When we hear news about the declining numbers—and even near-extinction—of some of the world’s largest animals, such as tigers and rhinos, we usually think about that loss in terms of the planet’s diminishing animal biodiversity and what we can do to conserve what’s left of these species. But new research results from the University of Florida published earlier this month show that we stand to lose much more than those specific forms of fauna.
For millennia, elephants have been important cultural, national and spiritual symbols in Thailand. At the beginning of the 20th century, elephant numbers there exceeded 100,000. Today, however, it is estimated that only 2,000 wild elephants remain in Thailand, largely due to capture in order to meet the demands of Thailand’s tourist industry or poaching for ivory and meat.
According to the University of Florida report, this overhunting not only decimates the elephant population, it has widespread effects on the forests in which they live. When wildlife is killed or removed from a natural habitat, then, we kill that particular environment itself.
What will this mean for Asian forests; and by extension, the forests on our own North American continent?
Seeds hitchin’ a ride
The results of the University of Florida study are reported in the November 2014 issue of Proceedings B, the Royal Society of London’s flagship biological research journal. The authors demonstrate how vital large animals are to maintaining the biodiversity of tropical forests in Thailand and how overhunting or removal of them leads to the extinction of a dominant tree, the Miliusa beech (Miliusa horsfieldii), with likely cascading effects on other forest biota.
The research is the first of its kind, quantifying the decades-long effects of animal seed dispersal across the entire life cycle of the trees—from seeds to seedlings to adult trees. Using more than 15 years of data from the Thai Royal Forest Department, the scientists looked at the growth and survival of trees that sprouted from parent trees and grew up in crowded environs, compared to trees from seeds that were widely transported across the forest by animals.
A long-term simulation on millions of seeds run on the University of Florida’s supercomputer showed that trees that grow from seeds carried by now-overhunted animals are hardier and healthier than those that are not. That means that the loss of animal seed-dispersers, such as elephants, increases the probability of tree extinction by more than tenfold over a 100-year period, putting the whole biological community at risk.
I have written before about whether or not the hunting of one animal can help the fate of the many. At the time I was writing about that issue, I wasn’t sure of my own position, given the good one animal slated for a trophy hunt could do for the conservation of the rest of that particular species. Then, after my post on the Great Bear Rain Forest, a reader wrote in and urged me to take a stand on the hunting of grizzly bears there. That’s why this new research out of the University of Florida caught my attention. Poaching, trophy hunting or the removal of even a single animal from its habitat is about so much more than just the loss of that species. It’s about the loss of an entire ecosystem.
In British Columbia, according to the Raincoast Conservation Foundation, trophy hunters kill 300 to 400 grizzlies every year. This is allowed despite the fact that bear viewing generates 12 times more in visitor spending than bear hunting and more than 11 times in direct revenue for B.C.’s provincial government. And in line with the results of the University of Florida study, not only are the grizzlies themselves at risk, the great British Columbia forests are in jeopardy.
When salmon spawn, they feed the bears, coastal wolves, eagles and ravens. These predators pull the salmon onto the shorelines; coastal wolves drag the carcasses even farther into the forest, where they feed thousands of insects and microorganisms. The decaying fish release nitrogen—nature’s superfertilizer—into the soil around them. This high concentration of salmon-derived nitrogen is what causes the trees along the coast and in the river valleys to grow so large. In turn, they create havens for bears, birds and wolves.
It seems to me now that with each elephant that is removed from a forest in Thailand, a beech tree disappears, too. And for every grizzly that is taken from our continent’s coast, one more red cedar is not given a chance to live a thousand years.
And that may be the real meaning of one animal’s loss.
Here’s to finding your true places and natural habitats,