More Than Half of Wild Coffee Species Are at Risk of Extinction
Wild coffee is not normally harvested, but it is crucial to the sustainability of cultivated varieties like Arabica and Rustica.
Coffee farmers in El Salvador. Image: Adam C Baker
But our dependence on java is threatened by climate change and deforestation. These anthropogenic pressures have put 60 percent of wild coffee species at risk of extinction, according to a study published Wednesday in Science Advances.
Just two varieties, Arabica and Rustica, dominate the modern global market for coffee, but 124 coffee species have been documented by scientists. Most grow naturally in tropical regions of Africa, Asia, and Australasia.
Researchers led by Aaron Davis, a coffee expert at the Royal Botanic Gardens, Kew, spent two decades cataloging coffee species and assessing their extinction risk. The efforts revealed that 35 strains grow solely in unprotected habitats, while 75 meet the standards of the IUCN “red list” for threatened species. The team also found that 45 percent of wild coffee species are not saved in seed banks.
Though they are not normally harvested for consumption, wild coffees could be crucial for the survival of their cultivated cousins, especially in the age of climate change.
“These species have useful traits for coffee development such as climatic tolerance and especially drought tolerance, pest and disease resistance, low or zero caffeine content, and sensory (taste) amelioration,” wrote the team.
In other words, wild coffee species have evolved a wide variety of adaptations that could be selectively bred into farmed strains that could benefit from them. Even if a wild species is vulnerable to extinction from drought or deforestation, it might also be more resilient to certain pests or diseases, and those specific traits could be integrated into cultivated varieties.
Climate change is already diminishing coffee yields by disrupting pollinators, facilitating the spread of pests, and causing both short-term extreme weather events and long-term environmental change. Warmer temperatures may render half of all land used for high-quality coffee production unproductive by 2050, according to a 2015 study in Climatic Change.
Wild coffee adaptations could bolster the genetic resilience of farmed species in the face of these challenges, but only if they are protected and preserved.
“Ultimately, we need to conserve existing wild coffee species in situ to ensure the preservation of remaining genetic diversity,” the team concluded. “At a time when so much focus is on addressing food security and livelihood income shortfalls for farmers, it is of great concern that the raw materials for possible solutions are highly threatened.”
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