Vineyards as vast, good-quality grasslands develop ecosystems

Grassland is a typical example of nature that is protected by human intervention.Grasslands are said to have covered 30% of Japan’s national land area 130 years ago, but they have dwindled to just 1% today.However, the ratio of endangered plants per unit area is extremely high (Graph on the right), and grasslands play an important role in conserving biodiversity.

In a full-scale ecosystem survey conducted with the participation of researchers from the National Agriculture and Food Research Organization (NARO), the presence of 168 species of insects and 288 species of plants, including endangered species, that appear in the Red Data Book of the Ministry of the Environment, was confirmed at Mariko Vineyard, a Mercian-managed vineyard in Ueda City, Nagano Prefecture. Many rare species, including endangered species, have been found in Jyonohira Vineyard in Katsunuma-cho, Yamanashi Prefecture.

A vineyard cultivated in hedgerow style, with grass grown under the vines, can play a role as a vast good-quality grassland with proper undergrowth cutting, enabling not only highly fertile plants but also native and rare species to inhabit it. In 2019, in order to also investigate the effects of grass growing on grapes themselves, we began conducting a preliminary study of spiders, soil organisms, and birds in the vineyards.

In response to the expansion of the market for Japan Wine, Mercian, whose history dates back to the establishment of Dainihon Yamanashi Wine Company, Japan’s first private-sector winery, plans to expand its company-managed vineyards.

Converting idle farming land into vineyards for Japan Wine will not only contribute to the expansion of the business. It will also create valuable grasslands and lead to the expansion of Japan’s traditional rural Satochi-Satoyama landscapes.

  • ブドウ種

  • Château Mercian Mariko Winery

Trends in grassland area in Japan

  • Trends in grassland area in Japan

    Aggregated from Successive-Year Forest Area Statistics and MAFF Statistical Tables

Number of endangered species by unit area

  • Number of endangered species by unit area

    Endangered plant species per hectare
    Source: Western Japan Grasslands Research Group (2007)

Surveys in the process of converting idle farming land into vineyards

the Tengusawa Vineyard in Koshu City, Yamanashi Prefecture, NARO and the Kirin Group are conducting a rare joint research project on a global basis to study changes in the ecosystems as a piece of idle land is converted into a hedgerow-style vineyard. In 2016, the land was still idle. Only an extremely small number of insect and plant species were found in the Tengusawa Vineyard, due to damage from deer eating the vegetation. Since the area was fenced and reclaimed in 2017, the landscape has changed to one like a vineyard, and we are seeing how the ecosystem has become richer during this process. In our research on insects, we use butterflies as an indicator, and the number of species quickly increased to 16 in 2019 from 13 in 2018. We will continue to conduct surveys over the next several years to test the hypothesis that vineyards cultivated in hedgerow style, with grass grown under the vines, on idle lands will enrich the ecosystem.

Rare species discovered

Mariko Vineyard

  • Zygaena niphona niphona

  • Sophora flavescens

  • Hemerocallis ctrina var. vespertina

  • Argyronome laodice japonica

  • Leonurus japonicus

  • Vincetoxicum pycnostelma

Jyonohira Vineyard

  • Platycodon grandiflorus

  • Cephalanthera erecta

The process of converting idle and devastated land into vineyards in Tengusawa Vineyard

Revegetation activities

In 2016, under the guidance of NARO, our employees began participating in activities to regenerate rare and native species and confirmed that native species have already taken root.In 2019, native species with blooming flowers were there to stay, and the field became like a flower garden in autumn. Furthermore, we began along with an international NGO Earthwatch Japan and its volunteers, an activity to revegetate Sophora flavescens, which is not a rare species at the national level, but is the sole grass used for feeding Shijimiaeoides divinus, an endangered IA (CR) butterfly. Volunteers are asked to bring Sophora flavescens back and raise them at home, and we will eventually plant them at the Mariko Vineyard.

  • Rare and native species regeneration activity

  • Flowering native species were stayed

  • Sophora flavescens revegetation activity