Wood Density

For centuries, land degradation triggered by deforestation has occurred in Ethiopia, in particular in the northern regional state Tigray, the area under study. In order to change this situation, the local government started to establish enclosures. In these sites, grazing is no longer permitted so that forest can naturally regenerate. In order to develop sustainable yield planning for forest rehabilitation

Nest-site selection is crucial for birds' breeding success and, therefore, studies on this topic are critical in order to understand what features species need. This is particularly important in areas with conservation issues, where habitats and/or trees with the required features may be scarce. However, little information is available on the nest-site selection patterns of woodpeckers breeding in southern temperate forests, where tree logging considerably reduced forest cover and, hence, availability of trees suitable for cavity excavation. In addition, previous studies did not include assessments at different spatial scales nor including quantitative wood density data. Therefore, the main objective of this study is to assess nest-site selection patterns (at the habitat and cavity-tree scales) of the Campo Flicker Colaptes campestris and the Green-barred Woodpecker C. melanochloros breeding in a threatened southern temperate forest of central-east Argentina. Moreover, we report the first wood density data of the trees used by these two woodpeckers when excavating cavities and assess niche partitioning by comparing their cavities and cavity-trees to one another. To assess selection at a habitat scale (recording forest cover and edge of stands and trees), we compared selected breeding habitats to randomly found habitats. At a tree-scale (recording tree height, diameter, wood density and wood decay status), we compared cavity-trees to randomly found trees. Most cavities were excavated in medium (DBH = 20-35 cm) or large (>35 cm) size trees with wood density < 0.5 g/cm 3. Generalized linear models indicated that woodpeckers' propensity to excavate a new cavity was negatively correlated with tree wood density (which was negatively correlated to wood decay status) and positively to tree size. Both woodpecker species focused more importantly on tree features compared to habitat features when excavating cavities. Because forest patches containing mid-and large-sized trees with main stems and/or branches with wood softened by decay processes have become less abundant in these forests due to uncontrolled logging actions, we emphasize the need to conserve trees with these characteristics to ensure the availability of the preferred features of these woodpeckers.

Los objetivos del trabajo fueron 1- Determinar los patrones de variación axial y radial de la densidad de la madera y longitud de fibras en el fuste de Robinia pseudoacacia, 2- Determinar la edad de transición entre madera juvenil y madera madura, 3- Construir un modelo descriptivo de distribución de la madera juvenil en el fuste en base a la densidad de madera y longitud de fibras. Se cortaron rodajas a 4 alturas en el fuste (0,3 m; 1,3m; 2,3m y 4m a partir del suelo) en 10 árboles (7-15 años) implantados en Buenos Aires, Argentina. Se determinó la densidad normal12% y la longitud de fibras en probetas radiales obtenidas cada 3 anillos de crecimiento en todas las alturas. La densidad de la madera mostró una homogeneidad de los valores a lo largo del fuste comercial (variación axial), con un rango que la clasifica como madera semi-pesada (750 - 823 kg/m3). La longitud de fibras mostró aumento radial de sus valores de médula a corteza y sin variaciones axiales. El modelo de madera juvenil se asemeja al modelo de cilindro central pero de menor diámetro en el ápice. El cono juvenil se formaría hasta la edad de 3-6 años.

Summary. The rate and maximum swelling of several North American wood species in water have been obtained with a computer interfaced linear variable displacement transformer. Since wood swells extremely fast in water even at room temperature, this apparatus made it ...

This book is written in Polish language.
This book contains two parts: a theoretical description and tasks. The theoretical part presents knowledge of wood physics, especially: hygroscopicity in wood (e.g. adsorption,  wood moisture content, fiber saturation point, equilibrium and maximum moisture content), dimensional changes (e.g. swelling and shrinking), density (e.g. porosity, specific gravity), electrical properties (e.g. electric resistance, electric capacity), heating properties (e.g. thermal conductivity, specific heat, heat of combustion) and acoustic properties of wood. There are a lot of calculation tasks (examples of application) in practical part.

In this study, the effect of density on the velocity of an ultrasonic wave in wood is investigated. The aim of the present study was to analyze the influence of density on the longitudinal velocity of an ultrasonic wave, propagated in the longitudinal direction. Experiments were conducted on 5 cm · 5 cm · 5 cm wood specimens selected from the following species: pinus caribea (Pinus caribea var. caribea), eucalyptus citriodora (Eucalyptus citriodora), eucalyptus grandis (Eucalyptus grandis), cupiú ba (Goupia glabra) and jatobá (Hymenaea sp.). The relationship between density and velocity was analyzed in two different manners: between and within species. The results obtained between species indicated that ultrasonic velocity tends to increase with increasing density. The results obtained within species also showed an increasing trend in ultrasonic velocity as density increased, but the relationship was not as significant as it was for between species.

