Natural Water Sanctuary Okudaisen Initiatives

Enabling Next-Generation Trees to Renew the Forest

A part of this sanctuary is home to tall Japanese beech and Japanese Oak trees. Unfortunately, however, the forest floor in this area had become overrun with bamboo grass, making it difficult for young next-generation trees to take root and grow.

Bamboo grass covering the forest floor beneath Japanese beech and Japanese Oaks

To provide room for young trees, we cleared part of the dense bamboo grass undergrowth. We also carried out a process called ground scraping, where the soil is exposed as much as possible to encourage fallen seeds to germinate. These efforts eventually created a favorable environment for young next-generation trees to begin growing.

Since bamboo grass can quickly regrow from underground rhizomes, we continue to clear the bamboo once a year to maintain the environment.

Measures to Prevent Oak Trees From Withering

In recent years, a disease known as oak withering—which causes various oak species to wither and die—has been spreading across Japan. Natural Water Sanctuary Okudaisen has not been immune to its impact. The photo below shows a neighboring forest of our Natural Water Sanctuary Okudaisen. Despite it being summer, the Japanese Oak trees have turned reddish-brown due to the disease.

A forest turned reddish-brown from oak withering

A section of our Natural Water Sanctuary Okudaisen once featured a stunning grove of Japanese Oak trees over 100 years old. But oak withering had crept dangerously close to it.

A stand of Japanese Oaks over a century old

Had the disease reached this area, not only would the Japanese Oaks have been wiped out, but there was also a risk of it spreading throughout the surrounding forest. As a result, with permission from both the landowner and Japan’s Ministry of the Environment, we decided to carry out preventive harvesting of all the Japanese Oaks in this area.

After preventive clear-cutting of Japanese Oaks

We carefully considered the best use for the harvested Japanese Oak trees. Logs with straight grain, free from warping or twisting, were made into whisky barrels, while the rest was effectively repurposed as flooring for the Suntory World Research Center.

The area where the trees were harvested is now being monitored and nurtured into a forest with greater tree species diversity.

Learn more about pest and disease control

Nature-Experience Education for Children

Our Natural Water Sanctuary Okudaisen is not only a place for research and forest maintenance, but also serves as a classroom for Outdoor School of Forest and Water as part of Suntory ”Mizuiku” - Education Program for Nature and Water that teaches children the importance of forests and water. Children explore the forest in person, touch trees and leaves, search for living things, and engage in various nature experiences.

Working with the Local Community

We are participating in the Tottori Symbiosis Village program promoted by Tottori Prefecture. This initiative involves soil conservation and management of unused farmland near the Okudaisen Bunanomori Water Plant. It also supports local agriculture and the development of processed food products, contributing to the community's growth.

As part of this effort, we worked with local farmers to cultivate buckwheat, which is now used to make buckwheat noodles, a local product sold under the name “Okudaisen Mitsukue Soba.”

Suntory staff sowing seeds alongside local farmers