Latewood Percentage Research Articles

Tree Resilience Indices of Norway Spruce Provenances Tested in Long-Term Common Garden Experiments in the Romanian Carpathians.

Provenance trials provide a valuable opportunity to evaluate the impact of extreme events on growth and wood properties. In this study, we have evaluated 81 Norway spruce provenances, tested in three provenance trials established in the Romanian Carpathians in 1972. The response to drought of the Norway spruce provenances has been examined using the following tree resilience indices: resistance, recovery, resilience, and relative resilience. The relationship between climate and growth, the correlations between wood traits, and the coordinates of the origin and tree resilience indices were also analysed. In each provenance trial, there were significant differences between provenances and years regarding wood widths and latewood percentage (LWP). Regarding drought extreme events, the years when they occurred in all three provenance trials were 2000 and 2003. Significant differences between provenances for at least one tree resilience index have been found in all provenance trials, for the year 2000. By using subperiods of 25 years, changes in the relationship between climate and growth have been observed. Several provenances with high radial growth and good resistance and/or recovery have been identified. Provenances that performed better in common garden experiments could be used in assisted migration, even in the proximity of the current natural range.

Pine processionary moth outbreaks and droughts have different tree ring signatures in Mediterranean pines

Defoliating insects’ outbreaks play a critical role in trees’ carbon cycle. The pine processionary moth (PPM; Thaumetopoea pityocampa) is the major defoliating insect of Mediterranean coniferous forests. The frequency and intensity of PPM outbreaks is projected to increase as winter temperatures become milder due to climate warming. An accurate evaluation of this projection requires a wide spatial baseline of the historical PPM incidence. PPM outbreaks affect tree secondary growth leading to narrow rings, providing a tree level signal. However, PPM defoliation rings can be confounded with drought rings, the most frequent cause of narrow rings in Mediterranean environments. Thus, an accurate identification of PPM rings demands the consideration of additional tree ring traits. Here, we introduce a multiproxy approach to identify and distinguish PPM and drought events. We sampled four Pinus nigra (3) and P. sylvestris (1) stands in Spain. We identified and verified years of PPM defoliation using remote sensing analysis and field observations of Regional Forest Service. We identified drought events through the combination of climatic data with radial growth reductions. We considered climate growth residuals, among-trees growth variability, latewood percentage (%LW), intrinsic water-use efficiency (iWUE) and minimum blue intensity (BI) to discern between droughts and PPM outbreaks. In comparison with drought rings, PPM rings showed 1) more negative residuals in climate growth models, 2) higher secondary growth variance, 3) higher percentage of latewood and 4) lower iWUE. Minimum BI did not differ between drought and PPM rings, but was lower than in the rest of the rings. The combination of these traits provides a signature to identify PPM rings, opening the opportunity to reconstruct PPM incidence on a broad spatio-temporal scale.

Inheritance of growth ring components and the possibility of early selection for higher wood density in Japanese cedar (Cryptomeria japonica D. Don)

Key messageWe elucidated the age trends of narrow-sense heritability and phenotypic/genetic correlations and the age–age genetic correlation of growth ring components of Cryptomeria japonica D. Don by investigating progenies of controlled crossings by soft X-ray densitometry analysis. Wood density in the C. japonica breeding program can be efficiently improved by selecting trees with a higher earlywood density and latewood percentage as early as forest stand ages of 5–9 years.ContextWood density within the trunk is affected by the intra-ring wood density profile and its age trend from pith to bark. Wood density can be efficiently improved by clarifying whether wood density and highly correlated intra-ring components are under additive genetic control.AimsThe aim of this study was to elucidate the age trends of narrow-sense heritability and phenotypic/genetic correlations of growth ring components and investigate the possibility of early selection for improving wood density in Cryptomeria japonica.MethodsWe quantified seven growth ring components (width, density, earlywood/latewood width, average earlywood/latewood density, and latewood percentage) for 5112 annual rings of 342 18-year-old trees derived from 24 controlled pollinated full-sib families of C. japonica plus tree clones by soft X-ray densitometry analysis. Genetic parameters and correlations among the seven growth ring components were analyzed using a linear mixed model and the breedR package.ResultsEarlywood density and latewood percentage exhibited a higher phenotypic and genetic correlation with ring density than the other ring components at almost all ages. Earlywood density and latewood percentage exhibited a lower correlation with ring width than the other ring components after a stand age of 5 years. The age–age genetic correlation of earlywood density and latewood percentage was 0.70 for a stand age of 17 years and was strong at stand ages of 5 and 9 years.ConclusionEfforts focusing on improving earlywood density and latewood percentage may contribute to improving wood density efficiently in tree breeding programs for C. japonica. Traits related to the ring density of C. japonica trees can possibly be selected as early as stand ages of 5–9 years, and the required period for progeny selection may be substantially shortened when selecting trees with high wood density.

