Student Fieldwork: Saltmarsh Restoration and Carbon Storage
Auger in ground
This summer, Kurotamunoye Amadi-Rapheal, a PhD student from Cardiff University’s School of Earth and Environmental Sciences, carried out fieldwork on the Gwent Levels with support from the Living Levels Partnership. Her research focuses on soil organic carbon dynamics in saltmarshes. These habitats are not only vital for wildlife and natural flood protection, but they also store huge amounts of carbon—sometimes more, per square metre, than forests.
The project is investigating how much soil organic carbon (SOC) builds up in restored saltmarshes over time, and whether these sites can eventually match the carbon storage levels of long-established natural marshes.
To collect the data, our Natural Heritage Officer, Josh Da Cruz, joined Kurotamunoye and her supervisor, Professor Tristram Hales, in sampling across the Levels. Restored sites included Newport Wetlands, created in 2000 through managed realignment, and Goldcliff, where saline lagoons were established in the 1990s. For comparison, soil was also collected from the natural saltmarsh at Peterstone, a long-established habitat with minimal human intervention, as well as from agricultural grassland at Great Traston Meadows.
Using a simple but effective method, an auger (about 10 cm wide) was pushed 30 cm into the ground, rotated, and pulled up to remove a compacted soil core. Each sample was then bagged for later laboratory analysis.
In line with Intergovernmental Panel on Climate Change (IPCC) guidance, 12 soil samples are needed per habitat type to give an accurate carbon measurement. Over two days, the team collected an impressive 98 samples — aided by two enthusiastic school holiday volunteers brought along by Professor Hales.
Collecting the core
Back at Cardiff University, the samples will be sieved and tested for organic and inorganic carbon, as well as key isotopes (¹⁵N and ¹³C). By comparing sites of different restoration ages, the study aims to answer vital questions: How quickly do restored saltmarshes accumulate carbon, and how long might it take for them to match natural systems?
The results will provide valuable evidence for restoration management, support carbon accounting, and highlight the role of saltmarsh restoration as a powerful nature-based solution to climate change.
This research not only deepens our understanding of blue carbon ecosystems in Wales, but also supports the Living Levels Partnership’s mission to protect and enhance the unique landscapes of the Gwent Levels. Looking ahead, the Partnership hopes to support more student research on the Levels by offering bursaries and other opportunities in collaboration with local universities.
Cardiff University’s School of Earth and Environmental Sciences are investigating soil organic carbon dynamics in saltmarshes.