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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Vliv kůrovcové gradace na rozšíření a potravní ekologii datlíka tříprstého (Picoides tridactylus) v Národním parku Šumava / The impact of a bark beetle gradation on the occurrence and feeding ecology of a three-toed woodpecker (Picoides tridactylus) in the Šumava National Park

Navrátil, Martin January 2014 (has links)
The main objective of this study was to find factors that influence the occurrence of three-toed woodpecker (Picoides tridactylus) in Šumava at a time when the bark beetle gradation caused by Kyrill subside. The research was conducted on five transects. To prove the presence of three-toed woodpecker was opted the method of an acoustic provocation, which reliability was well proven. The hypothesis was that the three-toed woodpecker prefers the trees infested by bark beetle instead of healthy trees. Surprisingly, however, he also prefered the stands where the main attack took place several years ago. Regardless of their health status the tree- toed woodpecker preferred non-intervention stands instead of the on- going management forest. Among other factors, the exposure was applied (preferred south and west) and elevation (median, minimum altitude of about 1100 m.). Another important result is that Picoides tridactylus prefers for its food stands still alive or just dead spruce trees infested by the bark beetle. Overall, it appears that the three-toed species has narrowly defined biotope demands, which are linked to the natural spruce forest unaffected by people. The results of this study could be used to better understanding of the ecology three-toed woodpecker, eventually can help to create a...
22

Neglected aspects of bark beetle (Coleoptera: Scolytinae) ecophysiology

DAVÍDKOVÁ, Markéta January 2019 (has links)
The thesis describes several unknown aspects of the spruce bark beetle, Ips typographus (L.), and the double-spined bark beetle, Ips duplicatus (Sahlberg.), life-cycles and ecophysiology. The first study focuses on I. typographus and its dispersal under epidemic conditions in the National park Šumava and introduces a novel method of fluorescent marking and detection of captured specimens. The second study is focused on ability of I. typographus to establish so-called sister-broods, i.e. re-emergence of females that are capable to continue egg laying without a need to mate again. The importance of sister-broods becomes apparent mainly in recent hot and dry vegetation seasons, which is demonstrated by a comparison of recent and historical data. The third study focuses on temperature-dependent development of I. duplicatus under laboratory conditions by the means of sandwich method. Altogether, the studies underline practical importance of ecophysiological studies on bark beetles as one of the tools for their effective management.
23

Biology and Management of the Dutch Elm Disease Vector, Hylurgopinus rufipes Eichhoff (Coleoptera: Curculionidae) in Manitoba

Oghiakhe, Sunday January 2011 (has links)
Hylurgopinus rufipes, the native elm bark beetle (NEBB), is the major vector of Dutch elm disease (DED) in Manitoba. Dissections of American elms (Ulmus americana), in the same year as DED symptoms appeared in them, showed that NEBB constructed brood galleries in which a generation completed development, and adult NEBB carrying DED spores would probably leave the newly-symptomatic trees. Rapid removal of freshly diseased trees, completed by mid-August, will prevent spore-bearing NEBB emergence, and is recommended. The relationship between presence of NEBB in stained branch sections and the total number of NEEB per tree could be the basis for methods to prioritize trees for rapid removal. Numbers and densities of overwintering NEBB in elm trees decreased with increasing height, with >70% of the population overwintering above ground doing so in the basal 15 cm. Substantial numbers of NEBB overwinter below the soil surface, and could be unaffected by basal spraying. Mark-recapture studies showed that frequency of spore bearing by overwintering beetles averaged 45% for the wild population and 2% for marked NEBB released from disease-free logs. Most NEBB overwintered close to their emergence site, but some traveled ≥4.8 km before wintering. Studies comparing efficacy of insecticides showed that chlorpyrifos gave 100% control of overwintering NEBB for two years as did bifenthrin: however, permethrin and carbaryl provided transient efficacy. NEBB showed a gradual increase in development rate with increasing constant temperature. Lipid content of overwintering NEBB was higher in late fall than in mid-winter, which might show that depletion of fat reserves could jeopardize survival, but could be a result of conversion to cryoprotectants.
24

Adipokinetické hormony a energetický metabolismus lýkožrouta smrkového (\kur{Ips typographus} L.) / Adipokinetic hormones and the energetic metabolism in the spruce bark beetle (\kur{Ips typographus} L.)

