As an economist working on trade and environment issues, I want to point out that the information offered is insufficient to reach this conclusion. Sun plantations support less wildlife than shade plantations but at a higher yield of coffee. Thus, for any given quantity of coffee, less land is used and less rain forest is converted to coffee cultivation.
Natural forest supports more wildlife than sun plantations and perhaps more than shade plantations.
To assess the net effect of sun plantations on biodiversity for a given quantity of coffee, one would need to know the difference in yield, the rate at which expanding shade plantations absorb land from rain forest and other habitats, and measures of biodiversity for each type of plantation and each type of alternative habitat. If Dr. Ferrantino's scenario were correct, we would expect a landscape of small, highly productive sun farms and large, inefficient shade plantations. In fact, the opposite is generally true. Our key point is that shade plantations form a refuge for biological diversity in many agricultural areas that have already lost their original forest cover. Therefore, in an overall strategy to protect biological diversity, it is critical that traditional coffee farms stay in business.