Wood density information for a large number of tropical tree species is presented in units of ovendry weight in grams per cubic centimeter of green volume. The data base includes 1,280 entries from tropical America (40 percent), tropical Asia (36 percent), and tropical Africa (24 percent). The most frequent wood densities were 0.5 to 0.8 g/cm3. In all three tropical continents, the most frequent class was the 0.5 to 0.6 g/cm3. These data are useful for a wide variety of practical and scientific applications, including the estimation of forest stand biomass from wood volume data.

Este es un estudio exploratorio para dar uso a la madera de Eucalyptus urophylla para la elaboración de tableros aglomerados de partículas. Por lo tanto, los objetivos fueron determinar sus propiedades físico-mecánicas y evaluar los resultados bajo norma Alemana y Venezolana. La absorción de agua promedio a 2 y 24 horas de los tableros para la densidad real de 731 kg/m3 no cumplió con lo estipulado en las normas, para el caso de los tableros de densidad real 831 kg/m3 si cumplió con la norma. La variación del espesor (hinchamiento) promedio por inmersión en agua a 2 horas para los tableros con densidad de 731 kg/m3 no cumplió con lo exigido en ambas normas, pero si cumplieron los requerimientos para 24 horas. Para el caso de los tableros con densidad de 838 kg/m3 la variación de espesor a 2 y 24 horas cumplió con las normas. Respecto de las propiedades mecánicas, tanto el módulo de ruptura en flexión estática como la tensión perpendicular (adhesión interna) para ambos niveles de densidad superaron el valor mínimo aceptado en las normas, demostrando que las partículas de madera de Eucalyptus urophylla presentan buenas características tecnológicas para la fabricación de tableros de partículas de densidad media.

Timber species grouping (TSG) is essential for meaningful and costoptimal
use of wood. Bangladesh forests are exceedingly diverse and comprise
many woody species which are potentially suitable for versatile uses including
structural materials. Traditionally, widely known tree species are used for structural
timber because technological properties of most of the species are poorly known. In
this study, a hierarchical agglomerative cluster analysis based on three selected
wood properties [i.e., wood density, modulus of elasticity (MOE) and modulus of
rupture (MOR)] of seventy-nine timber species was done. The clustering process led
to the formation of four distinct species groups [i.e., very low (TSG1), low (TSG2),
medium (TSG3) and high (TSG4)]. However, the species grouping patterns also
varied from trait to trait. This might be due to moderate relationship between density
and MOE (r2 = 0.46) or MOR (r2 = 0.52). Species of the TSG1 group are mainly
characterized by extremely low trait values, while the TSG4 group consists of
species having exceedingly high trait values. The TSG2 and TSG3 groups are
characterized by low and medium trait values. Hence, it is suggested to select
suitable species from these groups, particularly the lesser known high-quality species
in afforestation and reforestation programs to meet future timber demand in
Bangladesh.

Cerrado is a biome that occupies about 25% of the Brazilian territory and is characterized by a gradient of grassland to savanna and forest formations and by high species richness. It has been severely affected by degradation and deforestation and has been heavily fragmented over the past 4-5 decades. Despite the recognized overall ecological importance of the Cerrado, there are only few studies focusing on the quantification of biomass in this biome. We conducted such a case study in the South-East of Brazil in a cerrado sensu stricto (cerrado s.s.) with the goal to produce estimates of above-and belowground biomass and to develop allometric equations. A number of 120 trees from 18 species were destructively sampled and partitioned into the components: leaves, branches and bole. Five models with DBH (D), height (H), D 2 H and wood density (WD) as independent variables were tested for the development of allometric models for individual tree aboveground biomass (leaves + branches + bole). One model based on basal area (BA) as a stand parameter was also tested as an alternative approach for predicting aboveground biomass in the stand level. Belowground biomass was estimated by subsampling on 10 sample plots. Mean aboveground tree biomass (bole, branches and leaves) was estimated to be 62,965.5 kg ha À1 (SE = 14.6%) and belowground biomass accounted for 37,501.8 kg ha À1 (SE = 23%). The best-fit equation for the estimation of individual tree aboveground biomass include DBH and wood density as explanatory variables (R 2 = 0.898; SEE = 0.371) and is applicable for the diameter range of this study (5.0-27.6 cm) and in environments with similar conditions of the cerrado s.s. sampled. In the stand level, the model tested presented a higher goodness of fit than the single tree models (R 2 = 0.934; SEE = 0.224). Our estimates of aboveground biomass are higher than reported by other studies developed in the same physiognomy, but the estimates of belowground biomass are within the range of values reported in other studies from sites in cerrado s.s. Both biomass estimates, however, exhibit relatively large standard errors. The root-toshoot ratio of the sample trees is in the magnitude of reported values for savanna ecosystems, but smaller than estimated from other studies in the cerrado s.s.

