Asymmetric inter-specific competition between invasive Phytolacca americana and its native congener

Abstract

Interspecific competition determines the invasive capability of alien plants. Phytolacca americana, one of the most destructive invasive plants in China, was first discovered and recorded in China in 1935. Since its arrival, the rapid expansion of the species has driven out a native congener, Phytolacca acinosa. In this study, we assessed the competitive interaction of the invasive P. americana the native P. acinosa in a pot experiment at Yunnan University. Our results indicate that P. americana severely inhibits the growth and reproduction of P. acinosa. Furthermore, P. americana demonstrated a superior resistance against both insect predation and bacterial infection. We suggest that this improved tolerance against herbivory and potentional pathogen damage may be a cornerstone to the invasive success of Phytolacca americana.