Research & reports

· Wikipedia (ja) · Japan

The Ginza Honeybee Project began on March 28, 2006, keeping Western and Japanese honeybees on Ginza building rooftops, producing and selling honey-based sweets, cocktails, and soap, greening over 1,000 sqm of rooftop space, and providing environmental education to local kindergartens and schools. Honey production grew from 150 kg in 2006 to 800 kg in 2009, and an agricultural production corporation, Ginza Mitsubachi, was established in 2010.

東京都産業労働局 · 東京都産業労働局 · Japan

The official page of the Agriculture, Forestry and Fisheries Division of the Tokyo Metropolitan Bureau of Industrial and Labor Affairs. The division describes its role as promoting production and infrastructure development in agriculture, forestry, and fisheries to raise profitability, while also providing spaces for education and recreation and contributing to countermeasures against global warming; the page links to related policies, press releases, and statistics for agriculture, fisheries, and forestry.

Yuki Iwachido, Himari Katsuhara, Kaho Maehara, Mahoro Tomitaka, Kensuke Seto, Shun Nonaka, Masayuki Ushio, Maiko Kagami, Takehiro Sasaki · Ecology and Evolution · Japan (Yokohama)

A 2026 study of 69 vacant lots in Yokohama, Japan — a city facing potential population decline — quantifying six environmental factors, five ecosystem functions, and the taxonomic and functional diversity and composition of plants, bacteria and fungi, then analysing ecosystem multifunctionality with structural equation modelling, a multiple-threshold approach and generalized linear mixed models. Environmental factors exerted the dominant influence on ecosystem functions, with soil moisture directly enhancing several functions and average multifunctionality. In contrast, spatial aggregation of vacant lots indirectly impaired them, mediated by increased plant richness and altered fungal composition; urbanization affected all ecosystem functions indirectly and had a direct negative effect on average multifunctionality that intensified at higher multifunctionality thresholds. The authors note that dispersed vacant-lot configurations in less urbanized areas may raise multifunctionality while reducing plant diversity, so planning in shrinking cities has to balance biodiversity conservation against multifunctionality. The data show that greening or cultivating vacant lots cannot be treated as simply 'the more the better'.

· 日本建築学会計画系論文集 90巻832号 pp.1219-1230 · Japan

A paper clarifying the value of community gardens created on vacant land and the factors that generate that value; focusing on intergenerational exchange and collaborative activity, it analyzes the effects of reusing vacant spaces in complexes and neighborhoods on local community.

Nakata Taichi, Naoyuki Nakahama, Nobuko Ohmido, Atushi Ushimaru · Journal of Ecology · Japan (Kyoto-Osaka-Kobe)

This study investigated the effects of urban habitat diversity on plant trait diversification in the Kyoto-Osaka-Kobe megacity, Japan, using a common garden experiment with seeds from 23 Commelina communis populations from rural agricultural lands, urban agricultural lands, parks, and roadsides. Urban habitats generally exhibited higher soil pH and land surface temperature. Urban populations, particularly those from roadsides, showed distinct traits such as increased plant height, larger plant height/width ratio, fewer shoots and leaves, and/or larger leaves compared to rural populations. QST-FST comparisons and trait-environment relationships strongly suggest that local adaptation to hot, shaded, and/or eutrophic urban environments drove the observed trait divergence among various urban populations.

Ryotaro HAYASHI, Yasushi Kyutoku, Atsuya SHIMAZAKI, Yoshiki HARADA · Transactions of Japan Society of Kansei Engineering · Japan

This study investigated the applicability of the leisure constraint model to community garden programs in Japan, using an online questionnaire (n=732) on participation constraints across four activity scenarios. Confirmatory factor analysis indicated that the model can be applied to Japanese community garden practices. However, exploratory factor analyses revealed many extracted factors had vague or inconsistent question combinations, suggesting a need for future research to construct a community garden-specific leisure constraint model.

