Traits associated with invasiveness in plants are often connected to dispersal ability or the plants’ capacity to exploit areas of high resource availability (e.g., disturbed areas). However, in low-resource ecosystems, traits that confer resource-use efficiency may be more advantageous. Another possibility is that exhibiting a high degree of plasticity between resource-exploitative and resource-conservative strategies makes a species more adaptable to different environments, and therefore more widely invasive. This study compared invasive and non-invasive species of Pinus for traits associated with exploitative ability (e.g., photosynthetic rate, specific leaf area, root:shoot ratio) and efficiency (e.g., water-use efficiency, photosynthetic nitrogen use efficiency, chlorophyll:N ratio), as well as the species-level plasticity between plants growing in high- and low-nutrient environments.
Results/Conclusions
It was found that invasive pines, by virtue of higher photosynthetic rate, leaf nitrogen content, and SLA, had higher exploitative capacity for sunlight and gas exchange, but did not appear to differ in exploitative capacity for belowground resources. Also, invasive species were more efficient, as indicated by higher photosynthetic rates per unit nitrogen and per unit transpiration. Finally, plasticity was greater in invasives for physiological but not morphological traits when comparing species growing in different nutrient regimes. Invasive species may succeed by being “jacks-of-all-trades” and adapting their resource-capture strategies to the local environment.
