Drivers of greenhouse gas emissions during recovery from fire in peatlands undergoing restoration (FIRE_RECOVER)

Lead Research Organisation: The James Hutton Institute
Department Name: Ecological Sciences

Abstract

European peatlands have historically formed in cool and wet conditions. The organic matter that is built up by plants every year is not degraded completely, and this means that, over time, the partly degraded organic matter has accumulated as peat with huge quantities of carbon locked away. In their natural state, peatlands areas continue to lock away carbon. We call such areas 'carbon sinks' and through this process, peatlands moderate the Earth's climate.

However, around the world, peatlands have been impacted by human activities such as drainage, use as cropland or production forests, burning, and over-grazing. In most of these cases, the rate at which the plants build organic matter and the rate at which it is degraded changes such areas to switch from being a net carbon sink to a net source. In the UK and across Europe, as much as 80% of former peatlands have been damaged in some way. Such areas no longer look like peatlands, but the peat underneath the current land use still behaves differently to other soil types.

Greenhouse gases (GHGs) such as carbon dioxide and methane released back to the atmosphere by disturbed peatlands amplify climate change in the same way as burning fossil fuels. Drainage and land use conversion can also alter the flow of water within and from these soils. It is only in hindsight that we have started to recognise how important it is to manage peatlands sustainably. Over the last decade or so, peatland restoration has been used as a tool to reduce greenhouse gas emissions from damaged peatlands, with >£20 mi spent in the UK alone.

Unfortunately, the current projected impacts of climate change include more frequent drought spells and, alongside this, an increased risk of wildfire. A major wildfire occurred in May 2019 that affected >60 km2 of peatland in the Flow Country in the far north of Scotland. This fire was extinguished within 50 m of an existing research station that has been monitoring greenhouse gas emissions on an area where restoration activities had recently occurred. The proximity of the fire damage offers us the opportunity to compare the greenhouse gas emissions of carbon dioxide and methane on burned and unburned areas that have otherwise had identical histories of land management and are on similar slopes, aspect and peat depths. The equipment we are using also monitors a range of weather variables such as the amount of sunlight and rainfall, as well as how much of that sunlight ends up heating the soil or how rainfall and evapotransporation losses affect the water table.

Therefore, by monitoring what happens to greenhouse gas emissions in burned relative to unburned sites, we will be able to measure whether burning has lasting impacts on greenhouse gas emissions (lowering the mitigation potential such sites have to offer) and whether they are more or less resilient to further fires. We therefore expect that this type of information will be of major benefit to those with an interest in the greenhouse gas mitigation potential of peatland restoration as a policy tool, or as a carbon offsetting mechanism. We also expect that the outputs created by this project will be of interest to the community interested in impacts of climate change and wildfire risk.

Planned Impact

The outputs from this project have high potential to influence peatland restoration policy and on-the-ground decisions. There is a critical and urgent need to develop a robust, evidence-based method to help prioritise investment in restoration and sustainable peat soil management. We will therefore use our existing and wide-ranging network of contacts to engage with policymakers in the UK and EU, both in the local to national government sectors and statutory bodies; land managers; as well as the academic research community:

Policy advisors who are involved in developing the next phases of mitigation and adaptation policy tools (for example, for the next Scottish Climate Change Plan) or policy advisors (in e.g. Natural England, SNH Peatland Action) will benefit from increased understanding of the long-term effects of fire on peatland restoration mitigation potential.

Land owners or organisations wishing to use voluntary standards for carbon offsetting via peatland restoration will also benefit from a better understanding of the risk fire may pose to investment. Information from this project will be available to further revisions of the Peatland Code.

If our data suggest that drought resilience post-fire is also affected, this will be useful information for government advisors in the context of developing future Fire Danger rating tools (see Pathways to Impact). This information will also be useful to Wildfire Forum members and the wider land management community, both in Scotland as well as England and Wales. In the global academic community, we anticipate wide interest in the GHG budget and micrometereological data sources this project will generate. These data will be of long-lasting value to those in the global greenhouse gas modelling, remote sensing and atmospheric science communities for meta-analyses or as validation data for models.

Land managers and the general public will also benefit from an increase in the general understanding of the impacts of wildfire on peatlands and the contribution wise management decisions have on climate mitigation and water regulation. A wide dissemination of our results through social media, infographics and multimedia will allow the impact of our project to be widely known and to outlast the project itself.

