土器川河川敷における特定外来生物アレチウリの実生の発生と定着

抄録

Invasive alien plants have encroached and outcolonized many native species in almost all Japanese river floodplains in recent years. Sicyos angulatus is one of the most notorious invasive alien lianas. To select the effective season for exterminating S. angulatus, S. angulatus colony is explored seedling dynamics of S. angulatus in the Doki River floodplain from May to July 2020. Germination of seedlings of S. angulatus were started from early May in the part of the study area, and it gained momentum in July after beginning the rainy season. Many seedlings were dead around four weeks after germination, specifically, 59%, 78%, 38% of seedlings were dead respectively that germinated in May, June, July. The results of the model selection in generalized linear mixed models revealed that the rate of seedling death was determined by litter thickness and sky view factors. Almost seedlings that located a suitable site to survive were germinated in July. It was concluded that early August is the best season for exterminating S. angulatus in Doki River.