Comparison between flexural wood strength values obtained from three-point and four-point bending tests in wood were only reported in few previous works, but remains unclear. Thus, the aim of this study was to determine the relationship between wood strength (MOR) obtained by 4-point and 3-point bending tests in Eucalyptus. Two or three specimens were cut from the same scantling (thus considered as twin) and submitted to flexural vibration tests. Then 190 wood specimens were tested by 4-point bending tests and 138 twin specimens were submitted to 3-point bending tests. Wood strength determined from 3-point bending test presented significantly higher mean value (76.8 MPa) than that from 4-point bending test (73.0 MPa). A linear regression for converting MOR from 3-point to 4-point bending test was proposed for these Eucalyptus specimens: MOR4p = 0.889 × MOR3p + 5.14 in MPa (R²=0.74). The correlation of MOR in 3-point bending with density was higher (R²=0.57) than in 4-point bending (R²=0.45). The correlations between dynamic elastic moduli and moduli of rupture were similar (circa R²=0.57 for MOR3p and R²=0.65 for MOR4p).

This paper studies the relationship between apparent density and some anatomical properties of Eucalyptus nitens such as vessel frequency, vessel area, ring width, fiber cell wall thicknesses, and fiber length. The study involved 29 trees from 10 families of Eucalyptus nitens cut from a 17-yr-old plantation in Southern Chile. The properties were determined along the radial direction of the trees by using X-ray equipment and at selected positions through microscope and fiber quality analyzer equipment. The results showed that the anatomical properties of E. nitens did not change gradually from pith to bark, but they were better described by dividing the tree radius into three different wood-zones referred as

Leaf area index (LAI) is a key driver of water and nutrient use, carbon balance, and the rate of growth of plantation forests, but these interactions can be environment-dependent. Our aim was to determine the relationship between LAI and stem growth in four 5±8-year-old Eucalyptus nitens plantations and its dependence on site and fertilization. Fertilizers were applied at various intervals between planting and age 6 years at cumulative rates that ranged from 0 to 1600 kg N ha À1 and 0 to 700 kg P ha À1 . Stem growth and LAI were monitored for 2 years. Values of LAI ranged from 1.4 to 9.6, and temporal variations in LAI were small. Fertilization increased LAI by up to 3.1 units. There was a strong relationship across all sites and treatments between initial LAI and growth, and predictions using LAI were more precise than those using basal area as the independent variable. #

Cork oak (Quercus suber L.) has a dense wood that allows high-quality uses. In the present work, we study the influence of vessel characteristics, measured through image analysis and optical microscopy, on wood density, measured using X-ray microdensitometry, on 40-year-old trees. Vessel area increases with cambial age (5403-33064 lm 2 ), while wood density decreases (1.229-0.836 g/cm 3 ). The number of vessels is relatively constant at 6 vessels/mm 2 , while vessel proportion in cross-section increases from 3.3% near the pith to 20.5% near the bark. In growth rings closest to the pith, with high wood density and low vessel area, the relationship between the two variables is linear (R 2 = -32.1%, P \ 0.01) but with increasing tree age and vessel size, the wood density remains rather constant, suggesting that decreases in density might compromise mechanical support of the tree at a stage when the increase in crosssectional area alone might not provide mechanical stability. Other anatomical characteristics not considered in this study, like large xylem rays that increase with cambial age, may be responsible for the constant density.

Aboveground deadwood, consisting of downed woody debris (DWD), snags, and stumps, is an important component of boreal forest ecosystem structure. Accurate deadwood density estimates are essential for evaluating ecosystem biomass and carbon stocks. The objective of this study was to examine the relationships between deadwood density, tree species, and decay status, identified in the field by morphological characteristics. We sampled DWD, snags, and stumps of trembling aspen (Populus tremuloides Michx.), paper birch (Betula papyrifera Marsh.), jack pine (Pinus banksiana Lamb.), black spruce (Picea mariana [Mill.] B.S.P.), and balsam fir (Abies balsamea [L.] Mill.) in the boreal forest of central Canada. A total of 240 samples (99 DWD, 94 snags, and 47 stumps) were collected. Decay class and tree species explained Ͼ80% of the variation in wood density of all deadwood types. Wood density decreased consistently from the lowest to the highest decay class. Tree species identity was also important in determining the relationships between wood density and fieldassigned decay class for snags and stumps, but not for DWD, probably because of the five-class system used for DWD, rather than the three-class system used for snags and stumps. These results indicate that decay class and tree species are adequate predictors of deadwood density. FOR. SCI. 59(3):261-266.

