Resumo em Inglês:

Abstract The Brazilian Code ABNT NBR 7190 (1997) is currently under review process and one of the proposals is the change and add of some test procedures. Several specimen geometric configurations and test conditions have been evaluated by the study committee CE-02:126.10. The aim of this paper was the analysis of the tensile strength perpendicular to the grain through the current Brazilian Code and from an adaptation of ISO 13910 (2005). Pine and Indian Cedar were used and simplified relationships were proposed. Numerical simulations were performed to identify the stress distributions in the specimens. The results obtained by ISO 13910 (2005) did not differ statistically for the two species. Brazilian standard method cedar had a higher strength value than pine. The simplified ratios obtained ranged between 0,017 and 0,123. The numerical simulations of ISO 13910 (2005) specimens showed predominant failure by tension in the lower fiber due to stress concentration.

Resumo em Inglês:

Abstract Acrocarpus fraxinifolius stands out due to its uses in the timber industry and rapid growth. However, information is scarce regarding its fertilization. We aim to understand how soil preparation and phosphorus doses affect A. fraxinifolius initial development. The experimental design used was a randomized block design in a 2 x 5 factorial scheme, consisting of two types of soil tillage (minimum and conventional) and five doses of phosphorus (P) (0, 50, 100, 150, and 200 g of simple superphosphate) with four replications, and plots formed by two plants. The measurement occurs at 30 and 210 days after planting, assessing the height and diameter at the stem height. Initially, the minimum tillage provided had a higher average height and diameter. However, conventional tillage, acidity correction, and fertilization with 108 g of simple superphosphate per plant resulted in Acrocarpus fraxinifolius plants with better growth at 210 days after planting.

Resumo em Inglês:

Abstract Forest burning susceptibility mapping is a tool to mitigate wildfires, with several methods to develop them. This study aimed to compare the Analytic Hierarchy Process (AHP), Multiple Linear Regression (MLR), and Random Forest (RF) methods for mapping. Several variables were used to generate the maps. For MLR and RF methods, fire frequency between 1990 and 2010 was used as the response variable in the models. To validate the methods (AHP, MLR and RF), fire data between 2011 and 2018 were used in four stages. RF was the best method employed. Correct and incorrect values for this method were 74% and 26% and AUC 0.66. The sensitivity and specificity for the highest risk class were 31% and 96%. The low sensitivity values can be attributed to the randomness attributed to anthropic fire. The high specificity values point to a good separation of the higher risk class compared to the others.

Resumo em Inglês:

Abstract Phenological information contribute to silvicultural actions and conservation strategies. Here, we carried out the phenological monitoring of six tree species that were prominent in the structure of an open ombrophilous forest fragment in northeastern Brazil. Over two years, among September 2015 and August 2017, eight individuals of each species (48 trees in total) were visited every two weeks to record the reproductive and leaf phenophases, following the Fournier intensity scale. We calculated the intraspecific synchrony of the phenophases and the correlation of the phenophases of each species with meteorological variables (temperature, air precipitation and photoperiod). The species showed synchronous characteristics for the phenophases. Precipitation stood out in terms of a higher frequency of significant relationships with the reproductive phenophases. The results indicates that the end of the dry season is the most favorable period for seed collection and the monitoring of dispersers in this type of tropical forest.

Resumo em Inglês:

Abstract This study aimed to identify the best shade level for the growth of Schizolobium parabyba var. amazonicum and Eucalyptus urograndis seedlings to obtain more resilient seedlings with higher quality. We used an entirely randomized design was used, in a 2 x 4-factor scheme, with two species and four levels of shading, comprising 5 repetitions and 6 plants per repetition, totaling 30 plants per treatment. The four shading levels were characterized as follows: T1 (full sun), T2 (50%-shading screen), T3 (plastic), T4 (50%-shading screen plus wool blanket). For the production of Eucalyptus urograndis seedlings, it is recommended an unshaded environment, since one variable showed a significant difference. For the Schizolobium parahyba var. amazonicum species, it is suggested to produce it under shade, where is was achived (50% together with the wool blanket), better results for the most variables.

