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Agricultural peatlands are the most productive soils in the UK for the cultivation of many food crops. Historical drainage of peat for agriculture (i.e., cropland and managed grassland), without consideration of other associated environmental and climatic impacts, has resulted in a significant emission of greenhouse gases (GHGs). There is a need to reduce GHG emissions without compromising the rural economy and jeopardizing food security in the UK to a greater extent than is currently being experienced. In March 2023, in a bid to identify alternative land management systems for agricultural peatlands to support the UK’s commitment to achieving net zero GHG emissions by 2050, a group of forty investigators met at a workshop convened by the AgriFood4NetZero Network+. The workshop reviewed the state of knowledge surrounding the Fens of Eastern England and their importance for food provision, the economy, cultural identity, and climate change mitigation. A broad consensus emerged for research into how GHG emissions from agricultural peatlands could be reduced, whether alternative farming methods, such as seasonal farming or paludiculture, would offer a solution, and how a localized approach for the Fens could be defined. The development of a holistic, inclusive, and plausible land use scenario that considers all aspects of ecosystem services provided by the Fens is urgently needed.

Peatlands occupy 12% of the UK territory and can store large amounts of carbon (C). However, drainage, peat extraction, and other management activities have turned these ecosystems into greenhouse gas (GHG) emitters. Currently, peatlands account for ~ 4% of the UK’s total annual GHG emissions. Eddy covariance is considered the best method to measure landscape scale GHG exchange (CO2, CH4, N2O), between the Earth’s surface and the atmosphere. Recently many flux towers have been installed on UK peatlands under different land-use and in different condition, with some undergoing restoration. In total there are currently 30 operating, with 9 in Scotland (SCO2FLUX managed by The James Hutton Institute, JHI) and 21 across England, Wales and Northern Ireland (managed by UKCEH), including the Auchencorth Moss ICOS site. As part of the projects, NERC-MOTHERSHIP and SRC-CENTREPEAT, these peatland sites are being harmonised into a network. The data is being analysed using standard protocols in order to generate a powerful dataset to examine the exchange of CO2 and CH4 over UK peatlands. Some of the topics being investigated are: the spatial and temporal variability of emissions for all peatland classifications; the main drivers and controlling mechanisms of GHG exchange, such as the effect of water table depth on gas exchange and restoration impacts (e.g. raising water levels in agricultural peatlands); the value and effectiveness of restoration techniques (e.g. the timeline of recovery in the transition from forest to bog); improving the modelling of peatlands in JULES and other land-surface models; ground-proofing data for Earth observation techniques; assessing the contribution of peatlands to achieving net zero; examining the impact of wildfire on restoration from forest to bog. An overview of the network of sites and some highlights of the analysis to date will be presented.

The updated report, released March 2023, presents the results of research to update and expand the Peatland Code including updating existing Peatland Code Emission Factors to align them with the UK Peatland Inventory; investigating the potential to include new reporting categories in the Code; and assessing opportunities for improved emissions reporting.

Drained, lowland agricultural peatlands are greenhouse gas (GHG) emission hotspots and a large but vulnerable store of irrecoverable carbon. They exhibit soil loss rates of ~2.0 cm yr−1 and are estimated to account for 32% of global cropland emissions while producing only 1.1% of crop kilocalories. Carbon dioxide emissions account for >80% of their terrestrial GHG emissions and are largely controlled by water table depth. Reducing drainage depths is, therefore, essential for responsible peatland management. Peatland restoration can substantially reduce emissions. However, this may conflict with societal needs to maintain productive use, to protect food security and livelihoods. Wetland agriculture strategies will, therefore, be required to adapt agriculture to the wetland character of peatlands, and balance GHG mitigation against productivity, where halting emissions is not immediately possible. Paludiculture may substantially reduce GHG emissions but will not always be viable in the current economic landscape. Reduced drainage intensity systems may deliver partial reductions in the rate of emissions, with smaller modifications to existing systems. These compromise systems may face fewer hurdles to adoption and minimize environmental harm until societal conditions favour strategies that can halt emissions. Wetland agriculture will face agronomic, socio-economic and water management challenges, and careful implementation will be required. Diversity of values and priorities among stakeholders creates the potential for conflict. Successful implementation will require participatory research approaches and co-creation of workable solutions. Policymakers, private sector funders and researchers have key roles to play but adoption risks would fall predominantly on land managers. Development of a robust wetland agriculture paradigm is essential to deliver resilient production systems and wider environmental benefits. The challenge of responsible use presents an opportunity t