基博 川西, 143997, Motohiro Kawanishi · Kagoshima University Repository · Japan (Okinoerabujima Island)

A survey of flora in seven elementary school gardens on Okinoerabujima Island, Japan, clarified the distribution of vascular plants and compiled a list for educational use. The survey identified a total of 480 species, comprising 211 native, 100 exotic, and 157 cultivated plants. The school gardens were characterized by a large number of native species, including rare and endangered herbaceous plants, indicating their high potential for nature education.

Motohiro Kawanishi · Institutional Repositories DataBase (IRDB) · Japan

A survey of the flora growing in the gardens of seven elementary schools on Okinoerabujima Island, Kagoshima Prefecture, Japan, catalogued the vascular plants present as basic reference material for educational use. A total of 480 vascular plant species were recorded, of which 211 were native to Okinoerabujima Island, 100 were exotic, and 157 were cultivated. The school gardens hosted a large number of plants characterized by a high proportion of native species, including rare plants such as endangered herbaceous species. The survey sites were found to have high potential for use in teaching about the island's nature.

豊島区 · 豊島区 · Japan

The rooftop garden "Toshima Forest" on the 10th floor of Toshima Ward Office recreates the ward's former Musashino plateau, valley, and cliff-line terrain and vegetation, with tanks and biotopes for observing creatures of the Arakawa river system. The Board of Education runs environmental education programs for children linked to the garden, such as returning medaka fish to their habitat.

Nath T.K., Inoue M., Yim E.W., Takahashi S. · International Journal of Agricultural Sustainability · Japan

Using empirical data from two Japanese GIAHS sites, documents features of traditional agricultural practices and their values, including conservation of local crop varieties and revitalization of discontinued farming for rural livelihoods.

Mimura Y. · Journal of Ethnic Foods 11: Article 26 · Japan

Reviews the history, preservation, branding, and scientific research on Kyoto's heirloom vegetables (Kyo-yasai), highlighting how farmers, researchers, and municipalities sustain traditional landrace cultivation amid urbanization pressures.

住友不動産商業マネジメント株式会社, 武蔵野大学工学部サステナビリティ学科 · 武蔵野大学 / 住友不動産 共同プレスリリース · Japan

At Sumitomo Fudosan's Ariake Garden commercial facility, a resident-participatory container garden is launched jointly with Musashino University as a social experiment including urban permaculture workshops and wellbeing evaluation.

横浜市 環境創造局 · 横浜市 都市農業振興基本法に基づく地方計画 · Japan

Yokohama's latest five-year local plan under the Urban Agriculture Promotion Act, organising policies for sustainable farming, farmland preservation, citizen farms, harvest experiences and local consumption building on Midori Up and Megumi-no-Sato programmes.

東京都国分寺市 · 国分寺市 環境報告書 · Japan

Kokubunji's annual environmental report under the basic environment plan, evaluating urban farmland preservation, local consumption and biodiversity while documenting municipally supported programmes such as the Citizen Agriculture University and citizen farms.

Nakata Taichi, Naoyuki Nakahama, Nobuko Ohmido, Atushi Ushimaru · Ecology and Evolution · Japan (Kyoto–Osaka–Kobe)

In Japan's Kyoto–Osaka–Kobe megacity, the genetic diversity and structure of 24 Commelina communis populations were investigated across diverse habitat types, including rural agricultural land, urban agricultural land, urban park land, and urban roadsides. The establishment of diverse habitat types through urbanization was found to have no impact on C. communis genetic diversity and little impact on its genetic structure. This is likely due to the plant's high selfing rate and ability to adapt to urban conditions.

国土交通省 · 国土交通省（令和5年9月策定） · Japan

The core strategy of Japan's Ministry of Land, Infrastructure, Transport and Tourism aiming to mainstream and 'build in' green infrastructure across all sectors with the public and private sectors working in tandem. It sets out seven perspectives—collaboration, community, technology, evaluation, finance, global and digital—and positions a broad range of spaces, including urban farmland and everyday greenery, as multifunctional green social infrastructure for stormwater management, disaster risk reduction, biodiversity, health and community.

