Nalini Nadkarni, the ecologist revealing the secrets of cloud forests

WHEN Nalini Nadkarni first ventured into the canopy of a cloud forest, almost nothing was known about this unique ecosystem. To explore it, she and a small group of pioneers had to develop special tree-climbing techniques, which, over the intervening four decades, have allowed her and others to unlock the mysteries of forest canopy biology. Monteverde in Costa Rica, where Nadkarni does much of her fieldwork, is home to some remarkable species, including the resplendent quetzal. But it turns out that the entire ecosystem depends on a more modest and unlikely group of organisms called epiphytes. These tree-dwelling plants – which include a dreamy array of wonders from ephemeral mosses that drip off branches and luscious ferns that nestle in crevices to a dazzling variety of orchids – act like nutrient sponges, extracting chemicals from mist and rain and conveying them to the forest floor.

Seven years ago, Nadkarni, who is at the University of Utah, fell from the canopy and broke her back in five places. Nevertheless, she was back in her tree-climbing harness a couple of years later. Such grit is a hallmark of her career, which, as well as reaching the forest heights, has taken her to some other unusual places. As a self-professed secular “missionary” for ecology, she has worked with prisoners to breed threatened plants and animals, and has delivered sermons in churches and synagogues. Now, aged 68, Nadkarni acknowledges that her tree-climbing days are nearing an end. But she also knows that climate change poses unprecedented challenges to cloud forests and is determined to document how it is affecting the epiphytes on which they …