Fig. 6. Time series of ecosystem services (upper panel) and pollutant (lower panel) in each region vs. time as M1 (pollution discharge rate in region 1) increases linearly from 2.0 to 2.1. Other parameters: r (renewal rate of the ecosystem service) = 1; h (effects of extracting or using the ecosystem services) = 0.5; k (impact of the pollutant on the renewal rate of the ecosystem service) = 0.5; M2 (pollution discharge rate in region 2) = 0.75; c1 (decay rate in region 1) = 0.05; c2 (decay rate in region 2) = 0.1; D (transport rate between regions) = 0.1; s (maximum sequestration rate) = 0.5; m (the pollutant level at which sequestration is half the maximum rate) =5; q (which determines the slope of f(P) near P) = 6; σ = 0.05. P stands for amount of pollutant, and f(P) scales the sequestration to the amount of pollutant.