Growth Ring Width Research Articles

PHYSICAL, MORPHOLOGICAL PROPERTIES AND RAMAN SPECTROSCOPY OF CHESTNUT BLIGHT DISEASED CASTANEA SATIVA MILL. WOOD

ABSTRACT In this study, some of the physical and anatomical properties of Chestnut Blight Diseased (CBD) wood were investigated, and the study also included observations using Raman spectroscopy. The objective of these investigations was to determine the extent of the damage that is done to the wood of the diseased chestnut trees, which must be removed from the forest and used in the manufacture of industrial products. It was indicated that most of the adverse effects of the disease were in the vascular cambium. There was a clear indication of deterioration of the wood in the last growth ring next to vascular cambium. In the diseased secondary xylem region next to vascular cambium; vessel diameter, vessel frequency and vessel element length had a decrease, and vessel and other cells were irregular compared to healthy wood. Spores were detected and identified as Cryphonectria parasitica (Murrill). Annual ring properties (annual growth ring width, latewood percentage, etc.) were similar in diseased wood compared to healthy wood. The Raman spectroscopy results showed no significant changes in the structure of the cell wall or its components. After removing the diseased parts, unlimited usage of formerly wood is possible. Heat treatment of the wood is suggested before use in the interest of sanitation and dimensional stability.

Forward modeling of tree-ring width improves simulation of forest growth responses to drought

Abstract Drought is a key factor affecting forest ecosystem processes at different spatio-temporal scales. For accurately modeling tree functioning – and thus for producing reliable simulations of forest dynamics – the consideration of the variability in the timing and extent of drought effects on tree growth is essential, particularly in strongly seasonal climates such as in the Mediterranean area. Yet, most dynamic vegetation models (DVMs) do not include this intra-annual variability of drought effects on tree growth. We present a novel approach for linking tree-ring data to drought simulations in DVMs. A modified forward model of tree-ring width (VS-Lite) was used to estimate seasonal- and site-specific growth responses to drought of Scots pine (Pinus sylvestris L.), which were subsequently implemented in the DVM ForClim. Ring-width data from sixteen sites along a moisture gradient from Central Spain to the Swiss Alps, including the dry inner Alpine valleys, were used to calibrate the forward ring-width model, and inventory data from managed Scots pine stands were used to evaluate ForClim performance. The modified VS-Lite accurately estimated the year-to-year variability in ring-width indices and produced realistic intra-annual growth responses to soil drought, showing a stronger relationship between growth and drought in spring than in the other seasons and thus capturing the strategy of Scots pine to cope with drought. The ForClim version including seasonal variability in growth responses to drought showed improved predictions of stand basal area and stem number, indicating the need to consider intra-annual differences in climate–growth relationships in DVMs when simulating forest dynamics. Forward modeling of ring-width growth may be a powerful tool to calibrate growth functions in DVMs that aim to simulate forest properties in across multiple environments at large spatial scales.

Manifestation of cyclic solar activity in the paleoclimatic parameters ~100–150 Ma ago

Paleoclimatic data (the change in the width of the annual growth rings in fossil petrified trees) have been studied with a high spatial resolution on a time interval up to several million years in order to reveal quasiperiodic variations in the parameters of climatic processes. It has been indicated that the detected periodicities are often similar to present-day solar activity cyclicity. This circumstance indicates that solar activity affects climatic processes and the environment regardless of variations in (or constancy of) the climatic conditions during the considered period.

The diagnostic method ARCHI applied on declining pedunculate oaks

When evaluating tree architecture, condition and vitality, often, the prevalence and morphology of epicormic shoots are ignored or misinterpreted. However, epicormic shoots can play a fundamental role in tree survival and need to be taken into account when they occur. The presence and abundance of three morphologically different types of epicormic shoots can be used to distinguish between trees which are healthy, stressed, resilient (i.e. likely to recover after being stressed), undergoing natural crown retrenchment, or in a state of irreversible decline. Orthotropic and plagiotropic epicormic shoots, which respectively replicate the architecture of young trees and branches, act as the tree's “life insurance” against future catastrophe. On the other hand, ageotropic epicormic shoots, which have the characteristics of old age, indicate irreversible decline. Analysis of annual growth-ring width has shown that the architectural characters assessed for pedunculate oak (Quercus robur L.) are good indicators of the physiological state of the trees.

