If you like the aroma of fresh-brewed coffee first thing in the morning, you are not alone. Over 1.4 billion cups of coffee are poured worldwide each day according to the International Coffee Organization (ICO), with 45 percent (400 million cups) being consumed in the U.S.
But with climate change, there is an increased incidence of heat waves, and even if they are of short duration, they may be preventing Coffea arabica plants from producing flowers and fruit, according to new research conducted at Oregon State University.
The study at OSU’s College of Forestry revealed that when C. arabica plants were subjected to short-duration heat waves, they were unable to produce flowers and fruit, reports Science Daily. What does this mean? It means no coffee beans and no coffee to drink.
Coffea arabica – Changing environmental conditions
Coffea arabica is the world’s primary coffee plant species, accounting for 65-75 percent of the commercial production of the 20 billion pounds of coffee consumed globally every year. Coffee is also ranked as one of the world’s most valuable commodities and is an important crop that helps to sustain many economies.
C. arabica is now grown in 80 countries in the tropics worldwide. The plant needs one of two optimal environmental conditions: The subtropical regions, at high altitudes with well-defined rainy and dry seasons at altitudes between 1,800 and 3,600 feet elevation, or equatorial regions with frequent rainfall at altitudes of 3,600 to 6,300 feet elevation.
Arabica coffee is grown in relatively cool climates in the region between the Tropic of Cancer and Capricorn. The optimum temperature is between 15-24ºC (59-75ºF) year round. Ideal temperature and environmental conditions are necessary for photosynthesis to take place. Photosynthesis will not take place above these optimum temperatures, according to the study.
Leaf age and heat stress affects the coffee plant
Testing under controlled greenhouse conditions, the OSU researchers studied how leaf age and heat duration affected C. arabica plant’s recovery from heat stress. A major finding was that younger, “expanding” leaves were particularly slow to recover compared to mature leaves, while none of the plants that endured the simulated heat waves produced any flowers or fruit.
“This emphasizes how sensitive Coffea arabica is to temperature,” said lead author Danielle Marias, a plant physiologist with OSU’s Department of Forest Ecosystems and Society. “No flowering means no reproduction which means no beans, and that could be devastating for a coffee farmer facing crop failure.”
Results of the research were recently published in Ecology and Evolution. The National Science Foundation supported the study, co-authors of which were Frederick Meinzer of the U.S. Forest Service and Christopher Sill of the OSU Department of Forest Ecosystems and Society.
