Session

Decades of deep drainage of fen grasslands led to the development of a micro-relief, which is due to the decomposition of the peat deposits at varying depths. Therefore, implemented management in these systems are highly influenced by these micro-relief which makes them highly heterogeneous. However, the remained question is how the micro-relief influences forage quality and quantity and therefore the management of these fen grasslands via heterogeneously distributed species occurrences. In a degraded fen grassland located in the Northeast of Germany, we investigated the inter-annual variability of plant species diversity and their coverage under three levels of cutting frequency in a 3-year (2021-2023) experiment. Three strips with two, three, and four cutting events per growing season were designed (2-, 3-, 4-cutting systems). Forage quality and quantity were measured at different locations within each cutting system. We first found that although the 4-cutting system increased the number of species, this was mainly due to the appearance of species that are not typical for fens under near-natural conditions. The results showed that the dynamic of shallow groundwater level significantly affects the appearance of species and consequently yield. However, the response of biomass yield and forage quality varied differently depending on soil type and groundwater level. Our results present deeper insights into management-relevant properties of degraded fens which have implications for possible future pathways of more sustainable development of these ecosystems.