University of Tokyo and Sekisui House Launch Joint Research on Biodiversity and Health

TOKYO, Dec. 6, 2022  /PRNewswire/ —

– World’s First Research into Relationship between Rich-in-Biodiversity Garden Greenery and Health/Well-being –

The University of Tokyo’s Graduate School of Agricultural and Life Sciences (GSALS) and Sekisui House, Ltd. launched a joint research project on biodiversity and human health on December 1, 2022, to investigate the benefits that biodiversity and urban natural environments have on human health and well-being. This will be the world’s first initiative to comprehensively investigate the effects of interacting with the nearby nature of a garden rich in biodiversity on the health of residents and their attitudes and behavior toward nature.


The Laboratory of Conservation Ecology (*1), Department of Ecosystem Studies, GSALS at the University of Tokyo conducts research on the conservation of urban biodiversity and the management of ecosystem services (the benefits to human society provided by ecosystems). The Laboratory has been studying the relationship between nature and human health since 2016, and its research indicates that interactions with nature can lead to improved human health and well-being. However, the question of how these health benefits might vary depending on the quality rather than the quantity of nature has not yet been explored.

In 2020, the Laboratory investigated how two means of interacting with nature — the frequency of green space use and viewing greenery from the windows of homes — affect the mental health of urban residents (self-esteem, life satisfaction, happiness, symptoms of depression/anxiety, and loneliness). The results of this research showed that not only people who frequently use green spaces, but also those who live in houses with green view reported better mental health (*2). This suggests that people can benefit from the psychological effects of nature from within their own homes even if they are not physically present in green spaces.

Figure: Factors associated with the mental health of urban residents during the COVID-19 pandemic

In the figure, the magnitude of positive (right of the dashed line) and negative (left of the dashed line) effects indicates that each factor has a positive or negative relationship with each mental health measure. For example, "green view" is associated with low levels of depression and anxiety symptoms, while the "impact of COVID-19 on income" is associated with high levels of such symptoms. Analysis of the results showed that experiencing nature can affect mental health to the same degree as factors such as income that have been traditionally regarded as important to mental health.

Since 2001, Sekisui House has been pursuing the conservation of biodiversity by creating green networks in urban residential districts under its "Gohon no Ki" (five trees) Project, a proposal for creating gardens and communities with native tree species of the region concerned (*3). Joint research conducted with the University of the Ryukyus’ Kubota Laboratory and Think Nature Inc. since 2019 has revealed that this focus on planting native garden trees in line with the Gohon no Ki Project has increased biodiversity in urban areas (Japan’s three major metropolitan areas) where biodiversity has declined significantly (*4).

The new joint research project will combine analytical methods developed by the Laboratory of Conservation Ecology at the University of Tokyo’s GSALS with Sekisui House’s Gohon no Ki Project to conserve biodiversity in what is the first attempt worldwide to scientifically investigate the effects of biodiverse garden greenery on human health and well-being. This research will also aim to demonstrate, from the perspective of biodiversity, the importance of creating gardens rich in biodiversity rather than simply "greenery."

The Laboratory is conducting research to test five hypotheses regarding the relationship between human health and interactions with nature under the themes of mental health, physical health, cognitive functions, and community health. For the time being, the new joint research project will focus on two hypotheses related to mental health, and one hypothesis related to cognitive functions. This is, however, a long-term joint research project that will later also look at community health and other themes related to health.


The University of Tokyo GSALS Associate Professor Masashi Soga has commented as follows regarding this joint research project: "People have always turned to nature for relaxation and tranquility, and recent advances in research and technology have made it possible to quantify such intangible health benefits. However, very little is known about the role played by biodiversity in providing these health benefits. If we could shed light on this topic, we may be able to develop the kind of landscape and green space management that supports coexistence with nature because it is desirable from the perspectives of both conserving biodiversity and enhancing human health.

"This joint research project is a large-scale investigation of how interacting with nature in our gardens, perhaps the most familiar nature to most of us, affects our health and well-being. Garden biodiversity is an area that has been difficult to study up to now, but Sekisui House’s nationwide planting data will enable us to conduct the world’s first comprehensive investigation into the relationship between garden biodiversity and human health, and the way people appreciate and interact with nature. Up until now, discussions on the health benefits of nature have tended to focus on relatively large expanses of greenery such as green spaces and forests, but with this new study, we hope to shed light on the importance of actually ‘living with nature.’ Our research outcomes will hopefully be useful to promoting the conservation of urban biodiversity."

The University of Tokyo GSALS and Sekisui House aim to contribute to the conservation of urban biodiversity and creation of a nature-positive society by sharing the findings of the investigation of the way in which interactions with nearby nature in urban environments affect people’s mental health and the way they appreciate and interact with nature.


  1. Soga Laboratory, Graduate School of Agricultural and Life Sciences, University of Tokyo:
  2. A room with a green view: the importance of nearby nature for mental health during the COVID-19 pandemic:
  3. Sekisui House biodiversity conservation initiative (in Japanese):
  4. Sekisui House’s nature-positive methodology (in Japanese):

Supplementary information:

Application of Sekisui House’s Gohon no Ki concept to detached homes:

Application of Sekisui House’s Gohon no Ki concept to a condominium setting:

Application of Sekisui House’s Gohon no Ki concept to community development:

Source: Graduate School of Agricultural and Life Sciences, The University of Tokyo; Sekisui House, Ltd.


Source: University of Tokyo and Sekisui House Launch Joint Research on Biodiversity and Health