Reliable estimates of the biomass of Amazonian forests are needed for calculations of greenhouse gas emissions from deforestation. Interpretation of forest volume data for the region is the most practical means of obtaining representative biomass estimates. The density of the wood used in converting volume data to biomass is a key factor affecting estimates of biomass and of emissions. Interpreting density data for biomass purposes, which is different from the normal use of these data for commercial timber uses, is complicated by a variety of factors. There is variability among individuals of a given species, among geographic locations, and within the vertical and radial dimensions of individual trees. Considerable confusion has resulted from the variety of ways that densities are reported with respect to humidity at time of the weight and volume measurements used in calculating the density value. The most appropriate measure for biomass is basic density, or oven-dry weight divided by wet volume. Corrections for hollow trees and the position of samples within trunks are also needed. Here, available data are brought together for 268 species of trees, with an unweighted mean basic density of 0.65 (range 0.14-l .21). Weighting the mean by the volume of wood of each species in a sample of vegetation types, and weighting the means of the vegetation types by the extent of each in the region, yields a mean density of 0.69. Although the weighted mean density calculated here has a much firmer empirical basis than previously available estimates for this parameter, uncertainty is still considerable, particularly as a result of doubt concerning taxonomic identifications in the forestry surveys. Were the wood density of a small but botanically well-studied plot near Manaus to apply to the region as a whole, Brazil's 1990 emissions of greenhouse gases would be higher by an amount equivalent to two-thirds of the country's annual emission from fossil fuels.

We developed an individual-based stochastic-empirical model to simulate the carbon dynamics of live and dead trees in a Central Amazon forest near Manaus, Brazil. The model is based on analyses of extensive field studies carried out on permanent forest inventory plots, and syntheses of published studies. New analyses included: (1) growth suppression of small trees, (2) maximum size (trunk base diameter) for 220 tree species, (3) the relationship between growth rate and wood density, and (4) the growth response of surviving trees to catastrophic mortality (from logging). The model simulates a forest inventory plot, and tracks recruitment, growth, and mortality of live trees, decomposition of dead trees (coarse litter), and how these processes vary with changing environmental conditions. Model predictions were tested against aggregated field data, and also compared with independent measurements including maximum tree age and coarse litter standing stocks. Spatial analyses demonstrated that a plot size of ~10 ha was required to accurately measure wood (live and dead) carbon balance. With the model accurately predicting relevant pools and fluxes, a number of model experiments were performed to predict forest carbon balance response to perturbations including: (1) increased productivity due to CO2 fertilization, (2) a single semi-catastrophic (10%) mortality event, (3) increased recruitment and mortality (turnover) rates, and (4) the combined effects of increased turnover, increased tree growth rates, and decreased mean wood density of new recruits. Results demonstrated that carbon accumulation over the past few decades observed on tropical forest inventory plots (~0.5 Mg C ha−1 year−1) is not likely caused by CO2 fertilization. A maximum 25% increase in woody tissue productivity with a doubling of atmospheric CO2 only resulted in an accumulation rate of 0.05 Mg C ha−1 year−1 for the period 1980–2020 for a Central Amazon forest, or an order of magnitude less than observed on the inventory plots. In contrast, model parameterization based on extensive data from a logging experiment demonstrated a rapid increase in tree growth following disturbance, which could be misinterpreted as carbon sequestration if changes in coarse litter stocks were not considered. Combined results demonstrated that predictions of changes in forest carbon balance during the twenty-first century are highly dependent on assumptions of tree response to various perturbations, and underscores the importance of a close coupling of model and field investigations.

