Can the extinction risk of Irish vascular plants be predicted using leaf traits?

Abstract

Globally, 39% of vascular plant species are estimated to be threatened with extinction. Many factors are responsible for this figure; however, in numerous regions the primary drivers of plant extinction remain unknown. In this study, leaf traits were examined to determine whether there is an association between any specific leaf trait and extinction risk for the Irish flora. Ireland has a relatively small flora that is influenced by a temperate, oceanic climate. Fourteen leaf traits were measured for 1,029 angiosperm taxa, primarily from online herbarium images. Extinction risk was based on national Red List assessments for the Irish flora. Multivariate analysis of the data showed no correlation between leaf traits and extinction risk for the Irish flora. One-way ANOVA and Pearson’s Chi-squared tests largely supported this result, with some indication that leaf teeth may be associated with extinction risk. The correlation of extinction risk and leaf traits with phylogenetic relatedness was also considered, with the presence of a phylogenetic signal detected for the distribution of extinction risk across the Irish flora and significant phylogenetic signal observed for individual leaf traits. It was concluded that the leaf traits analysed do not significantly correlate with the extinction risk of the Irish flora and that leaf traits are not a good predictor of extinction risk for this flora.