The giant sequoia (Sequoiadendron giganteum) represents the peak of terrestrial biomass, standing as the most massive single organism on Earth. These colossal trees grow naturally only on the western slopes of the Sierra Nevada mountains in California, achieving dimensions that defy easy comprehension. The immense weight of a mature sequoia results from its extraordinary volume, as its trunk maintains a large diameter far up its height, unlike rapidly tapering trees. Understanding how much a sequoia weighs requires moving past simple scale measurements and diving into the physics of wood density, moisture content, and intricate volume calculations.
The Measured Mass of the Largest Specimens
The General Sherman Tree in Sequoia National Park, the largest known specimen, serves as the primary reference point for sequoia mass. Its total living weight, including all moisture, is often estimated to be over 2,000 tons. To put this figure into perspective, this single tree weighs roughly as much as 400 adult African elephants. The trunk alone, which holds the majority of the weight, contains a mass equivalent to nearly 15 adult blue whales or 25 military battle tanks.
These immense weights approximate the living tree, accounting for the significant water contained within the wood, bark, and foliage. The sheer scale of the largest sequoias means that every new growth ring adds an enormous volume of wood. For instance, an average mature giant sequoia can add enough wood mass in a single year to equal the volume of a 60-foot-tall oak tree. Although total weight estimates vary, the consensus places the most massive trees far beyond any other single organism.
The Elements That Define a Sequoia’s Weight
Dry Mass
A sequoia’s weight splits into two main components: dry mass (the permanent carbon structure) and the mass contributed by water and sap. The dry mass is the weight of the cellulose, lignin, and other organic compounds that form the wood, bark, and foliage. For the General Sherman Tree, the aboveground dry mass is estimated to be approximately 582 metric tonnes (642 US tons). This dry wood is naturally resistant to decay, allowing the tree to accumulate mass over thousands of years.
Water Content
The remaining weight in the living tree is composed of water, which is necessary for all biological functions and can account for a substantial percentage of the total mass. A living sequoia can be nearly 40% to 50% water by weight, a figure that fluctuates seasonally depending on environmental conditions and the tree’s current state of hydration. The thick, furrowed bark also adds significant weight, with the dry mass of the General Sherman’s bark alone estimated to be 48 metric tonnes. Even the foliage and branches add mass, though the root system, which is often excluded from published estimates, is also massive.
Calculating the Mass of a Standing Tree
Since it is impossible to place a standing sequoia on a scale, scientists must calculate its mass indirectly by first determining its volume. This process, known as dendrometric technique, begins with meticulously measuring the tree’s height and its diameter at various points up the trunk. Modern methods often utilize advanced tools such as laser rangefinders, terrestrial laser scanning, and photogrammetry to create a highly accurate, three-dimensional model of the trunk volume. The trunk volume is the most important measurement, as the mass of the branches and foliage are proportionally smaller.
Once the tree’s volume is calculated, researchers apply the concept of allometric scaling to estimate the weight. Allometry involves using small, measured samples—often from nearby felled or dead trees—to determine the average density and moisture content of the wood. This measured density is then scaled across the entire calculated volume of the standing tree to derive the total mass. Because wood density varies with age and location, and moisture content changes constantly, these immense weights are reported as scientific estimates with an inherent margin of error.