Variation in leaf-litter N and P concentrations as well as N:P ratio with mean annual precipitation (MAP) for all woody plants combined (A, B, C), shrubs (D, E, F), evergreen broadleaf trees (G, H, I), deciduous broadleaf trees (J, K, L) and coniferous trees (M, N, O) (corresponding regression equations are given in Tab. S3-2 in Appendix S3).