CANDYbog: Matter fluxes in South Patagonian peatlands - background
The DFG-funded project CANDYbog (Carbon, water and nutrient dynamics in vascular plant- vs. Sphagnum-dominated bog ecosystems in southern Patagonia) deals with temporal and spatial patterns as well as processes controlling matter fluxes in South Patagonian peatlands. In contrast to their northern counterparts that are often heavily anthropogenically influenced and well-investigated, these pristine southern peatlands are only poorly studied. Therefore, South Patagonian peatlands allow for the investigation of matter fluxes under nearly undisturbed conditions which is almost impossible in the northern hemisphere.
Undisturbed Sphagnum-dominated bog. (photo: Till Kleinebecker)
Beside bogs dominated by peat-forming Sphagnum mosses that are also typical for the northern hemisphere, also bogs that are dominated by cushion-building vascular plants can be found in South Patagonia. So far, it is almost unknown which conditions lead to either the development of cushion bogs or Sphagnum bogs. Undisturbed bogs have an important carbon storage function in the global carbon cycle. However, the carbon source and sink dynamics of South Patagonian bogs have not been investigated so far and thus it is unclear, how much carbon is stored or released, particularly by cushion bogs. The aim of the CANDYbog project is therefore to quantify the carbon, nutrient and water balance of South Patagonian peatlands as well as to identify and better understand the key processes controlling nutrient and carbon dynamics in these peatlands.
Sphagnum magellanicum and Astelia pumila side by side. (Foto: Till Kleinebecker)
Beside the relevance for the global carbon cycle, a better functional understanding of South Patagonian peatlands is particularly promising because they can be considered as model systems for undisturbed peatlands in the northern hemisphere. Therefore, South Patagonian peatlands can be particularly suitable to investigate the response of peatlands to changing environmental conditions, for example caused by global change including climatic changes or elevated atmospheric nitrogen inputs. It is expected that these changes in environmental conditions affect the vegetation composition and carbon storage function of peatlands. In this context, the cushion bogs may be an example of the expected changes in the vegetation composition of the northern hemispherical bogs towards a greater dominance of vascular plants. Thus, the results might give valuable insights for the conservation and restoration of bogs in the northern hemisphere.
The CANDYbog project is jointly organized by the Biodiversity and Ecosystem Research and Working Group Hydrology at the University of Münster, the working group Regional Hydrology at the University of Hamburg and our Argentinean partner from the Centro Austral de Investigaciones Científicas (CADIC) in Ushuaia (project partners and contacts are on the right column/below).
Among others, the research questions deal with
the differences in carbon and water balances between vascular plants and Sphagnum-dominated peatlands, especially in response to different environmental conditions
the effects of experimental shading and fertilization on Sphagnum mosses and cushion-forming vascular plants, on peat decomposition rates as well as nitrogen dynamics
the long-term carbon sequestration rate of South Patagonian bogs
In the CANDYbog project, a wide range of methods ranging from field measurements and experiments to laboratory experiments will be applied. During three extensive field campaigns in the summer months of Southern Patagonia both prevalent bog types will be intensively studied. The Sphagnum bog is situated close to Ushuaia in the Tierra del Fuego national park (postition in google maps), whereas the cushion bog dominated by Astelia pumila belongs to the Estanica Moat (position in google maps), a three hours car drive away from Ushuaia.
In Tierra del Fuego, glacial valleys are often filled by extensive mires. (photo: Till Kleinebecker)
One focus of the field work is a shading and fertilization experiment to get detailed insights into the dynamics of nutrients, biomass production and peat decomposition of the two bog types. Subsequent laboratory studies include, for example, the analysis of stable isotopes, incubation experiments or spectroscopic measurements.
In order to measure and compare fluxes of energy, carbon and water between the two bog ecosystems and the atmosphere at different spatial scales, the micrometeorological eddy covariance method as well as closed and ecophysiological leaf chamber systems will be used. In addition, dissolved and particulate matter fluxes will be quantified using hydrological methods. These prevailing carbon balances of the two bogs types will then be compared with the long-term carbon sequestration rates determined by the analysis of peat profiles.
The investigations are planned in close cooperation with our Argentinean partners in Ushuaia which are particularly interested in the role of fungi for decomposition processes of organic matter. Therefore an Argentinean PhD student will perform specific investigations that will be integrated in the planned field and lab experiments.
In bogs dominated by vascular plants, roots reach up to 2m below ground. Sphagnum peat is often found in the lower parts of the soil profile. (photo: Till Kleinebecker)
Information
Student Projects and Thesis
Currently one student is working on her theses:
Nina Reimann: Variability of CO2 accumulation in Sphagnum- and Astelia-dominated bogs in Southern Patagonia (Bachelor thesis)
Further topics for Bachelor and Master theses and research projects are available about the carbon and nitrogen dynamics of South Patagonian bogs! If you are interested – also to support the project as a student assistant – please contact Wiebke Münchberger.
Finished Theses
Lina Birkner: Impact of experimental nitrogen addition, sea spray input and artificial shading on the element content of Astelia pumila and Sphagnum magellanicum biomass (Research project 2017)
Juliane Kohlstruck: Impact of experimental nitrogen addition, sea spray input and artificial shading on the rate of photosynthesis of Astelia pumila and Spagnum magellanicum (Bachelor thesis 2017)
Bettina Breuer: Variability of CH4 fluxes of South Patagonian bogs (Research project 2016)
Claudia Frank: Variability of CO2 fluxes of South Patagonian bogs (Research project 2016)
Isabella Närdemann: Temporal and spatial variability of CO2-Fluxes in Sphagnum- and Astelia-dominated bogs in Southern Patagonia (Master Thesis 2016)
Hannah Koch: Experiments with salt tolcerace of Sphagnum magellanicum (Bachelor Thesis 2015)
Felix Nieberding: Classification of fuegian bog vegetation by means of high resolution air-borne image data (Bachelor Thesis 2014)
Publications and Conference Presentations
Münchberger W, Reimann N, Knorr KH, Gałka M, Borken W, Blodau C, Pancotto VA, Kleinebecker T (2018): Carbon cycling in contrasting pristine bogs in southern Patagonia (Tierra del Fuego, Argentina). Poster, European Geosciences Union, General Assembly 2018. Vienna, 7-12/04/2018 [Abstract] [Poster]
Lehmann JRK*, Münchberger W*, Blodau C, Nieberding F, Knoth C, Prinz T, Pancotto VA, Kleinebecker T (2016) High-resolution classification of South Patagonian peat bog microforms reveals potential gaps in up-scaled CH4 fluxes by use of Unmanned Aerial Systems (UAS) and CIR image classification. Remote Sensing 8(3): 173 [doi:10.3390/rs8030173] (* equal authorship)
Münchberger W, Blodau C, Kleinebecker T, Pancotto VA (2015): CO2 and CH4 fluxes of contrasting pristine bogs in southern Patagonia (Tierra del Fuego, Argentina). Poster, European Geosciences Union, General Assembly 2015. Vienna, 12-17/04/2015 [Abstract] [Poster]
