The Jemez River Basin - Santa Catalina Mountains Critical Zone Observatory (JRB-SCM CZO).

We are developing an interdisciplinary observatory in the southwestern US to improve our fundamental understanding of the function, structure and co-evolution of biota, soils, and landforms that comprise the Critical Zone (CZ). The observatory is designed as a natural laboratory for the earth science community to test hypotheses related to CZ function in relation to climatic and water cycle variation. We posit that CZ systems organize and evolve in response to open system fluxes of energy and mass that can be quantified at point to watershed scales. These fluxes include meteoric CZ inputs of radiation, water, and carbon that are modulated by surficial biota to produce fluids and biogeochemical components that undergo biotic and abiotic transformation during gradient-driven transport. We hypothesize that the coupling of physical, chemical and biological processes is related specifically and predictably to the timing and magnitude of these fluxes. Our CZ Observatory (CZO) is designed along two well-constrained climate gradients. The first is on rhyolitic parent material in the Jemez River Basin of northern New Mexico (JRB) and the second is on granite and schist bedrock within the Santa Catalina Mountains in southern Arizona (SCM). Measurement, modeling, and experimentation at sites that vary in parent rock, elevation, aspect, slope, soil development, and vegetation will enable quantification of the feedbacks between energy and mass fluxes (driven by chemical and physical gradients) and measured components of CZ structure.