caa a22 4500 605517592 CHVBK 20210128100720.0 cr unu---uuuuu 210128e20150801xx s 000 0 eng 10.1007/s10533-015-0110-7 doi (NATIONALLICENCE)springer-10.1007/s10533-015-0110-7 Old carbon in young fine roots in boreal forests [Elektronische Daten] [H.-S. Helmisaari, J. Leppälammi-Kujansuu, S. Sah, C. Bryant, D. Kleja] A large proportion of the soil carbon (C) in boreal forests originates from roots and ectomycorrhizal fungi, and accurate quantification of fine-root litter production is needed. Methods for determination of root turnover have been under debate in recent years. Two recently used methods—radiocarbon (14C) dating and use of minirhizotrons (MR)—have yielded different results. This has been attributed to analysis of different roots by use of these methods. At Flakaliden, northern Sweden, in a long-term soil warming and irrigation experiment, we compared MR lifespan with the 14C-derived age of fine roots from soil cores of the same root diameter class. We also determined the 14C-derived age of ingrowth core roots of Norway spruce. The median lifespan of fine roots around MR tubes installed 15years previously was shorter than 2.5years whereas the 14C-derived age of the fine roots from soil cores varied from recently grown to 14years. Correspondingly, the age of 14C in fine roots harvested from ingrowth cores installed in soil 3months previously was between 1 and 20years. Thus, cellulose in these roots contained older 14C than is possible from photosynthesis during the time of cellulose formation. By investigating whether the age of Norway spruce and Scots pine seedlings was less than their root 14C-derived age, we tested the possibility of root C originating from soil uptake. This was found to be unlikely, because fine roots of four and eight-year-old seedlings had 14C that was dated to be as old as or younger than the seedlings. We propose that further effort is required to identify the ecological conditions leading to root growth utilization of stored or recycled C. Springer International Publishing Switzerland, 2015 Fine root age nationallicence Minirhizotron nationallicence Picea abies nationallicence Radiocarbon nationallicence Root carbon nationallicence 14C nationallicence Helmisaari H.-S Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014, Helsinki, Finland aut Leppälammi-Kujansuu J. Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014, Helsinki, Finland aut Sah S. Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014, Helsinki, Finland aut Bryant C. NERC Radiocarbon Facility (East Kilbride), Scottish Enterprise Technology Park, Rankine Avenue, G75 OQF, East Kilbride, Scotland, UK aut Kleja D. Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7001, 75007, Uppsala, Sweden aut Biogeochemistry Springer International Publishing 125/1(2015-08-01), 37-46 0168-2563 125:1<37 2015 125 10533 https://doi.org/10.1007/s10533-015-0110-7 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10533-015-0110-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Helmisaari H.-S Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014, Helsinki, Finland aut NATIONALLICENCE 700 1- Leppälammi-Kujansuu J. Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014, Helsinki, Finland aut NATIONALLICENCE 700 1- Sah S. Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014, Helsinki, Finland aut NATIONALLICENCE 700 1- Bryant C. NERC Radiocarbon Facility (East Kilbride), Scottish Enterprise Technology Park, Rankine Avenue, G75 OQF, East Kilbride, Scotland, UK aut NATIONALLICENCE 700 1- Kleja D. Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7001, 75007, Uppsala, Sweden aut NATIONALLICENCE 773 0- Biogeochemistry Springer International Publishing 125/1(2015-08-01), 37-46 0168-2563 125:1<37 2015 125 10533