Wood analyses helped to determine the location and approximate construction period of the Roman bridge over the Drava River in ancient Poetovio (Ptuj, Slovenia)

We present the results of a dendrochronological study and radiocarbon dating of the wooden piles of the bridge over the Drava River in Ptuj. The piles, together with stone elements (a fragment of an imperial building inscription and parts of the architectural decoration) were retrieved from the riverbed in 1913 and are now in the Regional Museum Ptuj - Ormož. Using dendrochronology, radiocarbon dating of carefully selected annual rings in the wood and calibration with the wiggle-matching method, the date of the last (outermost) annual ring on the pile was determined to be 161 ± 27 cal AD (1σ) or 160 ± 32 cal AD (2σ). Since the pile contained no sapwood, the dating approximately agrees with the date of the building inscription on the stone slab, which attributes the commission for the reconstruction or construction of the bridge to Emperor Hadrian in the last years of his reign (117-138 AD). The dating of the wood has thus confirmed that the remains examined do indeed belong to a Roman bridge, probably built or renovated during the reconstruction of the road network in the area of the colony of Poetovio under Hadrian or one of his successors.

Radial growth patterns of Siberian larch in plantations of the Republic Mari El

Based on the measurements of 83 wood cores, the main patterns of changes in the width of the early and late zones in the annual ring of Siberian larch trees (Larix sibirica Ledeb.), as well as their total radial growth indices in the conditions of the Republic of Mari El were identified. It was found that the width of the early wood zone varies in trees from 0.15 to 11.3 mm, late wood – from 0.05 to 4.15 mm, the proportion of latewood – from 1.2 to 82.8 %, and the annual growth indices - from 13 to 423 %. The main factor in the variability of the total width of the annual rings and the layer of early wood is the age of the trees, and the contribution of weather conditions and other unaccounted factors (noise) to the overall variance of the annual growth parameters is no more than 20 %. The variability of the total width of the annual ring also depends on their genotypic features, which determine up to 42.7% of the total variance of the parameter in some cenopopulations. In the dynamics of the growth indices of larch trees, despite the existing specifics of each cenopopulation, the general sharp decline in their values after the droughts of 1972 and 2010, as well as the alternation of the periods of growth and decline, is clearly distinguished.

Tracheid dimensions of Norway spruce in uneven-aged stands

Tracheid length and width patterns from pith to bark at a height of 0.6 m in uneven-aged Norway spruce (<i>Picea abies</i> L. (H.) Karst) trees were addressed. The identification of the main factors and a comparison with even-aged stands were also pursued. 96 trees were sampled from experimental stands in Southern Finland. The material encompassed the variation in tracheid properties from early years to silvicultural maturity, i.e. from corewood to outerwood up to a cambial age of 111 years. Data from 39 Norway spruce trees from even-aged stands we utilized for comparison. Models fitted to the data indicated that annual ring widths did not influence mean tracheid dimensions but the latewood proportion showed a significant influence on tracheid dimensions. Tracheids in uneven-aged stands were slightly wider and longer at the base of the stem with a similar tree diameter, cambial age, and annual ring number.

Macroscopic structure of Pinus sylvestris L. wood during introduction to the Central forest-steppe

The macroscopic structure of Pinus sylvestris L. wood growing in the geographical cultures of the Central forest-steppe (Bryansk, Voronezh, and Volgograd climatypes), natural forests of the broad-leaved forest zone of the Bryansk region, the zone of the southern forest-steppe of the Voronezh region and the dry steppe of the Volgograd region was studied. The dependence of the annual ring width on the degree of humidification was found. When Pinus sylvestris L. moving in arid conditions of the dry steppe, changes in the annual ring width were noted, this is an adaptive feature of plants to environmental conditions. The early wood is more susceptible to changes in width depending on the growing conditions than late wood. In geographical cultures of Pinus sylvestris L. created in the Central Forest-steppe of the Voronezh Region climatypes from the Bryansk region have a decrease in the annual ring width and climatypes from the Volgograd region have an increase in the annual ring width, which is related to a change in the degree of humidification. Macrostructural features of wood can be an indicator of the climate in certain natural conditions.

