By Rajat Ghai – Down to Earth
World’s second-biggest rainforest could lose 6-9 % of its carbon capture ability, if the forest elephant goes extinct, says Saint Louis University research.
Africa’s iconic elephants are on the brink. But while the ‘African elephant’ usually conjures images of the species found on the savannas of the Continent (Loxodonta africana), it is its smaller cousin found in the world’s second-biggest rainforest that holds the keys to global carbon sequestration. That would go awry if the species bows out, according to new research.
The African forest elephant (Loxodonta cyclotis) plays a key role in creating forests which store more atmospheric carbon and maintaining the biodiversity of forests in Africa.
If it becomes extinct, the Congo rainforest of central and west Africa would lose between six and nine per cent of its ability to capture atmospheric carbon, amplifying planetary warming, the research published January 23, 2023, warned.
Stephen Blake, assistant professor of biology at Saint Louis University in the United States and senior author of the paper, was quoted as saying by the website Phys.org:
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.
How do forest elephants enhance carbon capture?
Blake and his colleagues found that these elephants acted as ‘gardeners of the forest’. Each forest has low carbon density and high carbon density trees. The former have light wood while the latter have heavy wood.
“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 2/5 less sunlight and able to grow in shade,” Phys.org noted in its article.
The African forest elephant strips away the low carbon density trees. This means that it removes the competitors of high carbon density trees. This also enables the sunlight to reach more high carbon density trees.
The elephants also spread the seeds of the high carbon density trees across the forest through their droppings.
“Elephants are the gardeners of the forest. 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,” Blake was quoted as saying.
But the forest elephants of the Congo are imperilled. They are listed by the International Union for Conservation of Nature as “Critically Endangered” — a category for species that have declined over 80 per cent within three generations.
Before the current paper, another one in November last year by the United Nations Office on Drugs and Crime (UNODC) had also drawn attention to the link between African forest elephants and ecosystem services.
Megaherbivores modify forest structure and increase carbon stocks through multiple pathways was published in Proceedings of the National Academy of Sciences (PNAS).