The Glandwr Forest Carbon Study was established in 2020 to evaluate whether simple nature-based interventions could help newly planted woodlands remove more carbon dioxide from the atmosphere.
This is the flagship study at Glandwr Forest and was designed together with leading scientists from Imperial College London, the Royal Botanic Gardens, Kew, the University of Sheffield, and ETH Zürich. “
"Microbiome manipulation and enhanced weathering influence tree growth in reforestation", published in Communications Sustainability, shows how simple nature-based interventions can boost carbon capture between 13% and 27% in the earliest stages of native woodland establishment.
More about the latest results here.
Read the scientific paper.
The results from the first four years of the study focus on the carbon stored aboveground in the trees and identify two practical, scalable interventions that could help make every hectare of new woodland work harder.
This large, careful piece of science looks at two types of forestry – broadleaf and conifer – and two nature-based treatments – basalt addition and soil microbial enrichment. The study is the largest field trial of its kind in the world: 72 individually managed research plots across 28 acres of Welsh hillside, the equivalent to 18 football pitches.
More than 25,000 trees have been planted as part of the study, and 6,400 trees have individual barcodes,
These are measured each year by citizen science volunteers as part of the Big Tree Measure census. This is a big effort, which is why we often call it community science volunteering.
The study ooks at two types of forests. The first is native broadleaf comprised of Birch, Alder, Cherry, Oak, Aspen and Rowan. The second type is a conifer forest comprised of Sitka Spruce, typical of commercial forestry plantations.
There is also a grassland control area that will be left unplanted to allow natural regeneration.
This experiment will reintroducing soil microbial and mycorrhizal communities sourced from established forest ecosystems in an effort to jump start reforestation.
Studies continue to find that introduction of native soil communities can dramatically increase plant survival. (1) How these fungi may in turn affect tree seedling growth and survival rates and ecosystem carbon sequestration at scale remains unknown.
The study will look at Broadleaf Soil Inoculation and Conifer Soil Inoculation in two types of forest being studied.
Enhanced rock weathering takes crushed basalt, a mining by-product, and applies it to the soil to capture CO2 as it weathers and to provide essential nutrients to for the trees. Basalt has been applied twice, the first time in 2020 prior to tree planting and the second time in 2023.
This is the first time that basalt addition is being studied in is a reforestation project at this scale. This method, proven in sugarbeet and pea crops, was hailed as one of the best near-term ways to remove carbon dioxide from the atmosphere. (2)
Basalt also contains nutrients that can stimulate mycorrhizal fungi and can support tree growth. (3) The study will look at the combinatorial impact of forest microbiome inoculation and enhanced rock weathering.
The study layout and individual tree measurements for 6,400 trees have created a strong data-set for monitoring, reporting and verification (MRV) of young forests. Bringing together a unique combination of citizen scientists from The Carbon Community and researchers from Swansea University, the Glandwr Forest MRV project is examining the correlation between on-the-ground measurements and drone overflights of 6,400 trees.
Each block in the study has 8 randomised test cells plus a grassland control. This is replicated 8 times across the site in a block design to account for microclimatic variation and ensure statistical validity.
Each of the planted cells will contain 400 trees, of which 100 will be individually tagged and tracked.
Over the first fives years, the project will measure the carbon stored in the trees and soil, and the results will identify the interventions where the most carbon has been sequestered above and below the ground.
References
1. Wubs, E., van der Putten, W., Bosch, M. et al. Soil inoculation steers restoration of terrestrial ecosystems. Nature Plants 2, 16107 (2016).
2. Beerling, D.J., Kantzas, E.P., Lomas, M.R. et al. Potential for large-scale CO2 removal via enhanced rock weathering with croplands. Nature 583, 242–248 (2020).
3. Battles, J.J., Fahey, T.J., Driscoll, C.T., Blum, J.D. & Johnson, C.E. (2104). Restoring Soil Calcium Reverses Forest Decline. Environ. Sci. Technol. Lett., 1, 15–19.
4. Verbruggen, E., Struyf, E, Vicca, S. Can arbuscular mycorrhizal fungi speed up carbon sequestration by enhanced weathering?Plants, People, Planet (2021).
