Straßen, Kanäle und Bahnanlagen als lineare Strukturen in der Landschaft sowie deren Bedeutung für die Vegetation
Within the intensively used agricultural landscape many common species as such are nowadays restrained to linear structures like railway embankments or roadsides. Regionally linear structures have got an important function for the maintenance of the regional species diversity. Linear structure of high age may be growing places for rare and little moving plants; but these structures are indeed no compensation for near-natural ecosystems, the more so as they themselves are endangered. Roadsides and railways contribute to the spreading of species especially when they are built, because the todays technical possibilities allow earth movements of unexpected dimensions. A moving distinctly along the linear structure is only possible, if there are additional possibilities of establishing, at least for pioneer species. Precondition is, however, an open respectively disturbed Vegetation cover. From the geobotanical point of view, the netting functions of linear structures are of low importance, especially in relation to the neighbouring ecosystems. Roadsides first of all are netting roadsides, nothing more, but also nothing less. Investigations should be done to the following aspects: - Influence of the age of linear structures to the species diversity. - Efficiency of surviving of endangered plant species. - Effects of the unfavorable ratio circumference : area. - Experimental investigations of spreading phenomena. - Importance of linear structures to the Vegetation of other continents than Europe. This however doesnt mean, that the object of investigation „linear structures" will be finally delt with, because of innovations in the traffic technics habitat conditions and species combinations will change.