Allometry and metabolic scaling in ecology

Body size affects the structure and function of all levels of biological organization. In ecological systems, body size strongly influences individuals (e.g. rates of individual growth, reproduction and mortality), populations (e.g. population growth rate, abundance and space use), communities (e.g. community abundance, food-web structure and interspecific interactions) and ecosystems (e.g. flux, storage and turnover of materials and energy). This is because individual metabolic rate – the rate at which an organism takes up and utilizes energy and materials – is largely controlled by body size. Here we review how body-size allometries at the individual level affect the structure and function of populations, communities and ecosystems. We use these results to identify and highlight exciting new applications of allometric theory in ecology.