Fig. 2. The resoponse of soil organic carbon (SOC) to warming.

Global percentage response of SOC stock (a) and content (b) to warming. Sample size (i.e., the number of soil profiles used to estimate the response) is shown for each soil layer depth (i.e., 0–0.3, 0.3–1 and 1–2 m) under each warming level (i.e., 1, 2, 3, 4, 5 °C warming). Black vertical bars show the 95% confidence interval. Solid lines show the linear regression line between response and warming level in three soil layer depths, and inset table shows statistics for the regression including the determination coefficient (R²), regression slope and p value. Values for warming levels are jittered to make the points more distinct.