Changing old viticulture for all the right rieslings

When April nights dip below freezing, Claude de Nicolay knows she won’t be getting much sleep. At 4 a.m., she climbs out of bed and heads outside to light around 300 candles set up between the vines at Domaine Chandon de Briailles, a biodynamic vineyard in the Burgundy region in France that de Nicolay owns and manages. Spring buds are emerging earlier because of warming March temperatures, yet frosts are still common in April. The candles produce just enough heat to thaw the buds and protect them from being destroyed by the Sun’s rays come daybreak.

Although the candles are “a lot of work”, de Nicolay chooses to use them, rather than electric heaters, because they help to minimize her contribution to climate change — the problem that has caused her vineyard to become dangerously out of sync with nature. “Agriculturalists are the first people who are affected,” de Nicolay says. “The future is really about how to be very gentle with the soils, to go back to more manual work, to stop using chemicals and to stop using too much energy.”

Wine-growers around the world from California to South Africa are feeling the heat as global warming increases temperatures, throws patterns of precipitation out of whack and drives up the frequency and intensity of extreme weather events and wildfires. France’s wine sector faces extra vulnerabilities, thanks to its strict appellation d’origine contrôlée — a classification system with rigid rules about geography, grape varieties and production techniques. Under this system, “the origin becomes a sort of collective brand”, says Cornelis van Leeuwen, a viticulturist at Bordeaux Sciences Agro in Gradignan Cedex, France.

France is the leading wine-producing country in terms of value. Last year, it exported wine worth €12.3 billion (US$13.3 million), accounting for about one-third of total global exports, according to the International Organisation of Vine and Wine, based in Dijon, France. This is in large part owing to the strong branding that the appellation system has created, exemplifying “how you find identity in a competitive world”, says Etienne Neethling, head of the international master programme in vine, wine and terroir management at the Higher School of Agriculture in Angers, France. Much of this has to do with terroir, which translates to ‘land’. But in the context of French wine, terroir refers to an entire philosophy of production: environmental factors, such as soil type, are understood to influence the flavour profile of the grapes. It also factors in where the product came from and who produced it and how — growers in different regions have different approaches to winemaking, and value different characteristics in their wine.

Terroir and the appellation system might be canny cultural-marketing strategies, but both might prevent French wine-makers from being agile and innovative in the face of changing environmental conditions. The appellation system’s strengths could become weaknesses if the country’s wine regulators and makers adhere too closely to custom and do not keep pace with a rapidly changing world. “We are extremely vulnerable because of our strict regulations,” Neethling says.

As climate change intensifies, French wine-growers have begun to advocate for legislative changes that reflect the realities of the pressures that they face in the field and cellar. In the meantime, they aren’t waiting for decisions to be formalized on paper, but are finding creative solutions that still adhere to the rules. As de Nicolay says, “We have to react quicker than our governments, because otherwise it’s going to be a real disaster.”

Action imperative

Compared with the 1980s, the grape harvest in France is now starting around three weeks earlier¹. “All producers have observed this earlier harvest,” says Jean-Marc Touzard, director of research at the Montpellier centre of the French National Research Institute for Agriculture, Food and Environment (INRAE).

In 2019, Neethling and his colleagues conducted a survey of 3,636 wine-growers from 18 countries, which has not been published. Among the 1,298 French respondents, more than 80% were already noticing the impacts of climate change on vine performance and wine quality and were thinking about short- and long-term adaptation strategies. “Being reactive is no longer sustainable,” Neethling says. “We need to make sure our vineyards are the most climate-resilient possible.”

In 2011, scientists and industry experts launched LACCAVE, a project aimed at examining the future of French winemaking. Sticking to business as usual, they found, was a strategy that “has no future”, says Touzard, who coordinated the project. The team also steered away from plans that relied solely on technology to save the day, he adds, because “it leads to artificialization of the wine industry” and “disconnection from the terroir”.

