Coffee and Genetic Diversity in Tropical Forests

A new study by a University of Michigan biologist Christopher Dick and a colleague at the University of California, Berkeley, Shalene Jha, has found that Shade-grown coffee farms support native bees that in turn help maintain the genetic diversity in tropical forests. Native bees carried pollen twice as far in a shade-coffee habitat than they did in the forest.

By pollinating native trees on shade-coffee farms and adjacent patches of forest, the bees help preserve the genetic diversity. Increasingly fragmented landscapes due to onslaught of agriculture are isolating native plant populations in many tropical areas. An estimated 32.1 million acres of tropical forest are destroyed each year this way.

Increasing tendency for coffee growers to resort to "sun coffee," which involves thinning or removing the canopy has to be seen against the backdrop of this new research. There is urgent need to encourage the traditional style of agriculture where coffee is grown in the shade of big trees.

The study was done in shade-grown coffee farms in the highlands of southern Chiapas, Mexico.

Details of the study appear in the latest issue of Proceedings of the National Academy of Sciences.