Fig. 2From: 13C NMR spectroscopy characterization of particle-size fractionated soil organic carbon in subalpine forest and grassland ecosystemsCP/MAS 13C NMR spectra in different particle-size fractions in forest (FR), transition (TR), and grassland (GS) sites. a Carboxyl-C, b aromatic-C, c O-alkyl-C, d alkyl-CBack to article page