Ecology is based on an understanding of the distribution and abundance of living organisms and interactions with their environment. This unit focuses on the ecology of populations, communities and ecosystems, and the processes that structure ubiquitous gradients (e.g. altitude, latitude, soil fertility, moisture) in terrestrial landscapes. Resource use along gradients involving biological interactions (e.g. competition, predator-prey, and herbivory) is a key theme of the unit. Topics covered include community structure and succession, dispersal and recruitment, flows of energy and matter in ecosystems, and the role of disturbance in regulating ecosystem dynamics. This unit provides an understanding of ecological principles relevant to current human impacts such as climate change, land clearing and urbanisation.