New research confirms controlled burning increases carbon storage soil

Burning dead heather so new shoots grow to feed the grouse. North Yorkshire Moors. England

Burning heather on grouse moors is a controversial subject; new research has now confirmed it can actually lock in or increase carbon in the soils of forests and grasslands - Credit: Getty Images/iStockphoto

A study from the University of Cambridge and published in the journal Nature Geoscience has confirmed that controlled burning used in land management can increase carbon storage in the soil.

The study found that controlled burns cause changes in soil composition, which not only offsets immediate losses but can actually lock in or increase carbon in the soils of forests and grasslands.

Most of the carbon in grassland habitats is stored in the roots of the plants, and the study also found that because controlled burning promotes new plant growth and can increase root biomass, it can further increase the amount of carbon stored in this way.

The importance of controlled burning to help prevent wildfires was also noted in the study, as researchers noted that fires that are too intense or too frequent - such as wildfires - kill soil bacteria and fungi and destabilise the soil, preventing carbon-rich organic matter from binding to minerals in the soil.

Commenting on the findings relating to soil composition changes and the subsequent increases in carbon storage, Amanda Anderson, Director of the Moorland Association said: “This concurs with research on carbon rich peatland, demonstrating that the formation of charcoal by burning above-ground vegetation has a beneficial effect on carbon storage in the soil and that the more vigorous regrowth of plants following a low-intensity burn has a net positive effect on carbon storage. We hope that this important independent research will be taken into consideration by lobby groups and policymakers.“

Adrian Blackmore, the Countrside Alliance’s Director of Shooting said: "Fire has been used as a management tool for many thousands of years, and in our uplands the cool, controlled, burning of vegetation has helped reduce the risk of damaging wildfires, and the considerable environmental damage and carbon loss that they cause, burning as they do with greater intensity resulting in the peat beneath the vegetation being burnt, and preventing the storage of water and carbon.

"The 2019 wildfire of Scotland’s Flow Country is just one example of what can happen when moorland is left unmanaged, with 22 square miles of this UNESCO world heritage site being severely damaged, and 700,000 tonnes of CO2 equivalent being released into the atmosphere, doubling the country’s greenhouse gas emissions for the six days it burned.

"This latest research by the University of Cambridge reinforces the important role that controlled burning has to play both in preventing wildfires, and for conservation, and policy makers need to take note of its findings."

The abstract overview of the paper concluded: "Given that 70% of global topsoil carbon is in fire-prone regions, using fire to promote soil organic matter stability may be an important nature-based climate solution to increase carbon storage."

The study can be found here