Resumo em Inglês:

ABSTRACT Coptotermes testaceus (Linnaeus, 1758) is the most important species of heartwood termite of adult trees in forests planted in Brazil. This study aimed to characterize the injuries promoted by the heartwood termite C. testaceus in Tectona grandis commercial stands. Tree bark with extend carton material on the outside, forming external galleries and internal stem with a high termite infestation, was found in August 2018, in clonal plantations of T. grandis of 4.2 and 7.2-year of age. Internal injuries were characterized by galleries inside stem length with the presence of some soil, carton material, and termites inside the galleries. The damage by C. testaceus may not show external signs, and the injury was only detected during the harvesting process.

Resumo em Inglês:

ABSTRACT The objective of this study was to analyze the performance of species-specific equations (SSEs) concerning generic ones in Annual Production Units (GEAPUs) and in a Forest Management Area (GEFMA) in the Brazilian Amazon. A total of 29,119 trees from 43 species were inventoried, harvested, and volumetric measurements were taken in ten APUs, with 10% of this total being separated for validation and comparison of the selected equations. After selection and validation of the equations (GEFMA, GEAPUs and SSEs) they were compared using precision statistics, by contrasting estimated and observed volumes and by residual analysis. Precision statistics were clearly lower for the SSEs. Trend lines near the average observed volume were shown for the SSEs when the estimates were contrasted with the observations. The residuals generated by the SSEs were smaller and statistically different than those of GEFMA and GEAPUs for the majority of cases. The most important commercial species (M. huberi) had its volume overestimated by 10.6, 9.3 and 3.0% when the GEFMA, the GEAPUs, and the SSEs were applied, respectively. Among the species that generally had very large trees, H. petraeum had its volume underestimated by 15.7, 16.6 and 4.4% by the GEFMA, GEAPUs and SSEs, respectively. The greater precision of the SSEs is reflected in better forest management planning decisions with respect to operational and economic aspects. These results show that besides being statistically valid, the SSEs are recommended for obtaining more precise estimates of commercial volume, especially since there is a great demand for reliable estimates for each individual species in forest management areas in the Amazon.

Resumo em Inglês:

ABSTRACT Thermally modified wood undergoes chemical, physical, and mechanical modifications, resulting in changes in resistance to wood biodegrading agents. The objective of this study was to evaluate the resistance to biodeterioration of thermally modified wood by the industrial process VAP HolzSysteme® of Eucalyptus grandis, Pinus taeda and Tectona grandis, submitted to the Lentinula edodes fungi (brown rot) and Pleurotus djamor fungi (white rot), and to analyze the chemical properties, contents of holocellulose, lignin, total extracts, and ash, before and after biodeterioration. Three treatments were considered for each species: Control - wood in natura, modified wood at 140 °C and 160 °C. The specimens were made according to ASTM D 1413 (ASTM, 1994), in a total of 108 samples per species, 36 per treatment for each species, with 12 samples submitted to the fungus L. edodes, 12 to P. djamor and 12 correction blocks. Different behaviors occurred among species under fungal action. For E. grandis wood the thermal modification increased the resistance to biodeterioration of the wood under the action of the L. edodes fungus, in the opposite way occurred for the species P. taeda. There was little variation between treatments in T. grandis wood for both fungi. Thermal modification conferred chemical alterations on the wood, influencing their behavior the biodeterioration by the fungal action in P. taeda species in a negative way, (increasing the degradation level), and E. grandis in a positive way, reducing the biodeterioration. However, in T. grandis species no significant differences were identified in the different treatments by the action of different rotting fungi.

Resumo em Inglês:

ABSTRACT Yerba mate is a tree species whose natural distribution occurs in the countries of Argentina, Paraguay, and Brazil, where most of the plantations are concentrated. For the establishment of plantations seedlings are commonly used. But alternatively, there are ex vitro vegetative propagation techniques like mini-cuttings technology, which has the potential to facilitate plant production and increase the amount of plants needed for the industry. Yerba mate is sensitive to drought stress, negatively affecting the plantation productivity. Therefore, the objective of this work was to evaluate the growth and physiological responses of yerba mate seedlings and mini-cuttings to conditions of drought stress (field capacity, moderate drought, and severe drought). Total height, diameter at root collar, accumulation of dry weight (roots, leaves and stem), leaf number and area, and the content of chlorophylls were measured as response variables. Drought stress produced a decrease in height, dry wight accumulation, leaf number and area, and chlorophyll content, which was more pronounced in a situation of severe stress. The comparative analysis did not detect significant differences between seedlings and mini-cuttings, and there was also no interaction between the water restricted factors under consideration and type of propagule.

Resumo em Inglês:

ABSTRACT Plantations with native tree species, which emphasize biodiversity conservation, may not succeed because of a lack of forestry knowledge about the native species. Cabralea canjerana is an important tree species, which is rarely present in area restoration programs because of the difficulty in establishing it in plantations. Despite this, the species is also known for its adaptation to different light conditions. Therefore, this research sought to answer: a) What is the appropriate light level for the initial establishment of Cabralea canjerana seedlings in the field? b) Does seasonality influence the morphological and physiological attributes of Cabralea canjerana plants? The treatments used were: four shade intensities (0, 18, 50 and 70%) and two seasonal periods (spring-summer and autumn-winter). Survival was evaluated at 30 and 360 days after planting, while the morphological and physiological attributes were evaluated at 180 (spring-summer) and 360 (autumn-winter) days after planting. We suggest that Cabralea canjerana be classified as a moderately shade-tolerant species, considering that even in a region with four well-defined seasons, like the one in the present study, its mortality rate was high in full sun, a fact that is corroborated by the morphological and physiological parameters. The planting of Cabralea canjerana seedlings in full sunlight is not appropriate because it causes low seedling survival. It is recommended that planting be carried out under 50% shading. Seasonality influenced the morphological and physiological attributes of Cabralea canjerana plants.

