Showing papers in "Iawa Journal in 2004"

IAWA list of microscopic features for softwood identification

Abstract: Pieter Baas – Leiden, The Netherlands Nadezhda Blokhina – Vladivostok, Russia Tomoyuki Fujii – Ibaraki, Japan Peter Gasson – Kew, UK Dietger Grosser – Munich, Germany Immo Heinz – Munich, Germany Jugo Ilic – South Clayton, Australia Jiang Xiaomei – Beijing, China Regis Miller – Madison, WI, USA Lee Ann Newsom – University Park, PA, USA Shuichi Noshiro – Ibaraki, Japan Hans Georg Richter – Hamburg, Germany Mitsuo Suzuki – Sendai, Japan Teresa Terrazas – Montecillo, Mexico Elisabeth Wheeler – Raleigh, NC, USA Alex Wiedenhoeft – Madison, WI, USA

Effects of a severe drought on growth and wood anatomical properties of quercus faginea

Abstract: We studied the growth response to drought of a Quercus faginea Lam. stand in a xeric site in NE Spain, that experienced an intense defoliation in 1993–94. This event coincided with very low precipitation from November to February, the period when total monthly precipitation exceeds evapotranspiration. We evaluated the effects of November–February precipitation (recharge precipitation, RP) on internode length, radial growth, and wood anatomy. Quercus faginea showed reduced longitudinal and radial growth during the years with low RP, and most sampled trees did not produce latewood in 1993–94 but showed wide earlywood vessels. We observed the reverse for years with a high RP. Radial growth was enhanced by increased precipitation during January and May of the growth year. If severe droughts become more frequent, due to a greater climatic variability, extensive dieback of marginal Q. faginea populations may be expected.

Within-tree variation in anatomical properties of compression wood in radiata pine

Abstract: Two trees of radiata pine, one showing severe lean, the other growing almost vertically, were assessed for the presence and anatomical properties of compression wood, including anatomy, lignin distribution, microfibril angle, basic density, radial and tangential lumen diameter and cell wall thickness. Both trees contained significant amounts of compression wood although the severity and amount of compression wood was greater in the leaning tree. Changes in lignin distribution seem to be characteristic of the mildest forms of compression wood with reduced lignification of the middle lamella representing the earliest change observed from normal wood. An increase in microfibril angle was associated with both mild and severe compression wood although examples of severe compression wood with the same or smaller microfibril angles than opposite wood, or with very small microfibril angles, were found. When segregated into mild and severe compression wood the average difference in microfibril angle was 4° and 8° respectively compared with opposite wood. Within-ring distribution of microfibril angle was different in severe compression wood compared to opposite wood with higher angles in the latewood.Severe compression wood showed a 22% increase in basic density compared to mild compression wood and opposite wood. The increased density was accounted for in terms of a 26% increase in tracheid wall thickness throughout the growth ring, offset by a 9% increase in radial lumen diameter, slightly greater in the latewood. There were no significant changes in density or cell dimensions in mild compression wood compared with opposite wood.

Influence of provenance variation on wood properties of teak from the western ghat region in india

Abstract: The three major teak provenances of the Western Ghats in India were characterised in terms of mechanical and anatomical wood properties. Within the same age of 21-year-old plantations, teak from the North Kanara provenance, generally known to display slow growth, had the lower values of static bending (modulus of rupture and modulus of elasticity) and longitudinal compressive stresses than the Malabar provenance (Nilambur). The weaker timber of North Kanara provenance was attributed to its relatively high percentage of parenchyma and low percentage of fibres in the narrower rings, probably as an adaptation to nutrient-rich soil condition. Observations of 65-year-old plantations reveal that there was a trend for bending stiffness (modulus of elasticity) and maximum stress (modulus of rupture) of the timber to be highest towards the southernmost geographic location (Konni) within the latitudinal range of 9° to15° S with a greater percentage of cell wall (with higher lignification) despite the slower growth rate and well defined ring-porosity with wider bands of earlywood parenchyma tissue. The study thus underlines the need to recognise the provenance source of variation to explain the varied growth-structure-property relationships of teak and to utilise the Indian genetic resources to the optimum in future teak improvement programmes.