Solutions will need to incorporate both science and centuries of wine-growing knowledge. For example, van Leeuwen and his colleagues have used chemical analysis to detect key molecules that influence aroma². The findings could help wine-makers to more closely control the style and quality of their final product by basing decisions about harvest time on their grapes’ chemical profiles. A research team at the University of Bordeaux in France has used gas chromatography, a technique to separate and analyse vapourized compounds, and tastings by a panel of experts³ to explore and better understand the fruitiness of red wines produced from grape varieties that seem ideal for Bordeaux’s future climate.

All solutions will need to be tailored to specific locations and driven by actions from a range of players, from individual growers and consumers to local and national authorities. This will all need to be done while “still trying to preserve the local identity of the wine”, Touzard says, yet at the same time accepting that “the taste, the flavour, will evolve”. The country’s wine-makers will walk a fine line between preserving the marketing advantages offered by time-honed knowledge and expertise and making sure that French vines aren’t left behind the rest of the world’s.

Adaptive management

From 2009 to 2019, France’s Occitanie appellation — that is, the geographical area in which the region’s wine grapes are grown — lost 12% of its vineyard area, according to FranceAgriMer, a national platform that manages agricultural products. This was due to a number of factors, including growers abandoning some wine plots that were replanted with wheat — thanks in part to the changing climate — and producers switching to different grape varieties for similar reasons, and thus forfeiting their appellation label. “The landscape shift is thus still limited, but it has started and is set to increase,” Touzard says.

As warming continues, Brittany and Normandy in the far north could become “a new picture of the French vineyard”, adds Hervé Quénol, the director of research at the French National Centre for Scientific Research in Rennes.

In the heat-burdened southern regions of the Rhône Valley and Languedoc, wine-growers are contending with increasing droughts and a lack of water, leading to smaller berries and lower yields. “Yield is very responsive to weather and, in the long run, to climate,” says Karl Storchmann, an economist at New York University in New York City, who specializes in wine. The market reflects this: the price of land in the southern Languedoc region, for example, has been “sliding down like crazy”, Storchmann says, to less than half its equivalent value in 1991.

In response to increasing drought, some southern appellations have relaxed rules that forbid irrigation. In 2000, just 4% of vineyards in Languedoc, Provence and the Rhône Valley were irrigated — they produced ‘table wine’, or wine that does not meet the appellation system’s quality standards. Today, 20% are irrigated, and they are allowed to do so in some cases under more flexible appellation rules. In certain areas, such as the Bouche du Rhône, 50% of vineyards are now irrigated. “We estimate that, in the south of France, the potential demand for irrigation could reach 50% of all vineyards by 2030,” Touzard says.

Irrigation raises questions about sustainability, especially if the water is taken from non-renewable sources such as aquifers. Irrigation can make vines more susceptible to drought in the long run, because the plants’ roots do not grow as deep. “The big question is whether irrigation should be a priority for viticulture,” Quénol says, “specifically in the south of France, because there is not enough water.”

In other regions, wine-growers are exploring solutions such as innovative soil management, changing their pruning regimes, introducing spatial variation between the vines based on microclimate or shifting to agroforestry by integrating trees and shrubs into their vineyards. Researchers at INRAE found that adding trees can lower a vineyard’s temperature by 2–4 °C. Agroforestry should be viewed as a long-term tool because, in the first years after planting, trees compete with vines for water, wine-growers have to invest time and effort into tending the saplings and rows of vines usually need to be removed to make room — translating to lost income in the near term. Eventually, the roots of the trees grow deep and no longer compete with the vines for water, and the trees will help with local climate mitigation. Following this strategy, and to boost biodiversity, de Claude and her colleagues have already begun planting fruit trees around their vines.

