DISPERSAL DISTANCE AND ACHENE QUALITY OF THE RARE ANEMOCHOROUS SPECIES ARNICA-MONTANA L - IMPLICATIONS FOR CONSERVATION

In The Netherlands, Arnica montana (Asteraceae) is a, rare plant speci es. Future survival in The Netherlands depends on its; ability to disp erse between source populations and habitats, newly created by man. Pl umed Asteraceae achenes are often considered to disperse over large di stances. Therefore, these species are expected to establish easily dur ing vegetation restoration. In this paper, the flying capability of:pl umed achenes is investigated in a wind-tunnel experiment. An effort is made to establish the correlation between seed quality and flying abi lity. It was shown that A. montana achenes are inefficient dispersers. Pappus size is significantly, but weakly, positively correlated with achene mass. Heavier achenes, therefore, stay closer to the point of r elease than lighter ones. There was a positive correlation between ach ene weight and both germination and seedling quality. Consequently, ge rmination and seedling quality declined considerably with increasing f lying capability of the achenes. It seems that A. montana, despite its plumed achenes, is adapted to an environment where moderate dispersal distances are required, up to several metres. Only low-quality achene s reach larger distances. Since large distance dispersal is a prerequi site of establishment of new populations, establishment of this specie s on isolated sites the Dutch landscape will depend on transport by hu man activity.