Unit 1.1: Critical Zone (CZ) Overview

Introduction

The Critical Zone (CZ) encompasses the external or near-surface Earth extending from the top of the vegetation canopy down to and including the subsurface zone of freely circulating fresh groundwater. Complex biogeochemical processes combine here to transform rock and biomass into the central component of the Critical Zone"soil. The Zone sustains nearly all terrestrial life including humanity, nonetheless ever-increasing negative impacts of human society on the Critical Zone continue.

This lesson is an introduction to Critical Zone science from which you should grasp the key concepts outlined below - do not fret over every detail - that will be accomplished through the remainder of the semester. This unit will stress that Critical Zone science truly is multi- and inter-disciplinary. Critical Zone processes are represented by coupled physical, biological and chemical processes"and an array of scientific expertise in many fields including geology, soil science, biology, ecology, geochemistry, geomorphology, hydrology, and more, is needed to understand the Critical Zone. In this lesson, you will:

• define the Critical Zone and its importance to humanity
• explain/give an example of the four driving questions of Critical Zone science:
  • how do variations in and perturbations to chemical and physical weathering processes impact the Critical Zone?
  • how do biogeochemical processes govern long-term sustainability of water and soil resources?
  • how do processes that nourish ecosystems change over human and geologic time scales?
  • what processes control fluxes of carbon, particulates, and reactive gases over different time scales?
• describe the main challenges and needs of an integrated national research effort focused on Critical Zone science
  • what is the structure of the integrated national research effort that exists?
  • who does this program serve?
• list some general human (and other) impacts on the Critical Zone

Unit 1.1: Critical Zone Overview

Pre-class

• Your instructor will assign you to a reading group. Each group will be assigned an article(s) to read and to make a brief (~5 minute) report to the class summarizing their reading assignment.
  • Articles should be reviewed prior to class to capture the main themes and topics discussed and how these relate to this class, module and entire course. As the course proceeds, you will begin to tie concepts learned in earlier lessons to the ongoing lessons and in the process will make the links that are at the heart of this very interdisciplinary science.
  • Research articles should also be reviewed prior to class using the following generic scientific analysis framework and any specific questions provided.
    • Reading Reports: Scientific Analysis Framework: Paper Review Questions (Microsoft Word 17kB Dec23 16)
    • Reading assignment for Unit 1.1 (Microsoft Word 2007 (.docx) 17kB Dec23 16)
  • Each group will pre-read and meet outside of class to prepar their brief presentation on one of the 4 reports listed below. Focus on concepts of general and broad importance, for example:
    • What do CZOs do?
    • Why is CZ science important? Why are CZOs important?
    • What are the common objectives of CZOs? Place these within the context of the four driving questions:
      • How do variations in and perturbations to chemical and physical weathering processes impact the CZ?
      • How do biogeochemical processes govern long-term sustainability of water and soil resources?
      • How do processes that nourish ecosystems change over human and geologic time scales?
      • What processes control fluxes of carbon, particulates, and reactive gases over different time scales?
• Pre-class reading articles:

1. Committee on Basic Research Opportunities in the Earth Sciences. (2001). The Critical Zone: Earth's Near-surface Environment. In Basic Research Opportunities in Earth Science (pp. 35"45). Washington, D.C.: National Academy Press.

• Please pay particular attention to Figure 2.1.
• 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.
  • Please pay particular attention to Figures 4"7, 10, 11 and 13, and Table 1.

1. Banwart, S., Chorover, J., Gaillardet, J., Sparks, D., White, T., et al. (2013). Sustaining Earth's Critical Zone: Basic Science and Interdisciplinary Solutions for Global Challenges, University of Sheffield, United Kingdom, ISBN: 978-0-9576890-0-8
2. NSF Review Panel (2011), Critical Zone Observatory Program, NSF (https://www.nsf.gov/geo/ear/programs/czo-panel-report-april11.doc)

In-class

Introduction Information 

• This unit begins with a lecture to introduce to you the highlights of what you read in their group assignment and individual reading and website browsing (see below, References and Resources).

