Abstract for presentation at Biodiversity Extinction Crisis Conference - A Pacific Response

The global biodiversity crisis requires the application of generalized management rules of thumb to reduce species extinction rates and the negative effects of invasive species. The development of predictive models relating ecological and life history traits to a species fate has received increasing attention in recent years; however, the analysis of a particular set of ecological or life history traits leading to a heightened probability of a species becoming threatened (responding negatively to human activity) or invasive (responding positively) has only been considered in isolation. This lack of a generalized theoretical framework for treating the related yet opposing fates of species results mainly from the confounding effects of phylogenetic units sharing evolutionary histories in cross-species comparisons. We overcame this problem by compiling and analyzing the largest-ever species database (8963 species) from a single plant family, Leguminosae, to evaluate whether those traits leading to higher threat risk are also those that reduce invasiveness. In general, shorter, range-restricted species had lower threat risk, as well as closed-forest and lowland species. Annuals were more likely to be classed as threatened than perennials, and trees were more threatened than shrubs, climbers and herbs. Conversely, species spanning two or more floristic kingdoms and major habitat types had a higher risk of becoming invasive. Likewise, climbers and herbs were generally more prone to becoming invasive than trees and shrubs. The presence of armaments and hairs also increased invasiveness, and the presence of hooks on fruit both increased invasiveness and reduced threat probability. These results confirm the hypothesis that evolved ecological and life history traits establish a fate continuum for species responding to the rapid modification of the planet by humans.