The periderm development in quercus suber

Abstract: In the cork oak (Quercus suber L.), the phellogen differentiates during the first year of growth in the cell layer immediately under the epidermis and divides to form 3–6 suberized phellem cells. Division of the phellogen only occurs after suberization of the previous divided cell. During the first four years of growth, the phellem cells have tannin-filled lumens and it is only in the 5th to 7th years that they acquire the characteristics of ʻadultʼ cork cells with empty lumens and thin suberized walls. The lenticels are formed by the lenticular phellogen, which differentiates under the stomata and has a high meristematic activity. In this region, the cells are unsuberized, with a loose arrangement and intercellular voids, constituting the filling or complementary tissue. After three years, the lenticels appear as small protuberances that soon become conspicuous. Inclusions of sclerenchymatous nodules and isolated sclereids occur occasionally mostly in the vicinity of, or in, the lenticels.

Patterns of decay caused by pycnoporus sanguineus and ganoderma lucidum (aphyllophorales) in poplar wood

Abstract: Populus deltoides clones are widely planted in Argentina, in a region called “Parana River Delta”. In this site, Pycnoporus sanguineus and Ganoderma lucidum (Aphyllophorales) cause white-rot decay in both living and felled poplar trees. The purpose of this work was to estimate, through laboratory decay tests, the ability of both fungi to degrade poplar wood and to describe the patterns of decay using light and scanning electron microscopy. Two exposure times were analyzed: 75 and 150 days. The percent weight loss produced by both fungal strains was similar for both exposure periods (c. 50–60% of wood mass) but microscopic observations showed there were different patterns of decay. Samples inoculated with P. sanguineus showed a selective delignification, whereas those inoculated with G. lucidum exhibited a combination of simultaneous decay and selective delignification. Separation among cells was the main diagnostic feature for selective decay. By contrast, the presence of erosion troughs, cell wall thinning, bore holes, rounded pit erosion and erosion channels were diagnostic for the simultaneous type of decay.

Histochemical study on heterogeneity of lignin in Eucalyptus species II. The distribution of lignins and polyphenols in the walls of various cell types

Abstract: We examined the effects of polyphenols on the analysis of lignin by histochemical methods, namely, the Maule color reaction coupled with microspectrophotometry and ultraviolet microspectrophotometry, in wood of Eucalyptus camaldulensis and E. globulus. Thin sections and wood meals were extracted with solutions of alkali at different concentrations. The amounts of alkali-soluble extractives increased with increasing concentrations of NaOH. By contrast, there was no clear correlation between amounts of Klason lignin and the concentration of NaOH. The visible-light absorption spectra of cell walls of all woody tissues from both species changed after alkali extraction. In particular, the spectra of cell walls of vessel elements changed considerably, even when only a dilute solution of alkali was used. Ultraviolet absorption spectra did not show clear changes after extraction with alkali. These results indicate that polyphenols in cell walls affect the results of histochemical analysis. Therefore, a preliminary extraction with alkali, namely, extraction with a 1% solution of NaOH, is needed to assess the precise distribution of lignins in the cell walls of Eucalyptus wood by histochemical methods. The cell walls of wood fibers of Eucalyptus camaldulensis contained both guaiacyl and syringyl units and those of vessel walls contained mostly guaiacyl units. However, the cell walls of wood fibers in Eucalyptus globulus contained mainly syringyl units, while those of vessel elements contained both guaiacyl and syringyl units. Syringyl-type polyphenols, which have spectra similar to those of syringyl-type lignins, were found in the cell walls of wood fibers and vessel elements and in cell corners among wood fibers in both species of Eucalyptus.

Intervascular pitting across the annual ring boundary in betula platyphylla var. japonica and fraxinus mandshurica var. japonica

Abstract: The structure of intervascular pits, located at the boundary between the outermost and the second youngest annual rings in Betula platyphylla var. japonica and Fraxinus mandshurica var. japonica was examined by field-emission scanning electron microscopy. Unilaterally compound pits were present in the intervascular common wall at the annual ring boundary in both species. On the outer annual ring side of the unilaterally compound pits, outlines of pit membranes were curved or trifoliate, and each pit aperture was often elongated and curved. The porosity of the intervascular pit membranes differed between the two species. In B. platyphylla var. japonica, microfibrils were loosely packed in the peripheral region of each pit membrane, and openings of up to 300 nm in width were observed. By contrast, microfibrils were densely packed throughout the entire pit membranes in F. mandshurica var. japonica, and no openings perforating the pit membranes entirely were found. In addition, each species exhibited some unique features. In B. platyphylla var. japonica, extensive ethanol-soluble material was detected not only in the intervascular pits but also on scalariform perforation plates. In F. mandshurica var. japonica, we observed fine curly fibrils of unkown chemical composition in the intervascular pit membranes.