Wood resource management based on charcoals from the Bronze Age site of Gegharot (central Armenia)

Excavations conducted at the site of Gegharot in north central Armenia, along the northeastern margin of the Tsaghkahovit Plain (Aragatsotn region) have produced a large quantity of well-preserved charcoals. With occupations dating to the Early and Late Bronze Age, the site has been excavated since 2000 under the supervision of R. Badalyan and A.T. Smith under the auspices of the joint Armenian-American Project ArAGATS. The examination of the wood anatomy along three sections under a reflected light microscope, necessary for the identifications of charcoals, was systematically undertaken completed with the observation of the ligneous structure on transverse sections using a stereomicroscope. This dendrological approach provides valuable data for aiding identification of which part of the tree used, recording growth ring width, estimating wood diameter, and ascertaining the state of the wood before carbonization.Different vegetational biotopes were identified from remains of the Early Bronze Age layers at the site: an open woodland with heliophilic shrubs (birch, maple, willow and Pomoïdeae), an open forest formation with notably oak with maple and ash trees and a wet zone with willows and ash trees. The estimated diameters of the wood used at that time did not exceed 12 cm. The wood collection from the Late Bronze Age levels indicates a pine and oak forest surrounded by open areas where birch trees and Pomoïdeae grew and wetlands with willow trees and elm as riparian forests. The onset of a colder and drier climate could be the cause of the disappearance of the ash trees, the appearance of oak pine forests and the reduced growth of the tree-ring width. The taxa list and the high frequency of the small diameters observed during both occupations can refer to a local woodland exploitation. According to the observation of the last ring before the bark, evidence from a single operation (T21), during the Late Bronze Age testifies to seasonal activities. Some large charcoals of pine or oak had exceptional long series of more than 60 tree-rings. The average curve built on the basis of the oak series has a length of 72 rings, the beginning of a tree-ring series building in Armenia for the Bronze Age.

‘Growth rings’ in crustose lichens: Comparison with directly measured growth rates and implications for lichenometry

Some species of crustose lichens, such as Ochrolechia parella (L.) Massal., exhibit concentric marginal rings, which may represent an alternative technique of measuring growth rates and potentially, a new lichenometric dating method. To examine this hypothesis, the agreement and correlation between ring widths and directly measured annual radial growth rates (RaGR, mm a−1) were studied in 24 thalli of O. parella in north Wales, UK, using digital photography and image analysis. Variation in ring width was observed at different locations around a thallus, between thalli, and from year to year. The best agreement and correlation between ring width and lichen growth rates was between mean width of the outer two rings (measured in 2011) and mean RaGR (in 2009/10). The O. parella data suggest that mean width of the youngest two growth rings, averaged over a sample of thalli, is a predictor of recent growth rates and therefore could be used in lichenometry. Potential applications include as a convenient method of comparing lichen growth rates on surfaces in different environmental settings; and as an alternative method of constructing lichen growth-rate curves, without having to revisit the same lichen thalli over many years. However, care is needed when using growth rings to estimate growth rates as: growth ring widths may not be stable; ring widths exhibit spatial and temporal variation; rings may not represent 1-year's growth in all thalli; and adjacent rings may not always represent successive year's growth.

DENDROCRONOLOGIA DE ÁRVORES DE Schizolobium parahyba(Vell.) S. F. Blake DE OCORRÊNCIA NA REBIO DE TINGUÁ-RJ

O Schizolobium parahyba (Vell.) Blake, popularmente conhecido por “guapuruvu”, apresenta anéis de crescimento distintos, evidenciados por maior espessamento de suas paredes no lenho tardio e pela presença de parênquima em faixa marginal. Neste contexto, o objetivo deste estudo foi construir a cronologia dos anéis de crescimento de árvores de S. parahyba de ocorrência na ReBio de Tinguá, RJ, visando gerar conhecimento sobre a dinâmica de crescimento da espécie, bem como sobre a sensibilidade da formação dos anéis de crescimento por fatores climáticos. Das 30 árvores selecionadas foram coletadas quatro amostras radiais do tronco, utilizando-se uma sonda Pressler. As amostras passaram por polimento mecânico para melhor visualização dos anéis de crescimento e posterior delimitação e mensuração da largura deles. Para verificar a sincronização da largura dos anéis de crescimento e gerar uma série mestra da cronologia para a espécie, foi utilizado o programa estatístico COFECHA. A espécie apresenta ótimo potencial dendrocronológico, confirmado por elevada correlação da largura dos anéis de crescimento dentre e entre árvores. Além disso, exibe elevado coeficiente de sensibilidade média, que demonstra resposta às variações ambientais. O crescimento da espécie é correlacionado com a precipitação na estação seca.

