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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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Dynamics of mountain spruce forest focused on natural regenaration development
Červenka, Jaroslav ; Svoboda, Miroslav (advisor) ; Tomáš, Tomáš (referee)
Disturbances have a major impact on the dynamic of forest ecosystems. However, there is lack of its exact consequences for mountain spruce forests in Central Europe. In 2007 heavy windstorm damaged a lot of stands in Šumava NP, subsequent bark beetle outbreak resulted in a large-scale dieback of spruce stands in this area. We took advantage of this opportunity. This study is focused on disintegration and structure of stands after the severe disturbance and in next step is focused on density and structure of natural regeneration in these stands. In addition we dealt with spruce regeneration (Picea Abies (L.) Karst.) on decaying logs. We compared two localities, disturbed (NP Šumava) and undisturbed site (CHKO Jeseníky). We concentrated on the change in saplings densities and on impact of decaying logs characteristic on this change. Finally we wanted to determinate impact of decaying logs characteristic on density of spruce regeneration. In area of Trojmezná we recorded 99 % mortality of parent stands. We founded only a few of adult tress which survived the disturbance, in addition we found several new trees, most of them with diameter about 10 cm. Live trees (DBH > 7 cm) reach density 16 trees per ha. The amount of dead wood was 2.5 times higher than before 10 years, one third were lying logs. Only natural regeneration of Norway spruce and rowan (Sorbus acuparia L.) was founded. Regeneration recruitments occurred in sufficient numbers, mostly on mosses (32 %), dead wood (27 %) and the nearest neighbourhoods of living mature trees or snags (28 %). Advance regeneration occupied 88 % of all regeneration. The density of individuals was similar along the elevation gradient. But in lower elevation of study area was situated higher regeneration recruitment then in the higher parts. With increasing elevation gradient regeneration was more homogenous in height and was lower. Best conditions for spruce regeneration provides logs with the largest diameters and logs with presence of white fungi Armillaria spp. or Phellinus nigrolimitatus. On the other hand logs with presence of Fomitopsis pinicola do not provide a suitable microsite for saplings. When we compare change in regeneration density on dead wood between the disturbed and undisturbed site, our results show significant increase in regeneration density at disturbed site (by 33 %). The increased regeneration density observed at the disturbed site was mostly associated with the smallest saplings on logs with the largest diameters. Three years after death of the parent stands no significant effect was recorded on the growth rate and survival of established spruce saplings on dead wood.
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Factors affecting efficacy of pheromone lures for spruce bark-beetles
Zahradníková, Marie ; Holuša, Jaroslav (advisor) ; Emanuel, Emanuel (referee)
This thesis evaluates the effectiveness of defensive techniques against the spruce bark beetle (Ips typographus L.) with a primary focus on pheromone traps and selected factors affecting their efficacy. The factors tested are the setup system of pheromone traps and type of pheromone dispenser baits, the effect on the efficacy of pheromone traps of increasing evaporated pheromones, a comparison of the biological efficacy of different types of pheromone dispensers and an assessment of their impact on the swarming curve. In addition, an evaluation of non-traditional methods of forest protection against the spruce bark beetle (water spraying of whole landings, efficacy of insecticidal sraying of whole landings, and the use of insecticidal nets) was conducted and the possibility of the spruce bark beetle s sex determination was also examined.
When comparing the systems of pheromone traps installation, (1) the standard way was along the stand edge with 20 m space and (2) traps concentrating in the centre of clear cut adjacent to each other with different baiting, the most effective way was found to be the standard trap arrangement and the system with traps installed in line with the dispenser in each pheromone trap. Efficacy decreased with a lower number of pheromone dispensers. The influence of increased amounts of evaporated pheromone on efficacy was tested. Pheromone traps with one, two or three dispensers were compared and it was found that a trap s efficacy was not increased with a higher amount of released pheromone. The Pheagr IT and IT Ecolure Tubus dispensers showed unchanged effectivity throughout the flight activity of spruce bark beetle, but other dispensers need to be replaced according to the instructions since their efficacy decreases, thus affecting the swarming curve. Trying to determine the sex of the spruce bark beetle by selected morphological parameters shows that the gender can only be reliably determined by an autopsy of genitals.
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Comparsion of treated logs and pheromone traps on spruce bark beetle in hills
Petrák, Karel ; Holuša, Jaroslav (advisor) ; Lukášová, Karolína (referee)
Purpose of this thesis was comparing of spruce bark beetle (Ips typographus) trapping methods in uplands. In six areas in region of Neveklov, there were installed pairs of devices, namely a slot trap type Theysohn and a poisoned tripod trap tree with pheromone evaporator. During the swarming activity of bark beetles, from April to the end of September 2015, the traps were controlled and bark beetles captured and counted. Evaluation is based on laboratory determination, number of captured beetles and determination of sex ratio. It was also made an economical comparison of both methods. During this study was captured in total 34.495 pieces of spruce bark beetle in two generations. Statistically there was no difference between number of captured beetles into slot traps or into tripod traps.
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Ekonomická efektivnost způsobů odchytu kůrovců
Bauer, Jan
The bachelor thesis compares the usual capturing device for (Ips typographus L.) in terms of economic efficiency on the number of captured beetles. The topic has been studied literature, compiled a literature review to assess the first ways of trapping bark beetles, and analyze the advantages and disadvantages of different variants of capture (SWOT analysis). On the basis of analysis were selected to meet the objectives of the two most common variants of capture - tree traps and pheromone traps for which was determined by the economic efficiency of capture based on observation and investigation variant of traps in one year and by comparing the type (Ips typographus L.).
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Communities of oribatid mites (Acari: Oribatida) of naturally regenerating and salvage logged mountain spruce forests of Šumava Mts
GALICOVÁ, Petra
The main aim of this study was to describe and compare communities of oribatid mites of selected areas in mountain spruce forests near Březník in the Šumava National Park, where different types of management were used after the spruce dieback caused by bark beetle gradation more than 15 years ago. Naturally regenerating and salvage logged areas were compared. Significant differences were found in the oribatid mite community composition between the areas with different types of used management. The oribatid mite community in naturally regenerating areas was in better shape and its abundance and species composition was similar to the community of a control area in a fully grown healthy spruce forest.
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Midgut proteinases in diapausing and post-diapausing adult of the spruce bark beetke \kur{(Ips typographus)}
ŠTEFKOVÁ, Kristýna
My work concentrates on feeding behavior of overwintering diapausing and post {--} diapausing bark beetles and developmental treshold. This is done either biochemically by measuring the enzymatic activity in the midgut and by assessing the feeding status from the size and consistence of the food bolus in the gut. Detailed knowledge of feeding behaviour and development treshold may help to predict the overwintering success of local populations with all the consequencies for spring dispersal and reproduction.
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Uplatnění obranných opatření proti lýkožroutu smrkovému v podmínkách s diferencovaným kalamitním základem
Šotola, Vojtěch
Thesis examine efficiency of protective measures against Ips typographus in locality with different salvage basis. Using protective measures, pheromone traps and trap trees, was in localities using in different ratio, from all trap trees to all pheromone traps. Collecting data conducted in year 2011 and 2012 in forest district Vítkov, forest ward Dubová and Červená hora. From conducted research results, combination both protective measures are more effectiveness. Most effectives ratio can evaluate ratio from 75 % trap trees - 25 % pheromone traps. From two years is not do any clear decision to using in forest experience.
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