Genetic improvement of fiber length and coarseness based on paper product performance and material variability – a review

Abstract: Improvement of specific gravity through tree breeding was an early choice made in the mid 20th century due to its ease of measurement and impact on pulp yield and lumber strength and stiffness. This was often the first, and in many cases, the only wood quality trait selected for. However, from a product standpoint, increased specific gravity has shown to lower many paper strength and stiffness properties and has been assumed to be directly attributable to increased fiber coarseness. As a result, it is currently not clear which fiber trait would best benefit a tree improvement program for paper products. This review found coarseness to be perhaps more important to paper strength and stiffness whereas tracheid length showed better promise from a breeding point of view due to its independence from specific gravity. However, both traits possessed strong heritability and influence on product performance and thus both would be beneficial to breed for depending on organizational goals and end product mix. The objective of this paper is to review and prioritize coarseness and tracheid length from both an end use and raw material perspective. To aid in prioritization, the variation, correlation, and heritability of both traits were reviewed along with significant genetic and phenotypic correlations. Variation trends within and between families as well as within a tree were reviewed.

Stem and root wood anatomy of the shrub phlomis fruticosa (labiatae)

Abstract: Wood from the stems and roots of the malacophyllous Mediterranean drought semi-deciduous species Phlomis fruticosa was studied. The stem is diffuse-porous with narrow vessels. Though narrow vessels impose high conducting resistance, they are less vulnerable to cavitations, thus providing safety during summer drought and winter freezing. The geographical distribution of the plant (up to 1400 m altitude) may be relevant to the occurrence of narrow stem vessels, which provide high resistance to cavitations from low temperatures during winter. Vessel grouping in the stem adds to the safety against cavitations. Root vessels are mostly solitary and have almost double the diameter of stem vessels. Diffuse-porosity, the presence of narrow vessels in stems and the values of vulnerability and mesomorphy indices, are adaptations to the two stresses imposed by the Mediterranean climate, i.e. summer drought and winter cold.

Torus lignification in hardwoods

Abstract: Tori in wood of Osmanthus americanus, Daphne odora, Celtis occidentalis and Ulmus alata were tested for lignins using KMnO4 staining in conjunction with TEM, and acriflavine staining in concert with CLSM. It was hypothesized that impregnation with lignin could explain torus survival during cytoplasmic apoptosis. KMnO4 staining indicated torus lignification in all four woods, whereas only Osmanthus and Daphne tested positive for lignin with acriflavine. Tori in Celtis and Ulmus showed some evidence of partial breakdown during cell maturation, which might expose non-lignin sites for KMnO4 binding and thus produce spurious results. The acriflavine data correlate with developmental studies in which torus ontogeny occurs by one method in Osmanthus and Daphne and by another method in Celtis and Ulmus.

Roles of auxin and gibberellin in gravity-induced tension wood formation in aesculus turbinata seedlings

Abstract: The lowest nodes of 6-week-old Aesculus turbinata seedlings were treated with uniconazole-P, an inhibitor of gibberellin (GA) biosynthesis, or a mixture of uniconazole-P and GA3 in acetone solution. To the seedling stems, an inhibitor of auxin transport (NPA) or inhibitors of auxin action (raphanusanin or MBOA) were applied in lanolin paste. The seedlings were tilted at a 45° angle and kept for 10 weeks before histological analysis. Decreases in both normal and tension wood formation followed the application of uniconazole-P. The application of GA3 together with uniconazole-P partially negated the effect of uniconazole-P alone. The application of NPA inhibited tension wood formation at, above, and below the lanolin-treated portions. The treatment of raphanusanin or MBOA also resulted in decreases in tension wood formation at the treated portions. The inhibitory effects of these chemicals applied on the upper side of tilted stems or around the entire stem were greater than on the lower side. The application of uniconazole-P in combination with raphanusanin, MBOA or NPA showed synergistic effects on the inhibition of tension wood formation. The results suggest that both auxin and GA regulate the quantitative production of tension wood fibers and are essential to tension wood formation.

