Carbon versus nitrogen release from root and leaf litter are modulated by litter position and plant functional type

Litters of leaves and roots of different qualities occur naturally above- and belowground, respectively, where they decompose in contrasting abiotic and biotic environments. Therefore, ecosystem carbon (C) and nitrogen (N) dynamics can be strongly affected by the combination of litter position and quality. However, it is poorly understood how C versus N turnover of litters depends on the interplay among plant functional type (PFT), organs, traits, and litter position.
In a semi-arid inland dune, soil surface and buried leaf litters and buried fine roots of 25 species across three PFTs (herbs, legume shrubs, and non-legume shrubs) were incubated for 3, 6, 9, 12, 18, and 24 months to investigate litter decomposition and C and N dynamics. Morphological and chemical (nutrient and NMR carbon) traits of initial litters of leaves and fine roots were determined.
The litter decomposition rates (k values) of surface leaves and buried fine roots did not differ, but buried fine roots and buried le...