Abstract
The distribution of blooming plants on the forest floor was investigated in a secondary deciduous broadleaf forest in Nakagawa Town, Tochigi Prefecture, Japan. One hundred thirty-six study grid plots of 5 × 5 m were set up on the forest floor (3,400 m2 in total), and the population of blooming plants in each study plot was recorded. This survey was conducted in 2022 and supplemented in 2023, with a total of 71 species and 9,758 individual plants in bloom. During seasonal changes, the number of blooming species demonstrated a two-peaked pattern in spring and mid-summer, whereas the number of blooming individuals was concentrated in spring. The TWIN-SPAN method was used to classify the number of blooming individuals of each species into eight types according to the presence or absence of the indicator species. The distribution trend of the typological classification of blooming species structure differed depending on the study plot conditions on the floor of the same forest and was largely influenced by the frequency of human use along walking paths and other areas. Higher numbers of blooming species and individuals were observed along the walking paths, which suggests that pressure from human use has caused diversity in the site environment.
