Non-living biomass, with a size less than a minimum threshold diameter (e.g., 10 cm) chosen by the host country for its UNFCCC national inventory accounting, lying dead, in various states of decomposition above the mineral or organic soil, including litter, fumic and humic layers. Live fine roots (of less than the threshold diameter for belowground biomass) are included in litter where they cannot be distinguished from it empirically.