Fig. 1. Portions of bulk soil organic C in particle-size fractions (in percentage; y) in relation to bulk soil organic C concentrations of the A_p horizon (0–20 cm; x). Linear regression functions: >200 µm: y = 0.042x + 0.651, R² = 0.780**; 200–63 µm: y = 0.182x + 0.743, R² = 0.841**; 63–2 µm: y = 0.733x + 46.2, R² = 0.926***; 2–0.1 µm: y = -0.795x + 44.7, R² = 0.991***; <0.1 µm: y = -0.193x + 8.503, R² = 0.777**. *, **, and *** Significant at the 0.05, 0.01, and 0.001 probability levels