Palaeoecological studies as a source of peat depth data: A discussion and data compilation for Scotland

The regional/national carbon (C) stock of peatlands is often poorly characterised, even for comparatively well-studied areas. A key obstacle to better estimates of landscape C stock is the scarcity of data on peat depth, leading to simplistic assumptions. New measurements of peat depth become unrealistically resource-intensive when considering large areas. Therefore, it is imperative to maximise the use of pre-existing datasets. Here we propose that one potentially valuable and currently unexploited source of peat depth data is palaeoecological studies. We discuss the value of these data and present an initial compilation for Scotland (United Kingdom) which consists of records from 437 sites and yields an average depth of 282 cm per site. This figure is likely to be an over-estimate of true average peat depth and is greater than figures used in current estimates of peatland C stock. Depth data from palaeoecological studies have the advantages of wide distribution, high quality, and often the inclusion of valuable supporting information; but also the disadvantage of spatial bias due to the differing motivations of the original researchers. When combined with other data sources, each with its own advantages and limitations, we believe that palaeoecological datasets can make an important contribution to better-constrained estimates of peat depth which, in turn, will lead to better estimates of peatland landscape carbon stock