SUSTAINABILITY

The Moat Project*3 was started in collaboration with the Ministry of the Environment. It's the first private-sector business endeavor that takes up the challenge of bringing back the living creatures that originally existed in the Imperial Palace moat. Water quality worsened after the water flow from the Tama River ceased in 1965, and although our company has been helping improve the waterfront environment, including installing a water-cleaning facility for the moat in the basement of the Otemon Tower ENEOS Bldg., the Moat Project is an endeavor that can be said to go a step further. It collects endangered water plant species, small living creatures, and mud and cultivates them in biotopes*4 on the roof of our company's building and Hotoria Square.

When I first heard of the Moat Project, I was excited at the challenge of bringing back rare species and passing them on to future generations. The endeavor is in itself unique, but its method of approach that incorporates various people and organizations also has value. Rather than being carried out by Mitsubishi Estate alone, it's a collaborative effort among government, NGOs, and specialized agencies. I believe many ordinary people have also participated in collecting wildlife at the moat and introducing them to Hotoria Square.

When the collected mud was placed in an environment managed in the experimental site in Hotoria Square, seeds that had been dormant sprouted, and the water plant, Mizohakobe (waterwort) that no longer lives in the moat was revived. The seeds in the mud also included three species of rare water plants on the Red List in 23 Wards of Tokyo.

When seeds are dormant for a long time, they eventually die. I think it's extremely valuable that they were moved to a different place and an environment was created so they could sprout.

Now they're being safely cultivated at the biotopes, but at first it was difficult. We were truly lucky to have found endangered species since we didn't know at first if there were any seeds in the mud. Not knowing what kind of environment these kinds of delicate plant species preferred, we had to fumble through everything including pH, managing water temperature, and adjusting water current.

Marunouchi is striving for urban development that nurtures greenery throughout the area in both hard and soft infrastructure, such as the Moat Project. TOKYO OASIS is a service that visualizes the allure of greenery so that it can be enjoyed. Sites in the Marunouchi area where people can enjoy the outdoors are listed as OASIS SPOTS. Users can easily search for a route to those spots on a smartphone and enjoy a pleasant walk outside. The service was launched on a trial basis in the summer of 2020, and new functions were added based on comments from people who tried the service. A field test was again started in July 2021. The service is available in five languages and can immediately be used without having to register or install an app. It can also be readily used by inbound tourists who are visiting.

TOKYO OASIS is based on the Marunouchi Environment Atlas, an information platform developed by the Ecozzeria Association that turned environmental information on the Marunouchi area into a database. It digitalized hourly information on shade cast by street trees and buildings. I think this upgraded version is distinctive for including places to sit down and information on individual trees in the area.

When developing the service, we paid careful attention to how to handle the various ideas people have regarding ‘enjoyment.’ For example, we prepared three routes to OASIS SPOTS, one for shady sites, one for sunny sites, and one for the closest site. At first, we focused on summer routes offering shade that hinged on ‘coolness,’ but the meaning of ‘enjoyment’ isn't fixed even for the same person. For instance, people may want to walk in the sun even in summer after having been in a cool, air-conditioned place for a long time. We want each individual to find comfort that suits them by choosing to use the service. In addition to Hotoria Square that was mentioned earlier, OASIS SPOTS include places to relax, open spaces, and parks.

I think the attraction of greenery is not only plant life such as trees, but everything it encompasses such as the environment and spaces the greenery creates. TOKYO OASIS reflects the shade made by trees in the shady routes, and by surveying each of the approximately 3,500 trees in the area, it introduces information like the tree species and heights, as well as the amounts of CO2 absorbed and carbon storage. In the background is the idea that the love for greenery, which is part of the attraction of Marunouchi, will grow through users learning about the role of trees.

The role of greenery in decarbonization is extremely important. On that point, as a new initiative our company is starting a biomass power generation project that utilizes street trees. This project reuses branches from street trees that have been pruned for maintenance as fuel for biomass fuel generation with the aim of producing regional recycling-oriented power generation using renewable energy. There is also a plan to use the pruned branches from trees introduced in TOKYO OASIS in this way in the future. Marunouchi is an area that has succeeded in an advancement of symbiosis with nature not seen elsewhere in the 23 wards of Tokyo. Greenery has become an element of people's well-being in various aspects. In day-to-day settings as well, people's impressions of the area will greatly change because of an abundance of trees and plants.

The field testing for TOKYO OASIS has just started. To continue considering what constitutes an enjoyable walk outside, we intend to gain more feedback from users to bring together Marunouchi and people, which will lead to discovering new attractions and value in the area. For instance, it would be great if the service could visualize the allure of the changing four seasons by suggesting places to go to in different seasons, such as places fragrant with flowers and where migratory birds can be seen.

In the Moat Project, going forward our company will work to increase spaces like Hotoria Square through other development projects. Finding optimal solutions isn't simple, since site conditions and development concepts differ for each building, but we're searching for such approaches as ways to leave behind diverse wildlife for future generations. It would also be ideal if we could collaborate with other area businesses to tackle creating such spaces together instead of going it alone.

Matsui: The Ecozzeria Association is working on other endeavors to communicate the attraction of greenery in addition to TOKYO OASIS. The nature program called Shizen no Copain (Nature's Friends) offers opportunities for people to connect with nature and others by looking at nature in a new way. Plus, we've joined the executive committee for the Marunouchi Honey Project, which collects honey produced in Marunouchi, in an effort to build a community and energize the area through activities entailing beekeeping, commercialization of honey, and sales. Through these various activities, we hope that Marunouchi is accommodating to both people and nature, and becomes an area where that interconnection is apparent. We also aim to take action by cooperating with various bodies including government, companies, and groups to increase the quality and amount of greenery that reaches beyond the Marunouchi area, which is interlaced with the greenery of the Imperial Palace, by forging further connections to greenery in other surrounding areas.