|
|
Influence of European beech (Fagus sylvatica) and Norway spruce (Picea abies) on composition of low molecular mass organic acids and on composition of microbial community in forest soils
Zývalová, Jana ; Tejnecký, Václav (advisor) ; Kaštovská, Eva (referee)
Locations of interest for this diploma thesis are located in the Jizera Mountains and represent forest soils developed on acidic rocks (porfyric granite). The sites are tens of meters apart, making sure that all the abiotic conditions affecting the soil-forming process are very similar. The only significant difference between the localities is the species composition of the overstorey vegetation. On one site there is only the European beech (Fagus sylvatica), on the other only the Norway spruce (Picea abies). At both locations, soil samples were taken from each horizon L-B in which basic soil parameters and elemental contents (active and exchangeable soil reactions, moisture, cation exchange capacity, basic saturation, dissolved organic carbon and others) were analyzed. The low molecular mass organic acids were determined by ion-exchange chromatography. The bacterial phyla in the soil were calculated based on the Illumina sequencing to which preceded DNA isolation and quantitative PCR. Based on the results of the analyzes, the monitored soils were characterized as acidic with an unsaturated to strongly unsaturated soil sorption complex. Between the beech and spruce stands, differences in the contents of some water-extractable elements and the exchangeable elements (Ca, K, Mg, Fe, Al) and moisture...
|
|
|
The role of winter chemical maintenance of roads on ecosystems
Zývalová, Jana ; Mihaljevič, Martin (advisor) ; Galušková, Ivana (referee)
The annual use of de-icing salts leads to a continuous increase of Cl- and Na+ concentration in the surroundings of treated roads. It particularly affects soil and water environment and vegetation. The Na+ are accumulated in soils, they are bound into the cation exchange complex (CEC). It leads to the displacement of other cations (Ca2+ , Mg2+ , K+ , NH4 + , etc.), which are washing out from soils. The excessive amount of Na+ disturbs the soil structure and leads to a soil particles dispersion. Thus, the mobilisation of heavy metals (Cd, Zn, Pb, etc.) can occur. Increase of pH and electrical conductivity (EC) has an effect on the overall chemistry of the soil. Cl- are more mobile than Na+ in the soil column and they are flushed into water, where they altogether contribute to an increase of total dissolved solids and they cause acute and chronic contamination. The vitality of aquatic communities is influenced by the long-term exposure to the stress conditions. Finally, a shift from alkali to halophytic communities can occur. A slowdown, even stoppage of water layers mixing can be observed in water reservoirs. Biogeochemistry of water sediments is changed due to the anoxia of the benthic waters. Vegetation in the surroundings of treated roads shows visible symptoms of damage. The coniferous trees are...
|
guest ::
RSS feed.