Catherine L. Cardelús is a researcher who studies canopy soil. Canopy soil is formed in a tree’s branches (its canopy) when dead leaves and other falling things collect. This material breaks down, becoming canopy soil. Canopy soil helps preserve a healthy water cycle (how water moves through the environment) in rainforests. This benefit is one reason Cardelús is interested in the canopy soils in large choibá trees in rainforests in Costa Rica.