed carbon and less volatile material. However, the other genetic materials studied also meet the specifications for energy use and can be highly viable given their physical, chemical, energy, and thermal properties

Growth and Wood Quality from 32-Year-Old

In a provenance and progeny test of Eucalyptus pellita, installed with seeds from 25 open-pollinated progenies from Helenvale and Coen in Australia, one individual from each progeny of the two provenances was selected. Height and DBH measurements were taken forming three diameter classes. From the felled trees, a 0.10 m disk was collected at the base of each tree to obtain samples, considering the pith, intermediate and bark positions, to evaluate the density at 12% moisture ( 12), fiber length (Fl), and fiber wall thickness (Fwt). In the canopy projections, soil samples were collected for chemical analysis. The samples were processed based on the standard methodology for anatomy and wood properties. Factor analysis did not group the soil variables with those of dendrometry, indicating no significant effect between these sets of variables. On the other hand, multivariate analysis indicates that Fwt in the intermediate position was influenced by groups of soil variables that comprise both F1 and F2 factors. Thus, we can infer that the higher values of Fwt (I) are related to lower Ca, Mg and pH and lower values of P, organic matter and cation exchange capacity. By showing statistical significance in the analyses, these results suggest that Helenvale should be chosen for vegetative reproduction (cloning) of the material that makes up the Batatais Forest collection based on the wood quality variables studied