This course will provide an overview of “the biotic controls on chemistry of the environment and the geochemical controls of the structure and function of ecosystems” (Howarth R. W. 1984). This will include the elemental cycling of major components of local and global biogeochemical cycles. Topics will include exploring the transfer of energy and nutrients within terrestrial and aquatic ecosystems, and the interactions among sources of nutrients to each ecosystem. The movement of the elements of carbon (C), nitrogen (N), phosphorous (P) and sulfur (S) will be evaluated, along with their incorporation into other minerals and solutes as they transfer from the atmosphere, through terrestrial ecosystem and into aquatic systems over both short and long timescales.