National Repository of Grey Literature 61 records found  previous11 - 20nextend  jump to record: Search took 0.01 seconds. 
Bacteria associated with decomposing deadwood
Tláskal, Vojtěch ; Baldrian, Petr (advisor) ; Uhlík, Ondřej (referee) ; Bárta, Jiří (referee)
Deadwood is a hotspot of microbial diversity and its decomposition contributes to carbon and nitrogen cycling in temperate forests. The historically recognized importance of fungi in the decomposition of deadwood has recently been complemented by the description of bacterial functions thanks to the rapid progress of culture-independent methods based on the analysis of nucleic acids. To study different aspects of deadwood decomposition, a temperate mixed forest in Zofinsky prales National Nature Reserve was selected as a site with rich historical forestry data where deadwood decomposition represents an important process in wood turnover. The aim of this thesis is to describe role of bacteria in deadwood decomposition at fine scale resolution with respect to community composition, enzyme transcription, and metabolic potential of dominant species. Effects of deadwood age together with pH and water content on the bacterial community composition proved to be more important than tree species identity. Bacteria showed distinct composition between early and late community in decomposing deadwood. The bacterial community was also under a significant influence of fungal community composition. Despite being in a close contact, bacterial and fungal communities differed significantly between deadwood and the...
Vegetation of post-mining sites determines soil microbial community structure and soil processes
Urbanová, Michaela ; Baldrian, Petr (advisor) ; Chroňáková, Alica (referee) ; Bárta, Jiří (referee)
This thesis consists of three published articles and one submitted article, and is focused on the evaluation of the effects of vegetation on soil microbial communities and processes on brown coal post-mining sites. The research sites served as deposits of infertile waste material, by which the indigenous vegetation has been buried and thus the whole ecosystem was destroyed. The restoration of the ecosystem structure and functions at these areas was based on the improvement of biotic and abiotic properties of excavated soil substrate either using assisted afforestation or using spontaneous plant succession. In this work, biochemical and molecular techniques were employed in order to testify the effect of the vegetation on soil microbial processes, structure of soil microbial communities and to follow the chemical changes in the litter composition during its decomposition. Litter chemistry, enzymatic activities and microbial biomass were followed by standard biochemical procedures including spectrometry and HPLC. Bacterial microarray was used for assessing the composition of bacterial communities in the soil of successional plots. 454-pyrosequencing was employed for detailed identification of fungal and bacterial community composition in the litter layer and the bulk soil under different tree...
Biotic threats to garden monuments: algae, cyanobacteria and invasive plant species
Pergl, Jan ; Perglová, Irena ; Albrechtová, J. ; Antl, Tomáš ; Abarenkov, K. ; Baldrian, Petr ; Cihlářová, L. ; Klečka, Jan ; Kohout, Petr ; Kvasničková, Jana ; Maršálek, Blahoslav ; Maršálková, Eliška ; Pejchal, Miloš ; Petružálková, M. ; Petřík, Petr ; Pyšek, Petr ; Sádlo, Jiří ; Štefl, Lukáš ; Tedersoo, L. ; Větrovský, T. ; Vlk, Lukáš ; Vojík, Martin ; Vosátka, Miroslav ; Zezulka, Štěpán
Chateau, city parks and gardens are perceived as harmonious parts of the landscape. Unfortunately, even these areas have to face various threats, and they can be a threat to the surrounding environment. The exhibition /catalogue presents a look at the organisms that threaten parks. These threats cover unwelcomed invaders covering invasive plants and small microorganisms in the soil, on facades, statues or in water. On the other hand, some species that are intentionally brought to the parks can be risky not only the gardens themselves but also their surroundings.
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The importance of bacteria for deadwood decomposition in forest ecosystems
Némethová, Ema ; Baldrian, Petr (advisor) ; Bárta, Jiří (referee)
Forest ecosystems represent a huge reservoir of carbon. The volume of deadwood in managed forests is in the tens of m3 h-1, while unmanaged forests have the volume of deadwood in hundreds of m3 ha- 1. Deadwood is a substrate with a high potential for decomposition. However, deadwood is a specific habitat that has a high C/N ratio and changes due to ongoing decomposition. The C/N ratio decreases with increasing decay time. In addition to the C/N ratio, the pH also changes during the wood pulping process, due to the decomposition of plant biomass by fungi. Moreover, deadwood has a high impermeability. The main decomposers of dead wood are fungi. In addition to them, bacteria, which are numerous in deadwood, also contribute to decomposition. Bacterial communities that decompose woody biomass are affected by these factors, and their distribution is also affected by dead tree species. The aim of this study was to describe how bacterial communities associated with deadwood change during decay. The most significant factor in the decomposition by bacterial communities is the time of decay. Bacteria found in short-decaying wood (less than 16 years old) are more diverse than those found in long-decaying wood. Methylotrophic bacteria and N-fixing bacteria are common in short-decaying wood as well. N-fixing...
Structure and function of microbial communities of montane spruce forest
Štursová, Martina ; Baldrian, Petr (advisor) ; Uhlík, Ondřej (referee) ; Slaninová Kyselková, Martina (referee)
Structure and function of soil microbial communities in montane spruce forest Martina Štursová Abstract Coniferous forests are spatially heterogeneous environments and represent an important ecosystem that acts as carbon sink under current climate storing large amounts of carbon in standing biomass or as soil organic matter. The formation of organic matter via decomposition of dead biomass and transformation of rhizodeposited organic compounds is primarily mediated by microbial community of forest topsoil. Despite growing insight into the composition of these soil communities, little is known about the microbes actually responsible for those transformation processes, about the drivers shaping these communities or their response to increasing numbers of severe disturbances. Studies presented in this thesis contribute to filling the information. The studies were carried out in unmanaged spruce forests in the highest elevations of Bohemian Forest, in both, the undisturbed areas as well as those affected by bark beetle outbreaks at different time periods. Combination of methods including culturing of fungi, enzymatic activity measurements or high throughput sequencing were used to describe the microbial communities, their distribution in space and time, and factors involved in shaping these communities in those...
