Woodland loss is a major cause of biodiversity decline in African savanna parks. Decisions about whether remedial steps are possible and warranted depend on the cause. Climate, fire, elephants and human impact, often in combination, have been cited as major causes. The almost complete extinction of woodland in Amboseli National Park since 1950 has been at the centre of such debate. A 20-year study based on an experimental design to test overgrazing, pathogen, climate and elephant browsing theories of woodland