The effects of Japanese hop (Humulus japonicus) invasion and its interactions with co-occurring plants under variable environmental conditions
Invasive plant species pose substantial risks to wetland ecosystems, and with increasing globalization, ecosystems are more likely to be simultaneously invaded by multiple nonnative species. The invasive Japanese hop (Humulus japonicus) has been observed to grow over reed canarygrass (Phalaris arundinacea) and other vegetation in wetlands. However, there is limited research on H. japonicus, with few studies looking at its ecology as an invasive species, its interactions with other vegetation, and its role in wetlands. I addressed these knowledge gaps by studying the dynamics of H. japonicus invasion in a floodplain forest and examining its interactions with P. arundinacea under different light and water conditions. I found that H. japonicus reduces species richness and is replacing P. arundinacea stands. Additionally, shade and flooding reduced H. japonicus and P. arundinacea growth. Overall, these results demonstrate that creating canopy closure is an effective way to manage these invasive species.
