Marcel van Oijen studied mathematical biology at the University of Utrecht. He completed his PhD in plant disease epidemiology at Wageningen University, where he worked on modelling the impacts of environmental change on crops. He moved to the U.K. in 1999, becoming a Senior Scientist at the Natural Environment Research Council. There he focused on the use of Bayesian methods in the modelling of ecosystem services provided by grasslands, forests and agroforestry systems. He now works as an independent scientist and as such has written two books: Bayesian Compendium (first edition in 2020) and Probabilistic Risk Analysis and Bayesian Decision Theory (2022).