Stable carbon isotopes as indicators for micro-geomorphic changes in palsa peats
2011 (English)In: Biogeoscience Discussions, ISSN 1810-6277, Vol. 8, no 1, 527-548 p.Article in journal (Refereed) Published
Palsa peats are unique northern ecosystems formed under an arctic climate and characterizedby an unique biodiversity and ecology. The stability of the palsas are seriouslythreatened by climate warming which will change the permafrost dynamic and5 results in degradation of the mires. We used stable carbon isotope depth profiles intwo palsa mires of Northern Sweden to track environmental change during the formationof the mires. Carbon isotope (13C) depth profile of the yet undisturbed mireStorflaket indicated very low to no degradation of the peat in the water saturated depressions(hollows) but increased rates of anaerobic degradation at the Stordalen site.10 The latter might be induced by degradation of the permafrost cores in the uplifted areas(hummocks) and subsequent braking and submerging of the hummock peat intothe hollows due to climate warming. Carbon isotope depth profiles of hummocks indicateda turn from aerobic mineralisation to anaerobic degradation at a peat depthbetween 4 to 25 cm. The age of these turning point was 14C dated between 150 and15 670 years and could thus not be caused by anthropogenically induced climate change.We found the uplifting of the hummocks due to permafrost heave the most likely explanationfor our findings. We thus concluded that differences in carbon isotope profiles ofthe hollows might point to the disturbance of the mires due to climate warming or dueto differences in hydrology. The characteristic profiles of the hummocks are indicators20 for micro-geomorphic change during permafrost up heaving.
Place, publisher, year, edition, pages
2011. Vol. 8, no 1, 527-548 p.
Ecology Earth and Related Environmental Sciences
Research subject Earth Sciences with Specialization Environmental Analysis
IdentifiersURN: urn:nbn:se:umu:diva-46305DOI: 10.5194/bgd-8-527-2011OAI: oai:DiVA.org:umu-46305DiVA: diva2:437783