Fig. 2: Relationships between standardized fine root carbon and soil organic carbon stocks.
From: Fine root and soil carbon stocks are positively related in grasslands but not in forests
FRC and SOC are shown by soil depth along with a 1:1 line. Data points above the 1:1 line suggest inferred net accrual of SOC while data points below the 1:1 line suggest inferred priming. a Forests have no significant relationship between standardized FRC and SOC while (b) in grasslands the slope of the relationship between deep roots and deep SOC (>30 cm) is steeper (linear regression slope = 1.2, p = 0.015) than the slope between shallow roots and shallow SOC (<30 cm depth; slope = 0.9, p = 0.19). Detailed statistics across depths and ecosystem type are provided in Figs. S7 and S8.
