The critical zone ("CZ") is Earth's breathing skin -- the thin layer that spans from treetop to bedrock. The CZ is the zone where life and rocks interact -- the layer of air, vegetation, soil, water, and rock that reaches from the top of the canopy to unweathered bedrock. The myriad geological, biological, physical, and geochemical processes that occur there govern the fluxes of nutrients, minerals, and water between the solid Earth and the hydrosphere. As the layer that supports virtually all terrestrial life (including humans), it's enormously important.

     One of the fascinating things about the CZ — and one of the reasons I love working there — is the diversity of scientific disciplines that intersect there -- geology, biology, hydrology, chemistry, geomorphology, ecology, atmospheric science, and soil science. In our projects, we are collaborating with people from all of those disciplines.

     Richard Powers captured this in his wonderful novel, The Overstory, in a passage describing how one of his protagonists, Dr. Patricia Westerford, thrilled to this multidisciplinary exploration: "It thrills her to sit at meals and be part of the laughter and shared data, the dizzy network trading in discoveries. The whole group of them, looking. Birders, geologists, microbiologists, ecologists, evolutionary zoologists, soil experts, high priests of water. Each of them knows innumerable minute, local truths... Together, they form one great symbiotic association, like the ones they study."

     That's a pretty fair description of the Critical Zone Collaborative Network!

A section through the critical zone.

Modified from Chorover, J., R. Kretzschmar, F. Garcia-Pichel, and D. L. Sparks. 2007. Soil biogeochemical processes in the critical zone. Elements 3, 321-326. (artwork by R. Kindlimann)

We shall not cease from exploration

And the end of all our exploring

Will be to arrive where we started

And know the place for the first time.

           T.S. Eliot

“Little Gidding” in Four Quartets