scholarly journals How Bark Beetle Attack Changes the Tensile and Compressive Strength of Spruce Wood (Picea abies (L.) H. Karst.)

Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 87
Author(s):  
Radim Löwe ◽  
Miroslav Sedlecký ◽  
Adam Sikora ◽  
Anna Prokůpková ◽  
Roman Modlinger ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Picea Abies ◽  
Bark Beetle ◽  
Reference Group ◽  
Ct Scanning ◽  
The Czech Republic ◽  
Central European ◽  
Spruce Wood ◽  
Mechanical And Physical Properties ◽  
Individual Trees

Since 2014, forestry in the Czech Republic has been significantly affected by a bark beetle outbreak. The volume of infested trees has exceeded processing capacity and dead standing spruce (Picea abies) remain in the forest stands, even for several years. What should be done with this bark beetle wood? Is it necessary to harvest it in order to preserve the basic mechanical and physical properties? Is it possible to store it under standard conditions, or what happens to it when it is “stored” upright in the forest? These are issues that interested forest owners when wood prices were falling to a minimum (i.e., in 2018–2019) but also today, when the prices of quality wood in Central European conditions are rising sharply. To answer these questions, we found out how some of the mechanical properties of wood change in dead, bark beetle-infested trees. Five groups of spruce wood were harvested. Each of these groups was left upright in the forest for a specified period of time after bark beetle infestation, and one group was classified as a reference group (uninfested trees). Subsequently, we discovered what changes occurred in tensile and compressive strength depending on the time left in the stand and the distance from the center of the trunk. When selecting samples, we eliminated differences between individual trees using a CT scanning technique, which allowed us to separate samples, especially with different widths of annual rings and other variations that were not caused by bark beetle. The results showed the effect of log age and radial position in the trunk on tensile and compressive strength. The values for tensile strength in 3-year infested trees decreased compared to uninfested trees by 14% (from 93.815 MPa to 80.709 MPa); the values for compressive strength then decreased between the same samples by up to 25.6% (from 46.144 MPa to 34.318 MPa). A significant decrease in values for compressive strength was observed in the edges of the trunks, with 44.332 MPa measured in uninfested trees and only 29.750 MPa in 3-year infested trees (a decrease of 32.9%). The results suggest that the use of central timber from bark beetle-infested trees without the presence of moulds and fungi should not be problematic for construction purposes.

scholarly journals The Impacts of Calamity Logging on the Development of Spruce Wood Prices in Czech Forestry

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 283 ◽  
Author(s):  
Daniel Toth ◽  
Mansoor Maitah ◽  
Kamil Maitah ◽  
Veronika Jarolínová
Keyword(s):  
Czech Republic ◽  
Bark Beetle ◽  
Bark Beetles ◽  
The Czech Republic ◽  
Wood Harvesting ◽  
Spruce Bark ◽  
Spruce Wood ◽  
Forestry Sector ◽  
Socio Economic Impact ◽  
The Relationship

Currently, the decline in spruce wood prices is a serious problem for the forestry sector in the Czech Republic. We estimate that the fall in wood prices in European markets causes losses not only to the forestry companies producing, harvesting, and processing the wood, but also to the workers in the sector. These losses are mainly caused by a combination of several natural factors: drought, climate change, and the effects of bark beetles. In particular, spruce bark beetles cause the greatest damage. Due to this bark beetle calamity, unplanned logging has increased. In 2019, these damages have culminated. Almost 100 million m3 of wood has been harvested over the last decade due to the bark beetle and more than half of this volume has been mined in the last four years. Therefore, the losses in the forestry sector are around EUR 1.12 billion. The aim of this study is an analysis of the relationship between the volume of incidental logging and the decline in the price of spruce wood. These results show the strong correlation between the measure of unplanned wood harvesting and the decrease in wood prices, as well as an estimate of price development if the upward trend of incidental mining continues. The average price of wood in the Czech Republic could thus reach a historical minimum of EUR 79.39 per m3 of spruce and category SM/JE II (spruce/fir). In addition, the decline in wood prices will be reflected in the management of forestry and timber businesses, including stagnant wages for forestry workers. The socio-economic impact of the bark beetle calamity is high and is most affected by the decline in spruce timber prices.

scholarly journals Picea abies provenance test in the Czech Republic after 36 years – Central European provenances

2016 ◽  
Vol 61 (No. 11) ◽  
pp. 465-477 ◽  
Author(s):  
I. Ulbrichová ◽  
V. Podrázský ◽  
F. Beran ◽  
D. Zahradník ◽  
M. Fulín ◽  
...  
Keyword(s):  
Czech Republic ◽  
Picea Abies ◽  
The Czech Republic ◽  
Central European ◽  
Provenance Test

scholarly journals Occurrence of the Invasive Bark Beetle Phloeosinus aubei on Common Juniper Trees in the Czech Republic

