public static double Calculate_Establishment(ISpecies Species, float PAR, float PressureHead) { double frad = Math.Pow(SubCanopyLayer.CumputeFrad(PAR, Species.HalfSat()), Species.EstRad()); double fwater = Math.Pow(SubCanopyLayer.GetFWater(Species, PressureHead), Species.EstMoist()); return frad * fwater; }