The Critical Zone is Earth’s outer layer, spanning from the forest canopy to the base of circulating groundwater. It’s where rock, air, and water interact to support life. Over the past two decades, global scientists have studied how the lithosphere, hydrosphere, atmosphere, and biosphere work together in this zone. Critical Zone Observatories (CZOs) help examine how soil, water, and air shape landscapes and sustain ecosystems.

This session invites researchers from diverse Earth science fields—such as geomorphology, hydrology, ecology, pedology, geophysics, atmospheric science, and beyond. We wish to invite contributions and ideas that:

• Investigate interactions and feedbacks among Earth’s surface processes,

• Use field experiments or models to assess Critical Zone changes over time,

• Analyze how vegetation, climate, and geology influence surface evolution,

• Connect surface processes to hazards or resource distribution.