2024 Volume 23 Issue 2 Pages 63-70
The present study examined seven years of birch regeneration after clearcutting the fir, Abies sachalinensis, plantation, and scarification treatment in the Eniwa National Forest, Hokkaido. The clearcutting and scarification treatment was conducted in 2016. The test had four settings based on the combination of the presence/absence of scarification treatment and a deer-proof fence, which surrounded a part of the plot. Regeneration of tree species, including birches, was examined in 2018, 2019, 2021, and 2023. The cover and average stand height of the dwarf bamboo, Sasa senanensis, which competes with the tree species, were also measured. Results indicated that the cover of S. senanensis reached nearly 100% except in the scarified area outside the fence, and the average stand height recovered to approximately 80–110 cm. Prominent differences were found in the sapling density and the height of birches between inside and outside the deer-proof fence. Inside the fence, the sapling density tended to be larger in the scarified area than in the control area. In 2023, seven years after the treatment, the density of the birch saplings higher than 150 cm reached 18,000 / ha in the scarified area in the fence. All of the saplings outside the fence were less than 150 cm tall. These results showed that the scarification treatment after clearcutting the fir plantation was effective for the natural regeneration of birches.
