Resumo em Inglês:

Abstract Basic information about growth rate and response to silvicultural treatments on potential native species are bottlenecks for the wide use of these species for forest production. In this context, the objective of this work was to evaluate the silvicultural performance of four native species as a function of pruning intensity. The experimental design was completely randomized with ten replications and one plant per plot, in a 4 x 4 factorial scheme, four forest species, and four pruning intensities. At 30 and 42 months, height (H) and diameter at breast height (DBH) were evaluated, then the current annual increment (CAI) was calculated, as well as the mean annual increment (MAI) at 42 months. Guazuma ulmifolia showed higher growth in height and DBH compared to other species at both ages. The pruning resulted in a reduction of MAI in 0.15 cm. year-1 in DBH for every 25% of pruning intensity.

Resumo em Inglês:

Abstract To support threatened plant conservation, Bogor Botanic Gardens (BBG) has reintroduced 5 threatened plant species in Ujung Kulon National Park (UKNP) in 2009 and 2014. All reintroduced plants were propagated from seeds of BBG living collections, except Vatica bantamensis which came from wildings collected in UKNP. After transplantation in 2009, the survival and growth rate was monitored at six months, one year and eight years period, while those transplanted in 2014 were only monitored in 2017. The average survival rate varied depending on species and reintroduction sites, with the highest and lowest values being observed for Diospyros macrophylla at Dungus Balang and V. bantamensis at Legon Pakis, respectively. Seedlings transplanted at sites with more open canopy cover grew taller with larger diameters. Based on this study, local communities’ involvement through seedling supervision, prevention and reduction of disturbances as well as post-planting management were very important for the reintroduction success.

Resumo em Inglês:

Abstract The present study aimed to characterize medium density particleboard manufactured with CCB treated particles of Pinus sp. wood specie and alternative mixed vegetal oil-base bicomponent polyurethane resin. For this, three different resin concentrations (10 %, 12 % and 15 %) were used in combination with the presence or absence of the CCB preservative, resulting in six distinct treatments. The particleboards were produced according the Brazilian Standard - NBR and evaluated according European standards - EN. The results met the requirements of NBR and EN. The technical feasibility of making panels with those materials used were proved and the quality of the product according to its performance were verified, indicating the possibility to use alternative bicomponent polyurethane resin from mix vegetal oil. Statistical analysis demonstrated that adhesive and preservative factors and the interaction between them were significant on physical and mechanical properties.

Resumo em Inglês:

Abstract We examined the taxonomic diversity of native angiosperms in the semiarid region of Ceará State, Brazil, emphasizing species occurring in Steppic Savanna. The diversity of native angiosperms comprises 120 families, 604 genera, and 1,443 species. Fabaceae was the most taxonomically diverse family, while Croton (Euphorbiaceae) was the most species rich genus (33 sp.). Steppic Savanna species account for 58% of all angiosperms recorded in Ceará State, and 41% of all species listed for that phytophysiognomy in Brazil. An update of the species richness within the Steppic Savanna of Ceará State phytogeographical area is provided, also indicating distribution data for other phytophysiognomies in Ceará.

Resumo em Inglês:

Abstract Exogenous application of stress inductors can facilitate and accelerate some biological responses that promote plant defense. The objective of the experiment was to quantify some compounds linked to nitrogen metabolism as a function of the application of salicylic acid in Schinus terebinthifolius seedlings submitted to water deficit. The experiment was constituted of four doses of salicylic acid and three periods of water deficit. Quantifications included levels of nitrate, free ammonium, total soluble amino acids, proteins, proline, glycine-betaine and relative water content. When evaluating the relative water content in seedlings of Schinus terebinthifolius at 8 days, it was observed that the dose of 200 mg L-1. Seedlings showed physiological responses when subjected to doses of salicylic acid of 200 and 300 mg L-1. The increase in concentration of proline and glycine are advantageous, because these substances act as osmoregulators and cell protectors against deficit hydrical.

