The researcher is Raphael Ben-Shahar, of the University of Oxford, UK.
He spent 10 years researching elephants' habitats in the Chobe and Okavango area of northern Botswana, close to the border with Namibia.
The area is home to 60,000 to 100,000 elephants, about 10% of Africa's total.
findings are potentially very significant, because several southern African countries, Botswana among them, argue that they have too many elephants, and that the animals' habitats and the species that share them are suffering as a result.
Conservationists often argue that in these circumstances it is best to control the elephants' numbers, either by moving them elsewhere or by killing them, before they starve.
But Dr Ben-Shahar
says that in large nature reserves it is the environment that regulates elephant numbers rather than the reverse, with a stable but finely tuned ecosystem of plants and animals that works perfectly well on its own.
"There is no need to cull elephant herds to maintain an ecological equilibrium," he
said: "A staggering amount of biomass passes through the guts of northern Botswana's elephants.
Analysing the different pressures on the plants, Dr Ben-Shahar
compiled a comprehensive life history cycle of different species.
concluded that in the study area the elephants were "nowhere close" to becoming a threat to the vegetation.