Transpiration in plants

• Water enters plant roots at all hours of the day.
• Some trees absorb as much as 5 litres of water per minute.
• Over 95% of the water that enters a plant through the roots exits the plant via the leaves.
• Only a small amount of the water is used for processes inside the plant.
• The loss of water via the leaves is known as transpiration.
• Transpiration is the loss of water vapour from the leaves of a green plant.
• Water is lost from all plant surfaces but it is lost mainly through the leaves.
• As water is lost into the atmosphere it evaporates and helps to keep the plant cool.
• As water is lost through the plant stem and leaves more is brought in by the roots to replace the water that is lost.
• Water and ions from the soil enter the plant and move up through the plant.
• The water and ions are transported to all parts of the plant.
• It is used in processes like photosynthesis and growth.
• The rate of transpiration varies from plant to plant and from day to day.
• When a plant losses more water that it can absorb through the soil it wilts.
• This is because the plant cells lose water and become soft/limp.
• The cells lose their turgor (hardiness) and the leaves hang down.
• Sometimes the whole plant droops.
• If the loss continues to occur the plants will die.

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