RESUMEN El trabajo se enfocó en la determinación de la densidad normal y las propiedades mecánicas de la madera de Acacia melanoxylon implantada en Argentina, y en analizar la relación entre estas variables. El material se seleccionó al azar del obtenido del aserrado de 20 árboles provenientes de cuatro sitios del sudeste de la provincia de Buenos Aires. Se determinó la densidad aparente conforme a la norma IRAM 9544 y los ensayos mecánicos se ejecutaron sobre cuerpos de prueba pequeños y libres de defectos según los lineamientos de la norma ASTM D 143. El valor medio de la densidad fue 564 kg.m-3 y la tensión de rotura mostró los siguientes valores medios: 89,9 N.mm-2 en flexión; 49,5 N.mm-2 en compresión paralela a las fibras; 11,7 N.mm-2 en compresión perpendicular y 11,6 N.mm-2 en corte paralelo. La dureza promedio alcanzó 45,3 N.mm-2 y el módulo de elasticidad en flexión exhibió un valor medio de 10926 N.mm-2. Los resultados de las propiedades mecánicas son los esperados para una madera de densidad media y pueden considerarse adecuados para el uso de la especie en la industria de la construcción y del mueble. Los modelos de regresión entre la densidad y las propiedades mecánicas exhibieron valores del coeficiente de determinación (R 2) comprendidos entre 0,70 y 0,87. El modelo de regresión entre el módulo de elasticidad y la resistencia en flexión mostró un valor de R 2 igual a 0,72. ABSTRACT The aim of this paper was to determine the density (at 12 % m. c.) and the mechanical properties of sawn wood of Argentinean Acacia melanoxylon, and to study the relationship between these properties. Test samples were randomly selected from the material obtained by sawing 20 trees harvested in four different plantations grown in the southeast of Buenos Aires province. Density was determined according to IRAM 9544 and mechanical tests were carried out by following the procedures of ASTM D 143. The mean value obtained for density reached 564 kg.m-3. Strength exhibited the following mean values:

Wood represents the defining feature of forest systems, and often the carbon in woody debris has a long residence time. Globally, coarse dead wood contains 36-72 Pg C, and understanding what controls the fate of this C is important for predicting C cycle responses to global change. The fate of a piece of wood may include one or more of the following: microbial decomposition, combustion, consumption by insects, and physical degradation. The probability of each fate is a function of both the abiotic environment and the wood traits of the species. The wood produced by different species varies substantially in chemical, micro-and macro-morphological traits; many of these characteristics of living species have 'afterlife' effects on the fate and turnover rate of dead wood. The colonization of dead wood by microbes and their activity depends on a large suite of wood chemical and anatomical traits, as well as whole-plant traits such as stem-diameter distributions. Fire consumption is driven by a slightly narrower range of traits with little dependence on wood anatomy. Wood turnover due to insects mainly depends on wood density and secondary chemistry. Physical degradation is a relatively minor loss pathway for most systems, which depends on wood chemistry and environmental conditions. We conclude that information about the traits of woody plants could be extremely useful for modeling and predicting rates of wood turnover across ecosystems. We demonstrate how this trait-based approach is currently limited by oversimplified treatment of dead wood pools in several leading global C models and by a lack of quantitative empirical data linking woody plant traits with the probability and rate of each turnover pathway. Explicitly including plant traits and woody debris pools in global vegetation climate models would improve predictions of wood turnover and its feedback to climate.

1 Although monocarpy is rare among long-lived plant species that grow in stable habitats, one monocarpic species, Tachigali vasquezii, is extremely abundant in the rain forests of the Bolivian Amazon. We analyse how T. vasquezii is able to maintain itself successfully by comparing its life-history traits with those of polycarpic tree species of the same community. We then evaluate the relative importance of such traits using population matrix models. 2 Monocarpic species are expected to have a high fecundity. Seed production per basal area for T. vasquezii is indeed nearly twice that of an average polycarpic species, but this is not sufficient to maintain stable populations. 3 Life-history theory predicts that a monocarpic strategy is advantageous if juvenile survival rates are high compared with adult survival. Although seedlings of T. vasquezii have a lower mortality rate than polycarpic species, its sapling have higher mortality. 4 We found that the success of T. vasquezii is due to its very high diameter growth rates in the larger size classes, which are four times higher than that of an average, co-occurring polycarpic species. Fast diameter growth is enabled by investment in large, leafy crowns and by a low wood density. Applying this high diameter growth in a population model yielded a population growth rate close to that of polycarpic species. Life table response experiment analysis of Tachigali and polycarp models showed that higher growth compensated for the negative demographic effect of 100% adult mortality following reproduction. 5 Rapid growth enables T. vasquezii to reach reproductive maturity in only 49 years, compared with 79 years for an average polycarpic species. It also reduces the risk of dying before reproducing, and 50% more seedlings survive to maturity for T. vasquezii compared with polycarpic species. 6 The dramatic negative demographic consequences of one-time flowering can therefore be completely balanced by taking a shorter time to reach maturity. Taking a time perspective, it appears that Tachigali vasquezii has an advanced, rather than a delayed, reproduction.

