Module 1: CZ Background

Timothy White (Pennsylvania State University)

Strengths of the Module

These units address the five central InTeGrate goals of:

1. Addressing geoscience-related grand challenges facing society by reviewing the foundational documentation and web links for the rationale behind the Critical Zone observatories program. In particular, CZ science seeks to address the questions of "How do the physical, chemical and biological components of Earth's weathering engine transform mineral and organic matter to nourish and sustain ecosystems, regulate the migration and fate of toxins, sculpt terrestrial landscapes, and control the exchange of greenhouse gases and dust with the global atmosphere?" (Frontiers, 2006)
2. Developing students' ability to address transdisciplinary problems by considering four framing questions central to Critical Zone science that each deal with the interconnections between soils, hydrology, meteorology, geomorphology, and ecology.
3. Improving student understanding of the nature and methods of geoscience and developing geoscientific habits of mind by reviewing the methods and strategies scientists have employed at a variety of CZO study sites.
4. Making use of authentic and credible geoscience data through activities exploring the US Department of Agriculture's (USDA) Natural Resources Conservation Service (NRCS) WebSoilSurvey.
5. Incorporating systems thinking by considering systems diagrams that illustrate interconnections between different CZ components.

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Module Goals

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

• Accurately define the Critical Zone 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.

Linking Unit Content to Course Objectives

Below is a brief outline of examples within each Learning Unit where instructors can find resources that meet the overarching learning objective for the whole curriculum and each of the four primary learning objectives of the Critical Zone curriculum.

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

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Four primary objectives:

Objective 1) Identify grand challenges that face humanity and societies, ways which humans depend upon and alter the Critical Zone, and the potential role for Critical Zone science to offer solutions for these challenges.

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• Unit 1.1: The first 6 items listed under References and Resources provide information and insight into human interactions and effects on the CZ.
• Unit 1.2: The Soil Erosion, and threats to soils, websites provide information specific to some of humanity's influence on soils.
• Unit 1.3: The two items listed under References and Resources along with all of the pre-class readings for the discussion will engage the students in considerations of humanity's effect on various aspects of the CZ.

 
Objective 2: Use and interpret multiple lines of data to explain Critical Zone processes.

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• Unit 1.2: The students learn to use the USDA NRCS WebSoilSurvey tool to gather information about soils at a site and the soil characteristics of that site that influence land use and cover.
• Unit 1.3: The discussion is meant to stimulate the students to consider processes unique to each "sphere" of the CZ and then draw these together to explain CZ processes within the whole system.

 
Objective 3) Evaluate how the structure of the Critical Zone influences Critical Zone processes/services.

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• Unit 1.2: The first five items listed under References and Resources will provide information about the structure of soils with the CZ. The WebSoilSurvey activity will also provide insight into structure of the CZ and soils.
• Unit 1.3: The discussion readings (and discussion) will require that the students consider the structure of various aspects of the CZ and then draw this information together to consider the CZ as a whole system.

 
Objective 4) Analyze how water, carbon, nutrients, and energy flow through the Critical Zone and drive Critical Zone processes.

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• Unit 1.3: The discussion readings (and discussion) will require that the students consider the flow of water, C, nutrients and energy into and out of the CZ system.

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Assessments

This module uses a variety of assessment approaches:

• A one-page baseline knowledge statement of Critical Zone science to be compared to another statement written at the end of the semester;
• A short essay with responses to specific questions on soils;
• A report based from the results of an online soil-mapping exercise;
• The development of a qualitative Critical Zone system model; and,
• An introduction to the semester project report in Unit 1.1.

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Module Outline

• Unit 1.1: CZ Overview (One 75 min class session)
• Unit 1.2 Role of Soils in the Critical Zone (Two 75 min class sessions)
• Unit 1.3: Introduction to system modeling and sample design (One 75 min class session)

In these three units, students will:

• Define the CZ stressing:
  • importance and state of the CZ
  • temporal and spatial scales of study
  • the science as a transdisciplinary and international pursuit
  • observatory and environmental gradient approach
  • outstanding questions
• Build framework for considering CZ processes and function
  • Access and consider existing online data
  • Introduce system modeling, research approaches, infrastructure and sample design

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References

• Brantley, S., White, T., White, A., Sparks, D., Richter, D., Pregitzer, K., et al. (2006). Frontiers in exploration of the Critical Zone. In Frontiers in exploration of the Critical Zone: Report of a workshop sponsored by the National Science Foundation (NSF) (pp. 1–30). Newark, DE.