Verbreitung und Standorte des schmalblättrigen Kreuzkrauts (Senecio inaequidens) und anderer Neophyten in der Stadt Basel (Schweiz)

In the city of Basel (Switzerland) Senecio inaequidens and five other neophytes(Ambrosia artemisiifolia, Berteroa incana, Cynodon dactylon, Helianthustuberosus s.l. and Juncus tenuis) were mapped onto 61 500 m 500 m quadrats. Ateach locality frequency, biotope and soil quality were recorded. In Basel S. inaequidensis moderately spread and sparse. Since its first occurrence on railway areas inthe early eighties of the last century S. inaequidens has started to colonise the city,many individuals or low density stands were observed in this study occuring acrossthe city. In Basel S. inaequidens grows mainly on open soils with humus rich soil orcoarse gravel. A. artemisiifolia, B. incana, C. dactylon, H. tuberosus s.l. and J. tenuisare in Basel sparsely spread and sparse in number. For each species information onthe history of its colonisation, their current distribution, frequency, and its ecologyin Basel are shown and discussed.