This issue of Microbiology Australia is devoted to the field of microbial ecology, currently rapidly growing into a mature, vibrant and exceptionally relevant component of the discipline of microbiology. Indeed, I maintain that all microbiologists are microbial ecologists since the field covers the study of the interactions between living microorganisms and their environment. Microbial ecology links those areas in which microbiologists are traditionally trained (biochemistry/chemistry/microbiology) with ?ecology?, which is generally taught within the life sciences in our universities. ?Oekologie? (ecology), coined by Ernst Haeckel in 1866, can be described as the scientific study of the distribution and abundance of living organisms and the interactions between organisms and their ecosystem including the biotic and abiotic components. Partly due to the channelling of microbiology students into the contemporary field of molecular biology, the majority of microbiologists are not exposed to ecology, and they are generally not aware that they are microbial ecologists.