Assaf is an ecosystem modeller interested in the interactions and feedbacks within natural systems and how these respond to and interact with changes in climate and fire. His interests include combining data and different modelling approaches to answer fundamental and applied questions regarding vegetation dynamics, Critical Zone structure and function and the feedbacks between vegetation, soils, climate and fire at different spatial and temporal scales.

He holds a BSc. in biology from the Hebrew University in Jerusalem and an MSc. in Environmental and Soil Science from Tel Aviv University. He did his Ph.D. at the University of Melbourne, where he combined spatial analysis, fieldwork, and developed a new numerical model to study the role of climate and fire on the coevolution of the Critical Zone to show that asymmetric hillslopes in South-eastern Australia might have resulted from eco-hydro-geomorphic feedback between microclimate, forests, soils and fire.