The current situation of neophytes in the city of Braunschweig (Germany)

The flora of the city of Braunschweig contains at the moment 342 neophytes (post-1492 aliens). The whole number of vascular plants is 1187. A checklist summarizes the neophytes and information about their distribution and their habitat. 135 of them can be seen as naturalized, 207 as unsteady [till now]. The spreading of the neophytes in Braunschweig occured in general since about 1870. Between 1987 and 2002 the number of newly found neophytes increased by 65 %. The main source for this apparently unlimited influx is the horticulture. Methods and first results of a longtime monitoring for non indigenious species are shown. Remarkably high amounts of neophytes are to be found in the surrounding villages which are incorporated into the city, railway areas and the inland port, river banks as well as borders of urban woods. The occurcnce and association of selected species are documented by plant sociological releves. The effects of the neophytes on the indigenous flora are discussed; till today there is no hint that a neophyte has displaced an autochthonous species. At least the necessary research work is listed