French Vintner crisis: Bordeaux banks on biodiversity for sustainability

It was a crisp autumn day in the vineyards of Saint Emilion, the vines asleep for the winter, as winegrowers, scientists and children planted hedges to create habitats for mites needed to prey on vine pests.

This marked the debut of an ambitious biodiversity project launched by pioneering French vintners in a bid for sustainability.

The biological diversity of Saint Emilion's 8,000-hectare vineyard landscape, intertwined with wine since Roman times and protected by UNESCO as a World Heritage site since 1999, has been precariously reduced by urbanisation, chemical vine treatments, and one-crop farming.

The long-term goal of the community project, unveiled to coincide with St. Catherine's Day when "all trees take root", is an attractive and functional landscape.

It will come with dozens of kilometres of interlinking green corridors that allow animals to move between 1,100 wine estates, and reduce soil erosion, vine treatments and fertilizer and pesticide run-off.

The corridors, for the moment, however, are few, far between, and fragile. Where a variety of crops grew 50 years ago, grapevines reign supreme, often cultivated from the edge of the ditch alongside the road to within steps of the cellar door.

"In Saint Emilion, vineyard land sells for between one and three million euros per hectare, so when we let grass or poppies grow, it seems incomprehensible," said Xavier David-Beaulieu, owner of Chateau Coutet, a 14-hectare estate with one hectare of woods and prairie.

Historical legacy
Viticulture has made the area wealthy but monoculture provides an ideal habitat for pests like spider mites and leafhoppers to colonise and infest a field, destroying the grape quality and yield. For decades, chemicals provided the answer, but led to a vicious cycle of dependency.

Pesticides
"When you treat with insecticides only three percent of the bugs are a menace to the vineyards, the other 97 percent are useful," said Patrice Hateau, director of Chateau Fombrauge.

In the case of spider mites, the insecticides also kill their natural enemy, the predatory mite Typhlodromus. "Just one Typhlodromus per vine leaf means you don't have to treat for red or yellow spider mites."

Hernicides
Herbicides, used to make the vine rows pristine, exacerbate the problem. "Ninety percent of the bugs live at soil level."

Increasing Complexity
"The more an environment is complex, the less vulnerable it is," said Maarten van Helden, a researcher in Integrated Pest Management and Biodiversity at the National School for Agricultural Engineers (ENITA) and consultant on the Saint Emilion project, which is now part of a larger biodiversity study in France, Spain and Portugal awaiting approval from the European Union.