Sites

Maima

Kuresoo

Agali

Laiuse

Rewetted former peat extraction site (4 treatments where the water level is above the ground at different levels: 0-10 cm, 20-30cm, 30-50 cm, 100 cm) and control site. The restoration was done in 2019.

Site PI Ain Kull (ain.kull@ut.ee)

Size:

I treatment (0-10 cm) – 4.8 ha

II treatment (20-30cm) – 3.4 ha

III treatment (30-50 cm) – 1.2 ha

IV treatment (100 cm) –  16 ha

Control site –  5.2 ha                                    

Coordinates:

Maima

Revegetation former peat extraction site.

Site PI Ain Kull (ain.kull@ut.ee)

• Challenge: Due to deep drainage, widely fluctuating water levels, high surface temperatures, and many other unfavorable conditions, spontaneous recovery of vegetation, especially at milled peatlands, is a very slow and unpredictable process. Even 20-30 years after peat extraction, the vegetation can cover only a few percent of the degraded area. Raising the water level eliminates the extreme risk of fire during dry weather and reverses the release of carbon (greenhouse gases) to sequester carbon.The management of milled peatlands and the restoration of ecological functionality in marshes with degraded water regimes is an important scientific challenge in the whole temperate zone in the context of climate change and declining habitat and landscape diversity, including in Estonia, because we have not dealt with the management of former milled peatlands for decades.
• Solution: An increase in water levels slows down peat mineralisation and reduces CO₂ emissions, but the total GHG flux after raising the water level temporarily increases at the expense of N₂O and CH₄ but begins to decrease in the second or second third year after the restoration activities. Reduction of GHG flux is faster in better-vegetated areas.
• Expected outcomes: Knowledge of the abounded peat extraction field (peat layer thickness and type, water level depth and surface layer moisture, distance from vegetated areas, etc.) can accelerate vegetation towards the desired communities by raising water levels or sowing plant fragments. Restoration of milled peatlands supports the development of vegetation – increases biodiversity.
• Transferability: The factors influencing the management and success of peatland restoration and the nature conservation impact of the results have not been studied anywhere on such a large and complex scale. The results have a high practical value considering the large area of former peat extraction sites, their share in greenhouse gas emissions, and the importance of organising residual swamps accordingly. As an innovative solution, three sources with different levels of detail (ground measurement, drone image, satellite image) are used for vegetation analysis, resulting in a verified cross-scale vegetation monitoring methodology. This will allow the development of methods for monitoring larger restoration projects, as remote sensing data can easily cover large areas, and it is also possible to use retrospective condition assessment via the satellite image archive.

Kuresoo 

Rewetted forestry-drained peatland

Site PI Kaido Soosaar (kaido.soosaar@ut.ee)

• Challenge: Kuresoo bog restoration action is an example in Estonia where it will be possible to assess the impact of hydrological regime restoration on Sphagnum moss growth and the effectiveness of different damming technologies.
• Solution: With a higher water level, the CO₂ emissions decrease, but CH₄ and N₂O increase, in opposite in low groundwater level CO₂ emissions increase.
• Expected outcomes: Rewetting will reduce GHG emissions by XX%. Increasing biodiversity.
• Transferability: Proposed method is relevant in all countries where peatlands have been drained for forestry.

Agali II

Forestry-drained peat.

Site PI Ülo Mander (ulo.mander@ut.ee)

• Challenge: The site in Agali is located in the Järvselja Training and Experimental Forestry District, Estonia. This is a 40-50 years old Downy birch forest on a N-rich peat and together with 8 other drained peatland forest sites in the neighborhood with existing dataset of greenhouse gas (GHG) fluxes and relevant environmental parameters (2013-2016) can be considered as a Järvselja Living Lab. The SMEAR Estonia station which is also located in the region can have a supporting role.
• Solution: The Agali Downy birch peatland site is planned for the detail process analysis of the impact of water level manipulations on the greenhouse gas emissions. It is equipped with eddy tower (Fig. 2 for all 3 GHGs (LiCor for N2O + Aerodyne for CH4 & N2O), automated chambers for soil fluxes of all 3 GHGs (Picarro-connected) and tree stem chambers at 4 heights (Fig. 2), and two experimental plots (3 replicates in each) for water level manipulation (flooding and drying) in combination with freezing-thawing experiments.
• Expected outcomes: Elevated water level will reduce peat mineralisation hence CO2 flux from the soil. The experimental plots (Fig. 4) enable to analyse the effect of soil moisture (water level) and freezing-thaw cycles on GHG gas fluxes. Isotope analyses (15N and 13C) and microbiome studies will be used for partitioning fluxes between the N2O source processes and CH4 production and consumption.
• Transferability: To analyse the long-term impact of the flooding on all ecosystem compartments, we plan to flood the forest section in the neighbourhood of eddy tower. The adjacent Apna river can be used for that purpose. The proposed method is relevant in all countries where peatlands have been drained for forestry.

Vända

Constructed wetland

Site PI Kuno Kasak (kuno.kasak@ut.ee)

• Challenge: Agricultural runoff degrades water quality and causes eutrophication of surface, marine and freshwater; hence, it is important to the reduce the impact of anthropogenic eutrophication in continental waters and at the coastal zone.
• Solution: Constructed wetlands (CW) can be used as an effective measure for water quality improvement. Also provides an opportunity to successfully create or restore valuable wetlands habitat for wildlife use and environmental enhancement. Restored wetlands are used to improve water quality of wastewater, agricultural runoff or buffering and treating stormwater. When constructed wetlands are used for these purposes there is a need for monitoring to ensure the maintenance of the wetland systems
• Expected outcomes: Constructed wetlands treating agricultural runoff sequester C and nutrients into ecosystem and also provide habitat for a variety of wildlife species.
• Transferability: Constructed wetlands can be designed in a variety of system types and configurations to meet specific needs. These systems are cost-effective and easily operated and maintained.