Threat or invasive status in legumes is related to opposite extremes of the same ecological and life-history attributes

Abstract

1. The urgency and scale of the global biodiversity crisis requires the application of generalized predictors of a species' likelihood of going extinct or becoming invasive in non-native areas. A common approach is to correlate species' ecological and life-history characteristics (attributes, traits) with the probability of becoming either threatened (responding negatively to human activity), or invasive (responding positively). The limitation of previous studies is that the fates of becoming threatened or invasive have generally been treated in isolation. 2. Here we consider the problem of threat and invasiveness in unison based on analysis of one of the largest-ever species attributes data bases (8906 species) compiled for a single plant family (Fabaceae). We used generalized linear mixed-effects models (using taxonomic grouping to control for within-family phylogenetic relationships) to correlate species' life-history and ecological traits to three response variables: probability of being (i) threatened or not, (ii) invasive or not, and (iii) threatened or invasive. 3. We found that tall, annual, range-restricted species with tree-like growth forms, inhabiting closed-forest and lowland sites are more likely to be threatened. Conversely, climbing and herbaceous species that naturally span multiple floristic kingdoms and habitat types are more likely to become invasive. 4. Synthesis. These results support the idea that at least for one of the richest plant families, species' life-history and ecological traits correlate with a fate response to anthropogenic global change. Our results show that species do demonstrate particular susceptibility to either fate based on their evolved traits, and that traits generally correlated with invasiveness are also those that correlate with a reduced probability of becoming threatened. © 2008 The Authors.