Zur Keimungsbiologie von zwölf ausgewählten Ruderal-, Wiesen- und Xerothermrasenarten - Teil 5: Apiaceae

Abstract

Partzsch, M.: Germination biology of twelve ruderal, meadow and xerothermic grassland species - Part 5: Apiaceae. - Hercynia N. F. 45 (2012): 173 – 192. With the present study the series on investigation of germination biology of species from xerothermic and mesothermic grasslands and ruderally influenced habitats should be proceeding because germination is very important for establishment of species and the knowledge of this process is necessary to evaluate the success of restoration of species rich grasslands especially after disturbance. The following twelve species of the family Apiaceae were investigated: Bupleurum falcatum, Cervaria rivini, Conium maculatum, Daucus carota, Falcaria vulgaris, Heracleum sphondylium, Pastinaca sativa, Peucedanum oreoselinum, Pimpinella saxifraga, Seseli annuum, S. hippomarathrum, Torilis japonica.The germination experiments were carried out under three temperature-light regimes (8 / 4 °C, 20 / 10 °C, 32 / 20 °C; 12 h light : 12 h darkness; 45 days), simulating climate conditions in spring, summer and autumn. The collected diaspores were divided in two parts. Germination experiment of the first part was carried out in the year of harvest. The second part of diaspores was buried in soil from November till March, to ensure hibernation until the next experimental phase in following spring. Diaspore viability was tested before and after the experiments.The results show, that Bupleurum falcatum, Cervaria rivini, Conium maculatum, Falcaria vulgaris, Heracleum sphondylium and Pastinaca sativa germinated not or very low, Pimpinella saxifraga, Seseli annuum and S. hippomarathrum germinated between 30 and 50 % and Daucus carota, Peucedanum oreoselinum and Torilis japonica germinated with ca. 70 % in the year of harvest. Peucedanum oreoselinum, Pimpinella saxifraga, Seseli annuum and S. hippomarathrum showed optimal germination under warm conditions, and Daucus carota and Torilis japonica under hot conditions. Germination strongly increased in Conium maculatum, Daucus carota, Heracleum sphondylium, Peucedanum oreoselinum and Torilis japonica in a broad temperature range after hibernation, especially under cold conditions. This suggests a morphological or morpho-physiological dormancy. It seems that the other species have a much deeper dormancy because the germination was not promoted after hibernation. In general, the natural cold-stratification accelerated germination. Concerning the seed bank type, Conium maculatum, Daucus carota, Heracleum sphondylium, Peucedanum oreoselinum and Torilis japonica belong to the short-term persistent type and the other species to the long-term persistent type. Clear relations between life history and habitat preference and the germination behaviour of the species were not found.Results suggest that it needs long-term investigation for evaluation of restoration success on grasslands by the use of species of the family Apiaceae.