Overlapping fern and Bryophyte hotspots: Assessing ferns as a predictor of Bryophyte diversity

Bryophytes are significant contributors to floristic diversity, but they are often neglected in field surveys and collections. Thus, in order to obtain more accurate estimates of plant richness, there must be reliable estimates of bryophyte diversity. To address this, we examined whether another plant group, namely the ferns, could be used as a surrogate for bryophytes. We used datasets spanning the entire Australian continent for mosses, liverworts, liverworts+hornworts, ferns, and conifers (hornworts were aggregated into the group liverworts+hornworts). Two measures of richness were examined across the continent (as 50 km × 50 km grid cells): uncorrected richness and sample-standardised richness. We calculated the correlations among richness of all of the groups to test the hypothesis that fern diversity predicts bryophyte diversity (because of shared ecological preferences) while conifer diversity does not. Conifers showed very little correlation to either of the four plant groups, whereas ferns were highly correlated to mosses and to a lesser extent to liverworts and liverworts+hornworts. Liverworts, as well as liverworts+hornworts, and mosses were also strongly correlated. These results indicate that surrogates can assist in estimating the diversity and the conservation of other poorly collected plant groups