The interspecific competition between Humulus scandens and Alternanthera philoxeroides

Bioinvasion has become a serious environmental problem in the world in general and is considered the second biggest threat to biodiversity. Alternanthera philoxeroides is widely distributed and causes the most serious threat to biodiversity in China. The traditional physical or biological control methods are not effective in controlling the invasion and extension of A. philoxeroides. In the present paper, some physiological characteristics of Humulus scandens and A. philoxeroides were investigated in the field and laboratory. The results showed that H. scandens is more competitive than A. philoxeroides, the competitive rate (CR) of H. scandens against A. philoxeroides was 9.834. Additionally, the leaf, stem, and root biomass of A. philoxeroides decreased significantly when the two species co-occurred. Thus, the invasive abilities of these two invasive plants are different and H. scandens strongly inhibited the growth of A. philoxeroides. Moreover, as an annual herb, H. scandens can be easily eliminated by harvesting before its seeds mature. The result suggests that sowing seeds of H. scandens in the habitats invaded by A. philoxeroides could be an ideal biological control method.