TED-Ed: Valentin Hammoudi: How tall can a tree grow?

Californian sequoias are among the tallest trees, but they face height limitations due to the challenges of sap movement against gravity. Trees circulate two types of sap: phloem, which distributes sugars, and xylem, which carries nutrients. The movement of sap is driven by transpiration, capillary action, and root pressure. However, as trees grow taller, these processes become less efficient, leading to the hydraulic limitation hypothesis, which explains why trees have a maximum height. Researchers continue to study these limitations to understand the factors affecting tree growth.

What factors limit the height of Californian sequoias?

Explain the role of sap in the growth of trees.

What is the hydraulic limitation hypothesis?

Describe the process of osmotic movement in trees.

How do gravity and other forces affect the distribution of nutrients in tall trees?