Impact of Growth Characteristics on Properties of 2 by 8 Southern Yellow Pine Structural Lumber

Abstract Southern pine is one of the most important softwood resources in the United States, and the majority of southern pine is for lumber production, more specifically for construction. The lumber used for construction is required to meet strength-specifications as a method of ensuring the strength values within different classes. Most of the southern pine lumber is visually graded, which is based on knot, slope of grain, and wane. However, the presence of pith is not included in the visual grading system. The presence of pith indicates presence of juvenile wood, which has a negative effect on mechanical properties. The objective of this study was to evaluate the effect of pith on rings per inch, percentage of latewood, modulus of elasticity (MOE), and modulus of rupture (MOR) in 292 samples of southern pine No. 2 2 by 8 lumber. Lumber without pith had significantly greater MOE (11.1 vs. 10.0 GPa), MOR (39.7 vs. 36.4 MPa), and specific gravity (12% moisture content [MC]; 0.55 vs. 0.52) than did lumber with pith. The results show that the presence of pith is an important factor that can improve lumber grading, and it could be included in the visual grade system.

COLORED AREA, GROWTH-RING WIDTH, AND LATEWOOD PERCENTAGE IN HYBRID PINE F1 INTA-PINDO

The characteristics of the annual growth rings are indicators of the growth and quality of the wood. At 11 years of age, 90 F 1 hybrid pine trees of Pinus elliottii x Pinus caribaea var. hondurensis were sampled from two sites. The sample consisted of 15 families and 3 positions in the genetic growth ranking. Disks were taken at 0.10 m, 1.30 m, and 4.45 m, colored area (%) in the central zone of the log, ring width, growth-ring area, and proportion of latewood were evaluated. The data were analyzed with mixed linear models. Statistically significant differences were found between families for the studied variables, except for latewood percentage. Family 02 showed higher growth and a low proportion of pink core. Families 01 and 03 had a higher percentage of colored area. The percentage of colored area increased with tree height. The ring width decreased with tree height and was higher for families 01, 02, 03, 04, 05, and 07. The latewood percentage increased from the pith to the bark and from the tree base to the crown. To conclude, top-growth families exhibited higher mean ring width and ring area than lower-growth families but the same proportion of latewood. These are desirable characteristics for obtaining wood quality for structural uses.

Inheritance of wood properties and their radial variations in full-sib families of 36-year-old Japanese larch (Larix kaempferi (Lamb.) Carr.)

Key messageLarger differences of maximum load among families were found in mature wood compared to juvenile wood, suggesting the possibility of improving mature wood with higher resistance to rupture and maintaining characteristics of material in Larix kaempferi (Lamb.) Carr. by selecting specific mating parents.ContextBecause the wood from L. kaempferi trees is used for construction lumber, wood properties and bending properties should be focused on as targeted traits of tree breeding programs.AimsWe clarified the radial variation of inheritance for wood properties and bending properties and classified the features of bending properties among families in L. kaempferi.MethodsAnnual ring width, latewood percentage, air-dry density, microfibril angle, modulus of elasticity, modulus of rupture, and bending work at five radial positions were investigated for 15 full-sib families of 36-year-old L. kaempferi grown in two progeny test sites in Japan.ResultsHigher heritability at almost all radial positions was found in air-dry density. Phenotypic and genetic correlations between air-dry density and bending properties showed relatively higher values at almost all radial positions. Load-deflection curves in 15 families could be divided into three groups in juvenile and mature wood. Variation among groups for load-deflection curves in mature wood was relatively larger than that in juvenile wood.ConclusionAir-dry density can be used as a criterion to select trees with superior bending properties. Mature wood in L. kaempferi could be effectively improved by selecting individuals.

