Largest Living Thing- KQED Perspective aired October 2002
Ok when I ask a group of folks “what is the largest living thing on the Planet Earth?” Invariably someone responds – the blue whale! They have just exposed a common bias. I never said largest animal. But blue whales are the biggest sentient beings to have ever lived – 100 feet long, 100 tons! That’s equal to 5 brontosauruses, 25 African Elephants or 1500 human beings!
Many of us know that the largest single tree in the world is the General Sherman- a giant sequoia that weighs 4.5 million pounds! But in 1992 two biologists in Michigan got a lot of media attention when they announced they had found the largest living thing – a fungal mat that covered 40 acres. Of course in typical competitive fashion another group soon claimed that their organ-ism was bigger. It covered 1500 acres. And several years ago an even bigger mycelia mass of 2200 acres was found in Oregon. Stop boys! While the area covered by these lowly fungi may be extensive, their weight is nowhere near that of General Sherman.
But now we know that even the giant sequoias of California can’t compete with the Quaking Aspens of the Rocky Mountains. “What!” you say, “those wimpy little trees with the nervous leaves?” Yep. Years ago I noticed that when the aspens were changing color in the fall that certain clumps of trees would be a different hue than the adjacent clump. Even though the slope exposure, the soil, the moisture would all be identical there were clear differences in the leaf color. I was perplexed. I now know that I was observing adjacent clonal groups of aspens.
Researchers in Utah’s Wasatch Mountains have found what they claim is the largest living thing in the world- a 106-acre patch of aspens, which are totally connected by the same root system. There are 47,000 tree trunks, which are genetically identical and weigh over 13 million pounds. They have named this “individual” Pando, which is Latin for “I spread.”
But before they could break out the champagne marine biologists were clamoring for their favorite candidate – Australia’s Great Barrier Reef. It may be that the largest living thing is a coral reef, which also consists of identical clones in a common matrix. Will it never end? This is Michael Ellis with a Perspective.