Geology and botany
Roster had close ties with Elba, an island off the coast of Tuscany, where he spent his vacations, but where he also found a fertile terrain for scientific research. His rigorous and detailed geological and mineralogical notes filled many lacunae in what was then known of the natural history of the island. Furthermore, in 1895, Roster planted at his villa near Ottonella, along the Gulf of Portoferraio, one of the first gardens in Italy dedicated to the acclimation of exotic plants. This was no mere ornament to a gentleman’s estate, but a botanical garden dedicated to study and research. Roster’s work in the area of botany is documented by the numerous scientific papers that he published and his fine botanical photographs.