Comment on: “Peatland carbon stocks and burn history: Blanket bog peat core evidence highlights charcoal impacts on peat physical properties and long‐term carbon storage,” by A. Heinemeyer, Q. Asena, W. L. Burn and A. L. Jones (Geo: Geography and Environment 2018; e00063)

Chris D Evans,Michael Peacock,Neil L Rose,Tim J Thom,Andy J Baird,Rob Stoneman,Sophie M Green,Dylan M Young,Mark H Garnett,Susan E Page,Mark S Reed

doi:10.1002/geo2.75

Abstract

A recent paper by Heinemeyer et al. (2018) in this journal has suggested that the use of prescribed fire may enhance carbon accumulation in UK upland blanket bogs. We challenge this finding based on a number of concerns with the original manuscript including the lack of an unburned control, insufficient replication, unrecognised potential confounding factors, and potentially large inaccuracies in the core dating approach used to calculate carbon accumulation rates. We argue that burn-management of peatlands is more likely to lead to carbon loss than carbon gain. e00075

Highlights

We do not believe that the study design permits the effects of grouse moor burning to be reliably tested
A number of these criticisms appear to reflect misunderstandings or incomplete knowledge of both the site and previous research. They state that none of the depth profiles of Garnett et al (2000) detected the 1975 spheroidal carbonaceous particles (SCPs) peak. This is because Garnett et al used the 1950s SCP take‐off date to date their cores, and did not analyse SCPs up to the surface of all cores, where peat is less decomposed and reliable SCP measurement difficult (Swindles, 2010)
Heinemeyer et al argue that charcoal layers in the Moor House cores do not match the onset of experimental burn rotation in 1954, and suggest that a lower charcoal layer at 10–11 cm corresponds to this date, thereby invalidating the SCP take‐off dates of Garnett et al Subsequent work by Garnett and Stevenson (2004), not referred to by Heinemeyer et al, combined SCP and 14C data to show consistent dating of charcoal layers formed by experimental burns in the upper peat profile, and high agreement between the SCP take‐off date and the first appearance of bomb‐ enriched 14C in the peat profile, both of which occurred in the 1950s (Figure 1)

Summary

Introduction

We do not believe that the study design permits the effects of grouse moor burning to be reliably tested. The study lacks an unburned control, so rates of C accumulation in burned sites cannot be compared with a natural reference.

Results

Conclusion