VOA常速英语:咖啡在气候环境的影响下品种不断减少

It’s a really long way to go for coffee, but the coffee these scientists are looking for you won’t find at your local cafe. This is a rare wild relative that grows in the jungles of Sierra Leone. Coffee has 124 of these cousins across tropical Africa and Asia, but 60% of the family is at risk of extinction, says Aaron Davis, head of coffee research at the Royal Botanic Gardens, Kew.
So the main threat to the world’s coffee species is deforestation, and that’s because most coffee species actually occur in forests. Those forest species may fight off disease better than domestic coffees, or they may do better in a drought where they may tolerate higher temperatures better. Davis says those traits are increasingly important as the planet heats up.

The species we grow occur in very narrow climate envelopes. That means that as the climate changes, as temperatures increase and rainfall decreases, the suitable area for growing this coffee diminishes. That means trouble for coffee-producing countries where the bean is a major source of income. An estimated 100 million small farmers worldwide grow coffee.
Climate change threatens wild coffee too. That’s why Davis and his colleagues are searching the jungles for them now. We don’t want to be in a situation where we find ourselves for acquiring some wild plant or some wild genes only to find actually it’s extinct in the world. Davis and colleagues say there’s no time to waste. Their new study found nearly half of all coffee species are absent from the world seed banks.
Steve Baragona, VOA News.