1 CZ Background

In this module, we are introduces to the Critical Zone (CZ) as a complex system that requires directed transdisciplinary study to understand. CZ science is less than two decades old and is evolving. Many of the fundamental approaches and concepts of CZ science are derived from decades of soil science and related research endeavors now applied to conceptualizing and constructing systems models that will allow scientists to predict the effects of ongoing land use and climate change on the CZ.

Goals of this Module

The primary goal of this module is to recall, infer, and interpret a wide variety of scientific principles to analyze the CZ as a complex system of interacting regolith, water, air, energy and life. By the end of this module you will be able to:

• Accurately define the CZ and the relationship to the atmosphere, biosphere, hydrosphere, lithosphere, and soil.

• Effectively summarize: 1) the transdisciplinary nature of CZ science and the relationship to system science; 2) the importance (and degraded state) of the CZ to supporting most terrestrial life including humanity; and 3) the importance of long-term observatories to understanding and integrating knowledge of Earth surface processes.

Overarching Learning Objective: Describe and characterize how interaction among the atmosphere, lithosphere, hydrosphere, biosphere, and soil (The CZ) support and influence life.

• Unit 1.1: The primary goal of Unit 1 is to address this overarching learning objective and provide a generalized framework from which the details of CZ structure, function and processes can be considered through the remainder of the course.

• Unit 1.2: The interactions of the various “spheres” of the CZ are considered in this unit specifically aimed at understanding a central component of the CZ: soil.

• Unit 1.3: The qualitative system modeling activity helps to solidify students understanding of concepts learned in the first two units.