Deer are consuming the world’s largest organism, killing off its opportunity for growth –

In the Wasatch Mountains of the western US on the slopes above a spring-fed lake, there dwells a single giant organism that provides an entire ecosystem on which plants and animals have relied for thousands of years. Found in my home state of Utah, “Pando” is a 106-acre stand of quaking aspen clones.

Although it looks like a woodland of individual trees with striking white bark and small leaves that flutter in the slightest breeze, Pando (Latin for “I spread”) is actually 47,000 genetically identical stems that arise from an interconnected root network. This single genetic individual weighs around 6 million tonnes. By mass, it is the largest single organism on Earth.

Aspen trees do tend to form clonal stands elsewhere, but what makes Pando interesting is its enormous size. Most clonal aspen stands in North America are much smaller, with those in western US averaging just 3 acres. Pando has been around for thousands of years, potentially up to 14,000 years, despite most stems only living for about 130 years. Its longevity and remoteness mean a whole ecosystem of 68 plant species and many animals have evolved and been supported under its shade. This entire ecosystem relies on the aspen remaining healthy and upright. But, although Pando is protected by the US National Forest Service and is not in danger of being cut down, it is in danger of disappearing due to several other factors.

Overgrazing by deer and elk is one of the biggest worries. Wolves and cougars once kept their numbers in check, but herds are now much larger because of the loss of these predators. Deer and elk also tend to congregate in Pando as the protection the woodland receives means they are not in danger of being hunted there.

As older trees die or fall down, light reaches the woodland floor which stimulates new clonal stems to start growing, but when these animals eat the tops off newly forming stems, they die. This means in large portions of Pando there is little new growth. The exception is one area that was fenced off a few decades ago to remove dying trees. This fenced-off area has excluded elk and deer and has seen successful regeneration of new clonal stems, with dense growth referred to as the “bamboo garden.”