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The Impact of Natural Disturbances on the Central European Timber Market-An Analytical Study
Get PDFCentral European countries are strategic wood exporters in the European and international wood trade. In the context of wood exporters, Czechia, Germany, Poland, Slovenia, and Austria are the important countries providing the development and stability of the forestry and wood sector. The share of these countries' exports in total EU exports represents more than 52% of the volume of wood exported over 5 years. After the Netherlands, the five mentioned countries recorded the highest increase in roundwood production of all EU and EFTA countries in the years 2000-2022 (from 46% (AT)-126% (CZ)), and the European average is 26%. The last decade has been characterised by a significant destabilisation of the Central European timber market as a result of natural disturbances linked to climate change, which also threatens the long-term competitiveness and preservation of this sector in the economic systems of national economies. The article provides an analytical insight into the historical development of natural calamities and their macroeconomic consequences in Central European countries. The data forecast an unfavourable development of the timber market in Europe caused by the ongoing calamity situation, the pricing policy of the timber trade, the oversaturation of the market with lower-quality calamity timber, insufficient processing capacities for primary processing of wood and its use in secondary processing, and, last but not least, the limited stock of timber in the coming years in selected Central European countries (due to an extreme increase in harvesting plans within the last 5 years, with consequences that will be felt in the coming decade). For the continued economic function of forests and the availability of wood supply for future generations, the current evolution of calamities in forest ecosystems is critical, and long-term strategic measures based on empirical data are necessary. The information presented in this paper can serve as a tool for the objectification of strategic decisions in the development of forestry policies in selected countries.O
Characterization of randomly oriented strand boards manufactured from juvenile wood of underutilized wood species
Get PDFThe wood-based panel industry in Europe, which is dominated by the use of Norway spruce, will face new challenges due to environmental changes and the bark-beetle calamity, which started a new era of forestry. To explore the possibility of replacing spruce with other wood species, juvenile wood of nine underutilized wood species (Scots pine, European larch, poplar, willow, alder, birch, European beech, English oak and hornbeam) were used to make randomly oriented strand boards (OSBs). Single-layer OSBs were produced with 3% pMDI resin and 0.5% wax. Standard physical and mechanical properties were measured. The bending strength (MOR) values showed that there was no statistically significant difference between the values for, on the one hand, spruce (34.6 MPa) and, on the other, larch (25.9 MPa), poplar (25.2 MPa), willow (27.8 MPa), alder (34.3 MPa) or birch (27.1 MPa). A similar trend was found for the boards modulus of elasticity (MOE). The highest MOE values of 5,185 MPa and 4,472 MPa were found for spruce and alder, respectively. There was no significant difference between spruce and other wood species in internal bond strength. Boards made from high-density wood species showed better physical performance, whereas those made from low-density wood species (except pine) gave better mechanical properties. Strand-generalized characteristics, such as the slenderness ratio and specific surface, were analyzed for all investigated physical and mechanical properties. European larch, poplar, willow, and alder are potential wood species for manufacturing OSBs in future without mixing species, as they can replace spruce in the wood-based panel industry.OA-hybri
Open Source Tools for Text Processing
No full textV rámci projektu Innovative Open Source Courses for Computer Science je řešen kurz zabývající se zpracováním textů pomocí počítače. Cílem příspěvku je představit hlavní motivy zvolené koncepce tohoto předmětu, stručně seznámit s nejdůležitějšími prvky a inovativním pohledem na problematiku a uvést ukázky vybraných částí návrhu předmětu.It is being solved within the project Innovative Open Source Courses for Computer Science computer-based word processing course. The aim of the paper is to introduce the main motives of the chosen concept of this subject, briefly acquaint with the most important elements and an innovative view of the issue and state examples of selected parts of the course design.Published Versio
Wood-water interactions of thermally modified, acetylated and melamine formaldehyde resin impregnated beech wood
