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Transpiration of water in xylem Stoma in a tomato leaf shown via colorized scanning electron microscope The clouds in this image of the Amazon Rainforest are a result of evapotranspiration. Transpiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems and flowers.
This transport process is called translocation. [2] In trees, the phloem is the innermost layer of the bark, hence the name, derived from the Ancient Greek word φλοιός (phloiós), meaning "bark". [3] [4] The term was introduced by Carl Nägeli in 1858. [5] [6] Different types of phloem can be distinguished. The early phloem formed in the ...
Transpirational cooling is the cooling provided as plants transpire water. Excess heat generated from solar radiation is damaging to plant cells and thermal injury occurs during drought or when there is rapid transpiration which produces wilting. [1]
Overview of transpiration. 1-Water is passively transported into the roots and then into the xylem. 2-The forces of cohesion and adhesion cause the water molecules to form a column in the xylem. 3- Water moves from the xylem into the mesophyll cells, evaporates from their surfaces and leaves the plant by diffusion through the stomata.
Evapotranspiration is a combination of evaporation and transpiration, measured in order to better understand crop water requirements, irrigation scheduling, [4] and watershed management. [5] The two key components of evapotranspiration are: Evaporation: the movement of water directly to the air from sources such as the soil and water bodies.
Water is constantly lost through transpiration from the leaf. When one water molecule is lost another is pulled along by the processes of cohesion and tension. Transpiration pull, utilizing capillary action and the inherent surface tension of water, is the primary mechanism of water movement in plants. However, it is not the only mechanism ...
The rate of transpiration can be estimated in two ways: Indirectly - by measuring the distance the water level drops in the graduated tube over a measured length of time. It is assumed that this is due to the cutting taking in water which in turn is necessary to replace an equal volume of water lost by transpiration.
Stomatal conductance, usually measured in mmol m −2 s −1 by a porometer, estimates the rate of gas exchange (i.e., carbon dioxide uptake) and transpiration (i.e., water loss as water vapor) through the leaf stomata as determined by the degree of stomatal aperture (and therefore the physical resistances to the movement of gases between the air and the interior of the leaf).