Figure 5: Scatter diagram of δ¹⁵N versus δ¹⁸O of nitrate in the soil samples at the ecosystems of forestland and grassland.

The figure has not been directly taken from Kendall et al.³², which was compiled using their published data of the ranges of δ¹⁵N and δ¹⁸O values of potential nitrate sources from Kendall et al.³².