The net impact of greenhouse gas emissions from degraded peatland environments on national Inventories and subsequent mitigation of such emissions has only been seriously considered within the last decade. Data on greenhouse gas emissions from special cases of peatland degradation, such as eroding peatlands, are particularly scarce. Here, we report the first eddy covariance-based monitoring of carbon dioxide (CO2) emissions from an eroding Atlantic blanket bog. The CO2 budget across the period July 2018–November 2019 was 147 (± 9) g C m−2. For an annual budget that contained proportionally more of the extreme 2018 drought and heat wave, cumulative CO2 emissions were nearly double (191 g C m−2) of that of an annual period without drought (106 g C m−2), suggesting that direct CO2 emissions from eroded peatlands are at risk of increasing with projected changes in temperatures and precipitation due to global climate change. The results of this study are consistent with chamber-based and modelling studies that suggest degraded blanket bogs to be a net source of CO2 to the atmosphere, and provide baseline data against which to assess future peatland restoration efforts in this region.

A presentation about the carbon cycle and soil carbon in agricultural systems, providing a baseline of understanding for how we can contribute to net zero in arable agriculture.

The Peatland Code and the peatland elements of UK’s national GHG emissions inventory both seek to determine the greenhouse gas (GHG) emissions and removals that occur as a result of land-use and land-use change. The approaches are conceptually similar, multiplying estimated areas of peatland in any given condition category by an associated set of Emission Factors (EFs) that are derived from an analysis of published flux data. The EFs used for the two approaches share a common ancestry; an initial collation of UK-relevant EFs compiled for the Peatland Code (Smyth et al., 2015) was subsequently expanded and updated (by the same core team) for the UK GHG inventory (Evans et al., 2017). However, the Peatland Code currently includes only a restricted range of restoration options and associated EFs, all of which relate to the restoration of drained or degraded bog habitats. Options for restoration of fen habitat are not currently included, and neither are more heavily modified prerestoration habitats such as agricultural land, peat extraction sites or plantation forestry. Emission factors for these categories are included in the national inventory, but (in line with the requirements of national inventory reporting, and the constraints on data availability at this scale) generally apply single EFs to broad areas, effectively averaging out local-scale variability in site condition and management, including variations related to the effectiveness (or otherwise) of re-wetting and restoration interventions. Furthermore, the EFs used in the inventory are subject to periodic update to incorporate new data, whereas the Peatland Code EFs have not been updated since 2015. In Section 1 of this report, we provide a comprehensive update of EFs for all Tier 2 (empirically based, country specific) peat condition categories included in the national inventory. This update incorporates new UK datasets, including a growing body of data from the UK flux tower network, as well as internationa

Soil moisture has a close relationship with soil carbon. The carbon content of soil affects the response of the moisture content to meteorological input; the moisture content of soil affects the amount and type of respiration that can occur. This work seeks to elucidate this relationship by building a predictive data-driven model of soil moisture using data from the COSMOS-UK sensor network and using it as a predictor of soil organic carbon. We roll this model out across the UK and compare results to the Countryside Survey carbon map. Further, using flux tower observations of night time net ecosystem exchange (of CO2), a model linking soil moisture to respiration is created and used to propose functional forms for respiration in land surface models.

One of the major undetermined problems in evaporation (ET) retrieval using thermal infrared remote sensing is the lack of a physically based ground heat flux (G) model and its integration within the surface energy balance (SEB) equation. Here, we present a novel approach based on coupling a thermal inertia (TI)-based mechanistic G model with an analytical surface energy balance model, Surface Temperature Initiated Closure (STIC, version STIC1.2). The coupled model is named STIC-TI. The model is driven by noon–night (13:30 and 01:30 local time) land surface temperature, surface albedo, and a vegetation index from MODIS Aqua in conjunction with a clear-sky net radiation sub-model and ancillary meteorological information. SEB flux estimates from STIC-TI were evaluated with respect to the in situ fluxes from eddy covariance measurements in diverse ecosystems of contrasting aridity in both the Northern Hemisphere and Southern Hemisphere. Sensitivity analysis revealed substantial sensitivity of STIC-TI-derived fluxes due to the land surface temperature uncertainty. An evaluation of noontime G (Gi) estimates showed 12 %–21 % error across six flux tower sites, and a comparison between STIC-TI versus empirical G models also revealed the substantially better performance of the former. While the instantaneous noontime net radiation (RNi) and latent heat flux (LEi) were overestimated (15 % and 25 %), sensible heat flux (Hi) was underestimated (22 %). Overestimation (underestimation) of LEi (Hi) was associated with the overestimation of net available energy (RNi−Gi) and use of unclosed surface energy balance flux measurements in LEi (Hi) validation. The mean percent deviations in Gi and Hi estimates were found to be strongly correlated with satellite day–night view angle difference in parabolic and linear pattern, and a relatively weak correlation was found between day–night view angle difference versus LEi deviation. Findings from this parameter-sparse coupled G–ET model can ma