Autor:innen:
Dr. Simon Drollinger | Department of Physical Geography, Institute of Geography, University of Göttingen | Germany
Dr. Daniel Schwindt | Department of Physical Geography, Institute of Geography, University of Göttingen | Germany
Dr. Birgitta Putzenlechner | Department of Cartography, GIS and Remote Sensing, Institute of Geography, University of Göttingen | Germany
Dr. Timo Lehmann | Department of Cartography, GIS and Remote Sensing, Institute of Geography, University of Göttingen | Germany
Lindsay Holsen | Department of Physical Geography, Institute of Geography, University of Göttingen | Germany
Prof. Dr. Daniela Sauer | Department of Physical Geography, Institute of Geography, University of Göttingen | Germany
In contrast to pristine peatlands, drained peatlands have been identified as hotspots of greenhouse gas (GHG) emissions. Projections suggest that, due to severe human impacts, peatlands worldwide will shift from a global net GHG sink to a source in the near future, causing positive radiative forcing. Peatlands are also a relevant climate factor in Germany, accounting for ~7.2 % of the annual GHG emissions. Thus, restoration of peatlands constitutes an effective nature-based climate change mitigation measure. Accordingly, as a society, we need to ask ourselves whether we should restore afforested peatlands on a large scale to mitigate climate change. To allow for more careful consideration and to identify the measures providing the most effective changes in each ecosystem, the benefits of restoration must be contrasted with the initial investments and future losses when the land is taken out of economic production. Thus, a deep understanding of the effects of forest peatland restoration and its underlying processes across ecosystems and time scales is essential.
Here we present a dataset of two years of eddy covariance-derived carbon dioxide, methane and water vapour fluxes of a clear-cut forest peatland during early stages of restoration in the Solling mountains, Lower Saxony. We found large amounts of carbon to be released from the peatland to the atmosphere. This is due to extraordinarily high ecosystem respiration but low gross primary production rates and minimal methane emissions. Calculations of GHG fluxes are complemented by UAV flights, geophysical measurements and soil analyses to disentangle the spatio-temporal variability of influencing factors. We relate results of repeated electrical resistivity tomography to soil properties and discuss the effects of their spatial heterogeneity on gas fluxes. True colour orthophotos obtained from repeated UAV flights have been successfully used to delimit vegetation units and changes in plant composition with ongoing plant succession. Thermal images are used to assess fine-scale differences in soil moisture based on variations in heat capacity of different matter and to evaluate their potential to model and upscale spatio-temporal trends of thermal characteristics and ecosystem respiration in unprecedented detail. Finally, we evaluate underlying factors of GHG fluxes, discuss implications of restoration measures and outline potential future developments.