Abstract
Betula davurica (Asian black birch) is distributed in the central Honshu and Hokkaido regions of Japan. In these regions, the distribution of B. davurica is controlled by microtopography and surface soil. However, the factors affecting the distribution of B. davurica forests have not been studied in detail.
In this paper, we discuss the distribution characteristics of B. davurica forests and surrounding forests using data compiled from field surveys. We also examined the factors affecting the distribution of B. davurica forests on a landslide area on Mt. Takashino in the Soto-Chichibu Mountains.
Many B. davurica trees grow on the stony soil of gentle slopes in the landslide area. This stony soil originated from landslides of earth and sand during a period of dozens of years. In this area, the main local species, Quercus crispula and Quercus serrata, have low dominance. The main factors affecting the distribution of B. davurica forests are the characteristics of the landslide area. It is easy for seeds and seedlings to invade and grow on the gentle slopes, and the landslide forms a large canopy gap periodically. B. davurica can invade this canopy gap much faster than other species, as it has a rapid growth rate. Therefore, we concluded that B. davurica can form forests on landslide landforms.