Reading Groups Reports 

• Each group will give a ~5 min summary of their reading.

Introduction to Semester Project 

• By the end of the semester, you will write a 10-page proposal for a hypothetical NSF RFP (Microsoft Word 2007 (.docx) 22kB Dec26 16)

Website Browsing

• Begin with the following short video:
  • Critical Zone YouTube video from ResearchatSheffield
• While instructor meets with your peers to discuss semester project ideas, browse and explore the 5 web sites listed below
  • U.S. Critical Zone Observatory
  • NSF
  • U.S. National Research Council
  • Soil Transformations in European Catchments (SoilTrEC) and
  • Critical Zone Exploration Network

Homework 

Pre/Post Critical Zone Science Personal Reflection - First Writing Assignment (Microsoft Word 2007 (.docx) 15kB Jun5 16)

1. Write a one-page statement that describes the following four aspects of the Critical Zone:

• define what it is,
• explain where it is,
• describe how it functions and
• why it is important to society
• Consider each of the four CZO driving questions and briefly describe (1 page) what each means to you.
  1. How do variations in and perturbations to chemical and physical weathering processes impact the CZ?
  2. How do biogeochemical processes govern long-term sustainability of water and soil resources?
  3. How do processes that nourish ecosystems change over human and geologic time scales?
  4. What processes control fluxes of carbon, particulates, and reactive gases over different time scales?
• Finally, include a brief description of your learning goals for the semester to be compared to a similar statement to be written in the final week of the semester.

Additional Resources

The four reports for group reading are:

1. Committee on Basic Research Opportunities in the Earth Sciences. (2001). The Critical Zone: Earth's Near-surface Environment. In Basic Research Opportunities in Earth Science (pp. 35"45). Washington, D.C.: National Academy Press.
   • Please pay particular attention to Figure 2.1.
2. 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.

• Please pay particular attention to Figures 4"7, 10, 11 and 13, and Table 1.
• Banwart, S., Chorover, J., Gaillardet, J., Sparks, D., White, T., et al. (2013). Sustaining Earth's Critical Zone: Basic Science and Interdisciplinary Solutions for Global Challenges, University of Sheffield, United Kingdom, ISBN: 978-0-9576890-0-8.
• NSF Review Panel (2011), Critical Zone Observatory Program, NSF (https://www.nsf.gov/geo/ear/programs/czo-panel-report-april11.doc)

Websites and book chapters:

• U.S. Critical Zone Observatory Website: http://www.criticalzone.org
  
  • an important website that you will visit and use repeatedly throughout this course.
  • specifically note the 9 existing U.S. CZOs
• U.S. National Science Foundation Website: http://www.nsf.gov
  
  • the U.S. federal agency that funds the CZO network; click on "About" and read through this brief introduction to the NSF, following the MORE links for greater detail.
• U.S. National Research Council Website: https://history.aip.org/phn/21511003.html
  
  • Learn about how research strategies and policies are developed in the U.S.; browse the section on the Earth and Life Studies Division (DELS), and under DELS, read the "About us" section.
• Soil Transformations in European Catchments Website: (SoilTrEC); https://esdac.jrc.ec.europa.eu/projects/soiltrec
  
  • one-time European equivalent of the U.S. CZO program.
• Critical Zone Exploration Network Website: http://www.czen.org
  
  • the "go to" site for international CZ science; read the "About CZEN" section.
     
• White T., Brantley S., Banwart S., Chorover J., Dietrich W., Derry L., Lohse K., Anderson S., Aufdendkampe A., Bales R., Kumar P., Richter D., McDowell B. (2015) Chapter 2 " The Role of Critical Zone Observatories in Critical Zone Science, in Developments in Earth Surface Processes 19: 15"78, CZO link
  • Focus on sections 2.1, 2.3 and 2.4; 2.2 gets into too much detail about the individual CZO sites.