This course will delve into some of the critical ecosystem-level functions involving elemental and materials (e.g. water) cycles in the context of a variety of ecosystem types. The course will cover energy flow through these ecosystems, including organic matter production by photo and chemo autotrophs, and heterotrophic processing. The course will link elemental cycles with energy flow to help students better understand the interactions among C, N, P, S, and Fe cycles in ecosystems, and how cycling of these elements in necessary for maintaining the integrity of ecosystems. The course will build on system-based modeling introduced in Ecology (BLG 567), enabling students to build predictive models that explore ecosystem-wide impacts of perturbations to elemental or hydrologic cycles.