Two Bachelor or Master theses are available at the University of Koblenz-Landau to assess either litter decomposition or carbon cycling in aquatic environments exposed to multiple stressors.

Project 1: Litter decomposition in novel environments

Litter decomposition is a key ecological process for the energy supply within aquatic environments, but is known to be affected by several anthropogenic stressors. We aim to analyze the (interactive) effects of (i) invasive herbaceous plants, (ii) climate change (i.e., drought), and (iii) artificial light at night caused by increasing urbanization, on litter decomposition by macroinvertebrates in streams. Therefore, a mesocosm experiment should be conducted in artificial flumes at the Eußerthal Ecosystem Research Station (EERES). The student will be involved in the preparation of the experiment (installation of LED flumes, sampling of macroinvertebrates in streams, collection of leaf material from different plants, preparation of leaf bags, etc.), the conduction of the experiment (measurements of litter decomposition rates, sampling macroinvertebrates), and data analysis. Expected project time is ~May-July 2021. Results are planned to be jointly published in a scientific journal by the supervisors and the student(s).

Contact: Dr. Alexander Feckler (feckler@uni-landau.de), Dr. Jens Schirmel (schirmel@uni-landau.de)

Project 2: Carbon cycling in novel environments

Upon decomposition of leaf litter, its carbon can be transformed into CO2, CH4, particulate organic matter, and/or been incorporated as biomass. The significance and rate of one process or another depends on the oxic conditions, which are in turn linked to flow and light availability (among other drivers). The project will assess the significance of these two factors on CO2 and CH4 production (i.e., respiration/primary production and methane production) from leaf litter decomposition under shredder pressure and different leaf litter properties. This experiment will be carried out in flumes at the Eußerthal Ecosystem Research Station (EERES). In the course of the thesis, the student will be involved in the preparation of the experiment (installation of LED flumes, sampling of macroinvertebrates in streams, collection of leaf material from different plants, preparation of leaf bags, etc.), the conduction of the experiment (measurements of respiration/primary production and methane production), and data analysis. Expected project time is ~May-July 2021. Results are planned to be jointly published in a scientific journal by the supervisors and the student(s).

Contact: Clara Mendoza-Lera (mendozalera@uni-landau.de), Dr. Alexander Feckler (feckler@uni-landau.de), Dr. Jens Schirmel (schirmel@uni-landau.de)