Correlations between the anatomical traits of Gymnocladus canadensis Lam. in heartwood and sapwood of early- and latewood zones of growth rings

This paper shows correlations between vessel characteristics and differences in growth-ring width in heartwood and sapwood. Analyzed samples were from an iron-wood tree (Gymnocladus canadensis Lam.) that grew in the Muzljanski Rit area, of the Srpska Crnja municipality in Serbia. According to previous research, it was deduced that Gymnocladus canadensis Lam. belongs to ring-porous species with big vessel lumen in the earlywood zone and thicker cell walls in the latewood. Vessels were more numerous in the latewood zone, and the same was true for heartwood and sapwood. For both layers, sapwood possessed a few more vessels than heartwood, and a statistically significant difference was confirmed by t-test during the early phase. The greatest negative value of correlation coefficient was between the number of vessels and growth-ring width during the early phase for sapwood. The number of vessels decreased in the wider growth rings. The correlation between growth-ring width and the area of vessels had a statistically significant positive value of correlative coefficient, which means that wider growth rings had larger vessel areas in the early phase for sapwood.

Analysis of the growth characteristics of a 450-year-old silver fir tree

The growth characteristics of silver fir are of high importance for selection forest management, and for the current aims laid out in Serbia?s forest management focused on increasing the share of silver firs in Serbia?s growing stock. With the objective of increasing the understanding of the growth characteristics of silver fir, the growth of two silver fir trees felled during forest site production research on Mt. Goc, located in Central Serbia, have been analyzed. Both trees showed significant differences in their growth dynamics over long periods as results of micro-site and micro-stand effects (primarily ambient light regime). The common growth characteristic of the two trees, a 450-year-old tree as the main study object (labeled Tree A) and a 270-year-old Tree B is a long stagnation stage. For Tree A the latent phase, with small interruptions, lasted 410 years; one phase lasted 330 years in continuity, which is the longest period of silver fir stagnation recorded in Europe. Tree B showed a long-lasting stagnation stage that lasted 170 years. The long stagnation stage of Tree A, characterized by an average diameter increment of 1.4 mm/year (average growth ring width of 0.7 mm) and an average height increment of 0.08 m/year, shows the extraordinary silver fir capacity for physiological survival in complete shade. This study adds to the existing knowledge of the shade tolerance of the silver fir. Therefore, the silver fir belongs to the group of extremely shade-tolerant tree species. This characteristic makes silver fir an irreplaceable tree species in the selection forest structure. It offers a wide range of silvicultural flexibility in the management of these forests, and is applicable to silver fir selection Serbia?s forests.

Analysis of chip formation mechanisms and modelling of slabber process

During the primary transformation in wood industry, logs are faced with conical rough milling cutters commonly named slabber or canter heads. Chips produced consist of raw materials for pulp paper and particleboard industries. The process efficiency of these industries partly comes from particle size distribution. However, chips formation is greatly dependent on milling conditions and material variability. Thus, this study aims at better understanding and predicting chips production in wood milling. The different mechanisms of their formation were studied through orthogonal cutting experiments at high cutting speed for beech and Douglas fir. Under these conditions, ejection of free water inside wood can be observed during fragmentation, particularly on beech. As previously seen in quasi-static experiments, chip thickness is proportional to the nominal cut thickness. Moreover, the grain orientation has a great influence on the cutting mechanisms, so as the nominal cut and the growth ring widths. This chip fragmentation study finally allows the improvement of the cutting conditions in rough milling. In order to optimize machine design as well as cutting geometry, a geometrical model of a generic slabber head was developed. This model allows the study of the effective cutting kinematics, the log-cutting edges interactions and the effective wood grain direction during cutting. This paper describes the great influence of the carriage position on cutting conditions. The results obtained here can be directly used by milling machine manufacturers.