Shigita Gentaro, Tran Phuong Dung, Pervin Mst. Naznin, Duong Thanh-Thuy, Imoh Odirich Nnennaya, Monden Yuki, Nishida Hidetaka, Tanaka Katsunori, Sugiyama Mitsuhiro, Kawazu Yoichi, Tomooka Norihiko, Kato Kenji · Breeding Science, 73(3): 263-275 · Japan

Genotyping-by-sequencing of 755 melon accessions in the NARO Genebank identified ~39,000 SNPs to clarify genetic relationships and population structure and to construct a World Melon Core Collection, supporting conservation and use of genetic resources.

Hénaff E., Najjar D., Perez M., Mason C., McMeekin P. · Environmental Microbiome, 18:23 · United States (Brooklyn) / Australia / Italy / Japan

A pilot using three rooftop beehives in Brooklyn, NY, comparing hive substrates (honey, debris, swabs, bee bodies) to map surrounding urban metagenomes, then extending to hive debris from Sydney, Melbourne, Venice and Tokyo. Each city shows a distinct metagenomic profile, positioning rooftop beekeeping as a tool for reading the urban environment.

大阪府摂津市, 農林水産省 · 農林水産省 農山漁村振興交付金事例 · Japan

Settsu City grant case installing signage for disaster-cooperation farmland, showing a municipal public-support model linking urban farmland's disaster and green functions with conservation of citizen farms.

練馬区 · 練馬区 調査報告書 · Japan

Final report of Nerima's review panel building on the World Urban Agriculture Summit, organising directions for publicly supported urban agriculture under four pillars — circulation, environment, fairness and collaboration — including farmland conservation, agriculture-welfare links, ward allotments and outreach.

名古屋市 · 名古屋市 農業振興地域整備計画 · Japan

Nagoya's agricultural revitalisation area development plan, setting the institutional framework for municipally supported urban agriculture through conserving quality farmland, modernising facilities, promoting farmer-led citizen farms and collaborative local land use.

Amelie M. Vanderstock, Cecilia Grandi-Nagashiro, Gaku Kudo, Tanya Latty, Shoko Nakamura, Thomas E. White, Masashi Soga · Journal of Insect Conservation · Japan

An online survey was conducted with 443 adults in Japan to investigate the association between nature and gardening experiences, demographics, species identification knowledge, and biophilia (liking) and biophobia (dislike, fear, and disgust) towards invertebrates. Frequent gardeners were found to be more likely to express biophilia and perceive invertebrates as beneficial, and generally less likely to express biophobia. The results suggest that gardening can serve as a pathway to foster appreciation for invertebrate biodiversity in urban settings.

Yosuke Masuda, Takashi Oka, Erika Yoshinari, Takaaki Nishida, Tadashi Ikeda · Ecological research monographs · Japan

This research collected eight types of administrative plans from local governments across Japan related to the multifunctionality of farmland and reviewed the extent to which they describe these functions. Findings revealed that farmland's multifunctionality was incorporated into many municipal plans, with municipalities of a certain population size and high financial strength index tending to mention these roles more frequently. However, descriptions of functions like "disaster mitigation and response" and "water and food supply" in times of disaster were less common.

横浜市港北区 · 横浜市港北区 · Japan

The rooftop garden at Kohoku Ward Office in Yokohama reopened on April 1, 2022 after waterproofing and flowerbed renovation work. It is positioned as a measure against the heat island effect, for energy savings, CO2 reduction, and environmental education, with about 20 "green supporters" active Tuesdays 10am-12pm. The ward's green coverage ratio is reported to have fallen from 33.4% in fiscal 1992 to 24.1% in fiscal 2019.

中川 睦司, 高橋 秀和, 上田 健治, 渡辺 明夫, 赤木 宏守, 櫻井 健二 · 園芸学研究（Hort. Res. (Japan)）, 20(4): 379-385 · Japan

Using SSR markers on four Akita native eggplant varieties and 46 domestic landraces, phylogenetic and population structure analyses inferred the genetic relationships and likely introduction routes of traditional Akita eggplant cultivars.