The largest single-stemmed tree in the world is the giant sequoia, some grow up to 300 feet high or nearly 30 feet across. But growing even larger than that is a quaking aspen tree in Utah with a vast root system that has sprouted an entire grove of new trees. Known as Pando, the cluster of 40,000 tree trunks over a 106-acre area is actually a single organism. Some estimates date Pando’s age at 80,000 years, making it among the largest and oldest organisms on earth, but currently its survival is in peril. As Pando’s individual tree trunks die, they need to be replaced by new shoots springing up from its root system. Unfortunately, deer and other herbivores have developed a craving for aspen shoots, and they are on their way to grazing the ancient giant out of existence.