Species → African forest elephant

African forest elephant

Loxodonta cyclotis

30,000 individuals
Extinction risk Critically Endangered
MegaherbivoreCarbonTropical forestSeed disperser
African forest elephant (Loxodonta cyclotis)
Photo: VIGNA christian, Wikimedia Commons (CC BY-SA 4.0)

What if it disappeared?

Impact Major
Ongoing

Without forest elephants to selectively knock down certain trees and disperse the seeds of the largest ones, a Congo Basin forest would lose the higher wood density that this activity currently favors, with up to 60 tonnes less aboveground biomass per hectare.

Documented
Detail

Berzaghi, F., Longo, M., Ciais, P. et al. (2019). Carbon stocks in central African forests enhanced by elephant disturbance. Nature Geoscience, 12(9), 725–729.

By comparing forests where elephants are present to comparable forests from which they have been eliminated, the authors show that elephant disturbance favors dense-wood trees over fast-growing, soft-wood trees, which increases the amount of carbon stored per hectare.

By simulation

The continued disappearance of the forest elephant could, according to simulations, release an amount of carbon equivalent to several years of fossil emissions from many countries.

Extrapolated
Detail

Extrapolation à partir de Berzaghi et al. (2019) : résultat d'une simulation par modèle de dynamique forestière, pas une mesure d'un relâchement de carbone déjà survenu.

The model projects what would happen to the forest composition of the Congo Basin if the decline of the forest elephant continued without intervention. The result depends on the model's assumptions about the speed of forest recolonization and competition among tree species in the absence of elephants.

What's missing to confirm it: No field measurement, at the scale of the Congo Basin, yet confirms the carbon release that the model projects should the decline continue.