Green coffee-growing practices buffer climate-chan...( ANN ARBOR Mich.---Chalk up another e...)

ANN ARBOR, Mich.---Chalk up another environmental benefit for shade-grown Latin American coffee: University of Michigan researchers say the technique will provide a buffer against the ravages of climate change in the coming decades.

Over the last three decades, many Latin American coffee farmers have abandoned traditional shade-growing techniques, in which the plants are grown beneath a diverse canopy of trees. In an effort to increase production, much of the acreage has been converted to "sun coffee," which involves thinning or removing the canopy.

Shade-grown farms boost biodiversity by providing a haven for birds and other animals. They also require far less synthetic fertilizer, pesticides and herbicides than sun-coffee plantations.

In the October edition of the journal BioScience, three U-M researchers say shade-growing also shields coffee plants during extreme weather events, such as droughts and severe storms. Climate models predict that extreme weather events will become increasingly common in the coming decades, as the levels of heat-trapping carbon dioxide gas continue to mount.

The U-M scientists warn Latin American farmers of the risks tied to "coffee-intensification programs"---a package of technologies that includes the thinning of canopies and the use of high-yield coffee strains that grow best in direct sunlight---and urge them to consider the greener alternative: shade-grown coffee.

"This is a warning against the continuation of this trend toward more intensive systems," said Ivette Perfecto of the U-M School of Natural Resources and Environment, one of the authors. "Shaded coffee is ideal because it will buffer the system from climate change while protecting biodiversity."

Perfecto has studied biodiversity in Latin American coffee plantations for 20 years. The lead author of the BioScience paper is Brenda Lin, whose 2006 U-M doctoral dissertation examined microclimate variability
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