title: Differential allocation of carbon in mosses and grasses governs ecosystem sequestration: a 13C tracer study in the high Arctic.
abstract: *This study investigates the influence of vegetation composition on carbon (C) sequestration in a moss-dominated ecosystem in the Arctic. *A (13)C labelling study in an arctic wet meadow was used to trace assimilate into C pools of differing recalcitrance within grasses and mosses and to determine the retention of C by these plant groups. *Moss retained 70% of assimilated (13)C over the month following labelling, which represented half the growing season. By contrast, the vascular plants, comprising mostly grasses, retained only 40%. The mechanism underlying this was that moss allocated 80% of the (13)C to recalcitrant C pools, a much higher proportion than in grasses (56%). *This method enabled elucidation of a plant trait that will influence decomposition and hence persistence of assimilated C in the ecosystem. We predict that moss-dominated vegetation will retain sequestered C more strongly than a grass-dominated community. Given the strong environmental drivers that are causing a shift from moss to grass dominance, this is likely to result in a reduction in future ecosystem C sink strength.
authors.affiliation: IBES, University of Aberdeen, Aberdeen, UK. s.woodin@abdn.ac.uk
authors.forename: S J
authors.initials: SJ
authors.lastname: Woodin
authors.forename: R
authors.initials: R
authors.lastname: van der Wal
authors.forename: M
authors.initials: M
authors.lastname: Sommerkorn
authors.forename: J L
authors.initials: JL
authors.lastname: Gornall
mesh_terms: D001110:Arctic Regions; D018533:Biomass; D044002:Bryophyta / Q000502:physiology*; D002244:Carbon / Q000378:metabolism*; D002247:Carbon Isotopes / Q000378:metabolism*; D017753:Ecosystem; D007553:Isotope Labeling; D010788:Photosynthesis / Q000502:physiology*; D006109:Poaceae / Q000502:physiology*
chemical_list: D002247:Carbon Isotopes; D002244:Carbon