Previous studies comparing conditions of high versus low resource availability have pointed at differences in key traits that would allow aliens to benefit much more from high resource availability than natives. We generalize this idea by exploring how trait differentiation between aliens and natives changes along continuous resource availability gradients.We constructed a global database of three leaf traits (e.g. SLA, Amass and Nmass) important for plant carbon capturing strategies covering 2448 native and 961 alien species over 88 locations worldwide.Using rank correlations and mixed effect linear models, the relations between plant traits and climatic, edaphic and human disturbance gradients were assessed. Then, we determined how the differences in traits between natives and aliens changed along the same gradients.
Results/Conclusions
On average, across all environments, aliens were found to have higher SLA (2%), Nmass (16%) and Amass (5%) than natives, both globally and when controlling for co-occurrence. Also, higher average trait values were found towards higher resource availability. However, this trait difference between natives and aliens remained constant along the evaluated environmental and disturbance gradients. Also, differences between both groups in multidimensional trait space showed no relation with any of the evaluated gradients. We suggest that although increased resource availability benefits plant performance, these benefits are the same for both aliens and natives. Based on this, we reject the hypothesis that specifically high resource availability promotes invasions by allowing aliens to outperform natives due to differences in key resource acquisition traits.