What Affects Transpiration in Plants?
- Plants absorb water-soluble nutrients through the roots. The nutrient-rich water moves up the plant stem and into the leaves, where the nutrients are absorbed. The excess water then exits through stomata cells of the leaves. This is the plant's way of disposing of the water used to carry the nutrients but not necessary for the process of photosynthesis.
- The stomata are specialized cells on the surface of the leaf. Only about one in every 100 cells on the leaf is a stomata, which is surrounded by guard cells. The guard cells shrink or swell as conditions warrant, thereby changing the size of the stomata cell and regulating the water flow through the process of transpiration. Think of the stomata cells as the pores and the guard cells as your skin.
- The water evaporating from the leaves has a cooling effect, which helps regulate plant temperature under adverse conditions. It is also responsible for the cooler temperatures noted in a grassy lawn or wooded area when compared to a paved or concrete surface.
- Transpiration is the process of the natural flow of water from the roots exiting through the leaves. This works well, as long as there is adequate moisture in the root zone. When the soil becomes dry, the supply of moisture for transpiration is reduced, and under severe dry conditions is eliminated. This leads to drying leaves as the moisture in the leaf cells evaporates.
- Weather plays a major part in the amount of transpiration. Hot temperatures coupled with wind and low humidity prompts the highest level of transpiration. These same conditions evaporate moisture from the topsoil, reducing available moisture for the plant's roots. This compounds the likelihood of plant stress under these conditions.Gardeners often water or irrigate crops under dry conditions to reduce the amount of transpirational stress. Another option is mulch, which shades the ground and reduces soil evaporation, conserving the water supply the plant needs for the transpirational process.