Sustainable use of biological resourcesVineyards

Vineyard ecological survey for Japan Wine

We have invited researchers from the National Agriculture and Food Research Organization (NARO), and have been conducting ecological surveys of farmland producing raw materials in Japan since 2014. At Château Mercian Mariko Vineyard, on the Jinba Plateau in the Maruko district of Ueda City, Nagano Prefecture, we confirmed the existence of 168 species of insects and 288 species of plants, including endangered species listed in the Red Data Book of the Ministry of the Environment. Many rare species, including endangered species, have also been found in Jyonohira Vineyard in Katsunuma-cho, Koshu City, Yamanashi Prefecture. Both of these vineyards are cultivated in hedgerow style.
For this reason, we believe that converting idle farming land into hedgerow-style 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 and protection of Japan’s traditional rural Satochi-Satoyama landscapes.

  • ブドウ種

  • Château Mercian Mariko Winery

  • Mariko Vineyard

Rare species discovered

Mariko Vineyard

  • Zygaena niphona niphona: Near threatened species on the Ministry of the Environment and Nagano Prefecture Red List

  • Sophora flavescens: The only edible grass for feeding Shijimiaeoides divinus , a butterfly that the Red List of the Ministry of the Environment lists as critically endangered IA (designated as endangered IB by Nagano Prefecture)

  • Argyronome laodice japonica: Vulnerable species on the Ministry of the Environment's Red List. Near threatened species on the Nagano Red List

  • Hemerocallis ctrina var. vespertina: Near threatened species on the Nagano Red List

  • Leonurus japonicus:Near threatened species on the Nagano Red List

  • Vincetoxicum pycnostelma: Near threatened species on the Ministry of the Environment and Nagano Prefecture Red List

Vineyards as vast, good-quality grasslands develop ecosystems

Grassland is a typical example of nature that human intervention protects. 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 (see figure on the right), and grasslands play an important role in conserving biodiversity.
A vineyard cultivated in hedgerow style, with grass grown under the grapes, can play a role as a vast good-quality grassland with proper undergrowth cutting, enabling the development not only of highly fertile plants but also native and rare species. In response to the expansion of the market for Japan Wine, Mercian, whose history dates back to the establishment of the Dainihon Yamanashi Wine Company, Japan’s first private-sector winery, plans to expand the vineyards that it manages, which will contribute to the creation of grasslands. In 2019, in order to also investigate the effects of grass growing on grapes themselves, we began conducting a study of spiders, soil organisms, and birds in the vineyards.
For spiders, we start by investigating what they eat. Surveys of spiders in Japan Wine vineyards are rare, and we have already confirmed the existence of certain spiders in Nagano Prefecture for the first time.
We have also confirmed the existence of 55 birds from 7 species in vineyards, and 87 birds from 21 species in forests adjacent to vineyards. We observed many larks, buntings, pheasants, and tits, suggesting that vineyards are functioning as an alternative to grasslands, which are in sharp decline in Japan. We also found eggs, including lark and bunting eggs, in the vineyards, indicating that they also function as a valuable nest site for birds using the grassland environment.
We are also investigating earthworms, a kind of soil organism, on an ongoing basis.

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 at Jyonohira Vineyard

Jyonohira Vineyard in Katsunuma district of Yamanashi Prefecture is a vineyard operated by Mercian that started vertical shoot positioning cultivation in 1984 in an attempt to produce the finest Cabernet Sauvignon in Japan.
In surveys conducted between 2018 and 2019, we found many rare species, including Japanese bellflower (Platycodon grandiflorus) and silver orchids (Cephalanthera erecta), which the Red Data Book of the Ministry of the Environment designates as endangered.
More than 30 years have passed since we began cultivation, and we are very careful when cutting the grass, partly because it is a relatively small vineyard, which we speculate is the reason we can see these rare species.

  • Careful mowing at Jyonohira Vineyard

  • Platycodon grandiflorus: Vulnerable species on the Ministry of the Environment's Red List and near threatened on the Yamanashi Red List (NT)

  • Cephalanthera erecta: Vulnerable species both the Ministry of the Environment's Red List and the Yamanashi Red List (VU)

Studies into the process of converting idle farming land into vineyards

At Tengusawa Vineyard in Koshu City, Yamanashi Prefecture, we are collaborating with NARO to conduct a research project that is rare even on a global basis, relating to changes in ecosystems as a piece of idle farming land is converted into a hedgerow-style vineyard that can be harvested.
When we investigated idle farming land prior to its cultivation in 2016, we found only insect and plant species extremely lacking in diversity, as a result of damage from deer eating the vegetation. Since we fenced and reclaimed the area 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 vegetation surveys, we found that the flora was remarkably low in diversity owing to feeding damage from deer before development, but after development, it gradually changed from a plant colony of annual grass to one of perennial plants. At present, the amount of nekohagi (Lespedeza pilosa) and lawn marshpennywort (Hydrocotyle sibthorpioides), both indicator species for the quality of grassland, is increasing, and there are also signs of reedgrass. Through such signs, we have confirmed that the area is becoming a high-quality grassland. The insect survey monitors butterflies as an indicator. Before development of the vineyard, the only noticeable butterflies were the pale grass blue and browns. It appeared the reason for this was because, as we confirmed in vegetation surveys, the diversity of vegetation was extremely low due to feeding damage by deer, and only plants (edible grasses) in that these larvae could eat remained. Around 2019, thanks to the diversification of vegetation on the slopes, the number of edible grasses such as mugwort and red clover increased, and we observed many painted ladies (Vanessa cardui), clouded yellows, and common grass yellows. Considering that we were unable to conduct the survey in the spring of 2020 owing to the COVID-19 pandemic, we expect that the ecosystem has actually become even richer.

  • Rich vegetation inside the fence (left), and outside the fence where there are generally only fountain grass and bull thistles as a result of feeding damage by deer

  • Evolution of the Tengusawa Vineyard ecosystem

    Evolution of the Tengusawa Vineyard ecosystem

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

Revegetation activities

In 2016, under the guidance of specialists, we began activities aimed at regenerating rare and native species with the participation of employees, and we have achieved concrete results.
In fall, we collect dry grass from areas where there are rare and native species and sow it on the reclaimed land in fields in order to regenerate the vegetation. In the area where we regenerated vegetation, the average number of species present in 2016 was 8.2, but by 2020 this number had increased to 17.5. These areas are steadily becoming high-quality grassland, with tufted vetch (Vicia cracca), bromes (Bromus), lady’s bedstraw (Galium verum), queen coralbead (Cocculus orbiculatus), Thunberg’s geranium (Geranium thunbergii), toothed ixeridium (Ixeridium dentatum), reedgrass, violets, and nekohagi (Lespedeza pilosa) also becoming established. Native species with flowers have also become established, and in fall, these areas are like flower gardens.
Furthermore, along with an international NGO, Earthwatch Japan, and its volunteers, we began an activity to revegetate the shrubby sophora (Sophora flavescens), which is not a rare species at the national level, but is the sole grass used for feeding Shijimiaeoides divinus, a critically endangered IA (CR) butterfly. In 2018, volunteers collected, with the permission of the rice field owners, cuttings of shrubby sophora from the sides of rice fields near vineyards, and took them home to grow them. Two years later, at the end of May 2021, we planted the seedlings at Mariko Vineyard.
In the fall of 2020, we invited a lecturer from NARO whom we have tasked with ecological surveys of vineyards and held an environmental class for fourth grade elementary school students at the foot of the Jinba Plateau, where Mariko Vineyard is located.