Carbon stocks and properties of a drained and undrained peatland in West Iceland

Peatlands in Iceland have been affected by anthropogenic activity since early settlement times. The transformation of peatlands into agricultural land increased rapidly in the 1940s when the government subsidized peatland drainage for grazing and farming. According to the Environmental Agency of Iceland drained peatlands are the most significant source of GHG emissions in Iceland. Peatland restoration efforts have gradually begun in recent years, yet there is still limited research on the effects of drainage on carbon stocks in Icelandic peatlands. Soils of Icelandic peatlands receive frequent mineral deposits from volcanic activity as well as windborne material from eroding volcaniclastic deserts and Andosols; creating organic soils with andic and vitric properties which are rare elsewhere. Therefore, it is critical to enhance our understanding of carbon trajectories upon drainage of Icelandic peatlands. Here, we introduce an ongoing study comparing carbon stocks and carbon characteristics of a drained and undrained peatland. We conducted our study at the Lækur farm in West Iceland, where a portion of peatlands were drained in 1961 while other nearby peatlands have remained undisturbed. At each site, we work with three soil cores of 0.5 – 1 m depth. We use carbon structure derived by ¹³C nuclear magnetic resonance spectroscopy (NMR), C:N ratios and values of δ¹³C and δ¹⁵N to determine the decomposition state and quality of the soil organic material. Also, we compare carbon stocks between sites based on total carbon contents and dry bulk densities. The results from this study will increase our understanding of the influence of drainage on carbon stocks and carbon structure in Icelandic peatlands, and peatlands of volcanic regions elsewhere. This is particularly important when evaluating the effect of potential peatland restoration efforts.