Effects of riparian forests on the sediment quality and sediment processes
In this WP, we want to find out how riparian forests influence the sediment structure and quality as well as biogeochemical and microbial processes on the sediment surface in dependence of the respective land use (forests, crop fields, pastures, settlements). In specific, we are interested whether riparian forests improve the phosphorus buffer capacity of the sediments and how they may influence the potential of the sediments to act as habitat for fecal bacteria from anthropogenic sources (e.g. waste water treatment or manure application).
We will take water and sediment samples in 20-30 streams along a land use gradient from both sites with and without riparian buffer forests. Sediments will be analysed for grain size, organic content and nutrients, microbial respiration, P adsorption potential, and fecal bacteria.
We want to answer the following research questions:
- Can riparian forests reduce the benthic oxygen consumption compared to open reaches?
- Which environmental conditions stimulate or prevent the establishment and growth of fecal bacteria in stream sediments? Can these conditions be correlated to the existence of riparian forests?
- How do riparian forests influence the P adsorption capacity of the sediments and the P uptake and release? Under which conditions do sediments act as internal P sources for the stream?
- Can sediments act as early warning systems for a potential deterioration of the streams’ ecological state in the future?
The project will be linked to another current projects, see link below: