Abstract

If you push a tree really, really hard, do you think you could make it fall down? You would probably struggle, even if it looks quite small and thin. But it’s easy work for an elephant!

We call elephants ecosystem engineers because they can have a great effect on their landscape, pushing trees down as they search for food and water. However, humans can also have a big impact on a landscape, cutting trees for fuelwood for cooking or opening space for crops.

We wanted to find out who had the greatest effect on treefall in African woodlands known as savannas – humans, or elephants. We collected data on treefall rates and patterns and found that elephants had the greatest effect, but that humans were also responsible for high numbers of treefall. This doesn’t always kill the trees as they are resilient to disturbance, but, combined with other factors humans and elephants can put the woodlands at risk.