Effects of macro- and micro-structural variability on the shear behavior of softwood

Abstract: Longitudinal shear strength and shear modulus of spruce and larch wood with a maximum of micro- and macro-structural variability was determined using a new testing method. Oven-dry density and slope of grain were measured after the shear tests. For the spruce wood samples, a data set of fiber and cell wall properties, i.e., lignin content, microfibril angle, fiber length, lumen diameter, cell wall thickness, latewood proportion, and ring width, was available. A multiple linear regression analysis of all fiber and cell wall properties showed a significant, but not very strong effect on the variability of shear strength (R2 = 0.21). It is thus demonstrated that micro-structural variability plays a minor role in the variability of shear properties. By contrast, a multiple linear regression involving shear modulus, density, and slope of grain as three independent variables revealed an excellent possibility to model the variability of shear strength (R2 = 0.72). This study demonstrates the potential for non-destructive evaluation of the shear strength of solid wood.

Anatomical characterisation and variability of the thistle cynara cardunculus in view of pulping potential

Abstract: The thistle Cynara cardunculus L. is an herbaceous perennial with high productivity that is harvested annually and is a potential fibre crop for paper pulp production. The anatomical variation within stalks was studied (base, middle and top) and compared in C. cardunculus plants at different development phases. The stalk of C. cardunculus includes an epidermis, cortex and a central cylinder with fibro-vascular bundles with phloem, xylem and a fibrous sheath that is variable in arrangement and size within and between plants.At harvest, the pith represents 37% of the stalk transectional area and 7% of the total weight. There was a slight variation in quantitative features of, respectively, the three development groups studied; mean fibre length was 1.04 mm, 0.95 mm and 1.05 mm; mean fibre width was 15 μm, 16 μm and 21 μm; mean fibre wall thickness was 3.2 μm, 3.4 μm and 4.9 μm. Fibre length and width decreased within the stem from base to top, while fibre wall thickness increased. Mean vessel diameter was 22 μm and mean vessel element length 220–483 μm. In mature plants, parenchyma represents 39% of the total transectional area and fibres 25%. The proportion of fibres increases during plant development and in mature plants is highest at the stalk base.As regards anatomical features, Cynara stalks compare favourably to other annual plants and fibre biometry indicates good potential for paper sheet forming and strength properties.

Radial growth dynamics of tabebuia umbellata (bignoniaceae), a flood-tolerant tree from the atlantic forest swamps in brazil

Abstract: We studied the annual radial growth of Tabebuia umbellata (Sond.) Sandwith (Bignoniaceae) and its relationship to rainfall, temperature, photoperiod, flooding and phenology. This species showed cyclic annual growth. Growth was the greatest during the rainy season and flooding. Growth was associated with the presence of mature leaves on the trees. No increase in girth was observed during the dry season or during defoliation or flowering. The mean rate of radial growth was c. 6 mm/year. This flood-tolerant species maintained and increased radial growth during flooding.

Microfibril angle of the s1 cell wall layer of norway spruce compression wood tracheids

Abstract: The ultrastructural organization of the outer layer of the secondary wall (i.e. S1 layer) of Norway spruce (Picea abies (L.) Karst.) compression wood tracheids was investigated with emphasis on the microfibril angle. Light microscopy was used to study the orientation of soft rot cavities (viz. microfibril angle) in compression wood tracheids from macerated soft rot degraded wood blocks. In addition, surface and fracture characteristics of compression wood tracheids selected from a thermomechanical pulp were investigated using scanning electron microscopy (SEM). Results showed that the orientation of soft rot cavities varied little between tracheids and the angles were also consistent along the length of individual tracheids. The average S1 microfibril angle in two selected annual rings was 90.0° ± 2.7° and 88.9° ± 2.4° respectively. SEM observations of the compression wood tracheids from the pulp showed distinct fractures between S1 and S2 or within S1 and these fractures were oriented perpendicular to the tracheid axis. It was concluded that the microfibril angle of the S1 layer of compression wood tracheids is higher and less variable than normal wood tracheids. This is considered an adaptation for restraining the compressive forces that act on leaning conifer stems or branches.

