Mas and Dietsch examined publicly available criteria for shade-grown coffee, which included two programs currently in use: ECO-OK, now referred to as sustainable coffee certified by Rainforest Alliance, and Bird Friendly ®, certified by Smithsonian Migratory Bird Center (SMBC); and several programs never implemented: Mexican Shade Coffee, Mexican Shade Coffee PLUS, and a draft from the Specialty Coffee Association of America.
Traveling to Chiapas, Mexico the pair studied farming practices from traditional rustic management to a more intensive system shaded with only one tree species. They chose the area in part because, "Mexico produces more certified organic coffee than any other country and, while not the focus of this study, organic coffee production techniques, which prohibit agro-chemical use, provide an important complement to management of the shade overstory in conserving biodiversity."
The rustic system contained a higher diversity of butterfly species and birds more similar to those found in nearby forests. This was the only management system certified by the SMBC Bird Friendly ® Program suggesting that certification criteria can distinguish farms that provide conservation benefits. The Rainforest Alliance Program also successfully distinguished farms with higher levels of shade. However, important philosophical differences emerged between the programs, as Rainforest Alliance uses less strict criteria to engage farmers with lower levels of shade. The only management system to meet the criteria of all the certification programs was a rustic farm, and it was also the only system to show significantly higher diversity of fruit-eating butterflies and birds more similar to those found in forest reserves. The other programs resulted in various levels of certification for the farming practices.
Mas and Dietsch suggest setting specific realistic conservation goals based on the levels of habitat use and protection of forest fragments. Currently, many farmers and cooperatives include forest fragments as part of their land management.
"Just as all shade is not created equal, all certified shade-grown coffee programs may not produce the same conservation benefits," say Mas and Dietsch.
The study shows the important transparency provided by certification programs and the valuable role of science in evaluating criteria. The researchers suggest ecologists can test the underlying assumptions in maintaining an ecologically sustainable certification while conservation biologists can help define habitat use expectations and the appropriate use of shade-grown coffee certification to meet regional conservation goals. In the meantime, say Mas and Dietsch, coffee consumers can have confidence that current certification programs distinguish farms with beneficial levels of shade for biodiversity conservation.
*Mas is now a project manager for The Nature Conservancy in San Francisco and Dietsch is now at the Smithsonian Migratory Bird Center