You wouldn't know it to look at it, but a forest of aspen trees in Utah qualifies as one of the biggest—certainly the heaviest at 13 million pounds—living organisms on the planet. And scientists say it's in real danger for the first time in millennia, reports Live Science. The trees are known collectively as the "Trembling Giant," or Pando, from the Latin "I spread," per Pacific Standard. The latter speaks to the unique reason it's a single organism: The approximately 47,000 aspens are connected by a single root system and genetically identical to one another. New trees spring up not from seeds but from shoots in that root system, explains the New York Times. The problem is that a new study in PLOS reveals that Pando is in marked decline—and that decline seems to have begun about 40 years ago when humans started developing the surrounding area in earnest.
"It's been thriving for thousands of years, and now it's coming apart on our watch," says lead researcher Paul Rogers of Utah State University. Pando sits on more than 100 acres in Fishlake National Forest in Richfield, and the specific problem is that mule deer and cattle (cows are allowed to graze part of the year) are eating new shoots. "If this were a community of humans, it would be as if a whole town of 47,000 had only 85-year-olds in it," says Rogers. When communities started springing up in the 1970s, humans got rid of natural deer predators such as wolves and bears, and Pando is paying the price. One bright spot: Researchers say Pando is thriving in areas where unpenetrable fencing keeps the deer out, though that solution is an expensive one. (In another part of the planet, the world's oldest and funkiest trees are dying.)