Figure 2 : Percentage of α-glucosidase (AG), β-glucosidase (BG), cellobiohydrolase (CB), β-xylosidase (BX), N-acetylglucosamine (NAG), leucine aminopeptidase (LAP), and acid phosphatase (AP) activity below 20 cm in the top meter (A); and proportion of soil organic carbon (SOC), microbial biomass (MB), sum of C-degrading enzymes (Csum= AG + BG + CB + BX), sum of nitrogen-mineralizing enzymes (Nsum = NAG + LAP), and acid phosphatase (AP) below 20 cm in the top meter of soil among soil orders (B). Error bars show ± one standard error of the mean (Figure panel A: n = 19; Figure panel B: Inceptisol: n = 4, Mollisol: n = 5, Ultisol: n = 3).
Figure 3 : Correlations between soil and extracellular enzyme (EE) stoichiometry of carbon (C), nitrogen (N), and phosphorus (P) in surface (< 20 cm depth) and subsoils (> 20 cm depth). Blue lines show significant (α = 0.05) mixed-effects models of the relationship between soil and EE stoichiometry (site was used as a random effect; lines were not drawn where correlations were not significant). Gray ribbons show the standard error of the model. Data points represent individual soil samples (depths within each pit). Note the scales of the axes differ among plots.