"For decades, ecologists treated the forest canopy as a mere roof—a green ceiling sealing off the busy floor below. Recent climbers, harnessed and patient, have reported otherwise. Up there, whole communities of orchids, frogs, and insects complete their life cycles without ever touching soil, in a world governed by its own light, moisture, and chemistry. The old textbooks did not so much err about the canopy as overlook it entirely; their silence was not a wrong answer but a question never asked."