Age-specific and season-specific mollusk damage to seedlings of grassland Asteraceael

seedlings of the montane C. pseudophrygia and the closely related, widely distributed C. jacea revealed similar growth patterns and nearly the same damage, and therefore gave no indication that the lower altitudinal distribution limit of C. pseudophrygia may be caused by a more severe seedling herbivory. In contrast to Centaurea, the highly palatable Arnica montana seedlings were completely consumed within a few days after transplantation, irrespective of age class and without any regeneration events, supporting previous hypotheses that mollusk herbivory is a limiting factor for the geographical range of Arnica montana. In general, the results confirm that a high sampling resolution in time is of great importance to detect agespecific mortality factors in plant population studies.