Growth stresses and related anatomical characteristics in coconut palm trees

Abstract: The surface growth strains and the distribution of internal stresses in woody palms, coconut (Cocos nucifera L.), were determined by measuring the strains released by the kerf method using strain gauges. Measurements of the surface strains showed that longitudinal tensile stresses existed at the cortex, while longitudinal compressive stresses existed at the periphery of the central cylinder. These stresses may be generated from the fibers located in the scattered fiber and vascular bundles. In the central cylinder of narrow and wide trunks, both positive and negative stresses were observed, indicating the existence of some tensile and compressive stresses in the trunks. The amount of stress varied from base to top and from periphery to core because of the variation in proportion of the vascular bundles and the fibers, and the cell wall layers of fibers along these points. Furthermore, changes in the angle of vascular bundles and of the fiber microfibrils were correlated with the various tensile and compressive stresses located in the central cylinder of the trunks.

Wood anatomy of the tribe millettieae with comments on related papilionoid leguminosae

Abstract: The tribe Millettieae has traditionally included some 43 to 47 genera although more recent phylogenetic evidence has shown that a smaller core-Millettieae group of c. 23 genera may form part of a recircumscribed Millettieae sensu stricto. We have examined the wood of 27 genera, 16 of which are in the core-Millettieae and the remaining 11 belong in 4 groups, mostly with closer affinities outside Millettieae s.str. The wood anatomy of the various genera is nevertheless very uniform. Most genera are diffuse porous with no predominant vessel pattern. They have paratracheal parenchyma ranging from scanty through vasicentric, aliform and confluent, and often banded. Rays are mainly up to 5 cells wide. Axial parenchyma and rays are nearly always storied. The lianas Paraderris elliptica, Derris uliginosa, Ostryocarpus cf. riparius and Wisteria spp. have alternating bands of xylem and phloem, which are also found in some Dalbergieae. Even in the genera without such anomalous secondary growth there are many similarities between the wood of Millettieae and Dalbergieae. The wood of some genera in Sophoreae and Swartzieae is also compared. Our observations will be put in the context of recent cladistic analyses on both morphological and molecular data by other authors.

Variability of vessel characteristics in the xylem of ilex paraguariensis (maté-tree) from south brazil

Abstract: SUMMARY In this study the wood anatomy of two leaf-morphotypes (“Yellow” and “Grey”) of Ilex paraguariensis St. Hil. (Aquifoliaceae) from South Brazil was compared with special attention to vessel attributes and a possible relationship of leaf morphology and wood structure. Sampling was carried out in a 15-year-old plantation in the state of Parana, South Brazil. The anatomy of the juvenile and mature wood of five male and five female plants of each morphotype was investigated by light microscopy. In all plants the increment and the proportion of vessels decreased from pith to cambium, while vessel element length increased. Plants of the morphotype “Grey” had shorter vessel members (157–382 μm) and a lower number of bars per perforation plate (14–15) compared to the plants of the morphotype “Yellow” (vessel member length: 304–567 μm, bars: 22–24). No significant differences were found between the wood of male and female plants.

Intercellular space system in xylem rays of pneumatophores in sonneratia alba (sonneratiaceae) and its possible functional significance

Abstract: Sonneratia alba J. Smith is a fast-growing pioneer mangrove tree species, and woody pneumatophores are one of the main morphological characters distinguishing this species from other mangrove species. Xylem rays of the pneumatophores in S. alba were exclusively uni-seriate and homocellular with procumbent cells. Intercellular spaces developed mainly between rows of procumbent ray cells to form continuous canals along the pneumatophore radius. Short axial intercellular spaces were present at the end wall sites of spindle-like procumbent ray cells within the same row, and interconnected with the neighboring radial intercellular canals into an intercellular space network within the xylem rays. The radial intercellular canals of xylem rays were larger in the outer secondary xylem than in the inner secondary xylem of a pneumatophore, and in the underground part than in the aboveground part. Blind pits (unilateral pits) towards the radial intercellular canals developed in the radial walls of vessels and the transverse walls of ray cells. The blind pits of vessels were bordered and vestured, and arranged radially in two regular rows in larger radial intercellular canals, but in one row or diffusely in narrower canals. The structural characters of the xylem rays and the intercellular space system of the pneumatophore suggest their possible involvement in water transport in the secondary xylem. An intercellular space system did not occur in xylem rays of the cable roots and stems of this species.

