De flora van het Urbaan district

The urban areas in the Netherlands can be considered as a separate flora district; the so-called “Urban district”. It consists of large stony areas, with a “steppe”-like environment and a deviant climate. Characteristic for urban areas are often disturbed and trampled communities of ruderals and pioneers which are mostly dominated by species with a cosmopolitan distribution. Even more specific is the large number of thermophilic species, among which are a remarkable number of neophytes. Furthermore cities provide accomodation for wall vegetation. Plant species that show a strong preference for the urban environment are listed in Species list 1. The species that occur in the cities, but also in other areas in the Netherlands are listed in Species list 2. The Urban district comprises in any case all city centres, the larger ports and industrial areas (e.g. Rijnmond and IJmond), large railway yards and walls covered with vegetation.