Search

We monitored six healthy dominant trees and six girdled Scots pine trees for two successive growing seasons (2014 and 2015) to investigate the seasonal dynamics, cambial activity, and morphology of the new xylem and phloem cells formed under environmental stress when girdling was applied during the dormant period (15 January 2014). Microcore (1.8 mm) samples were collected weekly using a Trephor tool above and below the girdling area, and weather data were measured on site. Drought stress in combination with girdling reduced the total number of differentiation days cell formation. In 2014, no significant differences in tracheid dimensions were observed between the girdled area and the control trees, while in 2015, the control trees showed significantly smaller cell wall thickness and radial dimensions of the latewood tracheids (LW) compared to 2014 and girdled trees had no occurrence of LW. Under stressful heat waves and prolonged periods of no precipitation, the trees tended to reduce the number of tracheids that were formed and exhibited smaller radial dimensions (narrower tree rings) to increase their hydraulic efficiency. Trees responded to limited water availability by forming intra-annual density fluctuations (IADFs L) in the zone of the LW to overcome stressful conditions. Although xylem cell differentiation was affected by stressful conditions, no significant variability in phloem cell dimensions was observed. Thus, the phloem tissue was less sensitive to exogenous factors.

Hand spinning has become increasingly popular as a recovery of the traditional techniques of natural fibre processing and cultural heritage protection. Modern spinning wheels are usually made of easily available wood species, particularly hardwoods, and one spinning wheel usually consists of one or two species. However, the wood species that were used for the individual parts of old spinning wheels in Central Europe are still unknown. To improve our understanding of traditional craftsmen and their skills, we investigated old spinning wheels that originated from Central Europe in the 19th and the 20th century. In this study, we present a collection of 643 samples from 54 artefacts representing the region between the European Alps and the Western Carpathians. Spinning wheels were usually made of 3 to 5 wood species, and the species selection varied among regions. Generally, high wood density (> 600 kg.m−3) species prevailed in Austria and Western Slovakia, but lower wood density (< 600 kg.m−3) species were preferred in the south-eastern Czech Republic. Easily workable species were used for the production of the spinning wheels, primarily Tilia, Fagus sylvatica, Picea abies, and Acer. In addition to these species, a high proportion of fruit-bearing trees and three shrubs were identified. Wood anatomy, as an important scientific method, contributed to understanding the reasons for species selection and the suitability of their properties which will enable the conservation of sustainable folk traditions and crafts, as well as the knowledge of traditional craftsmen.

We studied the effect of local weather conditions on intra-annual wood formation dynamics and wood structure of European beech (Fagus sylvatica L.) from a temperate location in the Czech Republic in two consecutive years, 2010 and 2011, characterized by different amounts of precipitation. Microcores were taken at weekly intervals and transverse sections of cambial and xylem tissue were prepared for light microscopic observation. Air temperature and soil moisture content were measured daily at the research plot. Tree-ring formation patterns and vessel features showed different responses to climatic factors in the two years. In 2010, the onset of cambial cell production occurred almost 10 days later than in 2011, when a considerably reduced amount of rainfall was already observed in the winter and spring months, as shown in Standardized Precipitation Index (SPI) values. Lack of precipitation in 2011 caused premature cessation of cambial cell division and markedly narrower annual xylem increments. Vessel density and water conductive area were higher in 2011 than in 2010. Average vessel size in general did not change. In response to local weather conditions, beech controls its hydraulic conductivity mainly by changing the number of vessels and tree growth rate, followed by vessel size. The lower sensitivity of vessel diameter to hydrological alterations confirms previous studies by other authors.

Selected anatomical features and ground tissue composition were studied in four tropical hardwoods (Afzelia sp. [Doussié], Intsia sp. [Merbau], Astronium sp. [Muiracatiara] and Millettia sp. [Wengé]). These woods can be applied in musical instrument production, especially for xylophone bars. The measured density, 1st bending natural frequency and the logarithmic decrement of damping were used to calculate other acoustic properties such as dynamic young modulus of elasticity (Erf), specific modulus of elasticity (E´/ρ), internal friction (tan δ), and acoustic conversion efficiency (ACE). The correlations between anatomy and acoustic properties were determined. Despite difficulties in specifying general characteristics of hardwoods due to their complicated and variable structure, correlations valid between species were found for specific modulus of elasticity. Specific modulus of elasticity was negatively correlated with ray tissue volume and positively with ray height to width ratio and fiber length. The diversity in ground tissue composition was the main criterion for the species choice and probably should condition diverse correlations of anatomical features found for individual species. It seems that better acoustic properties (higher stiffness, ACE or specific modulus of elasticity) are performed by wood with longer fibers and slender rays, causing minimal deflection of adjoining fibers.

The dynamics of xylem formation in young Norway spruce (Picea abies (L.) Karst.) trees was analysed during one growing season in Rajec-Němčice in the Czech Republic. Microcores were taken from six 34-year-old trees in April to October 2009 at weekly intervals by means of a Trephor tool in a second generation spruce monoculture stand. The cambium activity started between 16–30 April and the last cells divided between 27 August and 17 September. The average length of cambium activity was 5.2 months. The cambium achieved its maximum width (12.3 cell layers) in June, whereas the dormant cambium contained 5.3 cell layers on average. Fitting the xylem increments to the Gompertz function showed that the period of most intensive cell formation was at the beginning of July. The total time necessary for the development of most cells was 156 days when modelled with WCDcalc script and 117 days when modelled with the Gompertz function.

The first permineralized angiosperm wood from the Cenomanian of the Bohemian Cretaceous Basin (Czech Republic) is described. The wood is diffuse porous, with vessels solitary and in radial multiples of 2–5, perforation plates are exclusively simple, and tyloses abundant. Rays are usually 4–7-seriate and heterocellular, narrower rays are rare. The fossil is designated as Paraphyllanthoxylon aff. utahense Thayn, Tidwell et Stokes. Other occurrences of Paraphyllanthoxylon are reviewed and the equivocal botanical affinity of the taxon is discussed.