S3: From idiosyncrasy to understanding: How the flow of energy, matter and information shapes wetscapes 2.0 and their development pathways
Project leaders: Prof. Dr. Florian Jansen (University of Rostock), Dr. Mia Bengtsson (University of Greifswald), Prof. Dr. Philip Marzahn (University of Rostock), Prof. Dr. Sebastian van der Linden (University of Greifswald)
Natural peatlands are characterized by strong self-regulating mechanisms, which have been well studied in bogs but less so in fens. These mechanisms are lost when peatlands are drained and rewetting does not lead to rapid regeneration. Rewetted fens typically exhibit a high degree of spatio-temporal heterogeneity in soil properties, micro-relief, vegetation patterns, and microbial communities. The spatial decoupling of processes during drainage leads to idiosyncratic patterns in rewetted fens of, inter alia, microrelief, conductivity, and most obviously vegetation, which hinder the predictability of the processes responsible for the biodiversity, GHG balance and paludiculture potential of these novel ecosystems. The rewetting process in general and the spatial patterns mentioned in particular, are related to the land use and land cover during drainage and the degree of peat degradation, e.g. by peat extraction, drainage, and differences in shrinkage. At the same time, these spatial patterns and the resulting differences in processes and distribution of information (e.g. eDNA and microbiota) are expected to determine the development pathways of rewetted fens, in particular the desirable return to near-natural conditions, including reduction of GHG emissions, new peat accumulation and the regeneration of natural habitats or a sustainable paludiculture. A deeper understanding of the spatial dependencies, intra- and inter-annual variability, and the future trajectories of restored wetscapes is urgently needed. Particular attention will be paid to the distribution of microbial communities and their relationship with other elements such as vegetation, biomass, hydrology and GHG emissions. The hydrological connectivity between patches, the ability to intercept residual runoff with suitable vegetation and the development of a porous topsoil are considered prerequisites for renewed self-regulation.