Verbreitung, Vergesellschaftung und Ökologie der Wiesen-Siegwurz (Gladiolus imbricatus L.) in Sachsen

Abstract

Hänel, S.; Müller, F.: Distribution, phytosociology and ecology of Gladiolus imbricatus L. in Saxony. – Hercynia N. F. 39 (2006): 69– 87.This study investigated the occurrence of Gladiolus imbricatus at the western border of its distribution area in Saxonian Upper Lusatia. The species has noticeably declined in Saxony. There are currently only seven known populations, only three of which contain a considerable number of individuals. The main reasons for its decline are the intensification of grassland management, the reverting of grassland to scrub following the cessation of traditional hay cropping, and increasing shade in its woodland habitats as a consequence of the abandoning of coppice- and middle-storey management. The recent occurrences of Gladiolus imbricatus are in both grassland and woodland habitats. The latter belong to the Stellario- Carpinetum association; the grassland habitats belong mainly to the Molinietum caeruleae association and in one case to the Crepis paludosa-Juncus acutiflorus community. The species is shown to grow in moderately to strongly acidic, humic soils. For the first time it is possible to establish ecological indicator values for Gladiolus imbricatus from measured ecological data, the calculation of indicator values of the relevés, and the phytosociology. The species reacts to decreasing illumination by reducing its dominance and fertility. The threat category of “highly endangered” in the German Red List of threatened plants is too low and should be changed to “threatened by extinction” in a forthcoming new version. Finally, protective measures are suggested that would help conserve the last Saxonian populations.