University of Oulu

Sanna R. Piilo, Atte Korhola, Lauri Heiskanen, Juha-Pekka Tuovinen, Mika Aurela, Sari Juutinen, Hannu Marttila, Markus Saari, Eeva-Stiina Tuittila, Jukka Turunen, Minna M. Väliranta, Spatially varying peatland initiation, Holocene development, carbon accumulation patterns and radiative forcing within a subarctic fen, Quaternary Science Reviews, Volume 248, 2020, 106596, ISSN 0277-3791, https://doi.org/10.1016/j.quascirev.2020.106596

Spatially varying peatland initiation, Holocene development, carbon accumulation patterns and radiative forcing within a subarctic fen

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Author: Piilo, Sanna R.1,2; Korhola, Atte1,2; Heiskanen, Lauri3;
Organizations: 1ECRU, Ecosystems and Environment Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, P.O. Box 65, 00014, Finland
2Helsinki Institute of Sustainability Science (HELSUS), Finland
3Finnish Meteorological Institute, Erik Palménin Aukio 1, 00560, Helsinki, Finland
4Water, Energy and Environmental Engineering Research Unit,University of Oulu, P.O. Box 4300, 90014, Finland
5School of Forest Sciences,University of Eastern Finland, P.O. Box 111, Joensuu, Finland
6Environmental Solutions, Peatland Use and Resource Economics, Geological Survey of Finland, P.O. Box 96, 02151, Espoo, Finland
Format: article
Version: accepted version
Access: embargoed
Persistent link: http://urn.fi/urn:nbn:fi-fe2020112592966
Language: English
Published: Elsevier, 2020
Publish Date: 2022-10-07
Description:

Abstract

High latitude peatlands act as globally important carbon (C) sinks and are in constant interaction with the atmosphere. Their C storage formed during the Holocene. In the course of time, the aggregate effect of the C fluxes on radiative forcing (RF) typically changes from warming to cooling, but the timing of this shift varies among different peatlands. Here we investigated Holocene peatland development, including vegetation history, vertical peat growth and the lateral expansion of a patterned subarctic fen in northern Finland by means of multiple sampling points. We modelled the Holocene RF by combining knowledge on past vegetation communities based on plant macrofossil stratigraphies and present in situ C flux measurements. The peatland initiated at ca. 9500 calibrated years Before Present (cal yr BP), and its lateral expansion was greatest between ca. 9000 and 7000 cal yr BP. After the early expansion, vertical peat growth proceeded very differently in different parts of the peatland, regulated by internal and external factors. The pronounced surface microtopography, with high strings and wet flarks, started to form only after ca. 1000 cal yr BP. C accumulation within the peatland recorded a high degree of spatial variability throughout its history, including the recent past. We applied two flux scenarios with different interpretation of the initial peatland development phases to estimate the RF induced by C fluxes of the fen. After ca. 4000 cal yr BP, at the latest, the peatland RF has been negative (cooling), mainly driven by C uptake and biomass production, while methane emissions had a lesser role in the total RF. Interestingly, these scenarios suggest that the greatest cooling effect took place around ca. 1000 cal yr BP, after which the surface microtopography established. The study demonstrated that despite the high spatial heterogeneity and idiosyncratic behaviour of the peatland, the RF of the studied fen followed the general development pattern of more southern peatlands. Holocene climate variations and warm phases did not seem to induce any distinctive and consistent peatland-scale patterns in C accumulation, whereas our data suggests that the changes in vegetation related to autogenic succession were reflected in the C accumulation patterns and RF more clearly.

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Series: Quaternary science reviews
ISSN: 0277-3791
ISSN-E: 1873-457X
ISSN-L: 0277-3791
Volume: 248
Article number: 106596
DOI: 10.1016/j.quascirev.2020.106596
OADOI: https://oadoi.org/10.1016/j.quascirev.2020.106596
Type of Publication: A1 Journal article – refereed
Field of Science: 1172 Environmental sciences
218 Environmental engineering
Subjects:
Funding: Academy of Finland (project CAPTURE, 296423) funded this project.
Copyright information: © 2020 Elsevier B.V. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
  https://creativecommons.org/licenses/by-nc-nd/4.0/