Excerpts: When he decided to become a forest ecologist, [Dr.] Alemayehu [Wassie] realized that in order to study Ethiopia’s native forests, he would have to study the forests surrounding churches.

If you see a forest in Ethiopia, you know there is very likely to be a church in the middle, says Alemayehu Wassie. Wassie, a forest ecologist, has spent the past decade on a mission: preserving ...