Coffee under threat

Coffee is one of the world’s leading love affairs. In the UK we neck down 95 million cups of the stuff every day. But new research suggests that up to 65% of the strains of wild coffee are at risk of extinction. Hannah Laeverenz-Schlogelhofer put the kettle on and sat down for a chat with Alex Summers, glasshouse supervisor at the Cambridge Botanic Gardens, to find out a bit more about the world’s favourite beverage...

Alex - Okay, just a standard instant coffee.

Hannah - Something for the afternoon pick me up.

Alex - Exactly, just to keep the caffeine in the system.

Hannah - With a steaming cup of coffee in hand, we headed to the tropics, well the tropical rainforest in the Glasshouse to see where our caffeine fix comes from.

Alex - The plant from which coffee comes from is a shrub. It's a shrub that can come from the understory of the forest or forest edge and it reaches a reasonable size. We're talking somewhere in the realms of six-eight foot. The leaves are oval, relatively large and they're opposite and the actual coffee that we drink comes from the fruit. So the coffee fruit is a red berry. Imagine something about two or three times larger than the berry you would find on holly. And that's what a coffee fruit looks like. The actual coffee bean is the seed inside that fruit.

Hannah - So when you drink coffee you're actually drinking the ground up seed of a coffee plant?

Alex - Absolutely. So pre-grinding stage those beans will be cured and dried and then they will be roasted and ground, and then you'll get the familiar powder that you will be used to for making coffee.

Hannah - When you see menus at an artisan coffee shop you see lots of different types of coffee. Where do these different types come from?

Alex - Types with coffee, I guess in a lot of cases, is very much like types with wines. So the environment has a huge part to play in the flavour of the coffee beans that you take from the plant, but also the variety of coffee as well. So there are two main species that are used in the production of coffee. There's coffee arabica and coffee canephora which is the robusta coffees. So the top end of coffees that tend to be the Arabica coffees and the real workhorse of coffee so your instant coffee comes from the robusta coffees.

Hannah - A study published in Science Advances reports the results of a global risk assessment for coffee and the results seem quite concerning.

Alex - So the key finding of the paper was that 60 percent of coffee species are at threat of extinction. So what we're talking about is the fact that those two species we were talking about, are two species within about 124 species of coffee. And within those 60 percent of them are threatened with the fact that they may no longer exist within decades to come. And that's major. Well we're actually looking at here is a huge resource if we want greater drought resistance or disease resistance within our coffee crops, then there is potential within the wild relatives of the two coffee species we've just spoken about to actually breed that in to those for future generations, and for future production of new varieties and crops.

Hannah - From increasing numbers of droughts, to faster spreading of disease, coffee species are facing a wide range of threats.

Alex - I think the core risks for the threat to coffee species across their range is habitat degradation and agriculture. And as we see forests cut down for many reasons, we see the loss of habitat for coffee, but also coffee species tend to be range restricted. This means that in many cases they've evolved to quite tight specific climatic conditions and therefore they're not very flexible in moving into new habitats or new ranges when their current habitat is degraded. Disease particularly in areas of domesticated crops where we tend to grow one or only very few varieties become a real problem.

Hannah -  With these species at risk, what can we do about it?

Alex - There's two areas that are highlighted here which is improved conservation in situ, so improved protection for areas or regions which have coffee wild relative species, but also from growing them outside of their normal range perspective. So things like we are here at the Botanic Garden, doing that is really important as well. Particularly because coffee have recalcitrant seeds, you can't store the seeds in dry cold storage. And in this case to build a collection of coffee outside of its normal range you have to grow it as a plant. And one thing that we have to recognise is the importance of botanic gardens to contribute to that. And also from botanic gardens perspective we all have to talk to each other more, and make sure that we are not all just conserving a small portion of that diversity, of both robusta and Arabica, but also of the other species.