It's what you can't see that matters.

The plants are on the run, trying to move to higher ground, where the air is cool enough to support their existence.

"Most of these species are not going to be able to tolerate climate change," says Ken Feeley, a tropical biologist from Florida International University in Miami, "mostly because climate change is happening so fast."

Feeley spoke as we hiked into the jungle with a small group of other scientists—through an area that contains more tree, plant, bird, and animal species than the entire eastern seaboard of the United States.

It is here that an international collective of scientists, called the Andes Biodiversity and Ecosystem Research Group, has mapped one of the largest field