Formation of pine wood density depending on the parameters of annual ring and latitudinal zoning

The article presents the results of studies of changes in wood density depending on annual ring width and its characteristics. Density is a basic indicator for assessing operational and technical properties of wood. At the same time, density is characterized by certain variability within the same species, depending on annual ring characteristics, influenced by environmental factors, age of trees and position in the trunk. The purpose of this study is to establish the formation of density depending on annual ring width and late wood for Scots pine (Pinus sylvestris L.) wood in the central European part of Russia. Density research was made using the specimens with one annual ring by the method of buoyancy. Absolute values of the annual ring of early and late wood were measured in cores. It was found that wood density is only influenced by late wood width in the annual ring, being under strict genetic control. In the southern taiga zone correlation between density and late wood width is varying between 0.49-0.66 and it is less than in the forest-steppe zone. The correlation of density with annual ring width in the southern taiga zone is 0.5. It is less than in the forest-steppe zone (0.57-0.81).

A Numerical Study of the Stiffness and Strength of Cross-Laminated Timber Wall-to-Floor Connections under Compression Perpendicular to the Grain

The use of cross-laminated timber (CLT) in multi-story buildings is increasing due to the potential of wood to reduce green house gas emissions and the high load-bearing capacity of CLT. Compression perpendicular to the grain (CPG) in CLT is an important design aspect, especially in multi-storied platform-type CLT buildings, where CPG stress develops in CLT floors due to loads from the roof or from upper floors. Here, CPG of CLT wall-to-floor connections are studied by means of finite element modeling with elasto-plastic material behavior based on a previously validated Quadratic multi-surface (QMS) failure criterion. Model predictions were first compared with experiments on CLT connections, before the model was used in a parameter study, to investigate the influence of wall and floor thicknesses, the annual ring pattern of the boards and the number of layers in the CLT elements. The finite element model agreed well with experimental findings. Connection stiffness was overestimated, while the strength was only slightly underestimated. The parameter study revealed that the wall thickness effect on the stiffness and strength of the connection was strongest for the practically most relevant wall thicknesses between 80 and about 160 mm. It also showed that an increasing floor thickness leads to higher stiffness and strength, due to the load dispersion effect. The increase was found to be stronger for smaller wall thicknesses. The influence of the annual ring orientation, or the pith location, was assessed as well and showed that boards cut closer to the pith yielded lower stiffness and strength. The findings of the parameter study were fitted with regression equations. Finally, a dimensionless ratio of the wall-to-floor thickness was used for deriving regression equations for stiffness and strength, as well as for load and stiffness increase factors, which could be used for the engineering design of CLT connections.

Age and Growth of Southern Bluefin Tuna, Thunnus maccoyii, Based on Otolith Microstructure

Age and growth of southern bluefin tuna (SBT, Thunnus maccoyii) were estimated based on otoliths collected by Korean tuna longline vessels in the Atlantic and Indian Oceans from 2015 to 2019. A total of 739 specimens were used to estimate age and growth of SBT, with sizes ranging from 66 to 181 cm in fork length. It was confirmed that the otolith is a suitable aging characteristic for determining SBT age, and otolith annuli can be used as an annual ring. The relationship between fork length (FL) and total weight (W) was W = 7.7e − 05FL2.722 (R2 = 0.874). The von Bertalanffy’s growth parameters estimated from the non-linear method using length-at-age data were L∞ = 170.0 cm, K = 0.200/year, t0 = − 1.615 years, with 95% confidence intervals between 166 and 175 cm for L∞, 0.17–0.23/year for K, and − 2.27 to − 1.09 years for t0 from bootstrapping. The Kimura’s likelihood ratio test results of the models under assumptions of common and different parameters between female and male concluded that the growth of SBT has no difference between genders.