Stem anatomy of Apioideae (Apiaceae): effects of habit and reproductive strategy

Apioideae is the biggest and the most diverse of four subfamilies recognised within Apiaceae. Except for a few, likely derived, woody clades, most representatives of this subfamily are herbaceous. In the present study, we assessed stem anatomy of 87, mostly therophytic and hemicryptophytic, species from at least 20 distinct lineages of Apioideae, and juxtaposed them with 67 species from our previous anatomical projects also focused on this subfamily. Comparing our data with the literature, we found that wood anatomy does not allow for a distinction between apioids and their close relatives (Azorelloideae, Saniculoideae), but more distantly related Mackinlayoideae differ from Apioideae in their perforation plate type. Vessel element and fibre length, and vessel diameter were positively correlated with plant height: phenomena already reported in literature. Similar pattern was retrieved for vertical intervessel pit diameter. Wood ground tissue in apioids ranges from entirely fibrous to parenchymatous. The shortening of internodes seems to favour the formation of parenchymatic ground tissue, whereas the early shift to flowering promotes the deposition of fibrous wood in monocarpic species. These results support a hypothesis on interdependence among internode length, reproductive strategy, and wood ground tissue type.

Wood anatomy of Magnolia rzedowskianaVázquez, Domínguez & Pedraza, endemic species of the Sierra Madre Oriental, Mexico

Introduction: Magnolia rzedowskianaVázquez, Domínguez & Pedraza is a tree species endemic to the cloud forest of the Sierra Madre Oriental; its scanty (distributed) and isolated populations are considered at danger of extinction.Objective: To describe the microscopic anatomical characteristics of M. rzedowskiana wood to contribute to the biological knowledge of this species.Materials and methods: Wood samples were determined by a non-destructive method, extracting two growth cores from five adult trees in each of the four sampling sites located in Chilijapa and Zotictla in Hidalgo, La Yesca in Querétaro and ejido La Trinidad in San Luis Potosí. Cores were sectioned into subsamples to elaborate fixed preparations from tangential, transversal and radial cuts. Characteristics were identified using an optical microscopy and described according to IAWA (International Association of Wood Anatomists) criteria.Results and discussion: Growth zones, diffuse porosity, solitary and multiple radial pores in intermediate arrangement between radial and tangential; scalariform perforation plate and libriform fibers; diffuse and scanty paratracheal and apotracheal axial parenchyma; biseriate rays combined with triserial, uniseriate and heterocellular rays composed of procumbent cells with a row above and below of marginal square cells with oil bodies. The wood is distinguished by mesomorphism and resistance to drought.Conclusion: The anatomical description of M. rzedowskiana is a contribution to biological knowledge. From an economic point of view, this wood has potential use to produce pulp for paper.

Comparative wood anatomy of Atraphaxis taxa in Turkey

The wood anatomy of four Atraphaxis taxa that have natural distribution in Turkey—Atraphaxis billardieri Jaub. & Spach, Atraphaxis billardieri subsp. tournefortii (Jaup. & Spach) Lovelius, Atraphaxis spinosa L., and endemic Atraphaxis grandiflora (Willd.)—were compared in this study. The wood samples were sectioned according to standard techniques. Samples were macerated with Schultze’s method. Tangential and radial vessel diameters, intervessel pit diameters, vessel wall thickness, vessel elements length, dimensions of libriform fibres (lengths, widths, cell wall thickness and, lumen diameter), and uniseriate and biseriate ray heights were measured, and the number of vessels per mm2, number of rays per mm, and number of vessels per group were counted. The qualitative features such as growth rings, vessel grouping, presence of helical thickening and storied structure, vestured pits, type of perforation plate, and arrangement of axial parenchyma were determined. These four species of Atraphaxis shrubs differ in some wood characteristics such as growth rings, vessel grouping, vestured pits, height and density of rays, number of vessels per mm2, and the dimensions of the vessel.

