Ronkainen, T. and McClymont, E.L. and Tuitilla, E.-S. and Väliranta, M. (2014) 'Plant macrofossil and biomarker evidence of fen-bog transition and associated changes in vegetation.', The Holocene., 24 (7). pp. 828-841.
Past vegetation assemblages, preserved in peat layers, are one of the key proxies when reconstructing historical peatland dynamics. Northern peatlands can be divided into two main types: fens and bogs. Compared with bog peat, the fen peat is usually more decomposed because of different eco-hydrological conditions and effective humification processes. A high level of decomposition hampers reliable identification of plant remains and constrains palaeoecological approaches. Biogeochemical studies on bog plants and bog peat have shown that plant group–specific biomarkers can be applied to identify fossil plants or plant groups from peat, given the identification of plant group–specific markers in living fen plants. In this study, we applied plant macrofossil, biomarkers and multivariate statistical analyses to two mid-boreal peat sequences to investigate whether biomarkers can be applied to distinguish fen and bog environments and whether plant-specific biomarkers can be identified from fen peat. Macrofossil analyses clearly separate dry bog hummocks, moist lawns and wet fen habitats apart. Corresponding division emerged when the biomarker data were combined with the macrofossil data. Moreover, we succeeded to separate bog and fen habitats apart by the changes in n-alkane and the n-alkane ratio distributions along the cores. The fen–bog transition zone was indicated by high sterol and triterpenoid concentrations and changes in degradation measures. However, it remains a challenging task to attain species-level information of past plant assemblages from highly humified fen peat layers based on biomarkers only.
|Keywords:||Biomarker, Degradation, Fen peat, Fen–bog transition, n-alkane, Past plant assemblages.|
|Full text:||(AM) Accepted Manuscript|
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|Publisher Web site:||http://dx.doi.org/10.1177/0959683614530442|
|Publisher statement:||The final definitive version of this article has been published in the journal The Holocene, 24, 7, 2014 © SAGE Publications Ltd at the The Holocene page: http://hol.sagepub.com/ on SAGE Journals Online: http://online.sagepub.com/|
|Date accepted:||No date available|
|Date deposited:||10 June 2014|
|Date of first online publication:||July 2014|
|Date first made open access:||No date available|
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