Publications

10 25 50
 
Description This project had three key objectives:

1. Assess whether the drivers of carbon dioxide and methane fluxes differ between burned and unburned areas
2. Whether the sites remain different or whether their responses coalesce as recovery takes place
3. Raise awareness of the potential for fire to influence GHG mitigation potential in peatland restoration beyond the initial loss of carbon via combustion

At present (March 2022), these objectives have only partially been met, due to very significant negative impacts of COVID which affected the quality and quantity of data we were able to obtain and slowed down analysis and publication of the resulting data. At present, we discovered that:
1. In the time that has passed since the large Flow Country wildfire, which took place in May 2019 (>60km2 burned), we observed higher variability in the fluxes of CO2 from the burned site than the unburned site (low confidence, due to poor data quantity as a consequence of repeated equipment failures during lockdown periods and low degree of overlap in time between the two monitoring stations from which the data were obtained). Methane fluxes did not seem to differ greatly (very low confidence due to low degree of overlap). The datasets were insufficient for further statistical analysis of the drivers at the time of writing.
2. There was evidence of differences between the burned and unburned sites in terms of soil moisture content (the burned site was wetter), soil temperature (the burned site's soil was warmer), air temperature (the burned site showed much greater variation between day and night temperatures), and the transfer of energy into the soil, the so-called 'soil heat flux' (the burned showed slightly greater variation between day and night soil heat flux). To the end of the project (March 2021) there was no evidence of these responses converging.
3. We have showcased our findings to date at the European Geosciences Union General Assembly 2021, the largest European meeting that brings geoscientists from all over the world. We have also discussed these findings in various workshops, meetings and events, with members of fire services, people involved in developing policy relating to fire management, land managers, and the general public.
Exploitation Route Research work will continue at these locations and so further impact is expected in future. For the time being, our discussions with e.g. fire services, members of statutory organisations, other scientists and the general public have brought the message out that the impacts of fire on regenerating peatlands can extend for at least 2 years and affect how the system functions overall, including, potentially, on carbon emissions beyond the initial loss through fire. We have deposited the data obtained from this project on the EIDC database so that other scientific teams working on fire impacts can use the generated data for future analyses.
Sectors Environment

 
Description Our findings have informed discussions within the Scottish Fire and Rescue Service as a result of a workshop hosted by project partner Prof Andersen (UHI) in March 2021 adn where findings from this project were discussed. The lessons learnt from this, and the linked FIRE-BLANKET project, are being translated into changes in how wildfire on peatlands are being managed by fire services (see impact section) - including the very next day, during the response of the fire services to a local wildfire in Northern Scotland (Dorrery, March 2021).
First Year Of Impact 2021
Sector Environment
Impact Types Societal

 
Description Influence on widlfire management by fire and rescue services (with linked FIRE-BLANKET project)
Geographic Reach Local/Municipal/Regional 
Policy Influence Type Contribution to new or Improved professional practice
 
Description Input to RSPB Peatland Oversight group
Geographic Reach Local/Municipal/Regional 
Policy Influence Type Contribution to new or Improved professional practice
 
Description Funding for research assistant to examine the changes in molecular composition of DOM samples from burned and unburned regions (Nicholle Bell)
Amount £3,882 (GBP)
Organisation ScotCHEM 
Sector Academic/University
Start  
 
Description Improving MOdelling approaches to assess climate change-related THresholds and Ecological Range SHIfts in the Earth's Peatland ecosystems (MOTHERSHIP)
Amount £891,416 (GBP)
Funding ID NE/V01854X/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 01/2022 
End 12/2026
 
Description Leverhulme PhD associated with Leadership Award (Roxane Andersen)
Amount £58,474 (GBP)
Organisation University of the Highlands and Islands 
Sector Academic/University
Country United Kingdom
Start  
 