Computational fluid dynamics model and flow resistance characteristics of Jatropha curcas L xylem vessel

Xylem vessels are the channels used for water transport in Jatropha curcas L. Vessel complexity has a great influence on water transport. Therefore, using anatomical experiments and numerical simulations, the water transport characteristics of J. curcas L xylem vessels with perforation plate and secondary wall thickening (pit structures) were analyzed. The results showed that the xylem vessel in J. curcas provided a low resistance path. The xylem vessel resistance was composed of three elements: smooth vessels, secondary wall thickening and perforation plate. The proportion of smooth vessel resistance was the largest, accounting for 66.20% of the total resistance. Then the secondary wall thickening resistance accounted for 30.20% of the total resistance, and finally the perforation plate resistance accounted for 3.60% of the total resistance. The total resistance of the vessel model was positively correlated with the pit depth, perforation plate height and perforation plate width and negatively correlated with the vessel inner diameter and pit membrane permeability. The vessel inner diameter and the pit depth had a great influence on the total resistance. The total resistance of the vessel inner diameter of 52 µm was 89.15% higher than that of 61 µm, the total resistance of the pit depth of 5.6 µm was 21.98% higher than that of 2.6 µm. The pit structure in the secondary wall thickening caused the vessel to be transported radially, and the radial transmission efficiency of the vessel was positively correlated with the pit depth and pit membrane permeability and negatively correlated with the vessel inner diameter. The pit membrane permeability had the greatest influence on the radial transmission efficiency, and its radial transmission efficiency was 0–5.09%.

KARAKTERISTIK STRUKTUR ANATOMI DINDING SEL JABON MERAH (Anthocephalus macrophyllus) PROVENANSI WAJO

Characteristics of anatomy structure cell walls can be used as a reference to determine the quality of wood, especially in the final product. Variability anatomy of wood is varies greatly between species, parts of the stem and place of growth and provenance. For the purpose of the study, teak wood samples from Wajo provenance. This study aims to identify the structure anatomy characteristics cell wall of jabon merah from Wajo provenance. The structure anatomy cell wall observed were a microfibril angle (MFA), a pit in cell wall, perforation plate, and tylosis. Results showed that the structure anatomy cell wall characteristics jabon merah from Wajo provenance had a MFA values of 22.21°,intervessel pits polygonal alternating, scalariform perforation plates, and have a tylosis in the vessel.

Numerical Study on Wind-Induced Noise of High-Rise Building Curtain Wall with Outside Shading Devices

Perforation metal plates with dense holes are often used as external curtain walls of high-rise buildings. When air flow passes through these holes at a high speed, complex vortex is generated and causes a significant issue of wind-induced noise. In this study, both Reynolds-averaged Navier–Stokes (RANS) simulations and large-eddy simulations (LES) were conducted to study flow around high-rise buildings with an external sunshade curtain wall. First, wind speed distributions at the height of a typical level under 16 wind directions were acquired. Then, the maximum wind speed ratio and its corresponding azimuth were identified. Second, the sound pressure levels in the vicinity of the shading devices with two types of perforation plate schemes were calculated to evaluate the acoustic characteristics by using the FW-H equation to simulate sound generation and propagation. The results indicate that the maximum wind speed around the buildings exists at the building corners, and the maximum wind speed ratio is 2.8 observed at 0-degree wind direction. Under two different wind conditions, the aeroacoustic performance of perforation plate is enhanced with reducing end plate size and increasing aperture size. The overall sound pressure level (OSPL) and A-weighted sound pressure level (ASPL) around the shading devices are 80 dB and 68 dB(A), respectively, for the improved perforation plate scheme under the 1-year return period maximum speed, which are changed to 58dB and 45dB(A) under the annual average speed. Therefore, it is believed that perforation plates with small end plate size and large aperture size are desirable for the noise prevention design of shading devices.

