Professor Mark J Bailey is Director of the Centre for Ecology & Hydrology (CEH). After graduating with a degree in microbiology and a PhD in insect virology, Mark spent four years as a postdoctoral fellow studying bacterial pathogenicity before moving to the NERC Institute of Virology and Environmental Microbiology, later CEH's Oxford site. Mark became the Oxford site's director in 2002 and Science Director of CEH's Biodiversity Programme from 2003 to 2012, when he was appointed Director of CEH.

Mark's research focus has been the development and application of molecular genetics and metagenomics to study the underlying principles of microbial ecology, microbial community dynamics, ecosystem function, habitat-regulated gene expression, the the functional activity of communities and the evolutionary relevance of the horizontal gene pool. Key research interests include biogeochemical cycling, functional diversity and microbial metagenomics in the study of soil-plant-microbe interactions, and the wider application of molecular ecology in the environmental sciences. Broader interests include the general ecology of systems and multi-scale trophic interactions, and the role and relevance of biodiversity in sustaining our planet.