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

   FIG. D1. Comparison of optimal P loadings and present values (PV) for policies taking account of and neglecting uncertainty in P_c, for discount rate = 0.01. The keys show the values corresponding to the colors. P and M concentrations are in kilograms per square meter.