Summary
Swiss research institutes (Eawag, WSL, ETH Zurich) have published a practice-oriented guide for the restoration of wet forests. These forests – including floodplain, swamp, and bog forests – have been systematically drained and cleared over centuries. The guide describes concrete measures such as filling in drainage ditches, renaturalizing water bodies, and the role of beavers as natural helpers. The goal is to promote biodiversity and strengthen resilience against climate change.
People
- Karen Bussmann-Charran (Researcher, Eawag, Biodiversity Synthesis Center)
Topics
- Biodiversity and forest ecology
- Climate change adaptation
- Water body renaturalization
- Nature conservation and land use
Clarus Lead
The restoration of wet forests is gaining strategic importance under climate change pressure: these ecosystems store CO₂ (particularly in peat moss), raise groundwater levels, and act as cooling islands for settlements. The new guide addresses a central implementation gap – until now, specialists lacked a standardized procedure for renaturalization. With practical action recommendations and solution approaches for resistance from forest owners, the Biodiversity Synthesis Center creates a bridge between research and field practice.
Detailed Summary
The guide emerged from a working group of the Biodiversity Synthesis Center, which systematically identified open questions about renaturalization and answered them in a user-friendly manner. Concrete measures include structural interventions such as removing seepage lines and renaturalizing streams, as well as targeted beaver settlement – these naturally create wet forest habitats through dam construction while simultaneously reducing costs.
The ecological added value is considerable: 84% of all Swiss species depend on floodplain areas. Wet forests are colonized by amphibians, insects, and other species within a short time. In parallel, these habitats offer climate adaptation benefits – elevated groundwater levels reduce drought stress, while lower soil temperatures have a cooling effect on adjacent settlements and contribute to flood protection.
Challenges exist in identifying all historical drainage ditches and in persuading forest owners who fear productivity losses. The guide provides resources for efficient planning here. Experience shows that owners appreciate the resulting species diversity and landscape beauty after implementation. The document is available in German and French and covers legal aspects, project planning, and specific renaturalization categories.
Key Messages
- Wet forests are essential for 84% of Swiss biodiversity and bind large quantities of CO₂
- Concrete renaturalization measures (ditch removal, beaver settlement) are cost-effective and work quickly
- Wet forests raise groundwater levels, reduce drought risks, and have a cooling effect on settlements – central to climate resilience
- Forest owners require persuasion but benefit in the long term from increased biodiversity
Critical Questions
Data Quality: On what basis is the statement that 84% of all Swiss species occur in floodplains founded? Is this a total species count or a subset (e.g., only invertebrates)?
Conflicts of Interest: To what extent were forestry associations or agricultural organizations included in the working group, and how were their concerns regarding productivity weighted?
Causality: Does the guide empirically demonstrate that beaver settlement leads to stable wet forests in all climate zones and soil types, or are these context-dependent results?
Feasibility: What time span is required before renaturalized wet forests achieve their full cooling and CO₂ storage functions, and how is this measured?
Risks: Can newly created wet forests favor invasive species, and how does the guide address monitoring obligations?
Legal Status: What liability regulations apply to forest owners for flood events after renaturalization?
Reference List
Primary Source: Guide "Promoting Biodiversity Through the Restoration of Wet and Moist Forests" – https://www.dora.lib4ri.ch/eawag/item/eawag:34971
Supplementary Sources:
- Eawag Press Release – https://www.eawag.ch/de/info/portal/aktuelles/news/mehr-biodiversitaet-durch-das-wiederherstellen-von-feuchtwaeldern/
- Swiss Biodiversity Strategy (Federal Office for the Environment)
Verification Status: ✓ 12.05.2026
This text was created with the support of an AI model. Editorial Responsibility: clarus.news | Fact-Check: 12.05.2026