Tree rings of Pinus pinaster often contain intra-annual density fluctuations (IADFs), which have been attributed to the succession of dry and rainy periods typical of Mediterranean climate, but their formation has not been studied yet under Atlantic climate. We analyzed the occurrence and climatic significance of replicated IADFs in ten monospecific stands in NW Spain. The frequency of IADFs was higher than previously reported for this species under Mediterranean conditions and consistently decreased with increasing elevation. The formation of bands of latewood-like tracheids within the earlywood was favored by dry previous August, cold previous winter and dry April. Bands of earlywood-like tracheids within the early latewood were also favored by low winter temperatures. However, their occurrence was geographically heterogeneous, with two groups of stands being defined by their distances to the shoreline. In coastal stands, cold May–August triggered IADFs formation, while in inland stands their formation was favored by dry May–July. Regional winter temperatures and April water balance were strongly related to the East Atlantic (EA) pattern, which greatly conditioned the occurrence of IADFs in the earlywood and the early latewood. By contrast, the presence of bands of earlywood-like tracheids in the late latewood was independent of the EA pattern, being strongly related to warm conditions in spring and especially to a wet October. The link between regional climate and the EA pattern strongly controlled the physiological processes that determine intra-annual growth dynamics and short-term cell enlargement of P. pinaster in NW Spain.

One hundred and thirty two woody, broadleaved Mexican species were studied. The quality index of pulp for paper was determined. Pulp quality was classified according to the Runkel ratio. Sixty-nine percent of all species studied provide excellent (2.3%), very good (7.6%), good (34.8%) and regular (24.2%) pulp quality. Thirty-one percent produce poor quality pulp. According to these results woody, broadleaved

The aim of this study is to find the most convenient procedure to make an easy differentiation between various kinds of wood. The wood samples used were: fir (Acer alba), poplar (Populus tremula), lime (Tillia cordata), sycamore (Acer pseudoplatanus), sweet cherry (Prunus avium), hornbeam (Carpinus betulus), walnut (Juglans regia), beech (Fagus sylvatica), oak (Quercus robur). The methods of investigation used were FT-IR spectroscopy, X-ray diffraction and thermogravimetry.

Bamboo has good potential to substitute woodbased materials especially in wood-based composite industry. Apart from being fast growing, bamboo also has a good mecahnical properties. Malaysia has a few bamboo species that can be utilised commercially. It was used in terms of traditional purposes and many other countries have also used bamboo as a material in wood-composite industry. For Malaysian bamboo to be accepted as a construction material in the furniture industry, basic properties as density need to be studied. This study was carried out to ascertain the density difference along the culm of the two most common local bamboo species -Gigantochloa scortechinii and Bambusa vulgaris. The study was based on the internodes and nodes sections and along the culm height. A 20 x 20 x thickness (mm) internode and node strips were used. The dried samples were determined for their mass and volumes. The results showed that, for both species, the density increased along the culm with no significant diferences among the sections of nodes and internodes. The results from both species also revealed similar densities with a highest difference of 0.08g/cm 3 . It was therefore concluded that the two species can be worked and used together where density is the paramount determinant for use.

This study aims to identify the behavior of wood in the marine environment as well as its use in interior and exterior design of small cruise passenger ships. The cruise industry is among the most exciting and fast-growing categories in the leisure marketplace, especially ın Mediterranean region, so that is a need for constant improvement of services and passenger comfort. Although the wood as a building material has the most significant influence on interior design and furniture production, the material choice and building methods are first defined in the design-phase. This study is founded on actual experience during the refurbishment of the passenger ship Anna Maru during the spring of 2016 in Psaros shipyard in Perama, Greece. The beginning chapter is formed by bringing out the vessel characteristic, design essentials, design process and design methods, which facilitated the successful completion of full treatment. In add-on, also are mentioned problems of noise and vibrations, which requires monitoring of international standards, proper usage of materials and reduction of costs. The final chapter discusses the examples of practical usage and execution of traditional wood products such as tropical hardwood, combined with the contemporary composite materials, as well as finishing techniques.

The wood density of Eucalyptus globulus is, next to growth, the most important selection parameter in breeding programs for pulping. It was measured as basic density in 9-year-old trees from 37 provenances grown in three sites, on cross-sectional discs taken at b.h. The wood density was highly signi®cantly in¯uenced by provenance but not by site. The across site range of variation of wood density in the different provenances was between 492 and 600 kg/m 3 . The provenances of subspecies maidenii had a signi®cantly higher density in relation to those from spp. globulus and bicostata (584 kg/m 3 vs. 533 and 543 kg/m 3 ). No correlation between growth and density was found. Compared to an earlier assessment of density using cores at 7 years of age, the values at 9 years were signi®cantly higher. The overall ranking of provenances by wood density showed a reasonable coincidence between the non-destructive 7-year assessment and the 9-year measurement, thereby allowing an early assessment of density in breeding programs. #

