Building on the inventory of European wetlands and the measurement of restoration impacts on biodiversity and ecosystem services in living labs, work carried out in other ALFAwetlands work packages, Work Package 4 pursues an ambitious objective to use models to upscale the knowledge from living labs to the EU-level and quantify how wetland restoration can contribute to achieving the EU policy climate mitigation targets.
Since degraded wetlands, especially drained peatlands, have high CO2 emission rates, restoration measures can help reduce Greenhouse gasses (GHG) emissions. Wetland ecosystems can store atmospheric carbon in the soils but also emit methane or nitrous oxides, gasses with a high global warming potential. Also, actions taken to restore wetlands can indirectly affect other land-based sectors and society. Therefore, an integrated assessment like the one in ALFAwetlands is important to inform policymakers about the trade-offs and benefits of restoration actions at larger scales.
What modelling framework do we use?
Spatially explicit modelling of GHG emissions and removals is used in Work Package 4. The GHG abatement potential of wetland restoration is evaluated within the Land Use, Land Use Change, and Forestry (LULUCF) sector including cropland, grassland, forests, and wetlands – a sector expected to increase its net annual GHG removals to 310 Mt CO₂-eq. by 2030. We use biophysical process-based models (e.g., EPIC, JSBACH, YASSO, HIMMELI, G4M, and 3PGmix) together with measured data to understand environmental and managerial drivers of ecosystem services (ES) in living lab experimental sites, namely carbon cycle, GHG fluxes (CO2, CH4, N2O), and primary production. The trained models upscale this knowledge into the high-resolution EU coverage, taking on the most up-to-date maps of wetlands. A global, partial-equilibrium economic model GLOBIOM projects scenarios of GHG removals in LULUCF, accounting for the simulated ES options in sectors including wetlands, costs of mitigation measures, biodiversity priorities, socio-economic demands, policy instruments, and other scenario constraints. We assess the trade-offs and benefits between climate mitigation, biodiversity conservation, and societal and economic impacts in GLOBIOM.
A total of four modelling tiers are present. In tier 1, GHG fluxes and other ES measurements serve to train the specialised biophysical models in living lab experimental sites (Task 4.1a). Furthermore, in tier 2, ES responses to altered hydrology regimes, climate change, and management actions are tested, and co-created management scenarios are scaled from experimental sites to living lab regions (Task 4.1b). In tier 3, large-scale biophysical models extrapolate these scenarios to the EU context (Task 4.2, 4.4). This is conditioned by learning from the specialised biophysical models in Task 4.3. In tier 4, land use modelling is carried out in GLOBIOM to assess the climate mitigation potential of ALFAwetlands scenarios vis-à-vis a baseline scenario, i.e., without wetland restoration (Task 4.4).
What scenarios do we analyse?
ALFAwetlands scenarios focus on restoring wetland ecosystems on degraded organic and wet mineral soils where degradation can be reversed (e.g., by drain blocking). Scenarios are also focus on rehabilitation of peatland and former riparian wetlands currently used as cropland, grassland, or managed forest where some functional aspects of wetlands can be restored. For example, by partial rewetting or flooding, setting aside from intensive production, or alternative management (e.g., afforestation, paludiculture, cropland conversion to grass, change in forest management). These scenarios and a baseline scenario are projected for policy-relevant climate mitigation periods and targets.
Baseline scenario. In Task 4.2, we perform a baseline EU-scale assessment of GHG emissions and removals for agriculture and LULUCF sectors (AFOLU) with an improved representation of wetland extent and processes. In this scenario, we assume that all existing wetlands are preserved and the organic and wet mineral soils in land categories other than wetlands are utilized as usual. Models are run bottom-up (modelling tier 1 to 4) to project referential ES without wetland restoration for the intermediate socio-economic development pathway and climate change.
Scenarios with wetland restoration. With restoration scenarios, we target GHG emissions and removals together with commodity production and C sequestration in all LULUCF land. Existing wetlands are preserved, while restoration or rehabilitation measures are projected for organic and wet mineral soils in cropland, grassland, and forests in Task 4.4. These scenarios include management measures co-created in the living labs, as well as other nature-based mitigation options known from the literature and the EU projects. Restoration strategies are extrapolated to similar environmental conditions by maximising the mitigation effect, while biodiversity indicators are used to prioritise biodiversity hotspots in the optimisation.
Who we are:
Work Package 4 is led by the International Institute for Applied System Analysis based in Austria. IIASA researchers lead the EU-scale assessment in Tasks 4.2, 4.3, and 4.4. The Finnish Meteorological Institute leads Task 4.1 and coordinates site-scale modelling efforts. Nature Resources Institute Finland leads the indirect land-use change impact assessment in Task 4.5 and provides overall coordination support. French National Centre for Scientific Research, the University of Tartu and the Latvian State Forest Research Institute provide other modelling and data support. The European Wilderness Society supports WP4 with communication and dissemination activities.
We are all happy to participate in these challenging and inspiring activities!