Flexural and Tensile Properties of f2x6 and 2x10 Southern Pine Lumber

Bending modulus of elasticity (MOE) and tensile properties parallel to the grain were studied on 702 pieces of 2 X 6 and 285 pieces of 2 X 10 No. 2 visually graded southern pine lumber. The overall rings per inch (RPI) in 2 X 6 pieces was 4.82, whereas 2 X 10 had an RPI average of 3.82. For latewood percentage (LW), 2 X 6 pieces found 45.88% of LW and 45.02% for 2 X 10 pieces. Bending MOE (Eb) mean for 2 X 6 was 10,615 MPa, whereas for 2 X 10 lumber, the mean was 13,665 MPa. The tension MOE (Et) mean for 2 X 6 lumber was 11,339 MPa, whereas for 2 X 10 the mean was 9735 MPa. The ultimate tensile stress (UTS) mean for 2 X 6 lumber was 28.42 MPa and the overall mean UTS for 2 X 10 lumber was 24.51 MPa. Linear regression models were useful to explain the relationship between Eb and Et. Strong coefficients of determination (r250.70 and r250.74) were found for both lumber sizes between these two properties. Moderate relationships (r250.43 up to r250.51) between Eb and UTS were also found for both lumber sizes. However, weaker relationships were found between Et and UTS (r250.32 up to r250.40). Three distributions were fit to the Eb, Et, and UTS data and evaluated for goodness of fit. The results suggest that Eb of 2 X 6 lumber might be adequately modeled by a normal distribution, and tensile properties of 2 X 10 lumber might be adequately modeled by a lognormal distribution.

Wood density and microfibril angle from pith to bark of a sugi cultivar (Cryptomeria japonica, Japanese cedar, Tosaaka) grown in a Nelder plot

The current stumpage price in harvesting of a 50-year-old sugi (Japanese cedar, Cryptomeria japonica) plantation is not enough to motivate forest owners to reforest. Therefore, it is vital to reduce the cost for reforestation after logging as well as for logging and wood transportation of the preceding stands. Low initial tree density has been emphasized as one of the important basic measures to reduce directly the reforestation costs. In this study, for better understanding of the mechanical properties and dimensional stability of lumbers from sugi trees grown in low initial tree density, we examined the effects of initial tree density on wood density and microfibril angle of the S2 layer in the secondary wall of tracheids in rings from pith to bark in a sugi cultivar (Tosaaka) grown in a Nelder plot (initial density zoning symbols; D (4823 trees/ha), E (3349 trees/ha), G (1615 trees/ha), H (1122 trees/ha) and J (541 trees/ha)). Ring width and latewood percentage in J tree (541 trees/ha) were significantly larger and smaller than those of other initial tree density zoning symbol trees, respectively. Average wood density and earlywood wood density in J tree (541 trees/ha) were significantly smaller than those of other initial tree density zoning symbol trees (Tukey’s honestly significant difference test (Tukey HSD), p < 0.05). However, effects of initial tree density on the microfibril angles (earlywood and latewood) in rings from pith to bark and the transition patterns of microfibril angle from earlywood to latewood in an outer ring (ring number 22) were not significant or very small. Heartwood width in H trees (1122 trees/ha) and J trees (541 trees/ha) were significantly larger than those in other initial tree density zoning symbol trees (Tukey HSD, p < 0.05). There were no significant differences of ring width, average wood density, earlywood density and microfibril angle between H trees (1122 trees/ha) and E trees (3349 trees/ha) in many rings from pith to bark (Tukey HSD, p > 0.05). Based on these results of Tosaaka, a sugi cultivar grown in a Nelder plot, it was assumed that mechanical properties and dimensional stability of lumbers from sugi trees grown in low initial tree density (1000 trees/ha) might be quite similar to those from sugi trees grown in the regular initial tree density (3000 trees/ha), although lumbers from J trees (541 trees/ha) might be different from those of sugi trees grown in the regular initial tree density (3000 trees/ha). By taking the effects of genetic factor (variation of sugi cultivars) and the interaction between genetic and environmental factor (initial tree density) into consideration, the effects of low initial tree density (1000 trees/ha) on mechanical properties and dimensional stability of lumbers from sugi plantations in Japan might be smaller than the effects recognized in Tosaaka in this study. In this study, we did not examine the effects of initial tree density on the knots and the cross grain of lumbers. Low initial tree density might increase the negative effects of knots and cross grain on mechanical properties of lumbers. However, recent wood processing technology could minimize these negative effects.

