Four major systems—the geosphere (solid Earth), hydrosphere (water), atmosphere (air), and biosphere (living organisms)—interact to create Earth’s ecosystems. Surficial geology is the interface with soil, water, and air that creates the diverse platform on which living things exist. Natural geologic heritage areas conserve not just the geologic foundation, but also places for ecosystem processes and change to occur. Conserving a variety of geologic heritage sites across an assortment of ecosystems maximizes natural area diversity. These intact ecosystems are more resilient and able to adapt to changes.