札内川における礫州へのケショウヤナギ実生の侵入と保全管理に関する検討

抄録

The purpose of this paper is to deal with studying on the invasion and conservation management of Salix arbutifolia seedling on gravel bed river in the Satsunai River. Firstly, we explored the seedling density by field surveys based on aerial photo over about 23km. Secondly, we conducted the vegetation survey by belt transect method in the same target area. Finally, we analyzed these data using GIS(ArcGIS10.6). As a result, we found willow trees were widely distributed close to waterside in this section. Especially, S. arbutifolia seedlings tended to be growing more in waterside than those of many other willow trees. We conclude that conducting the excavation to maintain double-row bars at the time of flash discharge can contribute to the graded age structure of S. arbutifolia formation because it can reduce the disturbance impact against seedlings growing along the waterside