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Assembly, successional development and functioning of microbial communities in deadwood
Bernardová, Natálie ; Brabcová, Vendula (advisor) ; Kopecký, Jan (referee)
Dead wood is one of the most important reservoirs associated with forest ecosystems. In natural forests, its volume is counted in hundreds of m3 ha-1 , whereas it reaches only tens of m3 ha-1 in productive commercial forests. In contrast to soil and plant litter, deadwood is unevenly distributed on the forest floor. The specific physicochemical properties such as high content of recalcitrant polymers, low nitrogen level and impermeability negatively affect the rate of decomposition especially in the initial stages of wood deconstruction. The deadwood decomposition is very slow in comparisons with other substrates, it accumulates and thus it represents the important reservoir of nutrients. This thesis is focused on the structure, development and function of microbial (fungal) community in decomposing deadwood in unmanaged forest. Functional screening of fungi isolated from fruit bodies collected from coarse deadwood was set aside. Physico-chemical properties of deadwood including pH, carbon and nitrogen content and microbial biomass were estimated for four wood decomposition stages and three different tree species. New generation sequencing (Illumina MiSeq platform) was applied for fungal community structure analysis based on ITS2 fragment. Fungal functional screening was based on physico-chemical...
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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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Ecology of deadwood-associated fungi in the ecosystems of nature-like forests
Zrůstová, Petra ; Baldrian, Petr (advisor) ; Konopásek, Ivo (referee)
Dead wood plays an important role in forest ecosystems in the context of C dynamics, nutrient cycling, forest regeneration and biodiversity. Decaying wood sustains biodiversity by providing habitats and energy for fungi, bacteria, invertebrates, and many other organisms. Dead wood is resistant to decomposition and its decay is driven mainly by filamentous fungi. Community structure of wood- inhabiting fungi changes during decomposition, but the relationship between substrate quality and decomposer community is still poorly understood. This work studied fungal community composition with respect to tree species, stage of decay, volume and physico-chemical properties (such as pH, carbon and nitrogen content) of dead wood. Fungi were identified using next generation sequencing approaches - 454-pyrosequencing and Illumina MiSeq sequencing. Tree species, volume of dead wood (branches x logs) and stage of decay were the main variables affecting fungal community composition. Higher enzyme activities and content of fungal biomass indicate faster colonization of small branches than tree trunks by fungi. Fungal community composition, wood chemical properties and enzyme activities changed during decomposition. Both content of nitrogen and fungal biomass increased during decomposition. Enzyme activites peaked...
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