Appendix A Primer on Biologically Mediated Redox Reactions in Ecosystems © 2013 Elsevier, Inc. All rights reserved. From Fundamentals of Ecosystem Science, Weathers, Strayer, and Likens (eds).

Figure A.1 Representation of the conversion of chemical potential energy into energy useable by organisms. The “stored” energy in the electron donor (D) is released as the electrons are transferred to the electron acceptor (A+). Enzymes involved in electron transport capture energy for use in biosynthesis. © 2013 Elsevier, Inc. All rights reserved. From Fundamentals of Ecosystem Science, Weathers, Strayer, and Likens (eds).

Figure A.2 Typical sequence of changes in biologically mediated redox reactions and concentrations of redox-active materials that occur after a wetland soil is flooded and the organic material (long green line) degrades. Solid lines show typical electron acceptors that are depleted as organic matter oxidation proceeds. (Modified from Mitsch and Gosslink 1993, after Reddy 2008.) © 2013 Elsevier, Inc. All rights reserved. From Fundamentals of Ecosystem Science, Weathers, Strayer, and Likens (eds). 3