Read this e-mail dialog with Thanksgiving's April Pojman for details. Any insight you may have on this would be appreciated. Sorry your message got lost in the tangled web of my inbox and just now reappeared. Thanks for the great question. Let's see, there are several issues here, biodiversity being just one.
Coffee is originally a shade-loving plant from Ethiopia.
Well, it hasn't really worked that way. Increased supply has driven the prices down, and many farmers have ended up with tremendous debt, have lost their land and moved into the cities. In order to do this, though, the native trees must be cleared, also removing the habitat for bird, bat, and insect populations. As in any monocrop system, this leaves vast area vulnerable to an insect or fungal attack that would otherwise be kept in check in the natural course of the food chain. The removal of the trees also eliminates the leaf litter that renews nutrients in the soil and protects it from erosion.