Below Ground Carbon Storage - 2023

Spatial datasets consider the lands contribution to preventing and mitigating climate change, through storage of carbon in the Soils (below ground). This below Ground Carbon spatial datasets represent a strategic resource for England, that indicate the range of carbon storage values in tonnes of carbon per hectare (t C Ha-1 ). At a local scale (e.g. 1:50 000). They are presented as a series of raster datasets for use in GIS Systems at a resolution of 25m2. These maps will assist users to find out where the most important carbon stores in soils in their areas.They are not suitable for field scale carbon mitigation as this would require field scale carbon assessment. As well as soil being an excellent natural carbon sink, locking carbon away from the atmosphere and reducing the amount of greenhouse gasses produced soil carbon has a number of other excellent benefits. The amount of carbon stored within mineral soil depends upon the soil type, with clay rich and silt rich soils storing more carbon than sandy soils. Within peat soils, carbon storage operates by a different process. In a non-compromised or fully functional state peat soils are fully saturated with water for most of the year. This leads to the minimal decomposition of plant biomass, so soil carbon builds up faster than decomposition can occur, so no equilibrium is reached, to form a very carbon-rich layer of peat. However, if the peats are damaged so leading to drying out the soil microbial activity can re-start, and as the carbon is utilised by the soil microfauna, carbon dioxide and methane are then released to the atmosphere, changing a carbon sink that is sequestering carbon, into a source of greenhouse gas emissions. (UK Peatland Strategy 2018) . Natural England produced a report in 2021 reviewing this research and compiling different land use. approximate values in tons per hectare of carbon for a wide variety of habitats in England (Gregg et al 2021) see Carbon Storage and Sequestration by Habitat 2021 (NERR094).

Framework created from Soilscapes and NE Natural England Peat Map (Natural England 2008).Soilscapes- 1:250,000 scale soils dataset. [https://www.landis.org.uk/soilsguide/soilscapes_list.cfm ]. the 27 soils carbon figure was assigned. This data was split in 2; Mineral Soils; Organo mineral & Peat Soils. Mineral soil split by habitats. modified by: PHI habitat overlying the soil (more natural / semi-natural the higher the score) with 50% overlap = 30% uplift carbon; the Ancient Woodland (NE 2019) with 50% overlap add 30% uplift in carbon. Organo Mineral & Peat soils: NE Peat Map (2008) was used to describe the shallow and deep peat soils, inc. peaty pockets. then conflated with the Soilscape for organo -mineral soils and peat soils with the NE peat map having priority. Modifiers were used & included: Indications that the habitats might be in good ecological condition, the PHI and the SSSI was used as a proxy. If no PHI overlap a 10% reduction; If the habitat overlying the soil is Fen = 2 x carbon figure. If the habitat overlying the soil is Raised Bog = 2.5 x carbon figure; Arable = reduced carbon lost from peat soils under. The Mineral and Organo mineral & Peat Soils rejoined to single England layer. Then Soil depth & Slope adjustment. Soil depth important to carbon stored. Most carbon in the topsoil, lesser amount of carbon held deep in soil profiles. Put into the model each soil type was allocated to one of four depth classes: Shallow soils with a profile likely to be 15-50 cm or less; The models assumed a 30 cm depth for carbon calculations; Normal depth mineral soils with a profile between 1 m and 1.25 m. The models assumed a 1 m depth for carbon calculations. Blanket peat soils. The models assumed a 2 m depth for carbon calculations. Raised bog and fen peat soils. Model assumed 4 m depth for carbon calculations. Slope, habitats occurring on steep slopes have thinner soil. A value of over 18o was used to show as a proxy for thinner soils. Slope occurring on; on slopes between 0-11o = 0%; on slopes between 11o - 18o = -10%; on slopes over 18o = -20%. NE PHI/ Ancient Woodland - OGL NE Living England - OGL NE Peatmap [2008] - Non- comercial licence Soilscapes - Cranfield University- NE Bespoke Licence SRTM- NASA ShuttleRadar Topography- Open Topography