More than 13,000 years ago, megafauna roamed Southern California.
However, they are fast began to disappear18 press release from the UCLA Institute for the Environment and Sustainability.
“the case? Humans, catastrophic fires and an ecosystem made vulnerable by climate change, according to a press release from La Brea Tartar Museum and Museum.
Although the massive Ice Age mammals, otherwise known as megafauna, were once thought to have been hunted to extinction, researchers from the University of California and the La Brea Tar Pits Museum now say in a report: Recently published study It is likely that wildfires set by humans led to their demise.
“The evidence points to unprecedented fire activity occurring with climate change, along with people coming to the region,” Lisa Martinez, a UCLA graduate student and study co-author, said in the release. “During this period, megafauna species disappeared.”
Fifteen thousand years ago, large mammals, such as the saber-toothed cat, roamed the terrain of Southern California in search of food, according to the museum.
The museum said such predators often find “free lunch” in “asphalt seeps” where the animals become trapped after wandering into “shallow puddles for a drink”.
However, that landscape will soon change drastically, according to the museum.
“Starting around 14,700 years ago, the climate started to become warmer and drier,” the museum said. “Trees died and herbivores began to disappear, resulting in a glut of dry fuel.”
The museum said humans came next.
“The power to create and control fire”
As the Earth faced a “severe drought,” humans arrived, according to the museum.
“Thanks to the ability to ignite and control fire, humans lit up the Earth,” the museum said.
The university said humans at the time used fire for a number of things, including clearing trees for travel, catching and driving away prey, and promoting the growth of plants useful for basketry and medicine.
The university said the wildfires, along with “a severe, centuries-old drought,” had forever changed “the landscape, vegetation, and ecosystems of Southern California.”
“Post-glacial forests” no longer exist, as chaparral bushes have dominated the area, according to the university.
unique biological record
For thousands of years, animals have been stuck in the La Brea Tar Pits, to preserve their bones. This allowed the bones to be accurately dated using carbon, according to the university.
Thanks to their “unique biological record,” the tar pits allow researchers to pinpoint the time of the megafaunal extinction, according to Emily Lindsay, UCLA associate professor and associate curator of the tar pits.
“We used samples from more than 170 animals from seven megafauna species – saber-toothed cats, dire wolves, lions, camels, bison, horses and sloths,” Lindsey, the study’s co-author, said in the release. “About 13,000 years ago, our record of all those animals stopped, and there was only coyote, coyote, coyote, coyote.”
The university said the megafauna’s disappearance coincides with evidence from the same time period “suggesting that large-scale bushfires ravaged the area”.
Evidence of massive wildfires has been found in abundant coal found in “sediments of lakes across southern California,” according to the museum.
The university said such charcoal evidence, likely the result of wildfires, was found in core sediment samples from Lake Elsinore, about 80 miles from the tar pits.
Prior to this time period, “there was very little coal in the geological record,” Martinez said.
parallel to the day
In the recently published paper, the university said, the researchers compare the transformation of landscapes 13,000 years ago to “the conditions that today lead to climate change and devastating wildfires.”
“Throughout history, fires have magnified the influence of humans, for better or worse,” said Glenn McDonald, a UCLA professor of geography and co-author of the study. “Humans today are responsible for at least three factors that lead to wildfires: the ignition itself, climate change, and the introduction of invasive species, which alter the structure of the fuel.”
The university said the researchers hope that future studies of samples taken from the tar pits will help paint a better picture of the “potential impacts of global warming”.
“This site is uniquely positioned to ask a lot of questions of key ecological importance today – things like what the long-term impacts of climate change will be,” said Lindsay.