MORAVCOVÁ, Martina January 2012 (has links)
The aim of the thesis was to elucidate the occurrence of adipokinetic hormones in the spruce bark beetle (Ips typographus) by competitive ELISA and LC/MS analysis. Total lipid and carbohydrate content as well as levels of glucose, trehalose and glycogen were measured to characterize physiological changes during particular phases of the life cycle.
25

Srovnání efektivity obranných opatření proti lýkožroutu smrkovému (Ips typographus (L.)) na vybrané lokalitě Lesního Závodu Boubín. / Effectiveness of protective measures against spruce bark beetle (\kur{Ips typographus} (L.)) at selected localities of LZ Boubín

VAČKÁŘOVÁ, Tereza January 2013 (has links)
The efficiency of various protective measures against the Spruce bark beetle (pheromone-baited traps, trap trees, poisoned traps - tripods.) and the impact of insecticide-treated trap trees on non-target organisms were studied in weekly periods in areas in the altitude of 1000m above sea level. Tree traps proved to be of much higher effectivity with an average of 3307 caught spruce bark beetles in comparison with pheromone-baited traps with only 457 beetles within the same period. Poisoned traps ? tripods baited with pheromone (FeSex Typo, producer ? Karel Ubik, CR) were more effective than pheromone traps and the average number of caught beetles was 1226. Among non-target insects caught in these traps were 61 species included 7 orders. The most common species was Thanasimus formicarius.
26

Evaluation of Spruce Forest Regeneration and Vegetation Changes / Evaluation of Spruce Forest Regeneration and Vegetation Changes

HREŽÍKOVÁ, Markéta January 2013 (has links)
The impact of a bark beetle outbreak, and the following sanitation management actions, on the mountain spruce forest in the central part of the Šumava Mountains were compared after twelve years of development. The survey was focused on natural regeneration of trees and herb-layer vegetation.
27

Hodnocení vlivů na životní prostředí - případová studie. Monitoring populační dynamiky lýkožroutů v plošných polomech po orkánu Kyrill. / Evaluation of the effects on the environment - a case study. The monitoring of bark-beetle population dynamics in the areal windbreak after Hurricane Kyrill.

VOJÍŘ, Lukáš January 2009 (has links)
My thesis deals with bark beetle in two model areas affected by disturbances in the Šumava Mountains which were caused by Hurricane Kyrill in January 2007. The localities are Černá hora and Kalamitní svážnice pod Trojmeznou. Monitoring on both of these localities was realized in a zone with no human intervention. On these two model areas population dynamics of bark beetle in areal blowdowns and spatial distribution of advance growth in the harmed area was determined. Based on the monitoring of individual localilities, we can presume population dynamics of bark beetle in the following years.
28

Vliv eneregetických rezerv na úspěšnost přezimování a reprodukční potenciál lýkožrouta smrkového (\kur{Ips typographus} (L.)) / The energetic state of the spruce bark beetle (\kur{Ips typographus} (L.)): Implications for winter survival

BARTOŠOVÁ, Eva January 2010 (has links)
The thesis deals with characterisation and changes of energetic status in the spruce bark beetle, Ips typographus, during pre-diapause, diapause and post-diapause quiescence.
29

Granbarkborre (Ips typographus) och Skyddad skog : Orsakar skyddad natur granbarkborreangrepp i produktionsskog? / Spruce bark beetles (Ips typographus) and protected forests : Do protected areas cause increased attacks of spruce bark beetle in production forests?

Eriksson, Gustav January 2021 (has links)
The aim of this report was to investigate whether the management of protected forests cause increased risk of infestation by the European spruce bark beetle (Ips typographus) in production forests, and whether the risk of infestation in production forests is greater in the vicinity of protected forests. The survey was conducted by using GIS-data covering suspected attacks and forests that are susceptible to infestations. The proportion of infested forests in three different buffer zones located around the protected areas were compared. The results show no evidence suggesting that protected areas serve as a hatchery for spruce bark beetles and no increased risk of infestations in the vicinity of protected forests were detected.
30

Právní úprava ochrany lesa v kontextu kůrovcové kalamity a globálních změn klimatu / Legal regulation of forest protection in the context of bark beetle outbreak and climate change

Matoušek, Oliver January 2020 (has links)
Legal regulation of forest protection in the context of bark beetle outbreak and climate change The aim of this thesis is to analyse current legal regulation of forest protection in Czech law, primarily areas related to ongoing bark beetle outbreak with the focus on forest management. In the interest of presenting the topic in its broader context, elementary aspects of forestry and other nature sciences are briefly discussed. Author also evaluates and gives his opinions on the current legal regulation and its imperfections throughout the thesis. The thesis is divided into four main parts. The first part serves as a brief introduction into the subject matter of the thesis i.e. legal regulation regarding forest protection. The first chapter of this part discusses the term "forest" from the point of view of natural sciences and details the importance of forest and different forest functions. Second chapter of the first part discusses factors harmful to forests, mainly bark beetles, droughts and climate change and the concurrent effect of those factors. Second part of the thesis maps the evolution of Czech legal regulation and tries to find parallels between previous and today's legal regulation. Oldest discussed legal document is the Maiestas Carolina of the 14th century. Thesis then moves on to the...

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