More on the biogeography of scarce vascular plants

A recent study of the distribution of 139 British scarce plants (Quinn et al., 1994, Biol. Conserv., 70, 149-57) found that degree of aggregation was correlated with habitat, dispersal ability (in space) and pollination type. Our reanalysis using a different classification of dispersal in space and new data on dispersal in time shows no relationship between aggregation and dispersal in time or space. We argue that present distributions of scarce plants are largely the product of recent habitat loss and that correlations with dispersal characteristics are therefore unlikely to be found.