Resumo em Inglês:

ABSTRACT Response of terrestrial ecosystems to changing climate has become an issue of central importance for land managers and policymakers. Climate extremes and trends have a strong control on productivity of semi-arid mountain ecosystems. Located in a transition zone from continental type climate to relatively mild Black Sea type climate in Turkey, the Ilgaz Mountains with their rich biodiversity, provide a unique opportunity to evaluate vulnerability of a typical semi-arid mountain ecosystem to climate change. Therefore, we evaluated spatio-temporal variation of annual net primary productivity (NPP) of Ilgaz Mountains predicted by Moderate Resolution Imaging Spectroradiometer (MODIS), as affected by topography and climate between 2000 and 2010. The annual MODIS NPP ranged from 500 to 912 g.m-2.y-1. Elevation, slope aspect, and vegetation type were significantly correlated with MODIS NPP The MODIS NPP was highly sensitive to droughts, and the mean MODIS NPP generally decreased across the study pixels in the study period. The response of MODIS NPP to climate was highly site- and time-specific. Multiple interactions among climate, plant composition, and topography were the principal determinants of the temporal pattern as well as drought sensitivity of MODIS NPP to climate between 2000 and 2010. Quality control charts showed that MODIS NPP decreased sharply in 2003 and 2007 droughts. The results obtained in this study contributed to our understanding of the interactions among climate, topography, and vegetation composition in a typical mountain ecosystem.

Resumo em Inglês:

ABSTRACT African mahogany is the common name given to different species of the genus Khaya. They are tree species native to the African continent, which have a wood quality that allows their noble use in making fine furniture, and in the civil and naval industries. Currently, African mahogany cultivation has received notoriety in Brazil and given its climatic conditions. The country has great potential for planting these species. The purpose of this work was to identify climatic aptitude zones for African mahogany in Brazil. Based on the Kppen classification and in the means of relative air temperature and annual rainfall, a base map interpolation was performed to select regions suitable and restricted to planting and adequate growth of African mahogany species. In general, the regions that presented temperatures between 22 °C and 30 °C were considered of high fitness, while temperature values below 14 °C restricts plantations growth. Regarding to precipitation, areas considered to be of high aptitude have between 700 to 3,000 mm.year-1, extreme values may indicate regions of low suitability and restricted to the cultivation of African mahogany. From the climatic characteristics, it was determined that about 60% of the Brazilian area was of high fitness, between 16% and 32% of medium fitness, and less than 20% as low fitness. The Northeastern semi-arid region proved to be restricted to the cultivation of these species due to the low annual rainfall and a few places in the South region was also restricted due to low temperatures and risks of frost.

Resumo em Inglês:

ABSTRACT The altitude is an important factor to affect the growth and development of saplings of the tree. However, the effect of altitude on the growth and properties of wood during their young stage it has been little studied. This study, therefore, aimed to evaluate the influence of two different altitude steps: 795 m (a.s.l. low-altitude) and 1350 m (a.s.l. high altitude) on the morphological, anatomical and wood density properties of saplings of Abies nordmanniana subsp. equi-trojani [Asch. & Sint. ex Boiss] Coode & Cullen (Trojan fir). Trojan fir is an endemic species in Turkey and its morphology and anatomy have less studied in the literature. The functional traits and wood density properties differed significantly between the two altitudes. The saplings grown at low-altitude showed greater taper degree, pith radius, pith proportion, and bark proportion than high-altitude. However, stem height, stem diameter, node number, and xylem proportion were found to be higher in saplings grown at high-altitude than low-altitude. Wood cell anatomy also varied significantly between two altitudes such that ring width, ray numbers, tracheid length, and tracheid width were higher at low-altitude, whereas ray height, ray width, tracheid lumen width, and tracheid wall thickness were greater at high-altitude. This study, therefore, suggested that the growth and development of fir saplings were better when they were grown at high-altitude than low-altitude.

Resumo em Inglês:

ABSTRACT The objective of this study was to compare different alternatives to estimate the stem volume of individual trees in four different forest formations in the Minas Gerais state, Brazil. The data were obtained in a forest inventory procedure performed by the Minas Gerais Technological Center Foundation. The stem volumes were computed by the Smalian expression up to the outside bark diameter equal to 4 cm. The volume data of outside bark, diameters (DBH) and total heights were used to fit a Schumacher and Hall equation for each forest formation, considering the structures of the linear fixed and mixed models. Next, 100 Multilayer Perceptron artificial neural networks (ANN) were trained in a supervised manner. In addition, we evaluated eight support-vector machine regression (SVMR). The criteria to evaluate the performance of all the alternatives studied were: the correlation between the observed and estimated volumes, the square root of the mean square error and the frequency distribution by percentage relative error class. After the analyzes, all the alternatives were verified to estimate the volume of the individual trees in the different forest formations. Although the alternatives presented close statistics in the validation process, the graphical analysis of the error distribution showed greater precision of the estimates of the mixed linear models for the four formations. Given the results, it is concluded that there is no absolute superiority of one alternative over the others, and that all of them should be evaluated to find the one which best describes or explains the dataset.