Effects of region and elevation on adaptation of leaf functional traits of an invasive plant Erigeron annuus in China.
A key scientific challenge relating to the threat of invasive plants on agriculture at the region level is to understand their adaptation and evolution in functional traits. Leaf functional traits, related to growth and resource utilization, might lead to adaptation of invasive plants to the geographical barriers (region or elevation). In the field experiment, we discussed the effects of region and elevation on leaf functional traits on invasive plant Erigeron annuus in farmland habitats in China. We compared leaf size, coefficient of variation (CV) of leaf traits, and fluctuating asymmetry (FA) of E. annuus from three regions (east vs. center vs. west) and two leaf types (vegetative vs. reproductive leaf), and from nine elevations (980-2100 m) in the west region of China. Our results indicated region and leaf type influenced leaf functional traits, and leaf size was significantly higher and CV of leaf traits and FA in reproductive leaves were significantly lower in the east region than in the west and center regions. Elevation and leaf type affected leaf functional traits, and leaf size was significantly higher and CV of leaf traits in reproductive leaves were significantly lower in moderate elevation. E. annuus has higher leaf size and developmental stability (lower CV and FA) in the eastern region due to the longer adaptation period. Therefore, leaf functional traits play an important role in the adaptation of different longitudes and elevations. It can also facilitate the understanding of the invasiveness and adaptation of leaf traits of invasive plants in the agricultural ecosystem during their spread process in China.