Research: Shade coffee buffers against climate change

Agroforestry management as an adaptive strategy against potential microclimate extremes in coffee agriculture. B. B. Lin.  2007. Agriculture and Forest Meteorology 144:85-94. DOI:10.1016/j.agrformet.2006.12.009.

A few months ago I wrote a detailed post on coffee growing and climate change. Climate change poses a significant threat to coffee growing, as arabica coffee grows best in temperatures around 20C (68F).  As this paper reiterates, the photosynthesis of coffee decreases markedly at temperatures between 20 and 24C (68-75F), and grinds to a halt at 34C (93F) and above. At the same time, the fruit ripens at an accelerated rate above 23C, reducing quality, as the best-tasting coffees come from cherries that have ripened slowly, intensifying and concentrating flavor.

This study looked at shade cover at farms in the Soconusco region of southern Chiapas, Mexico (Finca Irlanda, Finca Hamburgo, and Rancho Alegre) and how the amount of shade impacted temperature, humidity, and soil moisture. Although this has long been suspected, this study confirms that the fluctuations in microclimate decrease as shade level increases. Increased shade in coffee agrosystems can help mitigate the effects of climate change by buffering the coffee from climate variability.

Nearly 4 million Mexicans depend on coffee production. Farmers have already noticed changes in the climate, particularly longer dry seasons.  What will happen if farmers have to abandon their plots? As during the coffee crisis, many head north.

Photo by WRI.