This course presents the theoretical and applied aspects of the ecological environment in the context of urban and urbanizing regions. Ecosystem, and responses of ecosystems, populations and organisms to stresses placed on them by human activities are examined. The course covers the structural and functional relations in ecosystems, the nature of energy and nutrient cycles, and the behaviour of organisms in an ecosystem as well as competition, predation, and mutualism. Applications of ecological principles to urban and regional planning practice are discussed.