Competition of growth of grass and trees with a ans b
Elsa Boogaard
Lotka Volterra equations

(delta Grass / delta T) = [WUEg]*[Water]*[Grass]*(([Kg]-[Grass]-a*[Trees])/[Kg])

(delta Trees / delta T) = [WUEt] * [Water] * [Trees] * (([Kt]-[Trees]-b*[Grass])/[Kt])