The bark of the late triassic araucarioxylon arizonicum tree from petrified forest national park, arizona

Abstract: This paper contains a description of the only known non-banded bark in the geologic record. The bark is attached to a branch of the Araucarioxylon arizonicum tree that was found recently in the Late Triassic Chinle Formation (~ 220 Mya) in Arizona. In the fossil the vascular cylinder is almost totally enclosed in rough bark 2–11 mm in thickness. The inner bark is less than 1 mm thick and comprises a very narrow zone of presumed phloem containing infrequent fibers. The outer bark varies in thickness up to 10 mm, and consists of curving lenses of sequent periderm free of both dilation tissue and resin canals but is quite unlike the banded bark of Araucaria heterophylla. Wide zones of very thin-walled rectangular parenchyma cells arranged in radial files and groups of thin-walled spongy parenchyma, and small clusters as well as solitary sclerenchyma occur in the rhytidome. The vascular cambium contains 1–4 fusiform cells per radial file. Uniseriate rays are common in the secondary xylem and extend to the cambial zone. Small (1 mm in diameter), simple tunnels in the bark and wood indicate that the branch was attacked by phytophagous insects. A possible petrified beetle larva similar in form and size to Anobium is associated with these tunnels.

A new species of tapirira (anacardiaceae) from early miocene sediments of the el cien formation, baja california sur, mexico

Abstract: From the early Miocene El Cien Formation, Baja California Sur, Mexico, a new Tapirira species is described. Among the diagnostic features that relate T. peninsularis Martinez-Cabrera & Cevallos-Ferriz sp. nov. with extant species of the genus are libriform septate fibers, radial canals with 2–4 layers of epithelial cells, and scanty paratracheal to vasicentric axial parenchyma. In order to establish similarity between wood of T. peninsularis and fossil and extant species of the genus, cluster and principal component analyses were carried out. Numerical analyses support that Tapirira peninsularis is distinct from other extant and fossil species of the genus. Quantitative characters like frequency of radial canals, diameter of fibres, vessel element lumen, and height and width of the rays with radial canals are important in distinguishing between these taxa. Though these wood characters are quantitative, they also have been useful in the recognition of two subgenera within the genus. Recognition of this new species, along with the fossil record of the group, and a phytogeographic analysis suggest a low latitude North American origin for the genus, and a subsequent introduction to southern latitudes.

Two leguminosae woods from the miocene of gebel ruzza, egypt

Abstract: Early Miocene fossil woods of Gebel Ruzza, Egypt, were examined and two new records (Cynometroxylon schlagintweitii and Afzelioxylon welkitii) for Egypt are reported. A hot wet palaeoclimate is suggested for the Early Miocene collection site. The literature on fossil dicot woods from Egypt is summarised.

Fourier transform methods in image analysis of compression wood at the cellular level

Abstract: Compression wood affects the overall quality of construction timber and paper quality. We have investigated the microscopic features of lumen shape and tracheid shape for compression wood studies and detection in softwoods. In this paper, we describe a method for directly analyzing tracheid and lumen shape over an entire image. The method uses the Fast Fourier Transform (FFT) and reduces the two-dimensional image data to one-dimensional data, from which lumen and tracheid shape can be evaluated. We illustrate the method by comparison of compression wood images to normal wood images. The results of detecting severe compression wood were successful, while the detection of weak compression wood was not satisfactory.

