St.-Emilion winegrowers have launched an ambitious, community-based biodiversity project to create miles of interconnected "green" corridors throughout the 20,000-acre region of Bordeaux in a bid for sustainability.
The corridors are part of the Functional Landscape and Biodiversity Initiative, the first of its kind in France, and are expected to allow spiders, ladybugs and other natural predators of vine pests to move freely between the 1,100 wine estates, vanquishing mites, grape berry moths and green leafhoppers and reducing the vintners’ need for chemicals. Various flowers and plants that attract these predators will also be planted. Strategically located hedges will cut fertilizer and pesticide run-off and soil erosion.
Given the patchwork layout of St.-Emilion, the initiative required the cooperation of virtually every property. "If we don't get the whole community involved, it isn't sustainable," said Dr. Maarten Van Helden, an agro-ecologist and biodiversity specialist on the project. "For me, it's really important that it was the winegrowers who launched this program.'' The project is now part of a larger biodiversity study in France, Spain and Portugal.
The program is in part a response to the French government’s demand that vineyards cut chemical treatments in half by 2018. Biodiversity can reduce or eliminate the need for insecticides and weed killer. Unfortunately, soaring wine prices have encouraged vintners to plant vines nearly everywhere possible for the past 50 years, a practice which will have to be curtailed under the new initiative.
"In St.-Emilion, vineyard land sells for up to 3 million euros per hectare, so when we let grass or poppies grow, it seems incomprehensible," said Xavier David-Beaulieu, owner of Château Coutet.
One of the leaders in biodiversity in Bordeaux is Château Figeac. "Figeac is a microcosm of everything we must do in St.-Emilion," said Philippe Bardet, winegrower and technical advisor to the Conseil des Vins de St.-Emilion. Despite the increased value of vineyard land, Figeac’s proprietors have resisted the temptation to replant their 37 acres of other vegetation with vines. "The trees are my luxury," said owner Thierry Manoncourt.
But greenbelts won't solve the problem alone. Monoculture—row after row of immaculate vines, nary a blade of grass in sight—has filled Bordeaux's coffers, and created the perfect habitat for pests. For decades, chemicals provided the answer, albeit an imperfect one. "When you treat with insecticides, only 3 percent of the bugs [killed] are a menace to the vineyards; the other 97 percent are useful," said Patrice Hateau, director of Château Fombrauge. "Just one predatory mite per vine leaf means you don't have to treat for red or yellow spider mites." Weed killers exacerbate the problem. "Ninety percent of the bugs live at soil level."
Despite the difficulties involved, Hateau is banking on biodiversity. Herbicides are gone. Insecticides are rare and organic. Hedges provide homes for predators. "We take the best of the lutte raisonné, the best of biodynamics and the best of organic. It's sustainable viticulture and, in my opinion, the only sustainable future," he said.
Sustainability, of course, is the issue. But two Left Bank vintners warned of the risks of abandoning chemicals.
"Biodiversity is not always as easy as all that,'' said Pascal Baratié, vineyard manager at Château Haut-Brion. Stinging nettles and bindweed, two plants that can bring in natural predators, also carry Le Bois Noir, a vine disease. The wooded park around Haut-Brion shelters grape-devouring birds. And so far, biodiversity doesn't offer any solutions for two of the biggest threats to Bordeaux's vineyards, mildew and oïdium.
Philippe Blanc, general manager of Château Beychevelle, long a leader on sustainability issues in the Médoc, warned against forgetting economic viability. "We are conducting trials to drastically reduce sprays, but it is important to understand that it implies a far greater risk in terms of economics." As a stark illustration, he offered their Haut Médoc vineyard Beaumont, where they used only organic sprays. "It is a relative failure and we cropped 25 hectoliters per hectare [less than 2 tons per acre], which is absolutely unacceptable for wine sold at 5 euros per bottle," Blanc said.
There may be another advantage to biodiversity, however: "From the point when you limit your chemical interventions, you will reinforce the identity of your terroir,” said Hateau. “We are trying to free our terroir to express its complexity. People can share consultants, copy our methods, but no one can copy our terroir. It's the one thing that cannot be copied."