Climate regulation
Further details on the systemic and synthesis for this European Green Deal Criterion are available in the MERLIN Deliverable Report page 47.
Peatlands
For peatlands the primary climate regulation impact considered is the change in carbon dioxide and methane emissions following restoration. These were modelled from the measured water levels in the peat before and after restoration.
In CS5 restoration raised the water table from 50 cm below the surface to 23 cm below the surface and reduced greenhouse gas emissions from nearly 4000 tonnes CO2-eq per year to less than 600 tonnes CO2-eq per year.
In CS14 3 different restoration locations and one control location were monitored. The control location remained dry and with high emissions per ha (despite low total emissions because of the small area). The restoration sites all showed reduced greenhouse gas emissions, and one restoration location was even modelled to sequester carbon dioxide.
Rivers
The primary change, as measured in Merlin, in rivers following restoration that is linked to changing climate regulation and carbon storage is the increase in flood plain connectivity and the increase in soil carbon in these flood plains over time. These were modelled for the Merlin sites using data from the Intergovernmental Panel on Climate Change (IPCC) and showed an increase in carbon stored in the soil of between 0.3 and 0.6 tonnes of carbon per ha of floodplain habitat restored. Those where larger floodplain areas were reconnected showed the greatest increase in stored soil carbon.