© NOAA/Reuters
Before the rise of modern humans, there were "deer with twelve-foot antlers, and bison herds to the horizon" that ate huge amounts of plant matter, moving these nutrients to higher ground "through their deposit of feces, urine and, upon death, decomposing bodies. I wanted to know whether the world of the past with all the endemic animals was more fertile than our current world," lead study author Chris Doughty of Oxford University told The Washington Post.
Doughty's team applied a set of mathematical models to estimate the movement of nutrients vertically in the oceans and across the land, and how this movement changed with extinctions and declining animal populations. What researchers found was that these megafauna, or large animals, played a greater role in the spread of nutrients across the planet than scientists realized. Equally, whales and other marine mammals moved phosphorous from deep ocean water to the surface, which was then spread by seabirds and migrating fish across seas, up rivers, and deep inland to the mountaintops.
Previously, scientists studied nutrient cycling related to the weathering of rocks, which broke down and left nutrients in the soil. They also found that microbes and bacteria contributed to nutrient cycling. The team's new finding adds another dimension to the science, finding that fertilized ecosystems maintain natural functions vital to people. "Previously, animals were not thought to play an important role in nutrient movement," said Doughty in a statement.
Comment: For more on how the loss of the flora and fauna effect our terrestrial life, listen to the SOTT editor's interview with Lierre Keith, author of The Vegetarian Myth.
SOTT Talk Radio: Dissecting the Vegetarian Myth - Interview with Lierre Keith