Araucariaceous fossil woods from the Upper Triassic Ischigualasto Formation (San Juan Province, Argentina): paleofloristic and paleoclimatic implications

AbstractIn this contribution, fossil woods from the Valle de La Luna Member of the Upper Triassic Ischigualasto Formation at Ischigualasto Provincial Park, San Juan Province, Argentina, are described. The specimens are preserved as silica permineralization in tuffs intercalated with carbonaceous mudstone beds interpreted as distal floodplain facies. The fossil woods were assigned to the new species Agathoxylon argentinum since their anatomy differs from the known Mesozoic Gondwanan species of the genus Agathoxylon. The combination of characters present in the new taxon indicates an affiliation with the conifer family Araucariaceae. Signals of fungal-mediated wood decay were observed, comparable to the activity of basidiomycetes. Spherical structures attached to the walls of the tracheids were recognized and are interpreted as holocarpic chytrid fungi. The growth rings were quantitatively analyzed. Low values of percentage diminution, percentage latewood, and Ring Markedness Index, and a mean percentage skew of +11.5, were obtained, suggesting that the new species was an evergreen gymnosperm. The stratigraphic distribution and taxonomic composition of the Ischigualasto Formation fossil-plant-bearing levels were studied. A vegetation change is recorded in the fossil level bearing Agathoxylon argentinum n. sp., marked by the replacement of the corystosperm genera and a diminution of arboreal corystosperms. This floristic change, in addition to other evidence, indicates humid paleoclimatic conditions for the uppermost part of the Valle de La Luna Member of the Ischigualasto Formation.

A Comparative Study of the Bending Properties of Dahurian Larch and Japanese Larch Grown in Korea

The bending properties of Dahurian and Japanese larch grown in Korea were comparatively studied to facilitate the effective utilization of both species. The modulus of elasticity (MOE) and modulus of rupture (MOR) of the heartwood and sapwood of both species were observed in the tangential and radial directions using Korean standards. Overall, Dahurain larch showed better bending properties than Japanese larch. In the tangential direction, Dahurian larch had better properties than Japanese larch, but there was no difference in the radial direction between the species. In both species, the bending properties of the heartwood were better than those of the sapwood. In Dahurian larch, the bending properties in the tangential direction were greater than those in the radial direction, but there was no difference in either direction with Japanese larch. The bending properties of both species in both directions were positively correlated with latewood percentage and air-dry density. Bending properties in the radial direction had a negative correlation with the growth ring width, but there was no correlation between the growth ring width and bending properties in the tangential direction for both species. Finally, the MOE of both species was significantly correlated with the MOR.

