Farmers visiting Glenwherry Hill farm in February to view peatland management works and carbon monitoring.
Commodity watch by peatlands officer, Stephanie Clokey
Efforts to refine the way we calculate greenhouse gas emissions from peatlands have reveals a more complex story for Northern Ireland.
Known for storing vast amounts of carbon, peatlands have historically been considered significant greenhouse gas emitters. Research taking place in NI is challenging assumptions based on global averages that may not accurately reflect the unique characteristics of Northern Ireland’s peatland ecosystems, reiterating the need for further research.
One size doesn’t fit all
From the UK GHG Inventory reporting peatlands emissions are estimated to contribute around 10% of NI’s total emissions. However, these figures are largely based on Emission Factors that are derive from data collected from other geographical setting which are unlikely to represent conditions specific (e.g. climate, nitrogen deposition, etc,) to peatlands in NI. New site-based monitoring across a range of bog types including grazed, semi-natural, and areas with interventions, is needed in order for us to develop more bespoke local figures for emissions that accurately reflect our landscapes in NI.
Lowland raised bogs and upland blanket bogs differ in climate, hydrology, vegetation and land use within Northern Ireland and across the UK. As a result, applying the Intergovernmental Panel on Climate Change Tier 1 emissions factors and Tier 2 UK Specific, there may be an over estimation of emissions from NI Peatlands.
According to unpublished initial findings presented at the European Geosciences Union General Assembly by Ulster University earlier this year, the applied Tier 1 and Tier 2 values may not reflect the actual carbon dynamics occurring in NI peatlands.
Through the DAERA Environment Fund, the Centre of Ecology and Hydrology (CEH) installed a greenhouse gas (GHG) flux tower Glenwherry Hill Farm, Antrim in May 2023. The tower if one of 5 across the UK measure emissions and sequestration of CO2 and CH4, and data generated from this tower could aid in refining the Tier 2 Blanket Bog condition emissions factors . Early data showed that the grazed upland bog may be acting as a carbon sink; sequestering more carbon than it emits, contrary to what was initially expected. Although this may be in part due to a particularly wet summer, and the nuances of the particular area around the flux tower need more investigation.
Carbon sinks or carbon sources?
Peatlands are characterised by their high organic carbon. Under waterlogged conditions, plant material does not fully decompose, trapping carbon in the soil. However, when the water table drops, the organic matter is exposed to oxygen causing it to break down, releasing carbon dioxide (CO₂) through gaseous exchange or as runoff in the form of dissolved and particulate organic carbon. Additionally, wetter doesn’t always mean better as excess water can lead to an increase in methane production, although short lived, so it is necessary to find a balanced approach when considering peatland hydrology.
In Northern Ireland, 242,600 hectares of peatland exist, and the forthcoming Northern Ireland Peatland Strategy will outline Departmental strategic Objectives and Actions to help protect, enhance and manage our peatlands sustainably by 2040.
Bridging the gaps
While there’s momentum with GHG flux tower networks, PhD projects, new mapping, and a DAERA funded practitioner network, led by Ulster Wildlife is already underway, long term monitoring, data generation and analysis thereof is needed to capture a mor accurate picture of what is happening within our varied peatland ecosystems. More studies are needed to capture seasonal and hydrological variability, peatland condition specific emissions data, ecological diversity and larger site coverage, aiding in the refinement of Tier 2 factors. Developing Tier 2 emissions factors specific to Northern Ireland is a priority as by doing so would help provide a better evidence base needed to guide peatland management.
Open day
CAFRE Hill Farm are having an open day on 3 September, with talks on hill sheep and habitat management, peatland carbon emissions, peatland management; planning and implementation and Suckler Cows and Habitat recovery. You can book to attend by clicking here.
