Figure 3
From: Convergence of soil nitrogen isotopes across global climate gradients
Relationships among climate and soil parameters.
Relationships between mean annual temperature (MAT) and mean annual precipitation (MAP) and (A,B) soil δ15N (n = 910) and (C,D) soil [C] of surface soils (n = 828). Each point represents values for all samples averaged per 0.1° latitude and longitude. The relationship between soil [C] and soil δ15N is shown in panel (E) (n = 828). After accounting for the variation in soil δ15N explained by soil [C] (n = 828), the residual variation in soil δ15N is shown vs. (F) MAT and (G) MAP (n = 828). Gray regression line is not significant at P > 0.05. Values displayed in relationships with MAT and MAP were corrected for variation that could be explained by the other climate variable and soil depth.
