ABSTRACT
Iron and manganese represent the 4th and 12th most abundant elements, respectively, in the earth’s crust. Iron and manganese are two of the key elements involved in oxidation-reduction reactions in soils of the biosphere and are essential trace elements for living organisms. The biogeochemistry of iron and manganese is complex and is regulated by various biotic and abiotic processes. For example, microbial reduction of iron (III) and manganese (IV) coupled with organic matter decomposition greatly in uences biogeochemical cycles of many metals and nutrients in the environment. The biogeochemistry of iron and manganese in wetland soils and aquatic sediments follows several similar pathways. This is why we have chosen to present a discussion on the biogeochemistry of these two elements in the same chapter.
