Paricá (Schizolobium amazonicum) and embaúba (Cecropia sp.) as new raw materials for particleboards
In this work two potential new species for forest plantation projects in Northern Brazil were evaluated for their suitability in particleboard production. The main evaluated parameters of the laboratory boards were pH value and buffer capacity of the particles, compaction ratio, thickness swelling, modulus of elasticity (MOE), modulus of rupture (MOR) and internal bond (IB). The results showed that both species are highly suitable for particleboard production as they presented low densities (400–430 kg/m³), light color, good compressibility and no apparent adverse reactions after UF-resination.
Avaliação do potencial de utilização da madeira de Schizolobium amazonicum "Paricá" e Cecropia hololeuca "Embaúba" para produção de painéis aglomerados
Esta pesquisa teve por objetivo avaliar o potencial de utilizacao de madeira de Schizolobium amazonicum (Parica) e Cecropia hololeuca (Embauba) para producao de paineis aglomerados. Foram produzidos paineis experimentais com densidade nominal de 0,70 g/cm³, utilizando a resina ureia-formaldeido e particulas de madeira de Parica e Embauba, e mistura destas, em proporcoes de 75, 50 e 25%. A madeira de Pinus taeda foi utilizada como testemunha. Os paineis foram prensados com pressao especifica de 40 kgf/cm², temperatura de 160oC e tempo de prensagem de 8 minutos. Os resultados das avaliacoes de propriedades de absorcao de agua, inchamento em espessura, ligacao interna, modulo de elasticidade e modulo de ruptura, indicaram que as madeiras de Schizolobium amazonicum (Parica) e Cecropia hololeuca (Embauba) sao tecnicamente viaveis para producao de paineis aglomerados.
Sustainable forest ecosystems and management : A review article
Concerns about the sustainability of forest resources and ecosystems have been expressed almost from the beginning of modern studies of forest management by ecologists, biologists, economists, and other specialists. However, the focus of this concern has gone through several transformations. Environmental scientists have emphasized the maintenance of forest ecosystems in the face of different types of human *intervention. Economists and forest managers, on the other halnd, have emphasized the capacity of forest systems to provide valued ongoing flows of goods and services for human societies. This paper takes stock of forest resource and ecosystem sustainability from both ecological and economic perspectives. It seeks to identify how these disciplinary perspectives contribute to a better understanding of sustainability, and where the most significant conceptual and factual gaps are found. Of particular interest are two related themes: how economic efficiency and sustainability may differ in their implications for forest system management, and how criteria for forest system sustainability are related to the scale of management decisions (e.g., individual forest site versus region versus the global biosphere). FOR. Scl. 42(3):366-377. Additionai