Above? to belowground carbon allocation in peatlands shifts with plant functional type and temperature

Background Northern peatlands have accumulated vast amounts of carbon (C) as peat. Warming temperatures may affect peatland C stores by increasing microbial decomposition ancient peat through enhanced input labile root exudates expansion vascular plants, thereby accelerating atmospheric warming. Aims We set out to explore how much freshly assimilated is allocated belowground and if the above- allocation affected temperature plant functional types. Methods traced pathways two dominant types (i.e., sedges shrubs) in under different regimes combining selective removal mixed sedge-shrub vegetation situ 13C pulse-labelling. Aboveground well turnover were assessed quantifying leaves soil respiration measuring ?13C dissolved organic C. A depth-resolved quantification gave additional insight into patterns. Results Temperature did not rate at which was shoots, but higher decreased fraction that plants. Sedges CO2 faster their shoot biomass (faster depletion shoots) more than shrubs. Conversely, retained this better shrubs, leading lower measured sedges. Conclusions Climate induced will increase fresh assimilates substantially, even though part effect be offset reduced rates. If shrub density increases relative sedges, are likely respired translocated roots where they could reach and, potentially mobilize, stored deeper layers.