Preliminary evaluation of anatomical characteristics of four common Mongolian softwoods

To effectively and sustainably utilize wood resources from boreal forests in Mongolia, anatomical characteristics, tracheid morphology, cell proportion, annual ring width, and latewood percentage were preliminary determined in Pinus sylvestris, Pinus sibirica, Picea obovata, and Larix sibirica trees naturally growing in Mongolia. Based on the observation, the anatomical characteristics of four common Mongolian softwoods were the same as those previously observed in the same species or the same genus species. Based on the parameters of the Gompertz functions for annual ring width, silvicultural management, such as thinning timing and harvesting age, should be considered depending on the species when the plantation is established. The results of the model selection for relationships between latewood percentage and basic density indicated that the increase ratio of basic density corresponded to an increase of latewood percentage is almost the same irrespective of species, although there are species-specific values of basic density corresponding to specific latewood percentages. The results obtained in the present study contribute effective and sustainable utilization of wood resources from Mongolian forestry.

Effect of Growth Ring Width and Latewood Content on Selected Physical and Mechanical Properties of Plantation Japanese Larch Wood

In order to evaluate the physical and mechanical properties of plantation Japanese larch wood, various physical and mechanical indicators were measured with reference to Chinese national standards. The characteristics of the growth ring on the end face of wood samples were captured, with the mean latewood percentage being 21.4% and the mean ring width being 3.24 mm. Relationships between growth ring characteristics, latewood percentages, and the physical and mechanical properties of the plantation Japanese larch wood were investigated. The results revealed that it is most appropriate to use growth ring width to evaluate MOE and MOR, and to use latewood percentage to evaluate air-dry density, radial air-dry shrinkage, IBS and UTS. Regression analysis confirmed that air-dry density (R2 = 0.99), radial shrinkage (R2 = 0.97) and UTS (R2 = 0.96) had significant positive correlations with latewood percentage, while MOE (R2 = 0.88) and MOR (R2 = 0.90) had significant negative correlations with RW. IBS was not significantly related to either characteristic. RW can be used to define juvenile wood and mature wood, with the dividing ring width being 4.85 mm. There is a large difference in MOE and MOR between the two wood types.

PROPRIEDADES FÍSICO-MECÂNICAS E CARACTERÍSTICAS DE CRESCIMENTO DA MADEIRA JUVENIL DE PINUS EM FUNÇÃO DA IDADE E DO ESPAÇAMENTO DE PLANTIO

ABSTRACT Pinus forests have been implanted in the South of Brazil since the 1960s in different spacing and harvested in shorter terms to increase wood yield. Reducing the rotation period and changing the spacing of forest plantations can influence the wood’s physical and mechanical properties, as they are younger trees that do not yet have a significant amount of mature wood in their composition. In this context, this research aimed to study the influence of three levels of planting spacing (3.0 × 2.0 m, 4.0 × 2.0 m, and 2.0 × 2.0 m) and two ages (13 and 15 years old) on growth characteristics and physical-mechanical properties of wood, as well as the relationship between them. Apparent density, latewood percentage, rings per inch, strength and stiffness in static bending as well as compression parallel to the grain, and shear strength were evaluated. The evaluated planting spacings did not cause statistically significant changes in the mechanical properties of juvenile Pinus taeda L. wood. The studied ages did not influence the wood’s apparent density. However, changing the cutting age from 13 to 15 years significantly increased the strength and stiffness of the wood. There was a statistically significant correlation between tree growth characteristics and strength, and stiffness in bending and parallel compression, around 0.500 R2, which suggests that this parameter can be used to assist in estimating those properties. The wood of Pinus taeda L used in this study can be classified as structural wood, class C20 for 13 years-old trees and classes C25 and C30 for 15 years-old trees, according to NBR 7190/97 requirements.

