In addition, scientific studies show that biodiversity plummets dramatically on sun-coffee plantations compared to shade plantations. The remaining 6.6 million acres (2.7 million hectares) of shade-coffee plantations are the most important habitats for neotropical migratory birds in Meso America, the Caribbean Islands, and Colombia alone. In Mexico, more than 150 species of birds can be found on shade-coffee plantations -- more than in other agricultural habitats, and exceeded only in undisturbed forest. The number of bird species decreases by as much as 94 to 97 percent on sun-coffee plantations. From the canopy on down, biodiversity vanishes with the removal of the trees. Ongoing studies show that clearing the forest for sun-coffee plantations reduces the diversity of arthropods, plants, amphibians, and mammals as well.

For many cultivators, however, the high productivity associated with sun-coffee plantations outweighs the disadvantages of having to use large amounts of commercial fertilizers and chemical pesticides. And biodiversity is often sacrificed for the higher yields that allow producers to sell sun coffee at a cheaper price. Increasingly since the 1970s, shade plantations have been converted to full-sun plantations, which now account for 17 percent of coffee cropland in Mexico, 40 percent in Costa Rica, and 69 percent in Colombia. While shade coffee is usually more expensive to produce, connoisseurs say its taste is superior to sun coffee because the beans ripen more slowly.