Oligocene angiosperm woods from northwestern bohemia, czech republic

Abstract: Two species of fossil angiosperm wood are described from the Oligocene of northwestern Bohemia in the Czech Republic. One specimen from Kadan–Zadni vrch Hill is identified as Cercidiphylloxylon kadanense Prakash et al. Because of its superior preservation, the specimen is designated as an epitype to the original holotype specimen of the species and genus. Cercidiphylloxylon kadanense is known only from the locality of Kadan–Zadni vrch Hill, and it represents the oldest fossil wood of true Cercidiphyllum Sieb. & Zucc. Three other wood specimens from Zichov are attributed to Liquidambaroxylon speciosum Felix. Modern wood of some species of Cercidiphyllum Sieb. & Zucc., Liquidambar L., Altingia Noronha, Corylopsis Sieb. & Zucc., Distylium Sieb. & Zucc., and Hamamelis L. was examined to determine how to distinguish the wood of Cercidiphyllum (Cercidiphyllaceae) from similar woods of Hamamelidaceae. The number of bars in the scalariform perforation plates of the vessels is about 40 in Cercidiphyllum, and about 20 in the Hamamelidaceae. Rays are variable, even at intra-specific level, and are not suitable for distinguishing these woods. These criteria were found to be useful in evaluating affinities of the fossil woods.

X-ray microanalysis using thin sections of preservative-treated wood: Relationship of wood anatomical features to the distribution of copper

Abstract: The objective of this study was to understand the micro-distribution of a copper-based preservative in wood in connection with anatomical morphology and to consider the fixation of copper in wood. Bulk specimens and semi-ultra thin sections (0.5 μm) obtained from Japanese cedar (Cryptomeria japonica) were treated with a CuAz preservative solution. After fixation of the solution in wood components, SEM-EDXA (Scanning Electron Microscope equipped with an Energy Dispersive X-ray Analyzer) was used to investigate the micro-distribution of copper. The use of semi-ultra thin sections improved characteristic X-ray spatial resolution and made it possible to analyze the micro-distribution of copper. In both earlywood and latewood of the sapwood, copper was more abundant in the compound middle lamella than in the secondary wall and concentrated in the tori. Copper was most concentrated as crystalline deposits in longitudinal parecnhyma cells. Semi-quantitative analysis revealed the copper amount to increase in this order: secondary wall in tracheids < middle lamellae < membrane of half-bordered pits < tori in tracheid pits < deposits in longitudinal parenchyma cells. These different concentrations may indicate significant interactions between the amine-copper complex in CuAz and chemical constituents of wood.

Pathological anatomy of nectria canker on fraxinus mandshurica var. japonica

Abstract: The anatomical characteristics of Nectria canker on Fraxinus mandshurica var. japonica were analyzed. Typical cankers were conspicuous, round to oval, with uniform concentric rings of affected xylem in a target-like structure. Each concentric annual growth ring was wider than the corresponding annual rings lateral to the cankers. The xylem elements were extremely disoriented. The cambial zone became discontinuous and disappeared. An inoculation test with the causal fungus, Nectria galligena, produced similar anatomical abnormalities and revealed the process of canker formation. Fewer and narrower vessels were formed, and water conduction took place only in the large vessels of the current year in the cankers.

Silica-cast replicas for morphology studies on spruce and birch xylem

Abstract: Sol-gel mineralization has been used and evaluated as a tool for morphological studies on Picea abies and Betula verrucosa. Wood specimens and a pulped spruce sample were impregnated with a silica sol-gel and subsequently heated (calcined) to condense the surfactant-templated polysilicic acid into structured mesoporous silica. During this calcination process, the wood substance and the surfactant were removed and a silica-cast replica of the sample was obtained. The sol-gel mineralization method produced replicas that were studied by environmental scanning and transmission electron microscopy (ESEM, TEM) without additional sample preparation. The calcination induced some shrinkage above the fiber level, but the ultrastructural dimensions were not discernibly affected. The silica-cast replica method may therefore be a useful tool for studies of the wood ultrastructure, including the cell-wall pore structure (microcavities), down to the nanometer level.

Impact of air pollution on ring width and tracheid dimensions in abies religiosa in the mexico city basin

Abstract: Annual ring width and characteristics of latewood tracheids were characterized for the past 100 years for old trees of Abies religiosa growing in the Desierto de Los Leones within the air-polluted Mexico City basin. Sampled trees had lost nearly 50% of their branches and leaves. Radial variation in most measured characteristics followed typical trends for maturation until the 1970s, when trees were about 70 years old. From that decade onward, there was a continued reduction in annual ring width as well as a reduction in cell wall thickening and tracheid length, but an increase in lumen diameter. These xylem modifications started before the first visual symptoms of leaf damage were detected. We suggest that changes in annual ring width and tracheid size are caused by air pollution rather than by tree age.