Evaluation of visual impact of multiple image characteristics observed in edge-grain patterns

Twenty distinct computer-generated softwood-like monochrome edge-grain patterns were printed on matte paper. Four image characteristics including mean growth ring width, growth ring width fluctuation, growth ring contrast, and shading contrast were embedded in the patterns. These image characteristics were expressed numerically by line profile and multiresolution contrast analyses. Five visual impressions, varied, agreeable, vague, showy, and natural, of these patterns on 30 subjects were evaluated by ranking. To determine the importance of each image characteristics on the impressions, a multiple regression analysis was conducted by attributing a criterion variable to an impression and predictor variables to all four image characteristics. This analysis revealed the impacts of the four image characteristics on each impression quantitatively. The results suggested that shading contrast was one of the useful indicators to evaluate surface harmony or homogeneity related to varied impression. Although growth ring width fluctuation had been considered as an important visual feature of wood, its influence on the impressions was extremely small compared with the other three characteristics.

Continuing upward trend in Mt Read Huon pine ring widths – Temperature or divergence?

To date, no attempt has been made to assess the presence or otherwise of the “Divergence Problem” (DP) in existing multi-millennial Southern Hemisphere tree-ring chronologies. We have updated the iconic Mt Read Huon pine chronology from Tasmania, southeastern Australia, to now include the warmest decade on record, AD 2000–2010, and used the Kalman Filter (KF) to examine it for signs of divergence against four different temperature series available for the region. Ring-width growth for the past two decades is statistically unprecedented for the past 1048 years. Although we have identified a decoupling between temperature and growth in the past two decades, the relationship between some of the temperature records and growth has varied over time since the start of instrumental records. Rather than the special case of ‘divergence’, we have identified a more general time-dependence between growth and temperature over the last 100 years. This time-dependence appears particularly problematic at interdecadal time scales. Due to the time-dependent relationships, and uncertainties related to the climate data, the use of any of the individual temperature series examined here potentially complicates temperature reconstruction. Some of the uncertainty in the climate data may be associated with changing climatic conditions, such as the intensification of the sub-tropical ridge (STR) and its impact on the frequency of anticyclonic conditions over the Mt Read site. Increased growth at the site, particularly in the last decade, over and above what would be expected based on a linear temperature model alone, may be consistent with a number of hypotheses. Existing uncertainties in the climate data need to be resolved and independent physiological information obtained before a range of hypotheses for this increased growth can be effectively evaluated.

Variability of the compression properties of cork

The variability of the compression properties of cork was determined after field sampling covering the main production area in Portugal (10 sites) with samples taken from 20 trees per site at the time of cork stripping. In all cases, cork showed compressive stress–strain curves typical for cellular materials, which are characterized by an approximately “elastic” region up to a 5 % strain, followed by a large plateau up to 70 % strain caused by progressive buckling of cell walls, and a steep stress increase for higher strains corresponding to cell collapse. The radial direction of compression offered higher strength. The Young’s moduli averaged 10.4 and 9.2 MPa for radial and non-radial directions, respectively, spreading from 3.5 to 22.5 MPa for the non-radial and 4.2 to 21.5 MPa for the radial directions. The geographical location of cork production was the major factor of variability. Density, annual growth ring width and chemical composition influenced compression. Cork samples with higher density showed overall larger resistance to compression. The energy absorbed per unit volume to achieve the maximal deformation with full densification of cork is higher when the average annual ring width is smaller. Cork samples with relatively higher suberin content required less stress for deformation. The results encompass the natural variability of cork and are the most extensive to characterize cork. They allow a better insight into the differences that may explain the variation in cork properties and strengthen its use either in the known applications, i.e. as a sealant, or in novel applications.

Software for dendrochronological measurements

The tree-ring measurement tool (TREMET) program has been developed for measuring the width of tree growth rings by images with any resolution recorded by capture devices (flatbed scanners, digital cameras, etc.). The program can be used to obtain dendrochronological information from various samples (cores, saw cuts), particularly from difficult-to-treat samples. The TREMET program has been used to create a 676-year tree-ring chronology from juniper samples, including relic plants gathered on the Cola Peninsula. This program is the longest juniper chronology in the northwest region of Russia. Using the TREMET program, the longest tree-ring chronologies have been obtained for pine of the Khibiny Mountains (448 years) and the Cola Peninsula (561 years).