Resumo em Inglês:

Abstract An adequate amount of soil organic matter is considered essential for long-term sustainable agriculture, ensuring good productivity. Therefore, the present study quantified carbon and nitrogen stocks and microbiological activity in soil of three different areas: Forest-pasture System, Pasture System and preserved Caatinga - used as a reference of the experiment - located in a semi-arid region, in Watershed of Pajeú River, state of Pernambuco, Brazil. Eight trenches were opened in each system to collect soil samples at depths of 0 - 10, 20 - 30 and 50 - 60 cm, for chemical and microbiological analysis. In general, attributes of soil showed better results of land use in the following order: preserved Caatinga - Forest-pasture System - Pasture System.

Resumo em Inglês:

Abstract Plywood panel has a promising market in Wood Frame Construction System. Like any wood-based product, it can suffer deterioration, and preservative treatment is imperative. The preservative treatment can be done directly on a pressed panel - a conventional method that supposedly causes a decrease in physical-mechanical performance - or incorporated into the production process, by the previous treatment of veneers to develop panels with durability and quality. We compared the performance of these two processes. Panels were produced with Pinus taeda L., using 360 g m-2 of phenolic adhesive in a double line, a pre-pressing and hot pressing for 20 minutes under 1.2 MPa pressure and 130°C and treatement on veneers and panels with CCA-C. Tests followed Brazilian standards. Panels with previous treatment had lower water absorption and swelling. Preservation of the veneers also promoted higher retention levels and better penetration of preservatives. Both treatments did not affect the mechanical performance.

Resumo em Inglês:

Abstract According to the Brazilian standard for wooden structures, strength and stiffness increase linearly with decreasing moisture; however, as wood is a natural, heterogeneous and anisotropic material, certain strength and stiffness properties may not be affected even by large differences in moisture. Therefore, this work aims to evaluate the reliability of the resistance and rigidity transformation equations as a function of moisture, used to correct the properties when the test was not performed at 12% moisture. Furthermore, it was checked whether the humidity affects the properties of the studied species. Of the 15 properties analyzed, 2 did not show changes when analyzed at the fiber saturation point and at 12% moisture. Additionally, the correction equations of the Brazilian standard showed errors of up to 24% in the estimation of properties at 12% moisture. Thus, the need to correct the Brazilian standard for wooden structures is evident.

Resumo em Inglês:

Abstract Peanut crop waste (hulls), which have a chemical composition similar to wood, can be considered as a source of industrial raw material for the production of particleboard, provided that they are of similar quality to wooden panels. The present study aimed to produce and evaluate the physical and mechanical properties of medium density particleboards made of peanut hulls and pine wood particles bonded with urea-formaldehyde adhesive. The panels did not present satisfactory dimensional stability. The mechanical properties were significantly reduced with the addition of peanut hulls. In general, peanut hulls did not represent a good alternative to be used as a source of raw material for the production of particleboard. The inclusion of new parameters in the production process would be essential to improve the technological properties, such as: new particle geometries, use of paraffin, particle treatments and inclusion of denser species in the composition of the panels.

Resumo em Inglês:

Abstract The knowledge of tree attributes of the genus Copaifera sp. (copaiba), such as the height of the trunks, helps to estimate the productive potential of oleoresin and to propose more suitable ways of handling, aiming at optimizing production. This research aimed to test hypsometric equations and deterministic methods of Artificial Neural Networks (ANN) to estimate the total heights levels of the trunks of 31 copaiba trees of the Western Brazilian Amazon, at unknown ages. However, the ANN correlation coefficients obtained were greater than 0,99, demonstrating that they are appropriate for the estimation of height level (h100%). Among the ANN architectures, ANN 3 with 2 neurons in the hidden layer stood out. The application of ANN to estimate the total height of the trunk of Copaifera sp. native trees is a viable tool that can contribute to optimize modeling of the different important aspects to determine the productive potential of oleoresin.