The destruction of tropical rainforests — seen in shocking images of huge wildfires, vast clearcuts, and dying drought-stressed trees — is unfolding annually before the world’s eyes. But some serious changes in growing forests are occurring unseen, below the surface. As aboveground changes in those forests intensify, those effects are also filtering underground, and researchers are sounding the alarm due to potentially adverse changes to tropical forest roots. Roots are key to how rainforest trees and soils capture and store atmospheric carbon dioxide, especially as climate change progresses, says Daniela F. Cusack, associate professor in the Department of Ecosystem Science and Sustainability at Colorado State University. The hidden world of plant roots, and the impacts of human-caused stressors on them, is not yet well understood, but important clues are emerging. An overlooked science While underground plant growth is more difficult to study than what’s happening aboveground, roots are no less important than forest floor to canopy processes, explains Cusack, who is also a research associate at the Smithsonian Tropical Research Institute. Scientists began looking at the complex tropical forest underworld about 40 years ago. Today, they know tropical tree species’ roots grow in a mat on the forest floor to collect nutrients from composting vegetative matter. Some trees have shallow root systems that run for more than 100 meters (325 feet) to steady the tall trees, especially since strong winds often rock the canopy. Others have evolved large, thin extensions of the trunk that begin some six m. (20 ft.)…This article was originally published on Mongabay