Summary
This study demonstrates that stable nitrogen isotope (δ15N) depth profiles, when related to C/N ratios, can reliably detect the depth and timing of palsa uplift caused by permafrost aggradation. By analysing ten peat cores from two northern Swedish peatlands (Stordalen and Storflaket), the authors identified a characteristic δ15N pattern with peak enrichment at the 'turning point' where peat was lifted out of the groundwater-influenced zone. The calculated onset of permafrost aggradation fell within the Little Ice Age (80–545 years ago, mean 242–365 years), suggesting this isotopic method is a useful palaeoclimate and soil perturbation indicator.
UK applicability
The UK contains peatlands in Scotland, Wales, and northern England that may be sensitive to permafrost dynamics under future climate scenarios; however, current UK peatlands are predominantly below the active permafrost zone. This methodology could be relevant for monitoring historical permafrost extent in upland regions and for detecting peat perturbation from other causes (drainage, erosion, or land-use change) where δ15N and C/N relationships might signal subsurface disturbance.
Key measures
δ15N stable isotope values, C/N ratios, peat depth profiles, timing of permafrost aggradation (years before present), peat accumulation rates
Outcomes reported
The study measured δ15N and C/N ratios along depth profiles in peat cores from two Swedish peatlands to identify the depth at which permafrost uplift occurred. The researchers used these isotopic markers to determine the timing of palsa formation, finding permafrost aggradation occurred 80–545 years ago, clustering within the Little Ice Age period.
Topic tags
Dig deeper with Pulse AI.
Pulse AI has read the whole catalogue. Ask about this record, its theme, or how the findings apply to UK farming and policy — every answer cites the underlying studies.