Forests ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 12 ◽  
Author(s):  
Tomáš Fiala ◽  
Jaroslav Holuša
Keyword(s):  
Czech Republic ◽  
Bark Beetle ◽  
Invasive Pest ◽  
The West ◽  
The Czech Republic ◽  
Central European ◽  
Juniperus Communis ◽  
Naturally Occurring ◽  
Potential Pest ◽  
Common Juniper

The small cypress bark beetle Phloeosinus aubei is considered an invasive pest in several central European countries, and we have determined its current distribution on common juniper trees (Juniperus communis) in the Czech Republic. The results indicated that P. aubei is widely distributed in the country but is more common in the east than in the west. The beetle was mainly detected on older, damaged trees and on stems with diameters > 3 cm. The apparently widespread and abundant populations of P. aubei could explain infestations of the beetle on Thuja spp. and Juniperus spp. in gardens (three confirmed cases during the last 10 years). We consider P. aubei to be a potential pest on older, naturally occurring J. communis in protected areas where its population density could increase on weakened and damaged trees. We suggest that P. aubei can be monitored via simple inspection of dying and dead J. communis trees in the field.

scholarly journals Contribution to seed ecology of Sequoiadendron giganteum (Lindl.) Buchholz growing in the Central European conditions

2018 ◽  
Vol 64 (No. 2) ◽  
pp. 86-90
Author(s):  
Prknová Hana
Keyword(s):  
Soil Microflora ◽  
Routine Practice ◽  
Short Term ◽  
The Czech Republic ◽  
Natural Fire ◽  
Central European ◽  
Giant Sequoia ◽  
Sequoiadendron Giganteum ◽  
Individual Trees ◽  
Positive Effect

The properties of Giant Sequoia (Sequoiadendron giganteum (Lindley) Buchholz) seeds originating from a single cultivated Sequoia tree in the second gene strain in the Czech Republic were examined. The maximum germination level was set at 1.8%. This type is a pyrophyte, but nonetheless the short-term effects of a temperature of 100°C simulating a natural fire are still lethal. The seeds were planted with the same success in one case using a fungicide, which is routine practice in nurseries, and in another case using a “biological method” relying on the positive effect of soil microflora. Both stratified and non-stratified seeds can germinate, but stratification increases the number of germinating individual trees to at least double.

PEMANFAATAN KAYU AKASIA MANGIUM (Acacia mangium Willd) UNTUK MEBEL

2012 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
Djoko Purwanto
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Physical Properties ◽  
Treatment Process ◽  
Acacia Mangium ◽  
Physical And Mechanical Properties ◽  
Wood Fibers ◽  
Test Parameters ◽  
Mechanical And Physical Properties ◽  
Scale Scores

Timber Acacia mangium (Acacia mangium, Willd) for Furniture. The study aims to determine the mechanical and physical properties and the decorative value (color and fiber) wood of acacia mangium with using finishing materials. This type of finishing material used is ultran lasur natural dof ,ultran lasur classic teak, aqua politur clear dof, aqua politur akasia dan aqua politur cherry. After finishing the wood is stored for 3 months. Test parameters were observed, namely, physical and mechanical properties of wood, adhesion of finishing materials, color and appearance of the fiber, and timber dimensions expansion. The results showed that the mechanical physical properties of acacia wood qualified SNI. 01-0608-89 about the physical and mechanical properties of wood for furniture, air dry the moisture content from 13.78 to 14.89%, flexural strength from 509.25 to 680.50 kg/cm2, and compressive strength parallel to fiber 342.1 - 412.9 kg/cm2. Finishing the treatment process using five types of finishing materials can increase the decorative value (color and fiber) wood. Before finishing the process of acacia mangium wood has the appearance of colors and fibers and less attractive (scale scores 2-3), after finishing acacia wood fibers have the appearance of colors and interesting and very interesting (scale 4-5).Keywords: mangium wood, mechanical properties, decorative value, finishing, furniture.

scholarly journals Use of TanDEM-X and SRTM-C Data for Detection of Deforestation Caused by Bark Beetle in Central European Mountains

2021 ◽  
Vol 13 (15) ◽  
pp. 3042
Author(s):  
Kateřina Gdulová ◽  
Jana Marešová ◽  
Vojtěch Barták ◽  
Marta Szostak ◽  
Jaroslav Červenka ◽  
...  
Keyword(s):  
Bark Beetle ◽  
Synergistic Effects ◽  
Canopy Height ◽  
Surface Model ◽  
Multiple Time ◽  
Central European ◽  
Time Points ◽  
Bohemian Forest ◽  
Multiple Time Points ◽  
Surrounding Areas

