Other Definitions
mesophyte (dict)
|
MesophyteMesophytes are terrestrial plants which are adapted neither for a particularly dry or particularly wet environment. Such plants have some xeromorphic features in order that they should conserve enough water such as a cuticle, stomata with regulable diameter, and a greater number of stomata on the undersides of leaves, but lack others, meaning they do not retain too much water. Because of their lack of particular adaptation, when they are exposed to extreme conditions they do not survive well. For example, in hot weather they may overheat and suffer from temperature stress. They have no specific adaptations to overcome this, but, if there is enough water in the soil to allow this, they can increase their rate of transpiration by opening their stomata, thus meaning some heat is conducted away with the exiting water. In dry weather they may suffer from water stress (losing more water via transpiration than can be gained from the soil). Again they have no specific adaptations to overcome this, and can only respond by closing their stomata to prevent further dehydration. Their cells are thus likely to loose turgidity, prompting wilting. Wilting does actually have some benefits as it reduces the leaf surface area exposed to the atmosphere, meaning it reduces transpiration, and that exposed to solar radiation, meaning temperature stress is reduced. Although mesophytes often recover from such wilting, prolonged periods of it can lead to permanent wilting or cell plasmolysis and subsequently death.
|
 |