Water, Carbon, and Weathering in the Catalina-Jemez CZO

The Catalina-Jemez Critical Zone Observatory (CZO) was designed to test the hypothesis that critical zone structure evolves predictably in response to climatic forcing, and that the latter can be quantified on the basis of effective energy and mass transfer (EEMT) deriving from effective precipitation and net ecosystem production. Several findings support the predictive power of EEMT for CZ structure, including those pertaining to soil thickness, above ground biomass, valley density, clay content, and mineral weathering rates. To unravel the mechanisms underpinning these relationships, the Catalina-Jemez CZO was established along a climate gradient in Arizona and New Mexico and instrumented to quantify land-atmosphere exchanges of water and carbon, subsurface translocation of fluids and solutes, and surface water dynamics. Here we report on selected results that highlight how pulsed delivery of water into the weathering profile stimulates biota to directly impact in the geochemical transformation of rock to soil.