ABSTRACT
The laws of thermodynamics postulate that energy can be exchanged between physical systems as heat or work. The laws also postulate the existence of a quantity named entropy, which can be defined for any system. Thermodynamics can describe how systems respond to changes in their surroundings. Understanding the biogeochemical cycles in wetland ecosystems requires a fundamental knowledge of basic terminology and concepts used in biology and chemistry. In addition, the reader needs to be familiar with basic geology, soil science, and ecology terms. In oxidation–reduction reactions, there is a balance between reduced products and oxidized reactants. To calculate this balance, the number of molecules of each reactant or product must be multiplied by their oxidation number or state. Substances with positive reduction potentials are usually good oxidizing agents, while the substances with highly negative reduction potentials are good reducing agents. The reduction potentials of the various organic and inorganic substances are published in chemistry and biochemistry textbooks.
