Laufende Abschlussarbeiten
Bachelorarbeiten | |
| Juanita Voshage |
The influence of soil structure on reactive and conservative transport of chemicals in unsaturated soils Predicting the fate of chemicals in soils is a very difficult task, because effective reaction rates in soils depend on the soil heterogeneity , the dynamics of water flow in soils (hydraulic structure), the initial mixing of the reactants, and the speed of the reaction (Henri et al., 2024), among other factors (for example temperature). For this reason, experiments are needed to study reactivity of soils for different degrees of heterogeneity and different water fluxes. In this thesis, a second-order irreversible reaction is tested as a reactivity tracer for dynamic and static soil experiments. Betreuer: Efstathios Diamantopoulos, Ben Gilfedder |
| Eurich Johannes |
Biogenic VOCs emissions from soils Volatile organic components are classified independently of the process underlying their formation. Biological volatile components (BVOCs) are VOCs that are formed as a result of biological processes. The definition of these two groups of substances cannot be clearly distinguished from one another, as some VOCs can be produced both organically and inorganically. VOCs can also be formed from BVOCs through various reactions. For example, methane formed organically can be broken down by reacting with a hydroxyl radical in water and a methyl residue. This methyl residue would have been formed inorganically, i.e. a volatile organic component. This would not have been possible without the prior formation of methane organically. Many papers on the subject of BVOCs deal with emissions from plants. Other publications, such as Tang et al. (2019) directly look at the soil habitat and the biological processes taking place there and the organisms or parts of them involved. Other publications, such as Ruiz et al. (1998) also deal with the abiotic processes of BVOCs in soils. These interactions are based on, for example, the adsorption of gases on soil particles and the dissolution of the gases in water. This approach is also present in other papers, but represents a minority compared to the investigation of biological processes for the origin of VOCs. This work will investigate biological and abiotic VOC sources and sinks. This should lead to a better understanding of the processes in native soils and in the overlying soil layer of the atmosphere. Betreuer: Efstathios Diamantopoulos, Anke Nölscher |
| Theresa Wittig |
The effect of soil structure on soil evaporation Betreuer: Frederic Leuther, Efstathios Diamantopoulos |
| Alina Langaki |
The effect of crop resiudes on soil hydraulic properties Betreuer: Frederic Leuther, Efstathios Diamantopoulos |
Masterarbeiten | |
| Adina Rauscher |
Experimental and numerical investigation of the fate of insoluble pollutants in the rhizosphere Polycyclic aromatic hydrocarbons (PAHs) occur ubiquitously in terrestrial and aquatic ecosystems all around the world and are a group of chemicals among the so called “persistent organic pollutants” (POPs). PAHs comprise several hundred chemically related compounds and some of them are known to have toxic, mutagenic, and carcinogenic effects on humans and other living organisms Although PAHs are considered to be very poorly soluble in water, there appears to be transport of molecules in soil that allow them to be distributed, clog pores, or accumulate at the soil plant interface. Especially for high molecular weight PAHs, colloidal and particulate transport is assumed to be an important process. Little is known about the exact transport processes in soil and whether plants can influence this transport by suction Hypotheses
Methods To test the first hypothesis an experiment is to be carried out with undisturbed soil columns without plants. An irrigation head with needles will be used to supply water to the columns, which will also contain any tracers and particles. Three steps are planned: i nvisible tracer (e.g., chloride) chloride), p articles + PAH s, inv isible and visible tracer (brilliant blue) blue). For each step, the drainage at the bottom of the column will be collected and analysed, and at the end the distribution of the particle bound PAHs in the column will be investigated. To test the second hypothesis, undisturbed soil columns with maize plants are to be used. Again, particle bound PAHs will be supplied via the irrigation system; then drying and rewetting phases will follow. The drainage will be collected and analysed and the distribution of particle bo und PAHs around the root will be studied. Betreuer: Frederic Leuther, Efstathios Diamantopoulos, Eva Lehndorff |
| Sarah Bossinger |
Einfluss der Bodeneigenschaften auf die Verteilung der Naturverjüngung im Klimawald Bayreuth Der Klimawald 1.0 in Bayreuth entstand 2019 durch eine studentische Initiative, die bei einer Pflanzaktion zwölf verschiedene heimische und nichtheimische Baumarten auf einer durch Hitze und Trockenheit geschädigten, circa 1 ha großen Fläche pflanzte. Diese sollen besser an die zukünftigen Klimawandelszenarien angepasst sein als Fichte (Picea abies) und Kiefer (Pinus sylvestris), die in der Vergangenheit großflächig angepflanzt wurden. Neben den gepflanzten Bäumen hat sich auch eine üppige Naturverjüngung entwickelt, die bereits kartiert wurde. Dabei fiel eine ungleiche Verteilung über die Fläche auf. Ein signifikanter Zusammenhang mit den Lichtverhältnissen konnte dabei aber nicht gefunden werden. Neben den Lichtverhältnissen sind die Bodeneigenschaften ein wesentlicher Faktor, der das Wachstum von (jungen) Bäumen beeinflusst. Vorhergehende Untersuchungen legen nahe, dass die Fläche verschiedene Bodentypen und eine Heterogenität der Textur aufweist. Deshalb sollen in dieser Masterarbeit durch eine ausführliche Analyse verschiedener Bodenparameter Korrelationen zu der Verteilung der Naturverjüngung gefunden werden. Betreuer: Frederic Leuther, Eva Lehndorff |