Analysis of the wood composition in the fiber line of bleached hardwood kraft pulp

В настоящее время лиственные породы древесины широко используются как сырьё для целлюлозно-бумажной промышленности для производства различных волокнистых полуфабрикатов. Основными породами являются осина и берёза. Эти породы отличаются друг от друга по физическим свойствам, химическому составу и морфологии. Известно, что основным диагностическим признаком является отсутствие или наличие лестничной перфорационные пластинки на волокнах сосудов. Прочностные характеристики получаемых волокнистых полуфабрикатов зависят от исходного соотношения в них пород осины и берёзы. Полуфабрикаты с большим содержанием берёзы имеют более высокие показатели механической прочности. Проведен анализ породного состава поступающей щепы на варку и определено соотношение волокон осины и берёзы в волокнистых полуфабрикатах в разных точках технологического процесса производства белёной сульфатной целлюлозы. Породный состав щепы определен путём обработки гидроксидом натрия. Породный состав волокнистых полуфабрикатов определен методом компьютерной визуализации по основным диагностическим признакам. Для подтверждения правильности определения породного состава волокнистого полуфабриката в них установлены прочностные показатели. Анализ полученных данных показал, что колебания породного состава щепы в течение суток могут составлять 12,3–63,7%; размах значений доли волокон осины для проб из выдувного резервуара составляет 23,9–83,6%, для проб из 1-го пресс- фильтра – 18–89,5%. Подтверждена статистическая значимость зависимости физико-механических свойств полуфабрикатов от доли осины и берёзы в волокнистых полуфабрикатах при ее изменении в диапазоне от 10 до 80%. Currently, hardwood is widely used as a raw material for the pulp and paper industry for the production of various fibrous semi-finished products. The main species are aspen and birch. These species differ from each other in physical properties, chemical composition and morphology. It is known that the main diagnostic features are the absence or presence of a staircase perforation plate on the fibers of the vessels. Strength characteristics of the resulting fibrous semifinished products depend on the initial ratio of aspen and birch in them. Semi-finished products with a high birch content have higher mechanical strength. In this paper, the species composition of incoming chips for cooking is analyzed and the ratio of aspen and birch fibers in fibrous semi-finished products at different points in the technological process for the production of bleached sulphate pulp is determined. The native composition of the chips was determined by treatment with sodium hydroxide. The composition of fibrous semi-finished products was determined by computer visualization using the main diagnostic features. To confirm the correctness of the determination of the species composition of the fibrous semifinished product, strength characteristics were determined in them. Analysis of the obtained data showed that fluctuations in the species composition of chips within a day can range from 12.3 to 63.7%; The range of aspen fibers for samples from the blowing tank is 23.9 to 83.6%, for samples from the 1 st press filter – from 18.0 to 89.5%. The statistical significance of the dependence of the physical and mechanical properties of semi-finished products on the share of aspen and birch in fibrous semi-finished products with a change in the range from 10 to 80% has been confirmed.

The progressive and ancestral traits of the secondary xylem within Magnolia clad – the early diverging lineage of flowering plants

<p>The qualitative and quantitative studies, presented in this article, on wood anatomy of various species belonging to ancient <em>Magnolia</em> genus reveal new aspects of phylogenetic relationships between the species and show evolutionary trends, known to increase fitness of conductive tissues in angiosperms. They also provide new examples of phenotypic plasticity in plants.</p><p>The type of perforation plate in vessel members is one of the most relevant features for taxonomic studies. In <em>Magnolia</em>, until now, two types of perforation plates have been reported: the conservative, scalariform and the specialized, simple one.</p><p>In this paper, are presented some findings, new to magnolia wood science, like exclusively simple perforation plates in some species or mixed perforation plates – simple and scalariform in one vessel member. Intravascular pitting is another taxonomically important trait of vascular tissue. Interesting transient states between different patterns of pitting in one cell only have been found. This proves great flexibility of mechanisms, which elaborate cell wall structure in maturing tracheary element. The comparison of this data with phylogenetic trees, based on the fossil records and plastid gene expression, clearly shows that there is a link between the type of perforation plate and the degree of evolutionary specialization within <em>Magnolia</em> genus.</p>