Elephants ‘could help to save the planet’

Elephants could play a crucial role in the battle against climate change, a new study has shown.

The study showed that elephants play a key role in creating forests which store more atmospheric carbon – and are also important in maintaining the biodiversity of forests in Africa.

Ten million elephants once roamed Africa, but just 500,000 remain in pockets, and some populations are critically endangered.

The researchers found that if elephants in the area become extinct, the rainforest of central and west Africa, the second largest rainforest on earth, would gradually lose between 6-9% of their ability to capture atmospheric carbon, amplifying planetary warming.

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Assistant professor of biology at Saint Louis University and senior author on the paper Stephen Blake said, “Elephants have been hunted by humans for millennia. As a result, African forest elephants are critically endangered.

“The argument that everybody loves elephants hasn’t raised sufficient support to stop the killing. Shifting the argument for elephant conservation toward the role forest elephants play in maintaining the biodiversity of the forest, that losing elephants would mean losing forest biodiversity, hasn’t worked either, as numbers continue to fall.

“We can now add the robust conclusion that if we lose forest elephants, we will be doing a global disservice to climate change mitigation. The importance of forest elephants for climate mitigation must be taken seriously by policy makers to generate the support needed for elephant conservation. The role of forest elephants in our global environment is too important to ignore.”

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Elephants play multiple roles in protecting the global environment.

Within the forest, some trees have light wood (low carbon density trees) while others make heavy wood (high carbon density trees).

Low carbon density trees grow quickly, rising above other plants and trees to get to the sunlight. Meanwhile, high carbon density trees grow slowly, needing less sunlight and being able to grow in shade.

Elephants and other megaherbivores affect the abundance of these trees by feeding more heavily on the low carbon density trees, which are more palatable and nutritious than the high carbon density species.

This “thins” the forest, much like a forester would do to promote growth of their preferred species. This thinning reduces competition among trees and provides more light, space and soil nutrients to help the high carbon trees to flourish.

“Elephants eat lots of leaves from lots of trees, and they do a lot of damage when they eat,” Blake said. “They’ll strip leaves from trees, rip off a whole branch or uproot a sapling when eating, and our data shows most of this damage occurs to low carbon density trees. If there are a lot of high carbon density trees around, that’s one less competitor, eliminated by the elephants.”

Elephants are also excellent dispersers of the seeds of high carbon density trees.

“Elephants are the gardeners of the forest,” Blake added. “They plant the forest with high carbon density trees and they get rid of the ‘weeds,’ which are the low carbon density trees. They do a tremendous amount of work maintaining the diversity of the forest.”

Armed with this vital information, the arguments to conserve the forest elephants of the Congo Basin and West Africa have never been greater, the researchers say.

Populations of elephants have been eliminated from many areas of the forest, and in many areas, they are functionally extinct, meaning that their populations are so low that they have no significant impact on the ecology of the forest.

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