Restoration of temperate fens:matching strategies with site potential

The framework of fen restoration includes a variety of different concepts and techniques, which have been developed with different objectives and for diverse target states. Assessment of success can vary considerably, depending on the identified criteria, be it bird diversity, rare plants, peat formation or nutrient status. Some authors distinguish restoration of fens (i.e. returning damaged fens near to the pre-disturbance state) from mire rehabilitation (i.e. re-establishment of their selected functions, which may result in systems that have not existed at the restoration site in the past), whereas others focus on restoring key ecosystem functions of fens, such as peat formation and role in carbon cycling, formulating long-term targets. In this chapter we attempt to structure the discussion around fen restoration by identifying challenges and trade-offs in this field and to clarify how close these different concepts come to the objective of reinstalling or improving the provision of key ecosystem services. We focus on lowland fens in West and Central Europe (UK, The Netherlands, Germany, Poland). We will first discuss the concept of fen ecosystems, their ‘naturalness’, resilience and stability, and the ecosystem services they provide. Next, we introduce the main ecological gradients in fens, the drivers of fen degradation and the consequences for ecosystem services, followed by an overview of constraints, synergies and conflicting targets in fen restoration. We conclude with an overview of gains and trade-offs of various restoration strategies