Cloud forests are exceedingly rare, making up just one percent of Earth’s total forests. These uniques forests are created when warm, wet air rises up the through the mountainside, rapidly cooling off and condensing into fluffy clouds that float through the forest canopy, providing the entire ecosystem with its daily moisture. Some plants, like tree-bound bromeliads, have adapted to source all of their water from the clouds, appearing to grow out of the sky. Unsurprisingly, cloud forests serve as a biological hotspot, home to a multitude of endemic species.
But decades of deforestation have reduced cloud forest cover to just a fraction of what it once was. Climate change threatens to drive it down even further. As the climate warms, scientists predict that cloud levels will rise higher, perhaps only drifting through a narrow slice of forest.
In 2018, at a remote research site along the border of Peru’s Manu National Park, researchers erected a giant green curtain over the forest canopy in an effort to simulate the predicted changes to cloud cover under a warming climate. A spectacular array of tropical plants grows under the curtain’s shadow, and biologists have been busy studying how fewer clouds might impact this floral community.