Introduction 9 2. Learning from generations of sustainability concepts 25 3. A Generically Parameterized model of Lake eutrophication (GPLake) that links field-, lab-and model-based knowledge 4. A Generically Parameterized model of Lake eutrophication: the impact of Stoichiometric ratios and constraints on the abundance of natural communities of phytoplankton (GPLake-S) 91