Resumo em Inglês:

Abstract The aim of this study was to evaluate the distribution of chemical and physical fractions of soil organic matter (SOM) in anthropic horizons of soil profiles in the west of Pará. The highest total organic carbon values were observed in the superficial horizons, especially in the antrópico LAd and antrópico CHd (45.0g kg-1). Were observed predominance of recalcitrant organic material. It appears that most of the C found in the SOM fractions is associated with C stabilization mechanisms such as the recalcitrance provided by the presence of pyrogenic coal, in addition to its ability to present carboxylic groups that increase its interaction with the mineral fraction of the soil, characterizing the mechanism of chemical protection. It is observed that the SOM fractions can function as indicators that contribute to better understanding of the soil carbon dynamics in soils with antrópico horizons.

Resumo em Inglês:

Abstract The Euterpe oleracea Mart. has great importance in the neotropical forestry economy. Its berry is a product of great commercial value used extensively for human consumption. Most E. oleracea researches evaluate its food features, however, its potential use for phytoremediation and stipe use remains unknown. This research aimed to assess the seedling’s phytoextraction potential and the structural chemical composition in the seedlings and mature palm trees stipes. We used the Energy-dispersive X-ray fluorescence analysis to determine the concentration of the chemical elements. E. oleracea seedlings showed a great phytoextraction potential for aluminum and iron. The aluminum seedlings concentration was four times higher than preconized as a hyperaccumulator species. Calcium concentration was lower than considered normal, which may represent an antagonism effect caused by the strong presence of aluminum and iron. The fast uptake and accumulation of the seedlings highlight the potential to use this species in phytoremediation programs.

Resumo em Inglês:

Abstract The objective of this work is to evaluate the effect of fire on ant assemblages in savanna and forest typologies in the Reserva Natural da Serra do Tombador in Cavalcante - Goiás, Brazil. Ant pitfalls traps were installed and subdivided into Burnt Cerrado (BC), Unburnt Cerrado (UC), Burnt Forest (BF) and Unburnt Forest (UF), and the samples were sorted, assembled and identified. The constancy and abundance of individuals, and the frequency of distribution of the genera in the total area and by treatment were evaluated. The UF, BF, UC and BC had 19, 14, 8 and 15 genera, with Jackknife 1 index indicating 18.5, 24.4, 8.9 and 20.4 respectively. The Shannon diversity index for the genera was 0.8462, 0.7604, 0.6448 and 0.5992 for UF, BF, BC and UC respectively. The Cerrado showed greater abundance of individuals and greater ant diversity index in relation to Forest when in presence of fire.

Resumo em Inglês:

Abstract The process of forest death covers the entire boreal zone of the Northern Hemisphere. Due to the deterioration of the sanitary condition of forest areas, harmful organisms are becoming more active, where the most dangerous pest is Ips typographus. The aim of the work was to study the chemical structure of spruce wood in samples of various living conditions in the zones of active reproduction of bark beetles.The research studies the biochemical composition of Píceao bovata wood within the places of Ips typographus development (bythe example of the Udmurt Republic).The research was carried out within the European part of the Russian Federation, the Udmurt Republic region. The republic area is 42 thousand km2. A total of 15 sample plots were laid out and more than 8,000 trees were analyzed. It was revealed that in the subtaiga zone, the processes of death of spruce stands are observed.

Resumo em Inglês:

Abstract The development of vegetative propagation programs of Araucaria angustifolia still lacks on information about genetic factor that may influence on its success. We aimed to evaluate how mother tree sex and provenance influence on grafting success. So, we collected orthotropic branches from 26 mother trees male and female, of a clonal garden established from matrices from different provenances, and carried out an experiment using a patch grafting technique. Grafting survival, number and length of shoots did not differ between mother tree sex and provenance. The absence of significant variations between mother trees and no correlation with sex or provenance indicates that the morphological characteristics of rootstocks and shoots, and environmental conditions after grafting may have more influence on the success of grafting.

Resumo em Inglês:

Abstract We present the first records of insect visitors and pollinators of Bertholletia excelsa (Lecythidaceae) in a 25 years plantation outside the Amazon biome, flowering and producing Brazil nuts. We installed a platform to observe and photograph the insects. The collected insects were stored, mounted, and identified by specialists. Six species were observed, three of them classified as potential pollinators (Centris lutea, Eulaema nigrita, Eulaema cingulata). The species E. nigrita and E. cingulata were already reported as a pollinators of Brazil nut in Amazon. This is the first record of C. lutea as potential pollinators for B. excelsa.