2018 年 24 巻 p. 303-308
In recent years, the alien aquatic weed Egeria densa found in the river mainstream, has been reported in many other rivers. Intrusion prevention and control of this species is desired for both ecological conservation and river management. In this study, we determined the distribution of this species by using environmental DNA analysis in the broad area of Yamaguchi prefecture and we estimated the potential habitat by using GIS and maximum entropy modeling (Maxent). These results showed that the distribution of E. densa has already widely expanded in the Yamaguchi prefecture and there is a risk of invasion and overgrowth in the wide area except for in the mountain stream.