Hydric Soils Online Training Series

Module 4: Hydric Soil Processes - Redox Reactions and Redoximorphic Features
Module Description

This module begins with a review of redox reactions and redoximorphic features. Reduction and concurrent oxidation (redox) are the dominant chemical processes taking place in wetland soils. There are abiological and biological driven redox reactions in wetland soils. The module will focus on the reactions driven by microbial breakdown of organic matter in soils under saturated conditions that lead to unique anaerobic conditions that meet the hydric soil definition of USDA. The redox reactions lead to mobilization of soluble Fe and Mn (depletion zones and surfaces) and subsequent reoxidation (concentration zones and surfaces), collectively called redoximorphic features. Redox feature types are identified through images. Description of the features will be briefly reviewed, in preparation for use as components of field indicators of hydric soils.

Target Audience

Wetland field practitioners who need expertise in hydric soils and seek to understand how hydric soils are formed and how to recognize and interpret the information they provide when observed in the field.

Module Learning Objectives

By taking part in this online training, participants should be able to:

  1. Understand reduction and concurrent oxidation (redox), the dominant chemical processes taking place in wetland soils.
  2. Understand the reactions driven by microbial breakdown of organic matter in soils under saturated conditions
  3. Identify redoximorphic feature types for use as components of field indicators of hydric soils

Trainer Bio

John Galbraith, PhD, has been teaching about soils, agronomy, environmental science and wetlands since 1990 and coaches the soil judging team. He is also a Soil Information cooperative extension specialist. John received his B.S. and M.S. in Range and Wildlife Management at Texas Tech University. John received a Ph.D. in Soil Science at Cornell in 1997. In between, he worked for ten years as a USDA and university Soil Scientist in eight states, mapping ½ million acres of soil. He taught at Cornell and the University of Florida in 1998-99, then began working at Virginia Tech in 1999. John enjoys gleaning, sports, exercise, gardening, science, geology, and nature in general.

Presentation (Vimeo)

Link to Online Quiz

To complete this module, use the following link to access the module quiz on ClassMarker.  Once you complete and submit the quiz, it will be automatically graded and you will receive your quiz score and the correct answers.  Passing the quiz will also qualify participants to download a Certificate of Completion that the participant can submit themselves to accrediting organizations for continuing education credits.

To Take the Quiz and Receive a Certificates of Completion for this Module

Participants who both view the module presentation and complete the module quiz are eligible for an ASWM Certificate of Completion for 0.5 hours of training.

Using the ClassMarker online system, ASWM will ask you to certify that you completed viewing the entire hydric soils training module video presentation.

You will need to develop a username and password in ClassMarker. Once you click on the quiz link, you will be prompted again to provide your name and email address, which will be used to process your certificate.

To receive your certificate you must BOTH:

  1. Certify that you completed viewing of the video presentation.  Answering “no” will result in no certificate being issued.
  2. Complete all 5 quiz questions, getting three or more of the questions correct.  You will be provided three attempts to take the quiz for the module.  If at the end of your third attempt you have not been able to get three or more correct, you will not be eligible to receive a certificate.

You will be prompted to download your Certificate of Participation from ClassMarker after you complete the quiz.

Once you download your certificate, you can then submit the certificate to the accrediting organization of your choice to potentially receive continuing education units/credits.  

Please select the appropriate certificate process:

  • I am an ASWM Member:
    All ASWM members receive free Certificates of Participation for webinars.  Non-Members will be charged a processing fee of $10.00 US.  To receive your free Certificate of Participation, click here.

    If you are not a current ASWM Member, you must select the non-member certificate link to receive your certificate. 
  • I am not an ASWM Member:
    If you are not an ASWM member, please either:

A) Select the Non-member Certificate Option (to begin the module quiz, click here) to get your certificate. All non-ASWM Members are required to pay a $10.00 certificate processing fee.  You will be prompted to pay the processing fee using PayPal, with the option to sign in as either a PayPal member or as a guest (not requiring a PayPal account and using your credit card).  .  

B) We encourage you to go to the ASWM.org website and become a member so that you can receive certificates at no charge for the next 12 months.

If you have any questions, please contact Laura Burchill at or contact the ASWM office at (207) 892-3399.