Life-history correlates of plant invasiveness at regional and continental scales

We implemented cross-species and independent-contrasts multiple regression models to compare life-history correlates of invasion success between regional and continental spatial scales among non-native plants of eastern Australia. We focussed on three life-history traits that represent major axes of variation in plant life history: specific leaf area (SLA), plant height and seed mass. After controlling for residence time and cross-correlation with other life-history traits, small seed mass was significantly and uniquely correlated with invasion success at continental and regional scales. High SLA was significantly and uniquely correlated with invasion success at the continental scale only. Plant height could not explain unique variation in invasion success at either spatial scale. Variation among spatial scales in the significance and strength of life-history relationships with invasion success suggests that the search for predictive tools of invasion need not be fruitless, as long as predictive investigations are targeted at appropriate spatial scales.