Greenhouse Gases &
Net Climate Effect

Synthesis of the available data on Bavarian greenhouse gas emissions and their drivers with the aim of calculating regionalised emission factors for Bavaria. Another goal is to fill knowledge gaps through greenhouse gas flux measurements at locations with land use and/or other site-related factors that are currently underrepresented or missing in the dataset. Moreover, potential hotspots of emissions are examined as well.

Synthesis of existing data on greenhouse gas emissions from Bavarian peatlands

For two decades, Matthias Drösler's research group at HSWT has investegated the greenhouse gas balance of peatlands, with a particular focus on Bavaria. Therefore, there are greenhouse gas flux, meteorological and hydrological data from a total of 14 previous projects available. These form the basis for the calculation of emissions from Bavarian peatlands.

By the end of the project, our database for calculations and modelling will have grown to more than 150 measurement years and almost 80 measurement locations (sites) at seven Bavarian peatlands.

Dependence of greenhouse gas emissions on water level, shown for the different types of peatland and land use

The individual locations differ significantly in their land use, peat quality and management history; they include the land use types of grassland, arable land, forest, near-natural and rewetted along with degraded and abandoned peatlands on fens, bogs and peaty soils, respectively.

Greenhouse gas flux measurements in Benediktbeuern and Karolinenfeld

Grassland use, followed by forestry, is the most common form of management in Bavarian peatlands. Intensively managed and deeply drained peatland sites can be emission hotspots. Rewetting and a decrease in land use intensity are expected to reduce emissions quickly, although there is very little flux data shedding light upon the short-term development of GHG balances in the immediate aftermath of a rewetting measure. In the KliMoBay project, the effects of the rewetting of two drained fens under grassland use in Benediktbeuern (extensive use, shallow drainage) and Karolinenfeld (intensive use, deep drainage) are investigated. Since December 2019, the CO2, CH4 and N2O fluxes have been measured at the sites using a manual chamber approach, thus closing a gap in the previously available data set. In addition, research at the deeply drained Karolinenfeld site will increase information on grassland sites with a water level below 40 cm below surface, which consists of very few data points so far.

Above: Water table development at the grassland sites Benediktbeuern and Karolinenfeld

Bottom: CO2 flux measurement with transparent chamber before sunrise

Rewettting in Karolinenfeld

Greenhouse gas flux measurements at a forested bog in Mooseurach

The forested bog in Mooseurach is the only managed forest site on organic soil in Germany where CO2 exchange has been measured for over 10 years. When measurements started in 2010, there was a relatively dense 60-year-old spruce stand growing at the site. Due to increasing bark beetle infestation and a strong windthrow event (storm Niklas) in the spring of 2015, the forest was clear-cut in early winter 2015/2016 and has since been left to natural succession. The weak drainage system (long-term average water level approx. 25 cm below surface) is no longer maintained. As part of the KliMoBay project, the eddy covariance measurements at the site are supplemented with chamber-based CH4 measurements.

Above: Eddy covariance tower in Mooseurach with the 30 m-tall eddy covariance tower, that was in use before clear-cutting, visible in the background

Bottom: Fingerprints of net ecosystem exchange two years pre and four years post clear-cutting

team

Team of project 1

Weihenstephan-Triesdorf University of Applied Sciences (HSWT), Institute for Ecology and Landscape, Chair of Vegetation Ecology

Prof. Dr. Matthias Drösler (overall and sub-project management)
Dr. Janina Klatt (project coordination and data analyses)
Martina Schlaipfer (project coordination)
Clarisse Brehier (PhD student)
Heta Meyer (technician)