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Mechanické vlastnosti dřeva smrku ztepilého napadeného lýkožroutem smrkovým v různých stádiích poškození
Brüstl, Pavel
This thesis deals with the determination of mechanical properties of Norway spruce wood attacked by spruce bark beetle at various stages of damage by means of bending tested samples and impact strenght according to European standards. Due to the current occurrence of bark beetle calamities is only wood from these logs largely marketed. The main objective was to find out whether the wood affected by spruce bark beetle has comparable mechanical properties with undemaged wood and its subsequent use in construction as a construction timber. We did not notice any significant changes in the bending test where the modulus of rupture and modulus of elasticity of the wood affected by spruce bark beetle were comparable to those of the undamaged. On the contrary the impact strength test showed a decrease in the values for the maximum strength and toughness of the damaged wood compared to the undamaged. This shows us that wood affected by spruce bark beetle is becoming more fragile than undamaged trees. By done research we have found out that the bending strength of the wood affected by spruce bark beetle is not significantly different compared with undamaged trees. The theoretical part includes issues related to the testing of wood and its strength characteristics. Afterwards, there are listed the results of a statistical evaluation.
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Zhodnocení příčin nahodilých těžeb na LHC Svitavy v období 2009-2017
Tyller, Martin
The aim of this study was to determine causes and consequence of salvage cutting on the subjected territory in 2009-2017. Next aim was to evaluace these cutting in depending on abiotic factors. It was recommended to work with data of evidence of salvage cutting from the owner. On the base of evaluation the salvage cutting and causes was carry out the interpretation of these information. The next aim was to propose measures for stabilization the salvage cutting on the interest territor based on detected information.
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Zhodnocení dopadů sucha v roce 2015 na lesní porosty na revíru Dzbel, část Zadní hory, Lesní správa Prostějov LČR
Pospíšilová, Lucie
The forests are very susceptible to the climate changes, because they are not able to adapt quickly to the changes of the environment due to their longevity. The drought belongs to the group of primary abiotic factors, which significantly affect the health condition of the stands and thus also the extent of salvage logging. This diploma thesis evaluates the impact of extreme drought in 2015 on the stands of the forest area named Zadní hory (close to the town of Dzbel, Forest administration Prostějov). The most endangered tree species is the spruce, due to it´s predominant occurrence in the mentioned area. This work should evaluate the effect of both abiotics and biotics stressors on the drougt-weakened stands and suggest the options for reduction of the damages.
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Ektomykorhizy semenáčků smrku v porostech napadených kůrovcem
Loubalová, Karolína
This diploma thesis deals with the influence of tree dieback as a result of bark beetle attack on the ectomycorrhizal fungi community associated with the spruce seedlings. Seedlings were collected from forests located in three different permanent plots in the Tatra National Park, with different intensity of bark beetle attack (K1, K2, REF). Their biometric characteristics were measured and their micro-site conditions was described. The differences between the measured biometric parameters of the seedlings from the individual areas and the number of ectomycorrhizal species per seedling were tested by the scattering analysis in the Statistica program. Ectomycorrhizas from seedling roots have been categorized by morphological attributes into morphotypes; fungi generating these morphotypes were identified by comparison of the ITS rDNA sequences. Using the Canoco statistical program, it was found, which factors (micro-sites, biometric parameters) had influence on the ectomycorrhizal fungal community on seedlings, and whether it is related to the intensity of the bark beetle attack on forest. Seedlings from dead forest (K2) reached significantly higher elevations of aboveground part, root collar thickness, and had longer main root than the seedlings collected from healthy forest (REF), where on the contrary were the seedlings older (higher number of nodes). The type of area (intensity of bark beetle attack) and age were demonstrated as proof parameters in the Canoco program by CCA analysis in relation to the occurrence of ectomycorrhizal species on seedlings. By analyzing of RDA in relation to the occurrence of ectomycorrhizal species on seedlings classified into exploration types, the type of the area (intensity of bark beetle attack) and the micro-location of seedlings has shown as proving. The ectomycorrhizal fungal community associated with the spruce seedlings has been influenced to a certain extent by the state of the forest, however, the interpretation of these differences is difficult because there is a lack of data on ecology and physiology of individual ectomycorrhizal species.
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Long-term disturbance dynamics of spruce forest in High Tatra Mts.
Beranová, Jana ; Kuneš, Petr (advisor) ; Jamrichová, Eva (referee)
Spruce forest is an important production ecosystem for our civilization. Its development can be affected by three main types of disturbances: forest fire, windstorms and spruce bark beetle attack. Experiences with a massive and long-term attack of spruce bark beetle in the Šumava mountains and a strong windstorm in 2004 in the spruce forest in the High Tatra provoke questions, how natural are such severe disturbances. To understand the current development of forest ecosystems, it is necessary to study past structure of these forests and frequency of forest disturbances. This work is about locality Tatranská Lomnice located in the High Tatra mountains, in the belt of mountain spruce forest. In my work, I used mainly pollen and plant macro-fossils analyses. I compared my data with disturbance information originating from dendroecology for windstorms and from charcoal analysis for fires. My research found that according to the pollen assemblages, most of the disturbances did not have strong influence on the forest composition, and most likely they only caused the forest thinning. The most significant fire occurred around 1420. The most significant wind disturbance probably occurred in 1890. The was not found any effect of spruce bark beetle. In the past millennium disturbances affected spruce forest...
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The Issue of Spruce Monocultures in Connection with Occurrence of Bark Beetles in the National Park Šumava with Application into Education
Kadeřávková, Lucie ; Skýbová, Jana (advisor) ; Andreska, Jan (referee)
The diploma thesis deals with the issues of the spruce monocultures in the relation to the incidence of the bark beetle (Ips typographus) in the Šumava National park. The aim of the thesis is not only to unify and arrange the information, but also find out the level of knowledge about this topic among the pupils of the ninth grade of the basic school. The work also shows the level of knowledge of the pupils about the related problems and what are their opinions and suggested solutions. The thesis is divided into the theoretical and practical part. The theoretical part consists of eight chapters, that are devoted to the history of the Šumava forests, pine tree monocultures with the closer focus on the Norway spruce (Picea abies), the differences among the "natural" and "economical" forest and to the uniqueness of the Boubín primeval forest. In one of the chapters we get information about the huriccane Kyrill and its effects on the Šumava forests and followed by the information about the bark beetle calamities and about the bark beetle on its own. The last two chapters are devoted the solution of the current situation in the Šumava forests and their future perspectives. The practical part of the thesis contains mainly of the questionnaire survey proceeded among the pupils of the ninth grade of the...
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Spatial correlations in population dynamics of spruce bark beetle (Ips typographus): Example of Mantel test usage
Šimera, Ondřej ; Kindlmann, Pavel (advisor) ; Ferenc, Michal (referee)
Spruce bark beetle (Ips typographus L.) is the most common and abundant beetle from the Scolytidae family in European forests. It is the most important biotic factor causing disturbances and affecting forest ecosystems. Thus, it recently became a subject of discussions, how to manage the forests properly in order to find an adequate equilibrium among economical, turistic and natural values of the forest. Many studies have shown a positive effect of bark beetle outbreaks on biodiversity and natural forest regeneration. It is hard to tell if these outbreaks are regular or not because there are many factors which can elicit them. However, just these factors can help us predict the probability of unforseen population outbreak. One of these methods can be monitoring of surrounding areas because these areas tend to be synchronised. For this purpose, multiple mathematical models can be performed, such as the Mantel test, which determines the correlation between two matrices. Keywords: Spruce bark beetle, Ips typographus, population dynamics, spatial correlations, Mantel test
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Influence of weather and climate on Ips typographus calamities in Šumava mountains
Tůma, Lukáš ; Sládek, Ivan (advisor) ; Kožnarová, Věra (referee)
European spruce bark beetle (Ips typographus) is a natural forest pest that feeds on coniferous trees, mainly on spruce. Previous studies showed that population growth of bark beetle is supported by warm and dry weather and hindered by cold and humid weather. Temperature affects development rates and influences the number of generations bark beetle may produce during one season; furthermore, it affects survival rates during the winter. Low precipitation leads to water stress of spruce trees which become more prone to bark beetle infestation. High precipitation promotes growth of mold and other natural enemies of bark beetle. The aim of the experimental part of this thesis was to analyze the relationship between population dynamics of bark beetle and weather, using data from the Šumava national park. Data did not show a significant effect of temperature and precipitation on the population growth rate of bark beetle. The growth rate was significantly correlated only with the abundance of bark beetle in the previous year. For further examination of population dynamics of bark beetle in connection with climate characteristics, it would be required to obtain better and more long-term data on bark beetle abundance; harvested bark beetle wood may be influenced by a variety of interfering (e.g....
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