Solis-Montero, L., A. Flores-Palacios, and A. Cruz-Angon. 2005. Shade-coffee plantations as refuges for tropical wild orchids in central Veracruz, Mexico. Conservation Biology 19:908-916.
This paper in the journal Conservation Biology reports that shade coffee plantations in Mexico provide refuge for orchids from lower montane cloud forest habitats — the most endangered forest type in the country, now comprising only 1% of Mexico’s land.
The magazine of the American Orchid Society published a similar article years ago:
Nir, M.A. 1988. The survivors: orchids on a Puerto Rican coffee finca. American Orchid Society Bulletin 57:989-995.