Bob Ellis was born in the United Kingdom and gained an honours degree in forestry from the University of Wales in Bangor in 1956. He undertook post-graduate studies in Canada prior to joining the Tasmanian Forestry Commission in 1960. Ellis gained a PhD from the University of Melbourne in the 1960s and then worked for CSIRO in Tasmania on eucalypt silviculture and ecology, particularly that of highland forests dominated by Eucalyptus delegatensis. Ellis was one of the first people to study the causes of high altitude dieback in E. delegatensis forests and of the poor vigour of E. delegatensis regeneration established after clearfelling on upland plateau with a grassy understory. He also documented the colonisation by rainforest of former grasslands and eucalypt forests in upland plateau in north-east Tasmania following the cessation of Aboriginal burning in the early 19th century. Ellis used his knowledge of soils to provide a valuable insight into the effects clearfelling on soil nutrients in wet eucalypt forests.