Keio Forest: Shizugawa Forest | Tomohiro Ichinose, Dean of the Faculty of Environment and Information Studies
2024.05.28
Just a year ago, in the Okashira Nikki (Dean's Diary) entry published in May 2023 , I briefly introduced the Keio Forest (school forest). This time, I would like to focus on the Shizugawa Forest, which is the largest section of it. The Shizugawa Forest is the largest school forest, with an area of 63 hectares, accounting for 40% of the entire Keio Forest. The name Shizugawa comes from the former Shizugawa Town, which merged to become Minamisanriku Town. Located in the northeastern part of Miyagi Prefecture, it is an area known for its beautiful ria coastline, but it is also known for the devastating tsunami damage it suffered in the Great East Japan Earthquake of March 2011. Minamisanriku Town is a rare municipality where all its borders are watersheds, and the Shizugawa Forest is adjacent to Ishinomaki City and Tome City. Most of the forest is a plantation of conifers such as Japanese cedar, while the higher elevations are covered with deciduous broad-leaved trees like konara oak.
My research group has started environmental monitoring in the Shizugawa Forest as part of the SFC Sustainable Campus Program. Last fiscal year, we conducted aerial surveys of the entire area using drones, as well as surveys of mammals, birds, and insects in June, August, and January. In January, accompanied by staff from Tokyo Power Technology Co., Ltd., we also took measurements to estimate the amount of biomass stored in the trees.
Figure 1 is a composite of aerial images taken in January. The green areas are plantations, while the white and brown areas are deciduous broad-leaved forests. The contrast between the two is clear. For mammals, we installed camera traps in the forest and identified species from the captured images. A total of 11 species were photographed, including the Japanese serow, designated as a Special Natural Monument, as seen in Figure 2, as well as sika deer, Japanese badgers, and Japanese hares. Although an Asian black bear was reportedly photographed in the past, we could not confirm its presence last fiscal year. As for birds, 36 species were recorded, including the Japanese thrush, copper pheasant, and Sendai's warbler. Since the survey of birds during the breeding season was not sufficient, the number of species is expected to increase in the future. Regarding insects, although only limited surveys have been conducted so far, we have recorded 47 species, including the stag beetle *Dorcus striatipennis*. These surveys are scheduled to continue in fiscal year 2024, and we just conducted a survey on the weekend right before this Okashira Nikki entry was published.
Until 20 years ago, golden eagles inhabited the Minamisanriku region, including the Shizugawa Forest. Golden eagles are large birds of prey with a wingspan of over 2 meters; their breeding success rate has dropped sharply in recent years, and they are designated as an endangered species. In the Minamisanriku region, the Golden Eagle Habitat Restoration Project is underway, and the school forest is contributing as one of the target sites. Minamisanriku Town and Keio University have signed a partnership agreement, and the Minasan MIRAI Project is also in progress. Its use is expanding, with students from affiliated schools visiting the site. It is an environment completely different from the city—for example, there is no cell phone reception in most of the school forest—but it is a place where one can experience a rich natural environment.