The invention relates to a vegetation element for greening artificial or natural surfaces with dicotyledonous plants. The method comprises the step of forming a set of simulation agents representing said device agents, including the steps of, for each of the simulation agents, obtaining a set of agent profiles, and storing said agent profiles in a data store, and obtaining files describing class definitions for the simulation agents, and storing said files in the data store. The shield member may be snugly received in a shield-receiving void of an inner surface of the lens member. The amino acid residue in the first position is a tyrosine or tyrosine derivative.