This dataset contains the raw data published in:

Marrs, R. H., Marsland, E-L., Lingard, R., Appleby, P G., Piliposyan, G.T., Rose, R.J., O’Reilly, J., Milligan, G., Allen, K. A., Alday, J.G., Santana, V., Lee, H., Halsall, K., Chiverrell R.C. Experimental evidence for sustained carbon sequestration in fire-managed, peat moorlands. Nature Geoscience (2018).

METHODS
Site: Hard Hill within Moor House National Nature Reserve (NNR), located in the Northern Pennines of England, which covers 40 km2 of upland blanket bog, the largest area of ombrotrophic, mire-covered moorland in England (Rawes & Heal, 1978). Vegetation change in the experiment is detailed in Lee et al. (2013) and Milligan et al. (2018).

Experimental design: The Sheep-grazing and Burning Experiment was established at Hard Hill in 1954 to investigate the effects of low-density sheep grazing and long-term, prescribed burning on blanket bog vegetation. The experiment was set up with a randomized block, split-plot design with four blocks, each with two sheep-grazing treatments (background sheep grazing pressure versus no sheep grazing) applied randomly within block and the three prescribed burning sub-treatments applied randomly within sheep-grazing treatments. All the plots were burnt in 1954/5 (here denoted 1954), and thereafter, three prescribed burning treatments were applied: short-rotation, every 10 years (S); long-rotation, every 20 years (L); and no subsequent burn since 1954 (N). Each of the four blocks has an associated reference plot (R) which has not been burnt since at least 1923; the plots are referred to by the number of burns implemented since 1954; R=0-burn, N=1-burn, L=3-burns, and S=6-burns. Here, cores were only sampled from the grazed treatments as this is the “business-as-usual” management regime for most upland blanket bog in the UK. 

Field methods:  Two “Master” cores were sampled (July 2013) from the Reference plot of Block A (no burn since ca. 1923) for analysis of peat and C dry mass accumulation, air-fall Pb by XRF and for radiometric dating (MH13/1, MH13/4). 
In June 2016 comprehensive analysis of the peat and C dry mass accumulation rates was undertaken by sampling within each burning treatment with four cores from treatment R, eight cores from L and N and twelve cores from S; thus comprising 8 cores per block (1xR, 2xL, 2xN, 3xS) and 32 cores in total (MH16/1-32). Throughout, a hemi-cylindrical peat sampler (0.5 m x 0.05 m diameter) was used to extract the peat cores, and they were stored in guttering, sealed in plastic sleeves, and stored under refrigeration until analysis.

Lab methods: Major element and trace metal concentrations (ppm) including air-fall Pb were determined on a wet sediment basis at 5mm resolution for each core using an Olympus Delta Energy Dispersive (ED)-XRF) mounted on a Geotek MSCL-XZ core scanner.  Peat accumulation rates were derived using features or markers in the pronounced down-core atmospheric fall-out stable Pb profile measured by XRF. Four good age markers were detected and assigned ages from the radiometric dating at 1876, 1963, 1986 and the peat surface (2016). As 1963 was the closest to the start of the Hard Hill experiment this marker was used to estimate recent peat and C accumulation rates. 
Peat growth rates (cm yr-1) were then calculated for each core across the two periods (1876-1963 and 1963-2016), essentially pre- and post-experiment (Dataset #1). C accumulation was measured for the peat sequence using Near-Infra-Red Spectrophotometry (NIRS) cross-calibrated using a training set of direct mass loss-on-ignition (l-o-i) measurements. NIRS reflectance was measured on each 1-cm depth samples from all cores using a BRUKER MPA FT-NIR spectrometer; lightly-ground peat was scanned at 4 nm intervals between 3598-12493 nm. L-o-i was measured on each 1-cm depth section from four cores, one selected form each burning treatment; peat samples were ashed at 550˚C for 3 h  (Dataset #2). L-o-i and hence C concentration (as 40% of the burnt mass loss) was predicted from the NIRS data. This NIRS-based approach provides robust, rapid and non-destructive estimates for l-o-I and C concentrations. The C accumulation rate (g C m2 yr-1) was calculated using the measured or NIRS predicted l-o-I results for each core for the periods 1876-1963 and 1963-2016. Finally, the mass of C accumulated in the depth profile was calculated (Dataset #3).

DATASETS:
All datasets contain the same meta-data to describe the cores samples in each plot:
1.	Block: denoted A, B, C, D to describe the four replicate blocks, spatially separated.
2.	Burn.Treatment: denoted,
R = Reference plot, no burn since ca. 1923,
N = Burned in 1954 only,
L = Burned in 1954 and then every 20 years,
S = Burned in 1954 and then every 10 years.
3.	Sub.Rep, a number between 1 and 3 denoting the number of sub-cores sampled per replicated Treatment plot.

Dataset #1: Accumulation rates:
Provides data on the estimates of peat and C accumulation rates (both in g/m2/yr) for two time-periods, pre-experiment (1876-1963) and during experiment (1963-2016), these are denoted:
Peat.accumulation.rate.(g/m2).between.1963.2016
Carbon.accumulation.rate.(g/m2).between.1963.2016	
Peat.accumulation.rate.(g/m2).between.1876.1963	
Carbon.accumulation.rate.(g/m2).between.1876.1963

Dataset #2.NIRS vs L-o-I data:
This datatset contains the training set used to calculate the calibration curve between peat carbon concentration estimated by NIRS and loss-on-ignition. These were derived from a series of cores from different treatments; the data are estimated C concentrations (%) and denoted:
•	NIRS.C.(%) – data from NERS
•	Loss-on-Ignition.(%) – data from Loss-on-ignition

#3.Cumulative.C.with peat.depth:
This dataset contains the cumulative C concentrations through the depth profile of the peat cores in 1-cm slices (g/m2). Data are available from only one sub-core for each treatment in each Block. The raw data are denoted:
•	Core.depth.(cm) – the depth slice of the core
•	Cumulative.C.(g/m2) – the cumulative C going down the core.
References
Lee, H., Alday, J.G., Rose, R.J., O’Reilly, J., Marrs, R.H. (2013). Long-term effects of rotational prescribed-burning and low-intensity sheep-grazing on blanket-bog plant communities. Journal of Applied Ecology, 50, 625-635 
Milligan, G., Rose, R.J., O’Reilly, J., Marrs R.H. (2018). Effects of rotational prescribed burning and sheep-grazing on moorland plant communities: results from a 60-year intervention experiment. Land Degradation & Development, 29, 1397–1412.
Rawes, M., Heal, O.W. (1978). in Production ecology of British Moors and Montane Grasslands (eds, Heal O.W., Perkins, D.F.) 224-243. Springer-Verlag, Berlin.