Effects of plants on the structure, function and diversity of bacterial communities
Havlíčková, Petra ; Baldrian, Petr (advisor) ; Kopecký, Jan (referee)
Vegetation is known to influence the composition of microbial communities. Bacteria can act as roots symbionts or be involved in the decomposition of plant biomass. They can be influenced by soil chemistry but also by plant exudates. Some plants produce targeted exudates to attract specific bacteria to their roots. Bacteria associate with plants frequently but the effect of plant diversity on bacterial communities on their roots and in the surrounding soil remains unclear. The aim of this work was to describe the relationship between the diversity and community composition of bacteria and the diversity of vegetation in forest and grassland ecosystems. The study areas were selected to represent a gradient of vegetation in Bohemian Forest NP and in White Carpathian flowery grasslands. I hypothesized that the diversity and evenness of bacterial community increase with increasing plant diversity. The composition of bacterial community was characterized by 16S rRNA sequencing. The composition of vegetation was determined by phytocenological relevées and by molecular markers trnL. In grassland ecosystem, there was a positive relationship between plant and bacterial diversity only in shoots. The space and vegetation were identified as an important drivers of bacterial community composition in shoots. The...
Ecology of yeasts in forest soils
Mašínová, Tereza ; Baldrian, Petr (advisor) ; Marečková, Markéta (referee) ; Kolařík, Miroslav (referee)
Microbial communities inhabiting upper soil horizons represent an important component of forest ecosystems. However, despite the evidence that yeasts represent an integral part of topsoil fungal communities, their role in forest ecosystems received so far little attention. The aims of my PhD thesis were to describe yeast communities in soil and litter of a temperate forest using high- throughput sequencing of environmental DNA, identify dominant yeast species and to explore how the composition of yeast communities reflects the biotic and abiotic factors of the environment. I also aimed to isolate yeasts from forest topsoil, describe novel yeast taxa abundant according to the environmental DNA survey and screen representative isolates for the traits relevant to their involvement in organic matter transformation. I have demonstrated that in forest topsoil, yeasts represent a substantial proportion of fungal communities with higher relative abundance in soil than in litter. In litter, yeast communities differ significantly among beech, oak and spruce-dominated stands. Drivers of community assembly are probably more complex in soils and comprise the effects of soil chemistry and vegetation. Even though there are similarities in the response of the communities of yeasts and filamentous fungi to...
Physiology and ecology of saprotrophic basidiomycetes degrading dead plant biomass
Valášková, Vendula ; Baldrian, Petr (advisor) ; Tomšovský, Michal (referee) ; Koukol, Ondřej (referee)
(in English) My theis is focused on soil saprotrophic basiďomycetes, their role in the decomposition of dead plarrt biomass and intera.tioÍts with other members of microbiď community since these fungi play a particularly important role in biotransformation of soil organic matter arrd thereíorealso in the cycling of carbon and mineral nutrients. Three litter.decomposing basiďomycete isolratď from Quelvts petrueo Íorat: Eypholotna tascicularc, Rhodocolly bi,a butgrnrca ard Ggrnnopn sp., efficiently degrarled oak litter unrler both sterile and nonsterile conditions, but the rate of degradation and lignocellulolytic enzyme produc- tion considerably diftbred among isolates. Geuerally, the degrarlation camed by these iso- lates resembled decay caused by whiterot fungi. The fungi produced a broad range of lignocellulose-degrading enzyme: laccase, Mn- peroxidase, endo-I,4-p glucanase, endo-l,4 d >rylanase,p-glucosidase and iJ-xylosidase. Saprotrophic basidiomycetes thus probably contribute to the observed spatial variability in extrarellular enzyme activities in the up per srril horizon in oak forest. Spatial differences in eDzymeactivities were accompanied by diffe.rencesin the microbial commutrity composition, the relative amount of fungal biomass decreased with soil depth. The vertical gradients in soil...
Importance of fungal decomposition of wood in the ecosystems of natural forests
Štercová, Lucie ; Baldrian, Petr (advisor) ; Kolařík, Miroslav (referee)
The decomposition of organic substrates represents an important part of the global carbon cycle and affects its global change through CO2 release. In temperate forests, deadwood represents a large carbon stock, its amount and decomposition is crucial for ecosystem biodiversity and functioning. The fungi are omnipresent powerful decayers in all terrestrial ecosystems. Their ability to decompose all deadwood compounds, mainly lignocellulose, is highly important. Without fungi, the wood decompositions and the release of withheld nutrients back to nutrient cycles couldn't be performed. While many studies were concerned with the estimation of decomposition rates of deadwood, still deeper knowledge about microbial decomposition processes and the diversity of saproxylic species and their interaction is needed. The fungi are still underrepresented in dead wood studies. This study had two main objectives. First was to describe the fungal community on downed deadwood of Fagus sylvatica and Abies alba in natural forest of Salajka in the Czech Republic, to reflect the substrate changes during the different decay stages, and to link the enzyme activities to fungal community composition and their described ecophysiologies. Second aim was to describe the fungal communities on standing and downed dead logs of...

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