A nationwide survey by ecologists has revealed that over 2 billion tons of carbon is stored deep under the UK’s grasslands, helping to curb climate change.

However, decades of intensive farming, involving heavy fertilizer use and excessive livestock grazing, have caused a serous decline in valuable soil carbon stocks in grasslands across the UK.

The nationwide survey was carried out by a team of scientists from the Universities of Manchester, Lancaster, Reading and Newcastle, as well as Rothamsted Research.

The team found that 60% of the UK’s total soil carbon stored in grasslands – covering a third of UK land surface – is between 30cm and 1m deep. The team estimated the total grassland soil carbon in Great Britain to be 2097 teragrams of carbon to a depth of 1m.

Though the effects of high intensity agriculture are strongest in the surface layer of soil, they also discovered that this deep carbon is sensitive to the way land has been farmed.

Dr Sue Ward, the lead author of the paper from Lancaster Environment Centre, said:

“What most surprised us was the depth at which we were still able to detect a change in soil carbon due to historic land management.

“We have long known that carbon is stored in surface soils and is sensitive to the way land is managed. But now we know that this too is true at considerable soil depths under our grasslands.

“This is of high relevance given the extent of land cover and the large stocks of carbon held in managed grasslands worldwide.”

In contrast, the soils that were richest in carbon were those that had been subjected to less intensive farming, receiving less fertilizer and with fewer grazing animals. The team found that soil carbon stocks were 10% higher at intermediate levels of management, compared to intensively managed grasslands.

Professor Richard Bardgett from The University of Manchester said:

“Our findings suggest that by managing our grasslands in a less intensive way, soil carbon storage could be important to our future global carbon targets, but will also bring benefits for biodiversity conservation.”

He added:

“These findings could impact how grasslands are managed for carbon storage and climate mitigation, as current understanding does not account for changes in soil carbon at these depths.

“Our findings suggest that by managing our grasslands in a less intensive way, soil carbon storage could be important to our future global carbon targets, but will also bring benefits for biodiversity conservation.”

The research is part of a five year research project, supported by DEFRA, aimed at managing UK grassland diversity for multiple ecosystem services, including carbon capture.

 


The paper, ‘Legacy effects of grassland management on soil 1 carbon to depth’ is available in the journal Global Change Biology.

One thought on “Huge carbon stores discovered beneath UK grasslands

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s