Martin's research is at the interface of observations (monitoring and experiments) and models, focussed on developing process-orientated understanding to predict plant responses to global environmental change  (e.g., increasing CO₂, temperature, and changing water availability).

Martin is a member of the Scientific Steering Committee for the AmazonFACE experiment and part of the senior management team for JULES (the UK land surface model) under the Joint Land Modelling Programme (JLMP). Additionally, Martin previously co-chaired the leadership committee for CABLE, Australia's land surface model. Finally, Martin is an Associate Editor at New Phytologist.