Species of wild coffee threatened by climate change and deforestation

Most of the world's wild coffee species have a high probability of extinction in the coming decades due to more frequent and long droughts, loss of forests and the spread of deadly pests, according to a study¹ published on January 16th a Scientific progress.

The results indicate a potential threat to the multibillion-dollar coffee industry, dominated by two varieties: arabica (Coffea arabica) and robust (Coffea canephora) beans. The Arabica is susceptible to high temperatures, while the robust is sensitive to dry soils. But the genetic diversity within some of the 124 wildlife species could help farmers improve the viability of commercial plants in a changing climate.

"A number of coffee species have characteristics that allow them to grow in hostile and drier conditions," says study co-author Aaron Davis, a coffee researcher at the Royal Botanic Gardens, Kew, London. "But if you start losing species, you start losing options."

Evaluate the risks

Davis and his colleagues spent years cataloging specimens of conserved and wild coffee plants from all over the world, including remote forests in Africa, Madagascar and Mauritius. It took two decades to gather sufficient information on the distribution of wild species and the threats they face to assess the risk of extinction of each species. The team also looked for potentially useful traits in plants, including disease resistance, caffeine content and drought tolerance.

Using the criteria of the International Union for Conservation of Nature, the team found that 60% of all coffee species are at risk of extinction.

The numbers, according to Alan Andrade, a scientist of agricultural plants at the Brazilian agricultural research company of Minas Gerais state, are a warning to the entire coffee community. "Imagine how many flavors and aromas [remain] be discovered, "he says." Imagine how many unknown genetic traits could be the solution to future problems. "

Paper protectors

About 72% of coffee species, including wild Arabica coffee, grow in protected areas. But many of these places are considered "paper parks" with a lax execution, says Eimear Nic Lughadha, a vegetable scientist from Kew and co-author of the study. The status of protected areas will not be enough to save these species from extinction because deforestation and climate change can undermine their populations.

Maintaining the genetic diversity of coffee outside its natural habitat is a challenge. Unlike many crops, coffee beans can not be stored using conventional methods, which keep crops in conditions of low humidity and low temperatures. The most advanced techniques, such as keeping the seeds at freezing temperatures or using chemical compounds to slow down the growth of plants, are too expensive to use on wild species.

Living collections that attempt to safeguard wild coffee varieties in the form of seed or plant banks face their own set of threats. The most complete collection of coffee diversity resides in four genetic banks made up of adult trees. But these protected sites are underfunded, lacking qualified personnel or threatened by deforestation and pests, according to a 2018 Crop Trust report, an organization that works to preserve the diversity of crops in Bonn, Germany.

The future of coffee

But places like Ethiopia, where about a quarter of the population relies on coffee-related activities for their livelihoods, are exploring potential solutions to some of these problems. These include the subdivision of wild Arabica forests into carefully monitored conservation areas and areas where people can grow and produce coffee, honey and spices.

"Coffee is the main source of raw materials for the African countries that produce it, and local communities and governments have good reason to preserve it," says Tadesse Gole, an ecologist at the environment, climate change and the coffee forest in Addis Ababa. – author of a study² published on January 16, according to which wild populations of Arabica coffee could decrease by 50% by 2088 due to climate change.

But the burden of preserving these species should not be borne only by African nations. If the world benefits, says Davis, it's something everyone should contribute to.

"If it were not for those wild plants, we would not be drinking coffee," says Davis. "And if we stop preserving them now, future generations may not appreciate coffee the way we do it today."