Heirloom Grapes & Climate Change: Ensuring Wine Sustainability Through Genetic Diversity
Jim Richarson Photography
Last week, the Long Now Foundation hosted National Geographic photographer Jim Richardson for a talk about his recent work for the magazine: “Heirlooms: Saving Humanity’s 10,000-year Legacy of Food.” Richardson has been National Geographic’s “go-to” photographer for small-town America and topics related to agriculture and animal husbandry over the past few decades. His prescient discussion about the long-term effect of human agriculture on genetic variation got me thinking about terroir security in a different light. Assuming that humans have been tinkering with seed selection for over 10,000 years, I wondered how much human selection had limited or increased our current selection of grape varietals. As Richardson notes, “we conspire with the foods we like” – choosing the most useful varieties – and grapes are at the core of the human-wine conspiracy.
“Heirloom” is a designation for plants and seeds that are not used in modern, large-scale agriculture. Genetically engineered seeds and a few select hybrids dominate the agricultural market. Unfortunately, in selecting a few robust varieties, much genetic variability has been lost. It is often said that genetic variation provides the “raw material” for natural selection – the result of mutations that occur as a result, in part, by geographic variation and differences in selective pressures on an organism.
Selective farming has been devastating to genetic diversity. For many crops, as much as 95 percent of varieties have been lost since 1900, with a total crop diversity loss hovering around 75 percent since 1900. Many cultures are aware of the need to create “seed banks” to protect themselves from climatic variability. In his discussion, Jim Richardson identified a group of Peruvians who have created a regional cooperative to plant hundreds of varieties of potatoes in thousands of locations in the high Andes. This community not only values genetic diversity to ensure a sufficient harvest in variable climactic conditions and disease – they depend upon it. For many crops, saving and using heirloom seeds is one way of preserving thousands of genetically unique strains of corn and other crops. Richardson also sought out farmers in other environmentally stressed conditions to understand more about how they manage the risk of famine. An Ethiopian man who keeps a seed bank in his home held a pottery amphora and noted to Richardson: “These are my security.”
Appearing 65 million years ago, vitis vinifera grapes have been cultivated for about 8,000 years, beginning somewhere between the Black Sea and Iran and later spreading to secondary domestication centers across the region and beyond. That said, it is unknown whether the discovery of wine resulted in domestication or whether domestication led to the discovery of wine. Increased yields and sugar content for better fermentation, and more regular production were desirable traits chosen by farmers, though little is known as to whether the traits were a result of natural or human selection.
The cultivated grapevine has lost much diversity over the past 50 years due to the globalization of the wine industry, where only a few familiar varieties have been preferred. Around ten thousand grape cultivars are thought exist today in germplasm collections, but much research and DNA profiling needs to be done to determine the true number of vitis vinifera varieties and to identify the function and roles of specific genes. In Grapes, Vines and Wines, Jancis Robinson supposes that only about 20 percent of these varieties are actually growing somewhere. The New World has had its clever marketing approaches, resulting in many unique varietals being replaced with Sauvignon Blanc, Chardonnay, Pinot Noir, Merlot, and Cabernet Sauvignon. Perhaps the foremost aspect to Mondavi’s marketing genius was to recognize the very narrow bandwidth of the majority of the American public when it comes to wine appreciation.
Some Mediterranean cultures believed that wine “sprang from the blood of humans who had fought against the gods.” This is true insofar as humans chose vinifera grapes that would produce a better wine in the diverse winegrowing regions of the world. However, our fight with the gods is not over – and a quiver full of genetic variability might just be how we win a battle against climate change in the vineyards.