Fig. 2: Earthworm effects on nitrogen uptake of Festuca ovina.

Shown are earthworm effects on N content (%) and δ¹⁵N of Festuca ovina, a plant present in both of the studied vegetation types, i.e., heath (H) and meadow (M). Individual replicates of samples from unlabeled (white diamond shape) and δ¹⁵N labeled (red circle, where darker values indicate overlapping data) mesocosms are shown with average values (black square, ±std. err). Main effects and interaction effects are presented as text for each panel (effect of the labeled litter is indicated using the ¹⁵N symbol) along with symbols indicating significance level (P < 0.05 are shown using *, and significance levels <0.001 are indicated as ***). Note the cut off in the y-axis to show the δ¹⁵N signatures of the unlabeled and the labeled litter. Source data are provided as a Source Data file.