A 2018 report by the Crop Trust, which runs a global seed bank, also warned of the need to preserve the genetic diversity of coffee, including its wild varieties. Only a handful of gene banks hold coffee trees, the report found, and many of them are hampered by either aging specimens or a lack of adequate funding.
To assess the risks faced by wild coffees, Dr. Davis and his colleagues applied a barometer developed by the International Union for Conservation of Nature, an international organization that assesses biodiversity risks. Using that index, commonly used to document risks to big mammals like elephants and rhinos, they found wild arabica, which mainly grows in the forests of Ethiopia, to be particularly vulnerable to the effects of climate change.
If greenhouse gas emissions continue to rise at their current pace, changing climate conditions could move wild arabica from the conservation union’s “near threatened” category to “extinct” by the end of the century.
For Dr. Davis, the loss of wild varieties is important not just for plant breeders, farmers and coffee drinkers. The loss of a species also means less food and less shelter in its ecosystem. The result, in his view, is a diminished Earth. “Our planet becomes less diverse, less interesting,” he said.
His most recent expedition took him to Sierra Leone in December. He and his colleagues went searching for what they had feared was a lost coffee species, the slow-growing stenophylla, which hadn’t been seen on a plantation in more than 60 years.
On that land, the team found one plant — insufficient to propagate. So they kept walking. Across the border in Liberia, after a six-hour trek, they arrived at a hillside covered with stenophylla. It is now being tested in Sierra Leone.
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