Ecosystem Ecology is a lecture/discussion course that focuses on understanding the physical, chemical, and biological processes regulating the dynamics of terrestrial and aquatic ecosystems. We discuss classic and current topics in ecology that have built our understanding of ecosystem organization and function. The course integrates across disciplines of physiological, microbial, population, and community ecology to understand how and why ecosystems differ in composition, structure, and function, and how ecosystems change over time. The scope of the course includes examples from terrestrial, marine, and freshwater ecosystems. Selected topics for discussion include: "What are ecosystems and why are they so complex?" "The principles of biogeochemistry — nutrient cycling, mass balance, and microbial function." "Global ecology — are processes in ecosystems additive across a range of spatial scales?" "The use of chemical tracers of energy flow through organisms and their environment." "Do species matter for ecosystem function?"