Fig. 1: The storage of different dissolved organic matter (DOM) species in grassland soils.
From: Spatial patterns and environmental functions of dissolved organic matter in grassland soils of China
a Spectral properties of four fluorophores (C1, C2, C3, and C4) identified by parallel factor analysis. b Intensity of the four fluorescent components in Raman unit (R.U.). c Cumulative intensity (absorbance unit) of the four fractions with different molecular weights. VHMW, 25–100 kDa; HMW, 3.4–25 kDa; MMW, 1.2–3.4 kDa; LMW, <1.2 kDa. d Concentrations (mg·kg−1-soil) of dissolved organic carbon (DOC), dissolved organic nitrogen (DON), trihalomethane precursors (THM-FP), and haloacetic acid precursors (HAA-FP). e UV absorbance at 254 nm (A254), biological index (BIX), fluorescence index (FI), and humification index (HIX) of DOM. f Spearman correlation between DOC, DON, disinfection byproduct precursors, and A254 vs different DOM compounds. g Variation partitioning analysis for DOC and DON. Numbers in each circle are the unique effects of size fraction and fluorescent component, respectively, and the number in the overlapping area of the two circles is the shared effects of the two factors. *P < 0.05, **P < 0.01, and ***P < 0.001.
