Summer typhoons from the tropics bring warm; moist air to the southern islands, especially on the Pacific Ocean side.
[3] The Japanese temperate rainforest is home to about 5300 plant species, 40 percent of which are unique to Japan.
[1] The Japanese archipelago was not influenced by the glacier extension in the last ice age;[2] therefore, it provided refugia for many species.
Also, there is no dry, desert area within the islands; thus, flora moved fluently between north and south after the last ice age.
[1] In addition, the Japanese islands are isolated, reducing immigration of organisms from the Eurasian continent.
The understory is dominated by the bamboo Sasa veitchii in most lower elevation sites in western Hokkaido.
Also, Marie's fir, (Abies mariesii), Pinus pumila, oak (Quercus crispula), and Japanese cypress are commonly seen in the cool temperate zone.
The understory is dominated by another bamboo species called Chisimazasa (Sasa kurilensis); willow and shrubs such as (Camellia rusticana) are also common in this zone.
Today, however, society’s attention is being pulled back to the function of Satoyama and people have started to maintain the forest again.
Common disturbances in Japanese temperate rainforests are triggered by typhoons that have a strong influence on both the forests and human populations.
Ongoing losses from land conversion and climate change also represent serious threats to the conservation of Japanese temperate rainforests.