Environmental Change Research Unit - ECRU

Peatbiomarker

BIOMARKERS – A NEW POTENTIAL METHOD TO STUDY HIGHLY HUMIFIED PEAT COMPONENTS

Funded by the Academy of Finland

Duration 1.1.2010-31.12.2013

Acute and contemporary questions related to changes in climate have emphasized the importance of peatland research because peatlands store large quantifies of organic material i.e. carbon. The net carbon balance of mires is highly sensitive to changes in moisture conditions and consequent vegetation assemblages. It is essential to understand the historical peatland dynamics and related variation in vegetation assemblages, and the possible relationships of these changes with past climate events. Given the vital role of vegetation in the carbon budget, it is very important to be able to detect past changes in plant communities and understand their controls and impacts. Especially useful proxy methods for reconstructing these past changes are macroscopic plant remains. The top layers of mires usually contain relatively well preserved plant material for palaeoecological examination. Below, however, lie peat layers where almost all plant material has decomposed to such a state that reliable identification is impossible. Thus, well-decomposed peat constrains palaeobotanical studies.
British biogeochemists have, as pioneers and in collaboration with Finnish mire researchers, been developing a new way, biomarker analyse, to approach past peat layers. These studies applied organic geochemical analysis to separate, identify and quantify various peat compounds. The procedure encompasses species-specific analyses of modern peat forming plants for selected chemical compounds. Then the same analysis was applied for fossil peat layers that had earlier been analysed for macroscopic plant remains. The chemical analysis seemed to replicate the results of plant macrofossil analysis. Not only different plant groups such as Ericales, Cyperaceae and bryophytes could be separated from each other but the analysis also distinguished different mosses to species level, i.e. species-specific chemical “fingerprints” do exist.
Hitherto, such chemical analyses have only been applied to peat derived from less humified bog peat The results, however, encourage expanding the experiments to more humified material – i.e. to material that sets major palaeoecological challenges.
This proposal aims to introduce a new methodological approach to study historical changes in peatland vegetation dynamics and import the method into the Finnish scientific community.

Researchers

Docent Minna Väliranta, PI

Project partners

Docent E-S. Tuittila, Academy Research Fellow, Department of Forest Ecology, University of Helsinki, Finland
Prof. R. Evershed, The School of Chemistry, University of Bristol, UK
Dr, Lecturer E. McClymont, School of Geography, Newcastle University, UK

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