Newswise – in the results published in Proceedings of the National Academy of Sciences (PNAS)Researchers and colleagues at Saint Louis University report that elephants play a key role in creating forests that store more carbon in the atmosphere and maintain forest biodiversity in Africa. If the already endangered elephants become extinct, the rainforests of Central and West Africa, the second largest rainforest on earth, will gradually lose six to nine percent of their ability to capture atmospheric carbon, amplifying global warming.
“Humans have hunted elephants for thousands of years,” Blake said. As a result, African forest elephants are seriously endangered. The argument that everyone loves elephants has not garnered enough support to stop the killing. Shifting the elephant conservation debate towards the role forest elephants play in preserving forest biodiversity, that losing elephants means losing forest biodiversity, hasn’t worked either, as numbers continue to decline. We can now add the strong implication that if we lose our forest elephants, we will do global damage by mitigating the effects of climate change. Policy makers must take the importance of forest elephants in mitigating climate change seriously to generate the support needed for elephant conservation. The role of forest elephants in our global environment is too important to be ignored.”
Elephants play multiple roles in protecting the global environment. Within a forest, some trees have light wood (low carbon intensity trees) while others make heavy wood (high carbon intensity trees). Low-carbon trees grow quickly, rising above other plants and trees to reach sunlight. Meanwhile, high-carbon trees grow slowly, need less sunlight and are able to grow in shade. Elephants and other carnivores affect the abundance of these trees by feeding more heavily on low-carbon-density trees, which are more palatable and nutritious than high-carbon-density species. This “thinns” the forest, much as a forester does to promote the growth of their favorite species. This thinning reduces competition between trees and provides more light, space and soil nutrients to help high-carbon trees thrive.
“Elephants eat a lot of leaves from a lot of trees, and they do a lot of damage when they eat,” Blake said. “They strip leaves from trees, rip off an entire branch or uproot a sapling when eating, and our data shows that most of this damage is done to low-carbon-intensive trees. If there are a lot of high-carbon trees around, that’s one less competitor, which elephants eliminate.”
Elephants are also excellent dispersers of seeds of high carbon density trees. These trees often produce large, nutritious fruits that are eaten by elephants. These seeds pass through the intestines of elephants unharmed, and when released through the dung, they prepare to germinate and grow into some of the largest trees in the jungle.
“Elephants are the gardeners in the forest,” Blake said. “They are planting the forest with high-carbon-intensive trees and getting rid of the ‘grasses,’ which are the low-carbon-intensive trees. They are doing an enormous amount of work to maintain the diversity of the forest.”
Because of these preferences, elephants are directly linked to influencing carbon levels in the atmosphere. High-carbon-intensity trees store more carbon from the atmosphere in their wood than low-carbon-intensity trees, which helps fight global warming.
“Elephants have multiple societal benefits,” Blake said. “Children all over the world play with stuffed elephants in their bedrooms. African forest elephants also enhance the diversity of the rainforest in many ways.”
With this knowledge, Barzaghi is now looking to the future to determine how other animals in the rainforest affect its biodiversity and whether they have the same effect as elephants.
“The implications of our study extend well beyond just forest elephants in Africa,” said Berzaghi. “Just as we show that lower carbon-density tree leaves are less palatable to herbivores, these findings suggest that other large herbivores, such as primates or the Asian elephant, could They also contribute to the growth of high-carbon-dense trees in other tropical forests. Our goal is to expand on this by investigating those species and other regions.”
Armed with this vital information, the arguments for forest elephant conservation in the Congo Basin and West Africa have never been greater. Elephant populations have been wiped out from many areas of the jungle and, in many areas, are functionally extinct, meaning their numbers are too low to have a significant impact on the environment of the jungle. Blake calls for more protection for forest elephants.
“The illegal killing of elephants and the illegal trade is still active,” Blake said. “Ten million elephants once roamed Africa, now there are fewer than 500,000, most of the population living in isolated enclaves. These elephants range from critically endangered to critically endangered, with their numbers declining by more than 80 percent in the last 30 years or more. Elephants are protected by national and international law, yet poaching continues. These illegal killings must stop to prevent the extinction of forest elephants. Now we have a choice. As a global community, we can continue to hunt these highly social and intelligent animals and watch them go extinct, or we can find ways to stop them This illegal activity. Save the elephants and help save the planet, it really is that simple.”
Other researchers on this study include François Bretagneols and Clementine Durand-Bissart from the University of Bourgogne, France.
About Saint Louis University
Founded in 1818, Saint Louis University is one of the oldest and most prestigious Catholic institutions in the country. Rooted in Jesuit values and its pioneering history as the first university west of the Mississippi River, SLU offers its more than 13,500 students a rigorous and transformative education for the whole person. At the heart of the university’s diverse scholar community is SLU’s service-focused mission, which challenges and prepares students to make the world a better, fairer place.