Donald Ludwig, Steve Carpenter, and W. Brock. 2003. Optimal phosphorus loading for a potentially eutrophic lake. Ecological Applications 13:1135–1152.

   FIG. C1. Phosphorus loadings as function of P (P concentration in lake, in kilograms per square meter) and M (P concentration in mud, in kilograms per square meter), for three different discount rates ( = 0.05, 0.01, and 0.005). The key on the lower right shows the values corresponding to the colors.