0000000001026623
AUTHOR
Andreas Prinzing
Does an ant-dispersed plant, Viola reichenbachiana, suffer from reduced seed dispersal under inundation disturbances?
Many plant species use ants as seed dispersers. This dispersal mode is considered to be susceptible to disturbances, but the effect of natural, small-scale disturbances is still unknown. We investigated how small-scale disturbances due to inundation affect seed dispersal in Viola reichenbachiana, a dominant myrmecochorous herb in riparian forests. Inundation disturbances were high in depressions and low on hillocks of the forest floor. We found that V reichenbachiana was similarly abundant at highly and less disturbed sites, contrary to other, non ant-dispersed species. We also found that the motivation of ants to disperse seeds was higher at highly disturbed sites. Nevertheless, the number…
Geographic variability of ecological niches of plant species: are competition and stress relevant?
A species’ niche position may differ strongly between geographic regions, for instance due to the effect of competitors or ecophysiological stress. However, it is unclear whether such strong geographic niche variation is the rule or the exception. We compared the niche positions of plant species between central England and eastern central Europe (as available from the literature), using phylogenetically independent contrasts. We found that most species occupied similar niche positions in both regions. More importantly, we found that niche variation was not higher in species susceptible to competitive displacement. Nor was niche variation higher in species that reach the edge of their range …