Get PDFThe wood-water interactions of modified beech wood (Fagus sylvatica L.) were studied. Specimens were thermally modified at 180 (TM1), 200 (TM2) and 220 degrees C (TM3), acetylated (Acet), and melamine formaldehyde (MF) resin (Mel) modified. Afterwards, the water vapour characteristics, i.e. water vapour sorption isotherms, equilibrium moisture content (EMC), dimensional stability of specimens conditioned at 30, 65 and 90% RH and liquid water characteristics, i.e. water absorption, maximum moisture content (MC), leachability and swelling kinetics, were determined and the results compared with reference (Ref) specimens. From the results, it is evident that the scale of wood-water interactions was highly dependent on the thermal modification temperature and type of chemical modification. The water vapour isotherms of thermally modified wood decreased, whereas more severe treatment exhibited more distinct reduction. The EMC values of the Mel and TM1 specimens decreased only at high RH, whereas the most significant decrease, within the whole range of observation, was found in the Acet group. The maximum MC reduction was achieved by acetylation. As a consequence of swelling reduction, dimensional stability expressed as anti-swelling efficiency (ASE) was considerably improved. A relatively high initial linear-phase swelling rate was found for the Ref specimens, whereas modified wood exhibited comparatively slow and gradual swelling.OA-hybri
The Influence of Sugar Beet Cultivation Technologies on the Intensity and Species Biodiversity of Weeds
Get PDFSugar beet production is highly affected by weeds. The structure of crop rotation, the use of intercrops and different tillage techniques bring several benefits to sugar beet cultivation and create different living conditions for weeds. The response of weed communities in sugar beet stands has not been studied. The experimental plot is in the cadastral area of Ivanovice na Hané (Czech Republic). During an eight-year monitoring period (2013-2020), 46 weed species were identified. The dominant species was Chenopodium album. There were also summer and winter weeds. A more varied crop rotation increased the intensity of weed infestation, with winter weeds being the most common. On the contrary, a higher proportion of cereals in the crop structure favors the presence of summer weeds. The tillage technology and the inclusion of catch crops did not significantly affect the intensity of weed infestation in sugar beet stands or the spectrum of weed species. Current cropping technologies have driven the evolution of weeds. Due to their short life cycles and relatively simple genomes, weeds can respond very quickly to technological measures and, thus, change their harmfulness.O
The Role of Biochar Co-Pyrolyzed with Sawdust and Zeolite on Soil Microbiological and Physicochemical Attributes, Crop Agronomic, and Ecophysiological Performance
Get PDFThe overuse of synthetic fertilizers has been associated with negative environmental consequences. The use of biochar in this regard has been recommended as a win-win strategy. However, our understanding on the comparative influences of biochar prepared from various feedstocks mixed with other bulking agents on soil health and crop performance remained limited. Therefore, in the present study, three types of biochar produced from sewage sludge, food, and agricultural waste were analyzed and compared for their effects on soil enzymes (dehydrogenase, DHA; β-glucosidase, GLU; phosphatase, PHOS; urease, URE; N-acetyl-β-D-glucosaminidase, NAG; and arylsulphatase, ARS), soil basal, as well as substrate-induced respirations and plant growth and physiology characters. The results revealed that food waste-derived biochar co-pyrolyzed with zeolite and/or sawdust was more effective in improving soil physicochemical properties and carbon and phosphorous cycling enzyme (DHA, GLU, and PHOS) activities in addition to soil basal respiration. While the influence of wastewater sewage sludge-derived biochar was more pronounced on urease, N-acetyl-β-D-glucosaminidase, and arylsulphatase enzymes as well as plant biomass accumulation and physiological attributes. Moreover, agricultural waste-derived biochar was found to be effective in enhancing substrate-induced respirations. This study thus concluded that biochar derived from various feedstocks has the tendency to improve soil health and plant growth attributes which further depend on the type of modification prior to pyrolysis.OA-hybri
Effect of different stand densities on xylem and phloem formation in Norway spruce plantations
