The course introduces students to key principles of ecology pertaining to the flow of energy and material cycling on Planet Earth. It emphasizes interactions between abiotic and biotic environment and hence the basis for sustainable environmental management. The Course stresses the importance of ecosystems for their services to humankind, human-ecosystem interactions, and the understanding of ecological principles. It helps the students to understand and apply the principles in the management of environment and forms a basis for the understanding of the advanced undergraduate and postgraduate studies.