The presence of heartwood influences the use of wood in different ways (Hillis, 1987). The conceptual bases that allowed the precise definition and general physiological aspects involved in heartwood and sapwood formation were consolidated for some time, but some current techniques such as X-ray scans, infrared and gamma rays can be used for more detailed quantification and characterization of heartwood inside the main stem (Gominho, 2003). In this study we used the non-destructive method of gamma radiation attenuation to determine the basic and apparent density at 12% moisture content of wood portions (heartwood and sapwood) of mature trees of four forest species (Eucalyptus grandis Hill ex. Maiden - 18 years old, Eucalyptus saligna - 60 years old, Eucalyptus tereticornis - 35 years old and Corymbia citriodora - 28 years old). Six discs were sampled at breast height (DHB) of each species and the heartwood and sapwood were delimited by macroscopic analysis of the vessels (heartwood characterized by the presence of tyloses in the vessels, and sapwood, by the absence thereof) in each sample. The apparent density values ranged from 672 to 933 kg/m³ in the heartwood wood and 749 to 899 kg/m³ in the sapwood wood. The averages of apparent density did not differ significantly between the wood fractions. Despite the different ages of the plantations, the highest values of apparent density of wood, both in the heartwood and in the sapwood fraction were observed in Corymbia citriodora species.

keywords: density, gamma radiation, Eucalyptus, heartwood

1] Lidar-based aboveground biomass is derived based on the empirical relationship between lidar-measured vegetation height and aboveground biomass, often leading to large uncertainties of aboveground biomass estimates at large scales. This study investigates whether the use of any additional lidar-derived vegetation structure parameters besides height improves aboveground biomass estimation. The analysis uses data collected in the field and with the Laser Vegetation Imaging Sensor (LVIS), and the Echidna® validation instrument (EVI), a ground-based hemispherical-scanning lidar data in New England in 2003 and 2007. Our field data analysis shows that using wood volume (approximated by the product of basal area and top 10% tree height) and vegetation type (conifer/softwood or deciduous/hardwood forests, providing wood density) has the potential to improve aboveground biomass estimates at large scales. This result is comparable to previous individual-tree based analyses. Our LVIS data analysis indicates that structure parameters that combine height and gap fraction, such as RH100*cover and RH50*cover, are closely related to wood volume and thus biomass particularly for conifer forests. RH100*cover and RH50*cover perform similarly or even better than RH50, a good biomass predictor found in previous study. This study shows that the use of structure parameters that combine height and gap fraction (rather than height alone) improves the aboveground biomass estimate, and that the fusion of lidar and optical remote sensing (to provide vegetation type) will provide better aboveground biomass estimates than using lidar alone. Our ground lidar analysis shows that EVI provides good estimates of wood volume, and thus accurate estimates of aboveground biomass particularly at the stand level. (2010), Assessing general relationships between aboveground biomass and vegetation structure parameters for improved carbon estimate from lidar remote sensing,

The selection criteria for the first generations in the Portuguese Pinus pinaster improvement program have been the growth rate and form traits. In this work we study the consequences of this selection on wood quality traits. This study assesses genetic and phenotypic correlation between growth, wood density components, lignin content and mechanical traits (radial modulus of elasticity and radial modulus of rupture) of 46 half sib families from a progeny trail located in Leiria, Portugal, originated from seed collected in a clonal seed orchard. A total of 552 seventeen-years-old trees (about half of full rotation age) were sampled at 2 m height. Height measured at 12 years old presented a higher genetic control (h 2 = 0.34) relatively to DBH, measured at 12 and 17 years old respectively (h 2 = 0.17 and h 2 = 0.15). The results of this study also showed that DBH growth is more dependent on latewood components than earlywood components and that higher growth in Mediterranean regions can be due to an increase of the period of latewood formation. Further, we can conclude genetic selection based on growth will not result in a decrease of wood density, will not affect the occurrence of spiral grain, and is possible to obtain an increase in the radial modulus of elasticity. The present study also showed that it is possible to select for increased growth with lower lignin proportion. Results also suggest that selection for growth at 12 years will probably not affect negatively the wood properties at 17 years. ß

