Quick answer
The tallest living trees exceed 100 metres, but maximum height is limited by water transport, gravity, wind, temperature, crown damage and the energy cost of maintaining distant leaves. Species genetics sets the possible range, while site conditions determine how close an individual tree comes to it.
Key points
- The tallest known living trees are coast redwoods.
- Water must remain under tension in narrow xylem conduits from roots to leaves.
- Height records require careful measurement because leaning trunks and uneven ground distort simple estimates.
Why height helps a tree
Height lifts leaves above competitors and can improve access to light. A tall crown may also disperse pollen and seeds over greater distances. These benefits are strongest in forests where competition for light is intense.
Height is expensive. The tree must build and maintain a strong trunk, transport water over a long vertical distance and survive increasing wind exposure. At some point, the return from additional height becomes smaller than the hydraulic and structural cost.
The water-transport limit
Evaporation from leaves creates tension in continuous columns of water inside xylem. Cohesion between water molecules helps transmit this pull downward. Gravity and friction make it progressively harder to supply leaves as height increases.
When water potential becomes too negative, stomata close to reduce water loss. This also restricts carbon dioxide uptake and photosynthesis. Xylem can suffer cavitation, in which air disrupts water columns. Tall trees therefore face a narrow balance between supplying the crown and avoiding hydraulic failure.
Wind and mechanical limits
Wind load rises dramatically with crown size and exposure. Trunks taper, buttress roots and flexible branches help distribute forces. Trees growing in open conditions often become shorter and broader than members of the same species in sheltered forest.
Storms can repeatedly remove the top of a tree. Lightning, ice and snow also limit height. Some old giants have lost and replaced leaders several times, producing complex crowns rather than a single perfect point.
Species and site
Coast redwoods combine suitable wood properties, foggy coastal conditions, long growing seasons and the ability to absorb some moisture through foliage. Giant sequoias are more massive by volume but are generally not as tall. Eucalypts and Douglas firs can also reach exceptional heights.
Deep, aerated soil, reliable water, shelter and sufficient nutrients support height growth. Drought, shallow soil, salt exposure, cold treelines and strong wind produce shorter forms.
How tree height is measured
A clinometer can estimate height from angles and horizontal distance, but it is easy to measure the wrong top or assume a vertical trunk. Laser rangefinders improve accuracy. For record trees, climbers may use direct tape drops from the highest living point, combined with detailed crown mapping.
Online figures can become outdated when a tree grows, loses its top or is remeasured. A trustworthy record should state the date and method of measurement.
Could a tree reach 150 metres?
Models suggest an upper range, not an exact universal ceiling. Hydraulic and mechanical constraints make extremely large increases above present records unlikely under current Earth conditions. Evolution could alter anatomy, but gravity, water physics and atmospheric demand would still apply.
Frequently asked questions
What is the tallest type of tree?
Coast redwood, Sequoia sempervirens, holds the modern height record for living trees.
Does a tree keep getting taller throughout life?
Height growth commonly slows with age. The tree may continue adding wood, replacing shoots and expanding parts of its crown even when the highest point changes little.
Are tropical trees the tallest?
Some tropical trees are extremely tall, but the current record-holders are temperate coast redwoods.
Related Nature9 guides
- How Do Trees Transport Water From Roots to Leaves?
- How Do Trees Grow? Roots, Trunks, Branches and Leaves Explained
- How Do Trees Make Food Through Photosynthesis?
- How Long Do Trees Live?
Sources and further reading
- Forest Research: Tree roots and trenching
- FAO: The State of the World's Forests 2020
- IPCC: Special Report on Climate Change and Land
Information is presented for general education. Tree health, structural safety, protected wildlife and regulated plant-health problems may require qualified local advice.