The associations between arbuscular mycorrhizal fungi (AMF) and invasive plants are affected by changes in abiotic factors across altitudinal gradients. However, it is not yet known how AMF association affects the upward expansion of invasive plant in mountains. We conducted a field survey and a greenhouse transplant experiment to compare AMF association and plant growth performance among altitudinal populations of invasive Galinsoga quadriradiata.
Results/Conclusions
In the field, total mass and seed production, as well as root AMF colonization rate, significantly decreased with elevation. When populations were grown in greenhouse, the high-altitude populations achieved higher seed and total mass at lower AMF colonization rate compare to the low-altitude populations. Besides, high AMF association mitigated the intraspecific competition in low-altitude populations, and benefited the individuals to maintain seed production. Our results indicate that high-altitude populations adapted to low AMF dependency and the significance of AMF on the invasion of G. quadriradiata in mountains changes with altitude; AMF association contributes to decreased intraspecific competition and mitigate reproduction loss. It also suggests that high-altitude populations have greater potential to colonize novel habitats. Therefore, the spread of high-altitude populations should be more cautiously monitored.