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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...
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Structure and function of bacterial communities during succession on dead plant biomass
Tláskal, Vojtěch ; Baldrian, Petr (advisor) ; Marečková, Markéta (referee)
The decomposition of dead plant biomass substantially contributes to the carbon cycle and therefore is one of the key processes in temperate forests. While the role of fungi in litter and deadwood decomposition was repeatedly addressed, there are just a few surveys of bacteria associated with decomposing plant biomass. The development of bacterial community within leaf litter is likely driven by the changes in litter chemistry and by the availability of nutrients in the litter. Fungal activity greatly contributes to changing properties of substrate and thus influences bacterial community. Availability of nutrients is changing during biomass decomposition from easily accessible substrates toward more recalcitrant ones (e.g. lignin). The colonization of deadwood by bacteria is influenced by various factors such as microclimate conditions, tree species and volume. The aim of this thesis was to describe bacterial community dynamics during the first two years of decomposition of leaf litter and deadwood. In the leaf litter experiment, bacterial community was analysed in the live, senescent and decomposing leaves of Quercus petraea. This experiment was performed in the Xaverovsky Haj Natural Reserve, Czech Republic. Deadwood experiment was focused on the composition of bacterial community in the initial...
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Ecological roles of bacteria associated with plant litter
Tláskal, Vojtěch ; Baldrian, Petr (advisor) ; Seydlová, Gabriela (referee)
Leaf litter in temperate forests represents an important input of carbon into the soil. Main players in the decomposition of leaf litter are fungi and bacteria. While the role of fungi in litter decomposition was repeatedly addressed, there are just a few field studies where litter-associated bacteria were also considered. The aim of this work was to summarize available literature studying the structure and function of bacterial community during litter degradation. The nature of different possible substrates is discussed. Genetic approach is briefly outlined. Factors such as diversity, spatially distribution and abiotic factors that can influence community are also considered. It can be supposed that community composition changes with the change of litter chemistry and nutrient availability. The development of bacterial community might be driven by the decreasing availability of nutrients in litter. Labile compounds are utilised at the beginning of decomposition, while recalcitrant substrates are utilised later by specialist taxa. Members of the phyla Actinobacteria, Acidobacteria, Bacteroidetes and Proteobacteria seem to be dominant during decomposition. Different types of relationships between fungi and bacteria also most likely influence the composition of community. This review shows that the bacterial...
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