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. inaequidens is moderately spread and sparse. Since its first occurrence on railway areas in the 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 across the city. In Basel S. inaequidens grows mainly on open soils with humus rich soil or coarse gravel. A. artemisiifolia, B. incana, C. dactylon, H. tuberosus s.l. and J. tenuis are in Basel sparsely spread and sparse in number. For each species information on the history of its colonisation, their current distribution, frequency, and its ecology in Basel are shown and discussed.