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Litter decomposition and its role in biogeochemical cycles
Vicena, Jakub ; Frouz, Jan (advisor) ; Picek, Tomáš (referee) ; Krištůfek, Václav (referee)
Decomposition of litter is a key process in the soil nutrient cycle. It is a very complex process that is influenced by a number of factors. This dissertation studies these key factors influencing the rate of organic matter mineralization using modern analytical methods. The results of the dissertation are presented in four publications in international journals with IF and one manuscript ready for publication. The first publication shows a strong positive correlation between microbial diversity and organic matter decomposition per gram of carbon. In contrast, microbial respiration per gram soil was negatively correlated with bacterial diversity and positively correlated with fungal biomass. Thus, the relationship between microbial diversity and decomposition rate is context dependent. The second study (in manuscript form) shows that microbial respiration correlates with C/N of fallout only at the beginning of the experiment, but not at the end. However, respiration during litter decomposition at the beginning and end of the experiment is strongly negatively correlated with the C/N ratio of green leaves. This suggests that the stoichiometric C/N ratio may influence decomposition indirectly through correlation with other unknown parameters such as leaf morphology. The third study examined the...
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Influence of microbial community diversity on the decomposition of organic matter
Vicena, Jakub ; Frouz, Jan (advisor) ; Cajthaml, Tomáš (referee)
Microbial diversity plays an important role in the decomposition of soil organic matter. However, the drivers of this dependence still remain unclear. The work is based on long-term monitoring of soils of different successional stages of different diversity. Soil sampling was conducted on two dumps after brown coal mining in the Sokolov. Soils were X ray sterilized and inoculated by inoculum from both soils in two inoculation density which create gradient of microbial diversity. Then microbial respiration was measured in either supplied or not supplied by litter of Calamagrostis epigejos. Results showed a strong positive correlation between the microbial diversity and decomposition of organic matter if the microbial community is limited by available carbon. If there isn't carbon limit available, the decomposition rate is controlled by the amount of microbial biomass. Results demonstrated positive correlation between the rate of decomposition and the amount of fungal biomass. The soils with the addition of leaf litter showed priming effect in the initial stage of decomposition. In the control samples without addition of litter priming effect wasn't observed. Increasing humidity led to increase of decomposition rate. We can conclude with a clear conscience that similarly conclusive results associated...
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Influence of microbial community diversity on the decomposition of organic matter
Vicena, Jakub ; Frouz, Jan (advisor) ; Cajthaml, Tomáš (referee)
Microbial diversity plays an important role in the decomposition of soil organic matter. However, the drivers of this dependence still remain unclear. The work is based on long-term monitoring of soils of different successional stages of different diversity. Soil sampling was conducted on two dumps after brown coal mining in the Sokolov. Soils were X ray sterilized and inoculated by inoculum from both soils in two inoculation density which create gradient of microbial diversity. Then microbial respiration was measured in either supplied or not supplied by litter of Calamagrostis epigejos. Results showed a strong positive correlation between the microbial diversity and decomposition of organic matter if the microbial community is limited by available carbon. If there isn't carbon limit available, the decomposition rate is controlled by the amount of microbial biomass. Results demonstrated positive correlation between the rate of decomposition and the amount of fungal biomass. The soils with the addition of leaf litter showed priming effect in the initial stage of decomposition. In the control samples without addition of litter priming effect wasn't observed. Increasing humidity led to increase of decomposition rate. We can conclude with a clear conscience that similarly conclusive results associated...
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