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Importance of ecological stoichiometry in soil development.
Veselá, Hana ; Frouz, Jan (advisor) ; Hruška, Jakub (referee) ; Bonkowski, Michael (referee)
Ecological stoichiometry is a useful tool for understanding of ecological dynamics and related processes. There are only rare informations about nutrient cycling and nutrient dynamics in plant- soil system in restoration areas after coal mining. Different plant species have developed own strategies and treat differently with nutrients which can influence nutrient cycling and consequent nutrient return to the soil. In thesis, I investigated ecological stoichiometry as one of key factors which controls soil development in post mining sites. In general introduction, known facts are summarized about e.g. plant traits, decomposition process, nutrient cycling and consequences for soil development and restoration practices. But still, relationship between leaves, plant litter, and soil is poorly understood in restoration areas. The results of a doctoral thesis are presented in five papers, out of which three have been published, one has been already submitted and one manuscript is prepared for publication in an international journal with impact factor. In the first presented publication, the influence of soil fauna was studied (especially earthworms) on soil development. Soil development differed significantly between sites afforested with different tree species and it is strongly influenced by the...
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Wood ants of genus Formica as important ecosystem engeneers
Jílková, Veronika ; Frouz, Jan (advisor) ; Tajovský, Karel (referee) ; Bonkowski, Michael (referee)
This thesis consists of one chapter accepted for publication in a book and four papers published in international journals with impact factors. All of the contributions deal with the role of wood ants in energy and nutrient fluxes in forest ecosystems. Wood ant nests are known as hot spots of carbon dioxide (CO2) production and are also thought to affect methane (CH4) flux. Stable high temperatures are maintained in ant nests even in cold environments. This study is focused on quantification of CO2 and CH4 flux in wood ant nests, contribution of ants and microbes to CO2 production, properties of nest material that affect CO2 production and the role of ants and microbes in the maintenance of nest temperature. The research was conducted in temperate and boreal forests inhabited by wood ants (Formica s. str.). Gas fluxes were measured either by an infrared gas analyser or a static chamber technique. Ants and nest materials were also incubated in a laboratory. Material properties potentially influencing CO2 flux, such as moisture, nutrient content or temperature were determined. According to the results, CH4 oxidation was lower in wood ant nests than in the surrounding forest soil suggesting that some characteristics of ant nests hinder CH4 oxidation or promote CH4 production. Wood ant nests clearly are hot...
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