Variation in strength, stiffness and related wood properties in young South African-grown Pinus patula

The objective of this study was to examine the variation in and intercorrelation among wood properties determining the suitability of 16- to 20-year-old South African-grown Pinus patula trees for structural timber. A total of 1 112 sawn boards from 340 logs, 170 trees and 17 different compartments were examined. Sawlogs were taken from two height levels from each tree. The mean modulus of elasticity measured on edge (MOEedge) was far below, and the mean twist higher than the limits set for structural grade softwood timber in South Africa. All the desirable properties for structural timber improved with distance from the pith with the exception of the fifth percentile value for modulus of rupture (MOR), which was higher at the pith than for the boards processed adjacent to the pith. Boards processed from the lower part of the stem were superior in most of the important properties compared to the properties higher up in the stem. The correlation between the dynamic modulus of elasticity (MOEdyn) and MOR of boards processed from the logs taken higher up in the stem was much weaker than in the case of the boards processed from the log taken from the lower part in the stem, suggesting that indirect (non-destructive) prediction of MOR decreased in reliability with increase in height in trees. A relatively strong negative correlation was found between the mean growth ring widths of the pith boards and the mean MOEdyn values per compartment, suggesting that slower initial growth in a compartment resulted in increased mean stiffness of boards from that compartment.

Comparison of Different Wood Species as Raw Materials for Bioenergy

Background and Purpose: Most projections of the global energy use predict that biomass will be an important component of primary energy sources in the coming decades. Short rotation plantations have the potential to become an important source of renewable energy in Europe because of the high biomass yields, a good combustion quality as solid fuel, ecological advantages and comparatively low biomass production costs. Materials and Methods: In this study, the wood of black locust Robinia pseudoacacia, white willow Salix alba L., poplars Populus deltoides and Populus x euramericana cl.I-214, aged eight years were examined. Immediately after the felling, sample discs were taken to assess moisture content, ash content, the width of growth rings, wood densities and calorific values, according to the standard methodology. Results: The mean values of willow, poplar and black locust wood density were 341 kg/m3, 336 kg/m3 and 602 kg/m3, respectively. The average heating values of willow poplar and black locust wood were 18.599 MJ/kg, 18.564 MJ/kg and 21.196 MJ/kg, respectively. The FVI index (average values) was higher for black locust (17.186) than for poplar and willow clones, which were similar: 11.312 and 11.422 respectively. Conclusions: Black locust wood with a higher density, calorific value and ash content compared to poplar and willow wood proved to be a more suitable raw material as RES. However, it is very important, from the aspect of the application of wood of these tree species as RES, to also consider the influence of the biomass yield per unit area of the plantations established as “energy plantations”.

End grain water absorption and redistribution in slow-grown and fast-grown Norway spruce (Picea abies (L.) Karst.) heartwood and sapwood

Wood is susceptible to decay by rot fungi if it is exposed to high-moisture contents during long periods of time and it is therefore important to limit the duration of such periods. Critical points in outdoor wood structures are, for example, end grain surfaces in joints where water can get trapped after a rain. It is therefore of interest to study both absorption and redistribution of moisture in wood. This paper presents moisture content profiles during end grain water absorption and redistribution in Norway spruce (Picea abies (L.) Karst.) measured by computed tomography with the specimens in individual climate boxes. Heartwood and sapwood of two provenances (slow-grown and fast-grown wood) were included. No major differences were seen between the water uptake of the slow-grown and the fast-grown wood since the densities were similar despite of the large difference in growth ring width. However, for the sapwood specimens, the moisture content was higher further into the specimens than for the heartwood specimens in agreement with previous studies. For the slow-grown wood, the redistribution was also generally more rapid for the sapwood specimens than for the heartwood specimens.

