The herbarium collections of the Botanical Institute of Barcelona are international references in the study of climate change, evolution of flora, invasion of new species and regression of native flora in the face of changing uses of the land and changes due to climate fluctuations. These collections outline the process of knowledge of the plant world over time. The herbarium participates in national and international programmes studying plant diversity. The living plants and seed collections of the Botanical Garden are aimed at preserving the biodiversity of Catalonia and other regions with a Mediterranean climate, preserving genetic information and growing and re-introducing threatened species. The collections reflect the work on the conservation of threatened flora that has been carried out for many years. The Seed Bank takes part in several international conservation programmes and collaborates with fifteen centres in the Mediterranean region.