Relationship of sex ratio with stem inclination and stand condition in Urihada maple (Acer rufinerve)

Abstract

There is a population of Urihada maple dominated by female trees at a high elevation in Wakasa-cho, Tottori Prefecture. Compared to the surrounding populations with few female trees, there was a clear difference in the growing environment. Therefore, we expanded the scope of our survey to 610 trees at 30 sites growing at low to high elevations in eastern Tottori Prefecture, and considered the site environment in which many female trees appeared. Female trees of Urihada maple were most frequently found on inclined trees in areas with deep snow cover. In addition, most of the inclined trees growing in environments such as silver grass fields were female trees. These inclined trees in the silver grass field were thought to have suffered a temporary water shortage due to a combination of root system damage and a sunny environment, which caused many individuals to sexually change from male to female trees.