Others are looking into changing the make-up of conventional blends. For example, Bordeaux wines are typically made mainly of cabernet sauvignon and merlot, and to a lesser extent petit verdot, cabernet franc, malbec and côt. However, “the emblematic merlot is clearly less adapted to climate change than cabernet sauvignon, so wine-growers could be tempted to increase the cabernet sauvignon proportion”, Touzard says.

Another option is to introduce drought-resistant clones and varieties imported from hotter places such as Portugal, Italy and Greece. Since 2009, van Leeuwen has been investigating whether any of more than 50 varieties are better suited to Bordeaux’s warmer, dryer climate of the near future⁴. In 2019, the appellation of Bordeaux relaxed its rules to permit four new red varieties and two white ones. The appellation rules specified that, for now, growers can plant these varieties in only 5% of their vineyards, and these grapes can make up just 10% of any final blend.

Some wine-growers have also had to start implementing changes in their cellars. Heat- and drought-stressed vines produce grapes that are less acidic and more sugary, leading to wine with different flavours and aromas and a higher alcohol content. In Languedoc, for example, the average alcohol content for red wine was around 11% in the 1980s; now, it’s 14%¹. “The components of the berries are changing, which means changes in how the wine tastes,” Touzard says. “This could be a problem for specific markets with consumers who are really looking for traditional quality.”

To try to balance out flavours and aromas, some French wine-makers are introducing new yeast strains during the fermentation process, fermenting the grapes at cooler temperatures, testing different types of storage aside from wood barrels and adding oenological innovations to better control acidity or reduce alcohol content. Still others are testing new blends incorporating grapes harvested at different dates, or ones made of different varieties. However, van Leeuwen points out that terroir is dynamic, and the taste of wine has always changed over time. “Consumers adapt to new styles,” he says.

Optimism despite uncertainty

When Pablo Chevrot’s grandfather planted his first vines some 75 years ago at what is now Domaine Chevrot et Fils in Burgundy, he intended for his family to harvest grapes from those plants for up to a century. Some of those original vines are now collapsing — and given the pace of change, Chevrot knows that the ones he plants to replace them have little hope of ever making it to 100.

If planetary warming exceeds 3–4 °C, then some wine-makers — especially those who are committed to the conventional terroir way of production — are likely to be out of a job. In this scenario, food security would probably become too pressing an issue to justify the water that goes into making a non-essential good such as wine. For the time being, Chevrot is doing what he can to ensure a viable future for his vineyard. “Nobody can ignore what is happening,” he says. “The doors are slowly opening for adaptation.”

Chevrot, who has a degree in oenology, or the study of wine, stays on top of the scientific literature and is constantly experimenting with adaptations. “We’re working cleverly, but also going back to ancient ways,” he says. To deal with erratic frosts, he has begun pruning his vines later in the year, which postpones when buds first emerge from the vines. To cope with drought and high temperatures, he’s created higher canopies of leaves that provide more shade to the grapes. He works the land with horses, rather than tractors, to preserve the health of the soil, and six years ago he started to plant annual vegetation around the vines that helps to retain winter and spring water into the summer. In the summer, he cuts the annuals back to create “a sponge of organic matter” that continues to hold water and cool the soil, he says.

More and more French wine-makers are following a similar path. “They’re recognizing that the more climate-resilient or smart the vineyard is, the better they will be able to adapt to climate change,” Neethling says. They’re also seeing the importance of regenerative farming that focuses on natural resources, he adds, and the need to mitigate their environmental impacts.

Indeed, de Nicolay and her colleagues have been committed to a fully biodynamic approach since 2005. They are seeing positive results compared with their neighbours, who rely on machines and chemicals. When temperatures soar in mid-August, de Nicolay’s vines sport no yellow leaves — unlike those in nearby vineyards. “Wine-makers are asking how we do it,” she says. “They see our vineyard with much more life and strength against all these bad impacts.”

For now, the extra effort and care are paying off. “What will happen in the next years, we don’t know,” de Nicolay says. “But we stay optimistic because we believe we are taking the right direction.”

Source: Resources - nature.com