Managing UK upland peat for greenhouse gas removal

Le résumé fourni par la source

Much of UK upland peat is in a drained and/or degraded state, meaning it is a net source of CO2 emissions to the atmosphere. Typical restoration methods, such as rewetting, can improve this, however most restoration projects only achieve a lowering or cessation of emissions with few achieving a net-negative carbon balance. In this new demonstrator project, Greenhouse Gas Reduction – Peat, we are trialling methods of supressing methane emissions as well increasing carbon sequestration so that carbon negative restoration projects can be achieved.The projects aims to accelerate the transition from degraded, burn-managed heather (Calluna vulgaris) bog to actively peat-forming bog, while minimising wildfire risk and CH4 emissions. We will present preliminary results and further plans for three techniques, trialled alongside typical gully blocking:1) Sphagnum planting: This ‘nature-based’ intervention will involve Sphagnum (a peat forming moss species) establishment using micropropagated assemblages of hummock-forming species which show the highest rates of C accumulation. During the first years of Sphagnum growth, CO2 sequestration may be in excess of long-term peat accumulation rates as a functional upper ‘acrotelm’ layer re-establishes. Sphagnum can also act as a CH4 biofilter, improving the net greenhouse gas balance.2) Heather mowing and biochar production: As an alternative to managed burning, we will harvest old heather biomass using low-ground pressure vehicles, followed by biochar production and re-application. Biomass removal will reduce wildfire risk, while controlled pyrolysis will avoid damage to Sphagnum/peat from burning, and enhance biomass conversion to biochar above that achieved in uncontrolled burns.3) Suppression of methane production: CaSO4 can supress methane formation by offering a more energetically favourable metabolic pathway to microbes, meaning sulphate reducing bacteria are more active than methanogenic bacteria. This essentially ‘nudges’ the bacterial population in a direction more favourable for greenhouse gas balances.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.