1Tree mortality is an important process in forest ecology. We explored the extent to which tropical tree death is a predictable outcome of taxon and individual level properties by means of mixed-species logistic regression, for trees ≥ 10 cm in diameter. We worked in two lowland forest regions with markedly different floristic composition and dynamic regimes – the high wood density, low-mortality northeastern (NE) Amazon (in eastern Venezuela), and the low wood density, high-mortality northwestern (NW) Amazon (in northern Peru).2Among those genera that are shared between regions there were no detectable regional differences in mortality rates. This suggests that floristic compositional differences are a major driver of the twofold regional contrast in stand-level mortality.3In NE forests, mortality risk of individual trees is best predicted by low taxon-level wood density, slow relative growth, and large size, reflecting phylogenetically determined life-history strategy, physiological stress and senescence.4In NW forests, trees with low wood density and slow relative growth are also at most risk, but probability of death is independent of tree size, indicating that senescence is unimportant in this region.5Synthesis. This study shows that despite fundamental floristic and dynamic differences between the two Amazonian regions, mortality risk can be predicted with mixed-species, individual-based statistical models and that the predictors are remarkably similar, such that tree growth and wood density both play important roles.Tree mortality is an important process in forest ecology. We explored the extent to which tropical tree death is a predictable outcome of taxon and individual level properties by means of mixed-species logistic regression, for trees ≥ 10 cm in diameter. We worked in two lowland forest regions with markedly different floristic composition and dynamic regimes – the high wood density, low-mortality northeastern (NE) Amazon (in eastern Venezuela), and the low wood density, high-mortality northwestern (NW) Amazon (in northern Peru).Among those genera that are shared between regions there were no detectable regional differences in mortality rates. This suggests that floristic compositional differences are a major driver of the twofold regional contrast in stand-level mortality.In NE forests, mortality risk of individual trees is best predicted by low taxon-level wood density, slow relative growth, and large size, reflecting phylogenetically determined life-history strategy, physiological stress and senescence.In NW forests, trees with low wood density and slow relative growth are also at most risk, but probability of death is independent of tree size, indicating that senescence is unimportant in this region.Synthesis. This study shows that despite fundamental floristic and dynamic differences between the two Amazonian regions, mortality risk can be predicted with mixed-species, individual-based statistical models and that the predictors are remarkably similar, such that tree growth and wood density both play important roles.

Interspecific variation among wood density (WD), wood water content (WWC), tree mortality and diameter at breast height (d.b.h.) increment was examined for 27 tree species (from 13 families), based on a 9-year interval data obtained from a permanent 1-ha forest plot setup for long-term studies of tree dynamics in Kuala Belong rainforest, Brunei, on Borneo Island. The species were also categorized into three adult stature groups of understorey (maximum height Յ15-20 m tall, n = 14), midcanopy (maximum height, 20-30 m tall, n = 8) and canopy/emergent (>maximum height, >30 m tall, n = 5) tree species. All measured traits varied appreciably among species.Tree WD varied between 0.3 and 0.8 g cm -3 , and exhibited the least coefficient of variation (14.7%). D.b.h. increment was low, averaging 1.05 (95% confidence limits: 0.57-2.13) mm year -1 and was attributed to predominance of understorey species in the sampled plot. Overall, annual mortality was also low, averaging 2.73% per year. The three adult stature groups differed significantly in d.b.h. increment and WWC but not in tree mortality and WD. Across species and especially more so when phylogenetic effect is minimized,WD was negatively related to tree mortality and d.b.h. increment, while a positive trend was observed between d.b.h. increment and tree mortality. A negative trend was also detected between maximum plant height and WWC, which was interpreted as a consequence of increased evaporative demand and use of xylem stored water by taller trees in order to compensate for hydraulic limitations to water transport induced by frictional resistance. No doubt, the traits chosen may vary spatially, but the consistent interspecific patterns observed in this study among coexisting species of differing adult stature reflect 'vertical' niche differentiation and may help to explain population regulation in a multispecies ecosystem like tropical rainforest.

Gaseous ammonia treatments as well as thermal modification of timber are both applied to modify the surface colour of wood species. Physical and mechanical properties of solid wood after gaseous ammonia treatments have been so far scarcely investigated. Selected physical and mechanical properties, i.e., colour, equilibrium moisture content, wood density, bending strength, bending stiffness, and impact bending strength were investigated for oak, Norway spruce and Scots pine after gaseous ammonia treatment. Obtained data were compared with thermally modified timber data. While wood colour changes were comparable, most properties of the ammonia treated wood did not alter. There was no significant density change of ammonia treated wood; equilibrium moisture content changed moderately. Mechanical properties also remained within acceptable fluctuations. Results proved that gaseous ammonia treatment is a modification that improves the decorative value but has minimal effect on technologically relevant properties of solid wood. In contrast, property alterations of colour-equivalent thermally modified timber were much more pronounced, with possible limitations to some applications. M. Weigl ( ) · U. Müller · C. Hansmann Kompetenzzentrum Holz GmbH (Wood K plus), St.-Peter-Str. 25,