“What our results have suggested is that the changing climate, through the effect it had on vegetation, was the key thing that caused the reduction in the population and ultimate extinction of mammoths and many other large herbivores,” he said.
Professor Huntley and his colleagues created a computer simulation of vegetation in Europe, Asia and North America over the last 42,000 years.
They did this by combining estimates of what the climate was like during this period with models of how various plants grow under different conditions.
They found that the cold and dry conditions during the ice age, with reduced concentrations of carbon dioxide, didn’t favour the growth of trees.
So instead of forests there were vast areas of pasture, which was ideal for large herbivores, such as woolly mammoths. But as a result of a warmer, wetter climate and rising concentrations of carbon dioxide at the end of the ice age, trees emerged at the expense of the grasslands.
“During the height of the ice age, mammoths and other large herbivores would have had more food to eat,” said Professor Huntley.
“But as we shifted into the post-glacial stage, trees gradually displaced those herbaceous ecosystems and that much reduced their grazing area.”