A COMPARATIVE STUDY ON THE PHYSICAL AND MECHANICAL PROPERTIES OF DAHURIAN LARCH AND JAPANESE LARCH GROWN IN KOREA

To compare the wood quality of Dahurian larch and Japanese larch growing in Korea, the physical and mechanical properties were examined using the Korean standards. The proportion of heartwood was 82% and 72% in Dahurian and Japanese larch, respectively. The percentage of latewood was 42% in Dahurian larch and 35% in Japanese larch. The growth ring width of Dahurian larch was narrower than that of Japanese larch. Dahurian larch showed about 20% higher green moisture content compare to Japanese larch wood. Density and shrinkage of Dahurian larch were higher than Japanese larch. Axial compression strength, young`s modulus in compression, and shearing strength in heartwood of Dahurian larch were 11 MPa, 686 MPa, and 2.3 MPa, respectively, showing higher value than Japanese larch. The hardness was in the range of 13.8–38.7 MPa in Dahurian larch and 17.7–48.4 MPa in Japanese larch. The compression strength parallel to the grain and shearing strength in both species were significantly correlated with oven-dried density. Besides, the hardness in Dahurian larch was significantly correlated with latewood percentage and oven-dried density. In conclusion, the differences in the properties of both species were revealed and the results can be used for quality indices of both wood species.

Characterization and comparison of the wood anatomical traits of plantation grown Quercus acutissima and Quercus variabilis

Abstract Oaks are important tree species, providing essential biomaterial for the wood industry. We characterize and compare wood anatomical traits of plantation grown Quercus acutissima Carruth. and Q. variabilis Blume to provide more detailed information to understand xylem radial growth, structure, and function, as well as differences between sapwood and heartwood, to provide data relevant for tree breeding and value-added wood utilization of oak plantations in China. In this study, radial strips were collected at breast height from the main trunk of the two species. Latewood percentage and growth ring width were investigated by X-ray densitometry and a Tree Ring Analysis System, respectively. Vessel and fibre lumen diameter, vessel and fibre wall thickness, vessel density, fibre wall thickness/diameter ratio, tissue proportions, and pit membrane thickness in between vasicentric tracheids were observed with light microscopy and electron microscopy and quantified. There were significant differences in a few wood anatomical traits between the two species: vessel wall thickness and vessel lumen diameter were higher in Q. acutissima than in Q. variabilis, while higher axial parenchyma proportion in sapwood was found in Q. variabilis than in Q. acutissima. More abundant tyloses were found in heartwood than in sapwood of both species. Our work showed the intraspecific and interspecific variation of the two species. Most differences between sapwood and heartwood must be attributed to differences in cambial age during their formation.

Relationships between the Macrostructure Features and Acoustic Parameters of Resonance Spruce for Piano Soundboards

An experimental examination of the relationship between the macrostructure characteristics and the acoustic properties of Norway spruce was performed. The macrostructure features were found to comprise the density (ρ), percentage of latewood (%LW), slope of grain (α), and angle the annual rings in a cross section (β). The main acoustic parameters of the research were the sound velocity, dynamic Young’s modulus, acoustic impedance (Z), and radiation coefficient (R). The acoustic properties for both the cross section and the longitudinal direction were calculated. Non-destructive evaluation (NDE) is the appropriate approach to define acoustic properties. Ultrasonic direct transmission and a transitory excitation method were used to calculate and compare the acoustic properties. A modal analysis was performed to predict the frequency range that corresponded to the different mode shapes. There were no significant differences between the two methods, yet an 80% reduction of the velocity, Z and R was identified between the longitudinal direction and the cross section. The equations used to define acoustic radiation according to the latewood component were defined, and strong correlations between the macrostructure and acoustic parameters were confirmed. A tight relationship was observed between the reduction of sound velocity and material density exceeding 440 kg m−3.

Functional Relationships of Wood Anatomical Traits in Norway Spruce.

