Juuripaineeksi

Juuripaineeksi is a Finnish term that translates roughly to "root pressure" in English. It refers to the osmotic pressure that drives the movement of water from the soil into the xylem of plant roots. This pressure arises because the concentration of solutes, such as mineral ions and sugars, is higher within the root cells than in the surrounding soil water. Water moves from an area of lower solute concentration (soil) to an area of higher solute concentration (root cells) through osmosis, a process that does not require direct energy input from the plant.

This inward movement of water creates a positive pressure within the xylem vessels. Juuripaineeksi is a significant factor in the upward transport of water and dissolved minerals from the roots to the rest of the plant, particularly in shorter plants or during periods of low transpiration. It can be observed as guttation, where water droplets exude from the tips or margins of leaves, especially in humid conditions when transpiration rates are low. While important, root pressure is not the sole mechanism for water transport in plants; transpiration pull, driven by evaporation from the leaves, is generally a more powerful force in taller plants. The effectiveness of juuripaineeksi is influenced by factors such as soil moisture availability and the concentration of solutes within the root cells.