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Effects of soil alteration on nitrogen and carbon cycling
Růžek, Michal ; Oulehle, Filip (advisor) ; Šantrůčková, Hana (referee) ; Stadmark, Johanna (referee)
Forest ecosystems are facing changing environmental conditions induced by anthropogenic pressures, including atmospheric deposition. Elevated sulfur (S) and nitrogen (N) depositions have led to changes in forest soil conditions, inducing acidification and N eutrophication. However, the consequences of atmospheric deposition for the functioning of forest ecosystems may be tree species specific. To assess the effects of S and N inputs on soil functioning of two forest stands, a soil chemistry manipulation experiment took place in two adjacent forest stands - Norway spruce (Picea abies) and European beech (Fagus sylvatica) - in the Ore Mts. Over six years, separated and combined additions of S and N compounds (50 kg ∙ha-1 ∙year-1 ) were added to experimental plots in both stands to mimic enhanced atmospheric deposition. The aim of this research was to compare and investigate the soil C and N stocks and fluxes, and their responses in relation to acid and N treatments. We found that under ambient conditions, the beech stand contained more C and N in both the forest floor and the mineral soil compared to the spruce stand. Nitrogen cycling in the beech stand was less tight, with periodical soil N leaching. The manipulated increase of soil acidity (decrease of soil solution pH) reduced the availability of...
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Tree species influence on soil acidification: long-term trends and modeling
Oulehle, Filip ; Hruška, Jakub (advisor) ; Borůvka, Luboš (referee) ; Šantrůčková, Hana (referee)
Forest ecosystems belong to the part of environment most affected by the anthropogenic acidification. The structure of Central European forests was historically converted mostly into the Norway spruce monocultures. Such a forests received elevated acidic deposition since 1950s, from which large parts of mountain forests were killed by air pollution in 1970s and 1980s. After reduction of acidic deposition the forest soils were significantly delayed in chemical recovery compared to stream chemistry (Alewell et al., 2000). In this thesis we focused on long-term changes in soil chemistry at highly polluted area of Ore Mts., with particular interest in the tree species influence on soil acidification. The presented results including measurements of biogeochemical cycles within forest ecosystem at the Norway spruce (Picea abies [L.]) stand in the period 1992-2005 and at the European beech (Fagus sylvatica [L.]) stand between 2003-2005. The desorption of previously stored sulfur and the decrease of Ca deposition are the main factors controlling the recovery of soil solution at spruce stand. The reduction in Ca availability resulted in lower uptake by tree assimilatory tissues, measured as concentration in needles. The unexpected disappearing of nitrogen leaching from soil was undoubtedly the most...
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Are the characteristics of microbial community proper indicators of soil quality?
Šimek, Miloslav ; Šantrůčková, Hana
Soil is a dynamic, living, natural body that is vital for terrestrial ecosystems. It has many ecological and human-linked functions. Definitions of important soil attributes - soil quality and health - is reviewed. Several aspects concerning soil quality assessment that are analysed in detail include requirements on indicators of soil quality and health and use of characteristics of soil microbial community for soil quality and health estimations. Possibilities for using microbial biomass as one of soil quality and health indicators are discussed.
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