The quantitative assessment of wood anatomical traits offers important insights into those factors that shape tree growth. While it is known that conduit diameter, cell wall thickness, and wood density vary substantially between and within species, the interconnection between wood anatomical traits, tree-ring width, tree height and age, as well as environment effects on wood anatomy remain unclear. Here, we measure and derived 65 wood anatomical traits in cross-sections of the five outermost tree rings (2008–2012) of 30 Norway spruce [Picea abies (L.) H. Karst.] trees growing along an altitudinal gradient (1,400–1,750 m a.s.l.) in the northern Apennines (Italy). We assess the relationship among each anatomical trait and between anatomical trait groups according to their function for (i) tree-ring growth, (ii) cell growth, (iii) hydraulic traits, and (iv) mechanical traits. The results show that tree height significantly affects wood hydraulic traits, as well as number and tangential diameter of tracheids, and ultimately the total ring width. Moreover, the amount of earlywood and latewood percentage influence wood hydraulic safety and efficiency, as well as mechanical traits. Mechanically relevant wood anatomical traits are mainly influenced by tree age, not necessarily correlated with tree height. An additional level of complexity is also indicated by some anatomical traits, such as latewood lumen diameter and the cell wall reinforcement index, showing large inter-annual variation as a proxy of phenotypic plasticity. This study unravels the complex interconnection of tree-ring tracheid structure and identifies anatomical traits showing a large inter-individual variation and a strong interannual coherency. Knowing and quantifying anatomical variation in cells of plant stem is crucial in ecological and biological studies for an appropriate interpretation of abiotic drivers of wood formation often related to tree height and/or tree age.

Using dendrogeomorphology to estimate soil erosion in mixed native species and pine forests on Ultisols in Piracicaba, Brazil

This work aims to study and date the erosion process in a gully located at the Experimental Station of Tupi (Piracicaba, São Paulo, Brazil) using dendrogeomorphology. Dendrogeomorphology is a relatively new science that relates the growth of tree-rings with geomorphological processes allowing chronological reconstruction and occurrence of events. The relevance of this study is to know the potential of this science in tropical areas because currently this type of study is lacking in these areas. This technique was applied using exposed roots of species of Pinus ssp. The dating of the erosion process was based on the changes in the pattern of root growth, such as the width of the ring, eccentric growth, percentage of latewood and density of the wood that occur after exposure by erosion. Through the study of these changes the first year of root exposure was determined, and the annual rate of erosion was estimated. Erosion rates of 0.65 and 2.39 m/year were found, characterizing the longitudinal advancement of the gully. Finally, dendrogeomorphology demonstrates great potential as a tool in tropical areas. The data and information obtained can be translated into a dendrogeomorphological database and contribute to the expansion of this science in Brazil and areas of tropical environments.

Protaxodioxylon from the Late Jurassic to Early Cretaceous Kota Formation, Pranhita-Godavari Basin, India

The xylotomy of the silicified wood from the Late Jurassic to Early Cretaceous Kota Formation of the Pranhita-Godavari Basin is studied and its systematic affinity is identified here. The wood is characterised by distinct growth rings with mixed pitting on radial tracheid walls, and taxodioid cross-field pits. The combination of the features observed in the present wood indicates that, it belongs to Protaxodioxylon of the taxodiaceous Cupressaceae s. l., as a new species Protaxodioxylon sahnii sp. nov. The comparison of wood with the modern representatives of the family suggests its relation with Taxodium. The present fossil wood with distinct growth rings characterised by their low percentage of latewood suggests that the growth conditions were favorable. The riparian habitat was inferred for the Protaxodioxylon sahnii sp. nov., based on sedimentological and other associated plant fossils. The vegetation in the study area is possibly favored by the influence of a subtropical climate with seasons, and by high levels of precipitation along the river banks.

Wood and lumber properties of Larix gmelinii var. olgensis planted in Japan

In order to promote plantation establishment of Larix gmelinii var. olgensis (syn. L. olgensis A. Henry), a ‘near threatened’ species, the wood and lumber properties were preliminary investigated for five trees from two clones of 57-year-old trees planted in Japan. The mean value of dynamic Young’s modulus of logs was 10.16 GPa. The mean values of annual ring width, latewood percentage, basic density, MOE, and MOR of five sample trees were 2.1 mm, 29.3%, 0.47 g•cm-3, 8.06 GPa, and 60.4 MPa, respectively. In addition, the MOE and MOR of 2 by 4 lumber were 10.43 GPa and 42.4 MPa, respectively. These values were similar to those obtained from other Larix species. Thus, construction lumber could be produced from the wood from plantation grown L. gmelinii var. olgensis.