Burgruinen als Habitatinseln

Castles are buildings with a very long persistence, they are to be considered as habitat isles. In contrast to other parts of Central Europe castles in the Harz Mountains have not been the object of botanical surveys. 16 castles have now been investigated showing in summary more than 300 vascular plant species. The most frequent plants as well as those characteristic for castles are discussed in detail, considering in particular the wall flora. The following plant communities typical for castles are documented by phytosociological relevés: Cymbalaria muralis eommunity, Asperugo procumbens community, Lappula squarrosa community, Anthriscus sylvestris community, Onopordetum acanthii, Alliario-Chaerophylletum temuli, Lycium barbarum community. Using own investigations and relevant literature data a survey of the castles flora of the temperate region of Europe is given for the first time. Changes of the vegetation caused by castle ruins are discussed in detail. According to the results of the investigations guiding principles for the nature conservation of castle ruins are worked out; deficits in investigations are documented at least.