Title Carbon dioxide and methane fluxes and associated environmental observations between 2019 and 2021 from paired burned/unburned blanket bog undergoing restoration from afforestation at Forsinard, Sutherland, UK 
Description This dataset contains time series observations of land surface-atmosphere exchanges of net ecosystem carbon dioxide exchange (NEE), sensible heat (H) and latent heat (LE), methane (CH4) and meteorological observations measured at two locations in the Flow Country blanket bog complex, Caithness and Sutherland, UK. The tower over the area affected by wildfire after initial felling (UK-DKF) is located at 58.431, -3.96 and monitors across a footprint affected by a wildfire in early May 2019. The tower over the area felled for restoration after previous afforestation (UK-DKE-RESTORED, which was not affected by the wildfire) is located at 58.428, -3.967 and measures fluxes from a footprint identical in ground flora, topography, soil type and previous management to that of the FIRE tower, with the only exception that the fire did not reach as far as the footprint monitored. The dataset comprises eddy covariance CO2, water and energy fluxes, originally collected at 20Hz and processed to 30-minute data, as well as accompanying meteorological observations, originally collected at 15 min and processed to 30-minute data. The time period covered in this dataset is 25/09/2019 - 20/05/2021. 
Type Of Material Database/Collection of data 
Year Produced 2022 
Provided To Others? Yes  
Impact None yet (still under embargo) 
 
Description Sister Urgency grant - FIRE-BLANKET 
Organisation University of the Highlands and Islands
Department Environmental Research Institute
Country United Kingdom 
Sector Academic/University 
PI Contribution 1. Provision of estimated flux tower footprint area to the PhD studentship of Henk Pieter Sterk (UHI). 2. Mutual support in organisation of field set-up, field work, and scientific discussions.3. Contribution to joint FIRE-BLANKET/ FIRE-RECOVER online webinar.
Collaborator Contribution 1. Aerial imagery flown by unmanned aerial vehicle (UAV) during August 2019 (3 months post-fire and just prior to commencement of the eddy covariance-based gas flux and energy exchange monitoring period), to be used in joint publication (data still being worked on at present time). 2. Mutual support in organisation of field set-up, field work, and scientific discussions. 3. Organisation, hosting and chairing of joint online webinar.
Impact None as yet (data still being analysed)
Start Year 2019
 
Description Building fire resilience in the Flow Country Peatlands (25.3.2021) 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Workshop on fire resilience, hosted by UHI (ERI Thurso) with attendance from across the academic, peatland management and fire and rescue services sectors. The main lessons from the project, that fire impacts on the soil environments are long-lived, generated discussion both during and after the event (see influence on policy, practice and public).
Year(s) Of Engagement Activity 2021
 
Description Evening lecture (Newtonhill) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Greenhouse Gases, Peatlands & Climate Change in Scotland
Evening Lecture to the Newtonhill Women's Institute
Approximately 40 minute talk on the science behind climate change, sources of greenhouse gases, ways to mitigate emissions, the role of peatbogs in storing carbon and the importance of Scottish peatbog, including the FIRE-RECOVER project to study the impact of the 2019 fire on the Dyke restoration.
Year(s) Of Engagement Activity 2020
 
Description Flow Country Science Induction for RSPB staff 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact RSPB Co-Is and ERI colleagues hosted key RSPB staff from the science and practice side in a 2 day "Flow Country Science Induction" event in November 2021, which included the ongoing GHG monitoring at the FIRE-RECOVER sites and discussion of project outcomes.
Year(s) Of Engagement Activity 2021
 
Description Nature News article 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Dr Roxane Andersen (project partner) was interviewed for a Nature News article, published 12/2/2020, about the wider work on peatlands in the Forsinard Flows. The article included reference to the NERC FIRE_RECOVER project in the following section (albeit wrongly attributed to R Andersen). The article has been widely shared on social media and has therefore helped to raise awareness of the project. The article resulted in further contact to the project team by a Canadian research group interested in testing a model of fire risk.

"Three weeks after the fire, she and her colleagues submitted a successful grant proposal to the UK Natural Environment Research Council to study the impact of the blazes. The team will use ground measures, images from crewless aerial vehicles, and InSAR data to compare different types of peatland management - some had been restored more intensively, whereas others had been left to recover with fewer interventions. The researchers will assess how severely the peat burnt in each area, how it recovers and how much carbon was lost. They have also installed a fifth flux tower in the burnt area to measure how the fires affect carbon emissions. These data will be useful as researchers determine how best to restore sites to withstand future climate stresses, says Andersen".
Year(s) Of Engagement Activity 2020
URL https://www.nature.com/articles/d41586-020-00355-3
 
Description Webinar contribution 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Other audiences
Results and Impact Joint webinar for the FIRE-BLANKET and FIRE-RECOVER NERC Urgency projects. Around 80 people from various UK academic institutions as well as staff from Fire Services and conservation bodies attended an online webinar held on the 29th of October 2020.
Year(s) Of Engagement Activity 2020