C stocks

We measured vegetation and soil C stocks from samples taken at the beginning and end of the project. We also up-scale plot measurements to the landscape scale based on Ground Penetrating Radar (GPR) derived peat depth transects. Care was taken to not affect bulk density during sampling of peat sections, bulk density is a crucial parameter not only for the carbon stock measurement (see Garnett et al. 1998) but also when modelling C dynamics (see Kennedy et al., 2008 and Heinemeyer et al., 2010). We have also install permanent peat rods with (datum) surface marker plates to determine long-term peat growth and short-term peat shrinkage/expansion due to environmental changes (i.e. due to water table and thus peat moisture changes). This will include the total peat depth, which is quite often not considered as measurements are limited to a certain depth such as 1 m, but total peatland C stocks and models should consider the total peat depth (see Heinemeyer et al., 2010). This has become particularly evident in global C stock estimates (Tarnocai et al., 2009).

In August 2012 we took one manual peat depth sample down to the bedrock with a combination of a 1 m box corer and a D-shaped Russian peat corer for depth below 1 m (kindly provided by the YPP). This was done at 50 cm distance from the individual temperature and water table plots for all monitoring plots. We sampled 5 cm slices with minimal bulk density impact at the following depth intervals if depth allowed: 0-5; 10-15; 20-25; 40-45; 80-85; 120-125; 150-155 cm. If peat depth was deeper we also sampled at the very bottom of the peat column. We also recorded the main vegetation coverage percentages at the time of coring (i.e. % Calluna, sedge, rush, grass, moss, Sphagnum and bare ground). The same locations were surveyed again for peat depth in 2016 using GPR surveys.

We further 
manually recorded the peat depth along the same paths of the DMS automated GPR survey (see section on peat pipes). At ~25 locations in each sub-catchment peat depth was assessed manually using metal rods pushed to the bedrock and heather coverage was recorded at those locations from around 5 m2

Marking a 20 cm marker position on the steel rod

Manual peat sampling alongside GPR surveys

Ready-to-go steel rod with marker position visible and marker disk for protection