Redwood trees are the world’s largest single organisms, representing a scale of life unmatched by any other organism with a single trunk. Redwood trees fall into two species: the Coast Redwood (Sequoia sempervirens), the world’s tallest, and the Giant Sequoia (Sequoiadendron giganteum), the largest by volume. The immense size of these trees, which can survive for thousands of years, presents a unique challenge to researchers attempting to quantify their total weight. The final figures represent the staggering accumulation of mass over millennia.
The Estimated Total Mass
The General Sherman, a Giant Sequoia located in California’s Sequoia National Park, is the primary benchmark for this measurement. Its total estimated living mass, including the trunk, branches, foliage, and water content, is approximately 1,900 metric tons. This figure represents the weight of the entire organism standing in the forest, equivalent to nearly 4.2 million pounds.
The range for other large, mature redwood trees falls into the hundreds of metric tons, but the General Sherman is an extreme outlier due to its incredible girth and volume retention high up the trunk. While the Coast Redwood (Sequoia sempervirens) is known for its height, the Giant Sequoia’s immense diameter and low taper allow it to accumulate significantly more total wood volume and greater overall mass. The sheer bulk of the largest Giant Sequoias makes them the most massive known living single-stem trees on Earth.
Components Contributing to Mass
A redwood tree’s total weight is a combination of dry biomass and water content. Dry biomass is the solid, organic material, mainly cellulose and lignin, that accumulates over the tree’s lifespan. The General Sherman tree, for instance, has an estimated above-ground dry mass of approximately 582 metric tons—the weight of its material if all the water were removed.
Water is a significant factor, contributing a large percentage of the tree’s living weight. The difference between the total wet mass (1,900 metric tons) and the dry biomass (582 metric tons) indicates that water can contribute over 70% of the total trunk weight. Coast Redwoods, in particular, thrive in the fog belt and actively absorb moisture through their leaves, contributing to their living weight.
The mass is highly concentrated in the trunk and branches, with the root system contributing a small percentage of the total. Redwood root systems are shallow, generally extending only 6 to 12 feet deep, and lack a deep taproot. Instead, the roots spread horizontally for over 100 feet and often intertwine with neighboring redwoods, providing collective stability. This structure means the above-ground trunk and canopy hold the vast majority of the tree’s overall mass.
Calculating the Mass of a Living Tree
Directly measuring the weight of a living redwood is impossible, as it would require felling and weighing the specimen. Scientists rely on non-destructive measurement techniques to determine volume and density. The first step involves using advanced technology like Terrestrial Laser Scanning (TLS) or LiDAR (Light Detection and Ranging). These instruments create a precise, three-dimensional model of the entire tree, mapping the trunk, branches, and crown structure to accurately determine the total volume of wood.
Once the total volume is established, it is converted into a mass measurement. Researchers determine the wood’s density by taking small, non-invasive core samples from the tree, often at different heights. The density of Giant Sequoia wood is relatively low, around 0.34 metric tons per cubic meter. This density figure is then applied to the total volume measurement.
The final step uses allometric equations, which are mathematical models relating measurable parameters like diameter and height to the total biomass. These equations are refined and verified using data from the 3D scans and density samples, generating a highly accurate estimate of the total dry biomass. The ultimate living mass figure is then calculated by estimating and adding the weight of the water content, which fluctuates depending on the season and local moisture.
Contextualizing the Scale
The General Sherman tree’s estimated weight of 1,900 metric tons is a mass few other single living organisms can approach. For comparison, a fully grown blue whale, the largest animal on Earth, weighs a maximum of about 190 metric tons. This means a single large redwood can weigh as much as ten adult blue whales combined.
The calculated weight is comparable to some of the largest machines humans have engineered. The total wet mass of the General Sherman is roughly equivalent to the weight of three fully fueled and loaded Boeing 747 jumbo jet aircraft. This weight is an impressive testament to the redwood’s ability to capture and store carbon from the atmosphere over millennia. The massive weight of these trees underlines their ecological significance, representing one of the largest reservoirs of stored biomass in a terrestrial ecosystem.