Question about passive transport of water to the apex of a tree

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Discussion Overview

The discussion centers on the mechanisms of passive water transport in trees, particularly focusing on the roles of capillary action, transpiration, and the anatomical features of trees such as nodes and internodes. Participants explore how these factors contribute to the movement of water to the leaves at the apex of tall trees.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants propose that capillary action alone can only transport water a limited height, suggesting that tree anatomy, including nodes and internodes, may play a role in water transport.
  • Others argue that capillary action can potentially draw water up to about 120 meters, indicating a theoretical limit to tree height based on this mechanism.
  • One participant emphasizes the importance of transpiration, cohesion, and adhesion in the xylem as the primary drivers of water movement, rather than the structural features of nodes and internodes.
  • Another participant notes that while transpiration is crucial, trees must also maintain tension in the fluid columns to support water movement statically, especially under conditions of high humidity.

Areas of Agreement / Disagreement

Participants express differing views on the significance of anatomical features versus the processes of transpiration and capillary action in water transport. There is no consensus on the primary mechanism or the role of nodes and internodes.

Contextual Notes

Some claims depend on specific assumptions about tree anatomy and environmental conditions, such as humidity levels, which may not be universally applicable. The discussion does not resolve the complexities of fluid dynamics in tree physiology.

shivakumar
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TL;DR
sir, does the anatomy of nodes and inter nodes in stem and branches help the water and minerals to transport leaves at the apex of a tree?
Capillary action can work for few centimeters height but in nature, tree transport water to the leaves in the peak of the tree that are few meter tall by capillary action and transpiration alone. This is a miracle. Is this because of morphology and anatomy of tree? does nodes and internode help in the process of transportation?
 
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Capillary action, in a tree, can possibly draw water up to about 120 metres. That sets an absolute limit to how high a tree can grow on Earth.
The water is transported in the xylem and phloem of a tree.
https://en.wikipedia.org/wiki/Xylem
 
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shivakumar said:
TL;DR Summary: sir, does the anatomy of nodes and inter nodes in stem and branches help the water and minerals to transport leaves at the apex of a tree?

Capillary action can work for few centimeters height but in nature, tree transport water to the leaves in the peak of the tree that are few meter tall by capillary action and transpiration alone. This is a miracle. Is this because of morphology and anatomy of tree? does nodes and internode help in the process of transportation?
I think it's key to note that the pores in the leaves (where the water evaporates), are much smaller in diameter than of the xylem below. So the surface tension / capillary action in the pores at the top can be much stronger than in the tubes below, but needs to be transmitted to the fluid below via tension (negative pressure) in the fluid.

Here a good video on this:

 
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Water moves up trees mainly because of transpiration, cohesion, and adhesion in the xylem, not because of the nodes and internodes. Those parts help support the plant but it’s the transpiration pull that gets water to the leaves.
 
RicoGerogi said:
Water moves up trees mainly because of transpiration, cohesion, and adhesion in the xylem, not because of the nodes and internodes. Those parts help support the plant but it’s the transpiration pull that gets water to the leaves.

Yes, the continuous upwards flow happens because transpiration.

But a tree must also be able to "hold up" the fluid columns of more than 10m statically, even when no/little transpiration happens. For example, when ambient relative humidity gets close to 100%. Even that static part is not trivial, and requires tension (negative absolute pressure) in the fluid within the long tubes while avoiding bubble formation (boiling).
 
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