Quantifying the impact of restoration on peatland aquatic organic matter, microbial communities and greenhouse gas emissions

We are in a climate emergency. Reducing emissions of greenhouse gases is not enough to reduce global temperatures: we need to use nature to help. Peatlands are an extremely important solution for climate action because they are the most efficient carbon store on land when they are healthy. However, they have been damaged by human activities in the past, and many are now sources of greenhouse gases, especially carbon dioxide. Exploitation of peatlands has converted what should be a carbon store into a large source of global carbon emissions (4% of human land-use emissions).

Peatlands cover a small proportion of the Earth’s surface (only 3%) but store more carbon than all the world’s forests combined. In the UK alone, 10% of the land is covered in peat, but at least 75% of that area has been modified by human activity. Restoring these peatlands to healthy, carbon-storing environments is a central part of the UK’s commitment to the Paris Climate Agreement and Net Zero targets. Globally, over 40% of tropical, and 57% of temperate peatlands are degraded by human activities, and several countries have pledged to restore their peatlands as climate change mitigation measures.

Restoring damaged and modified peatlands to encourage uptake of carbon dioxide from the air and store it as carbon in plants and soil will impact the whole ecosystem, leading to changes in the plant species and water chemistry, which will in turn impact how peatland ecosystems take up and produce greenhouse gases. Restoration methods often involve blocking drains and re-wetting the soil, creating open water pools. These pools are potential ‘hotspots’ for carbon transfer between soil, water and air, and could lead to higher greenhouse gas losses from the peatland, but have not been investigated. It is important to understand how these peatland pools impact the greenhouse gas emissions from a peatland. Without a complete picture of the carbon cycle in an ecosystem, it is impossible to quantify the benefits of restoration projects for climate change mitigation, and with the UK aiming to restore 50% of the upland and 25% of the lowland peat by 2050, it is important to know that the restoration methods used are encouraging carbon storage, and lowering the greenhouse gas emissions.

I will study the greenhouse gas emissions from peatland pools to discover how restoration changes the carbon transfer between soil, water and air in an ecosystem. I will study pools in near-natural, damaged and restored peatlands, in cold and temperate biomes, to investigate how the creation of peatland pools impacts on the microbes living in the peat and water, and how the greenhouse gas emissions change when degraded peatland sites are restored. This project will result in new knowledge of how peatlands respond to restoration interventions at the microbial and ecosystem levels. It will lead to improved estimates for the greenhouse gas budget of peatlands, and guide future restoration projects. Peatland practitioners and modellers will be able to better predict how restoration will be impacted by changes in climate, and determine the capacity of peatlands to help reduce global greenhouse gas concentrations, and as a nature-based solution to climate change.