The availability of global digital elevation models (DEMs) from multiple time points allows their combination for analysing vegetation changes. The combination of models (e.g., SRTM and TanDEM-X) can contain errors, which can, due to their synergistic effects, yield incorrect results. We used a high-resolution LiDAR-derived digital surface model (DSM) to evaluate the accuracy of canopy height estimates of the aforementioned global DEMs. In addition, we subtracted SRTM and TanDEM-X data at 90 and 30 m resolutions, respectively, to detect deforestation caused by bark beetle disturbance and evaluated the associations of their difference with terrain characteristics. The study areas covered three Central European mountain ranges and their surrounding areas: Bohemian Forest, Erzgebirge, and Giant Mountains. We found that vertical bias of SRTM and TanDEM-X, relative to the canopy height, is similar with negative values of up to −2.5 m and LE90s below 7.8 m in non-forest areas. In forests, the vertical bias of SRTM and TanDEM-X ranged from −0.5 to 4.1 m and LE90s from 7.2 to 11.0 m, respectively. The height differences between SRTM and TanDEM-X show moderate dependence on the slope and its orientation. LE90s for TDX-SRTM differences tended to be smaller for east-facing than for west-facing slopes, and varied, with aspect, by up to 1.5 m in non-forest areas and 3 m in forests, respectively. Finally, subtracting SRTM and NASA DEMs from TanDEM-X and Copernicus DEMs, respectively, successfully identified large areas of deforestation caused by hurricane Kyril in 2007 and a subsequent bark beetle disturbance in the Bohemian Forest. However, local errors in TanDEM-X, associated mainly with forest-covered west-facing slopes, resulted in erroneous identification of deforestation. Therefore, caution is needed when combining SRTM and TanDEM-X data in multitemporal studies in a mountain environment. Still, we can conclude that SRTM and TanDEM-X data represent suitable near global sources for the identification of deforestation in the period between the time points of their acquisition.

scholarly journals The Climatology of Significant Tornadoes in the Czech Republic

Atmosphere ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 689
Author(s):  
Rudolf Brázdil ◽  
Kateřina Chromá ◽  
Tomáš Púčik ◽  
Zbyněk Černoch ◽  
Petr Dobrovolný ◽  
...  
Keyword(s):  
Czech Republic ◽  
Daily Variation ◽  
Convective Available Potential Energy ◽  
Vertical Wind Shear ◽  
Severe Damage ◽  
The Czech Republic ◽  
Annual Variations ◽  
Wide Range ◽  
Individual Trees ◽  
Common Era

In the Czech Republic, tornadoes may reach an intensity of F2 and F3 on the Fujita scale, causing “considerable” to “severe” damage. Documentary evidence is sufficient to allow the creation of a chronology of such events, from the earliest recorded occurrence in 1119 CE (Common Era) to 2019, including a total of 108 proven or probable significant tornadoes on 90 separate days. Since only 11 significant tornadoes were documented before 1800, this basic analysis centers around the 1811–2019 period, during which 97 tornadoes were recorded. Their frequency of occurrence was at its highest in the 1921–1930, 1931–1940, and 2001–2010 decades. In terms of annual variations, they took place most frequently in July, June, and August (in order of frequency), while daily variation favored the afternoon and early evening hours. Conservative estimates of human casualties mention 8 fatalities and over 95 people injured. The most frequent types of damage were related to buildings, individual trees, and forests. Tornadoes of F2–F3 intensity were particularly associated with synoptic types characterized by airflow from the western quadrant together with troughs of low pressure extending or advancing over central Europe. Based on parameters calculated from the ERA-5 re-analysis for the period of 1979–2018, most of these tornadoes occurred over a wide range of Convective Available Potential Energy (CAPE) values and moderate-to-strong vertical wind shear. The discussion herein also addresses uncertainties in tornado selection from documentary data, the broader context of Czech significant tornadoes, and the environmental conditions surrounding their origins.

Languages of borderlands, borders of languages: Native and foreign language use in intergroup contact between Czechs and their neighbours

Human Affairs ◽  
2013 ◽  
Vol 23 (4) ◽  
Author(s):  
Magda Petrjánošová ◽  
Alicja Leix
Keyword(s):  
Czech Republic ◽  
Foreign Language ◽  
Language Use ◽  
Intergroup Contact ◽  
International Project ◽  
Intergroup Attitudes ◽  
Online Questionnaire ◽  
Native Languages ◽  
The Czech Republic ◽  
Central European

AbstractIn this article we present a qualitative analysis of empirical findings from an international project on intergroup attitudes and contact in five Central European countries specifically concerning language use. The project concentrated on the interplay of intergroup contact and perception between the members of national groups in the borderlands between the Czech Republic and Austria, Germany, Poland and Slovakia. The open statements analysed here about the contact situations and the ensuing evaluation of the Others were collected as part of an online questionnaire (N=1959). After a short theoretical introduction we reveal the intertwined nature of construing language use: first in each specific borderland, then in the triads speaking together either in the native language of one of the groups (Czechs with Austrians and Germans) or with each speaking their own native languages (Czechs with Poles and Slovaks). Finally we highlight several effects we have observed as a result of being able to compare the situation in more than one neighbourhood, for instance, the effect of the different statuses of the languages involved, or the connection between the language used in contact and a feeling of proximity.

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