Road to Extinction: Elephants are Taking the Trees With Them

It's no secret that wild elephant populations are approaching dangerously low numbers. Overhunting, poaching, and shrinking habitats are keeping elephants down. Now, new research shows that if elephants go down, they're taking the trees with them.

That's at least according to a study recently published in the journal Proceedings of the Royal Society B, which details how tree species dominant in elephant habitats rely on the gentle giants to disperse their seeds and keep populations healthy. Without elephants, these tree species may face a crisis of local extinctions in less than a century's time.

"Previously, it's been unclear what role seed dispersal plays in tree population dynamics," researcher Trevor Caughlin explained in a statement. "A tree makes millions of seeds during its lifetime, and only one of those seeds needs to survive to replace the parent tree. On the surface, it doesn't seem like seed dispersal would be that important for tree population. What we found with this study is that seed dispersal has an impact over the whole life of a tree."

This was determined after Caughlin and his colleagues spent three years gathering tree data in Thailand, where elephants once exceeded 100,000. Today, there are not even 2,000 elephants left in the region, having been poached to near-extinction alongside tigers, civet cats, and other threatened wildlife.

The collected data was supplemented with more than 15 years of additional data from the Thai Royal Forest Department, allowing researchers to asses health and mortality of trees that grew in crowded environments, compared to those that were widely dispersed by elephants and other animals.

Predictably, tree populations fared much better when large animals were around to help seeds spread.

"This study fills a major gap in our understanding of how overhunting affects forest trees, particularly in tropical forests," added Richard Corlett, director of the Center for Integrative Conservation at the Xishuangbanna Tropical Botanical Gardens in Yunnan, China. "The message that 'guns kill trees too' should help put overhunting at the top of the conservation agenda, where it deserves to be."