Get PDFPreliminary results of an investigation of the thinning effect on Norway spruce tree growth in terms of xylogenesis and phloemogenesis are presented. Three plots were selected where the stand densities were reduced by pre-commercial thinning to 1800 trees/ha (plot A; mild thinning) and 1300 trees/ha (plot C; heavy thinning) in February 2020. Plot B had no silvicultural intervention and represented a control variant (4500 trees/ha). Three dominant 14-year-old Norway spruce trees were sampled (micro-cored) for studying the xylem and phloem formation in the 2020 growing season. The total differentiation duration was determined to be around 169.7 +- 12.7-179.3 +- 4.0 days. The average number of xylem cells formed in control plot B was only 140 mature cells, plots C and A were determined to have 175 and 200 mature cells, respectively. Plot A had the fastest growth rate of all the plots studied. In all three plots (A, B, C), the beginning of the early phloem, late phloem sieve cells, and axial parenchyma cells coincided. Nonetheless, in terms of total phloem cell increase, plot C displayed the fastest growth rate among the three plots studied. The first results showed that the rate of total increment in both xylem and phloem cells, as well as the total number of produced tracheids and sieve cells, seem to be positively affected after the thinning application.Postprin
Comparison of Methods for Estimating Damage by Wild Ungulates on Field Crops
Get PDFHigh numbers of large ungulates are locally accompanied by high levels of damage to field crops, causing economic losses and increased costs for the protection of agricultural fields. Quantifying the levels of damage can be problematic, with the degree of accuracy depending on the method used. The aim of this study was to compare the accuracy, workload and cost of four methods commonly used for estimating damage to wheat fields caused by large ungulates (esp. wild boar) in the Czech Republic. The results suggest that the manual processing of aerial photographs ("Uncrewed Aerial Systems [UAS] with Operator Delineation Method") was very laborious and the least accurate method, with a high risk of error. In comparison, the automatic evaluation of aerial images ("UAS Crop Height Method") and the "Ground-Based Assessment" both provided similar results when carefully analyzed and were equally demanding. The "Yield Method", comparing the net yield from damaged and undamaged areas, provided the same result of assessment and was the least laborious, although it does require the existence of comparable areas and for the conditions to be created in advance before the method is used. Equivalent results were achieved by the UAS Crop Height Method, which we recommend using in cases where the Yield Method cannot be applied.O
Alternative sources of proteins in farm animal feeding
Get PDFThe global demand for protein is on the rise owing to the exponential increase in the world population and to meet the global protein requirements, it is imperative to seek alternative sources of proteins in farm animal feeding. Recognizing the importance of proteins and the fact that a major portion of human protein requirements is derived from livestock in the form of meat, milk, and eggs, the available protein-feeding stuff in the form of soybean meal cannot be regarded as sufficient for feeding to livestock. Oil seeds such as rapeseed meal and canola meal have a crude protein content of 30%-40% and are widely used and hence a potential alternative protein source to soybean meal. Going forward, Grain legumes such as peas, faba beans, and lupins, another alternative source of proteins have the potential to replace traditional protein feeds completely or partially such as bone and fish meals. Duckweed with a protein content of 20%-45% is another plant-based potential protein source that can be employed in livestock feeding particularly pigs owing to its huge potential as a growth promoter as evidenced by studies in pigs and piglets. Because of their nutritional qualities and possible environmental advantages, insects represent another class of alternative protein sources that have enormous potential to function as sustainable protein sources. Several insect species have been assessed for use as animal feeds; the most promising ones include the yellow mealworm (Tenebrio molitor, TM), the common house fly (MD), and the black soldier fly (Hermetia illucens, HI). Byproducts from aquaculture and fisheries are abundant in macro- and micronutrients, and their utilisation can provide fishmeal and fish oil, which can then be further adapted for use as a source of protein in animal nutrition. Employing microalgae as an alternative source of protein in animal feeding is somehow a new concept. Many nutritional and toxicological studies have demonstrated the potential of algae biomass as a valued feed supplement or substitute for conventional protein sources such as soybean meal. While these alternative protein sources in livestock feeding may serve as useful tools, parameters such as feed safety and acceptability should be monitored based on feed safety regulations.O
Lectotypification of two names of Carex buekii hybrids (Cyperaceae) and notes on their morphology, ecology and distribution
Get PDFLectotypes are designated for two Carex buekii hybrid names. The typification is supplemented with notes on their morphology, ecology, and distribution.O