Pando colony

The trembling or quaking aspen tree (Populus tremeloides) has the widest distribution of any tree in North America, found everywhere except for the Deep South. Aspen is a tree that can reproduce from seed or by sprouting. Sprouts from an aspen arise from a single root system, and they have identical genetic makeup. These sprouts are known as a “stem,” since they are not individual trees. The average size of an aspen colony is about one acre. Aspen seed needs plenty of moisture to germinate, and it readily grows from seed in the east, but it does not develop from seed in the arid west. In the western region, much of the aspen that is present is the result of clonal growth that has been taking place for thousands of years. In 1968, a clonal colony of aspen named the “Pando Colony” was discovered by Burton V. Barnes near Fishlake National Forest in Utah.

Pando Aspen grove at Fishlake National Forest

Credit: - J Zapell

“Pando” means “spreading” in Latin. The Pando colony is thought to be the largest living organism, and one of the oldest life forms in the world. The exact age of this colony is disputed, but most experts believe that it is between 80,000 – 1,000,000 years of age. The 80,000 age estimate was developed by computing how long it would take to develop a colony of this size from an actively cloning aspen root system. The size of the Pando colony is 106 acres, contains 40,000 stems, and is about 13 million pounds in weight. The root system in the Pando colony is massive, weighing nearly 6 million pounds. This colony is considered to be a clone of a single male quaking aspen. The Pando colony developed when the climate of the west was much damper than it is today, and enhanced by periodic forest fires that destroyed evergreen competition from overrunning the colony. Following a strong fire, the root system persisted underground and sent up new stems from sprouts. It is estimated that the Pando colony has not produced any seed for at least 10,000 years. Today, the Pando colony is being attacked by deer, cattle, disease, and insects. In addition, the suppression of fire is stifling the growth, and allowing evergreen competition to invade this colony. The net result is that not many sprouts are developing, and those that do are being consumed. To help maintain this marvel of nature, the Forest Service has fenced off about 70 acres of the colony, and has begun a program of controlled burns, cutting of individual stems, and severing of the root system, all of which were designed to revitalize this massive life form. Besides Pando, there are some sea grass clonal colonies, fungal mats, and bacterial colonies that are believed to be some of the oldest living creatures.

Article by FCFCDB

Nature Note for 5/30/20