Neophytengesellschaften der Klasse Artemisietea im südöstlichen Niedersachsen
Till now in Northern Germany neophytic plant communities were hardly noted. In the present paper the sociology of the following species is investigated for the first time for the south-eastern part of Lower Saxony: Anstolochia clematitis, Aster lanceolatus, Aster tradescantü, Claytonia perfoliata, Erigeron annuus, Helianthus tuberosus, Impatiens parviflora, Parietaria officinalis, Reynoutria japonica, Rey-noutria sachalinensis, Solidago canadensis, Solidago gigantea and Tulipa sylvestris. To classify the often character-speciesless communities the deductive method of KOPECKY & HEJNY is used. Most of these neophytic plants have their chief importance in skirt communities of the order Galio-Caly-stegietalia, first of all in Aegopodion and Lapsano-Geranion. In contrary to the western and southern parts of central Europe they are hardly no object in bank eommunities. Their occurrence accumulates in ancient towns, especially like Brunswick. The rieh Stands of Parietaria officinalis and Tulipa sylvestris in Brunswick should be shown off here. During this work, the great importance of ancient parks for pro-tection of species turned out: Numerous species are able to hold their ground in the border of bushes. Solely the spreading of Solidago gigantea and Solidago canadensis has taken a threatening extent: At edges of the forests both Solidago species penetrate into native plant communities and destroy them. De-positing ofgarden refuse is the main reason of their quiek spreading. A list of plant communities belonging to the classes Artemisietea till now known for the eastern part of Lower Saxony is presented; probably it is valid for whole Lower Saxony.