Diagnostic features of Fraxinus excelsior L. with wavy-grained wood growing in Ukraine

Abstract. The paper presents analysis of biometric features of ash with wavy-grained wood, which has decorative appeal. The research results shows that fresh broadleaves ash forest stands growing in the Vinnytsya and Sokyryany Regions of Ukraine have high potential for growing curly ash. The differences between straight-grained and wavygrained wood density and macrostructure were analysed and estimated. Statistical evaluation of the aesthetic macrostructure of wood characteristics indicated that the length of wave varied from 3,25 to 10,83 mm and its amplitude varied from 0,37 to 1,74 mm. The average width and mean height of anomalies in wood formation were equal to 15,89 mm and 5,00 mm, and their mean occurrence was 30 times m-2. Average annual growth ring width of wavy-grained ash wood was clearly greater (by 25%) than that of straight-grained wood. The density of wavy-grained wood was 82 kg·m-3 higher than straight-grained wood after oven-drying and 70 kg·m-3 higher prior to oven-drying

RESIN YIELD AND TIMBER QUALITY OF Pinus caribaea TREES TAPPED USING RILL METHOD

Experiments to study the oleo-resin yield in different diameter trees, tapping depths andtapping heights were under taken in the wet zone in the Kalutara District. Oleo-resin yieldwas measured in Pinus caribaea trees belonging to two diameter classes (10 em - 20 cmDBH, >20 cm DBH classes), two tapping heights above ground (0.5 m and 1.3 m) andthree tapping depths (I mm, 2 mm and 5 mm).Results showed that oleo-resin yield was higher in larger diameter classes compared withlower diameter classes. Resin yield was also higher at 1.3m tapping height compared with0.5m height. Resin yield also increased as the tapping depth increased from I mm to 5mm. Based on these data it is recommended that the lowest tappable limit may be above20 ern DBH and it can expected to increase the yield of oleo-resin as well as health andvigour of the tree. It is suggested the height of tapping should be increased to yield moreoleo-resin. However the cost of tapping would increase when higher heights are to be used.A 5 mm depth starting from the live bark can be recommended as suitable depth in resintapping. This depth can increase the yield of oleo-resin while maintaining the health andvigour of the tree.Experiments to study the growth rate and timber quality of tapped and untapped P.caribaea trees were also done by measuring density and width of the rings. Log samplesfor this experiment were obtained from plantation at Guruthalawa in the Badulla district.At the time of sampling these trees had been tapped for 5 years.There were three tapped and three untapped trees which belonged to 3 diameter classes(20cm, 28cm, 36.5 ern). Each couple of tapped and untapped tree had the same diameter.For each tree, discs were extracted at 0.5 m height and 1.3 m height. The width of growthrings which is a measure of growth rate, were measured on untapped tree, tapped radiusand untapped radius in tapped tree. The data showed that wood production has not beenaffected considerably by resin tapping.The density which is an indicator for wood quality showed an increasing trend from pithoutwards. Density in the tapped trees was higher due to infiltration of oleo-resin into thewood after resin tapping. Except this variation, no other considerable difference wasobserved in density between tapped and untapped trees.

Phenological variation in xylem and phloem formation in Fagus sylvatica from two contrasting sites

Xylem and phloem formation, as well as cambium and leaf phenology, and their relation to weather factors, were studied from 2008 to 2010 in beech (Fagus sylvatica L.) trees from two sites in Slovenia with different elevations and weather conditions: Panška reka (PA) (400m a.s.l.) and Menina planina (ME) (1200m a.s.l.). During the vegetation periods leaf phenology and dynamics of xylem as well as phloem formation were monitored. Leaf unfolding, onset of cambial cell production and increased number of active phloem cells occurred simultaneously for each site: in mid-April at PA and in the first week of May at ME; all three events were positively related to temperature in the first part of the growth season. Maximum rate of xylem cell production occurred at PA from 20 May until 9 June and about two weeks later at ME. Maximum phloem cell production occurred more than 1 month earlier at both sites. Cessation of xylem and phloem cell production was observed at PA around 19 August and around 10 days earlier at ME. Differentiation of the last-formed xylem cells was concluded by mid-September at both plots. The differences in xylem and phloem formation phases were smaller in the second part of the growth season and can be ascribed to similar temperatures at both plots. Year to year variability of the observed phases was not statistically significant but the differences between the sites were. Phloem formation seems to be less subjected to fluctuations in environmental conditions since the growth ring widths were comparable at both sites. Temperature and growing degree days before the occurrence of most of the observed phenological phases significantly differed between the sites. This demonstrates that the observed differences in xylem and phloem formation between the sites can be attributed to high intra-specific plasticity of beech.