What is the Loss of Water from Plants Called?

Plants depend on water to grow, survive and reproduce. Water is transported from plant roots to leaves via vascular tissue and is then lost to the atmosphere through pores called stomata. The amount of water lost by plants to the atmosphere is called transpiration. In this article, we will delve deeper into transpiration, its importance and how it occurs.

The Importance of Transpiration

Transpiration is a vitally important process for two reasons. Firstly, it helps in the cooling of plants. Plants cannot regulate their temperature, so they depend on water loss through transpiration to cool their leaves down. Secondly, transpiration helps to transport minerals and nutrients from the soil up to the leaves. This is because transpiration creates suction that draws water and nutrients up from the roots through the xylem tissue, a process known as transpiration pull.

Types of Transpiration

There are three main types of transpiration: cuticular, lenticular and stomatal. Cuticular transpiration occurs through the cuticle, a waxy layer on the surface of leaves, stems and fruits. Lenticular transpiration occurs through lenticels, small pores on the surface of stems and roots. Stomatal transpiration is the most common type of transpiration and occurs through stomata, small openings that are mainly found on the underside of leaves. The amount of transpiration that occurs through each of these pathways varies depending on the plant species, environmental conditions and time of day.

Factors that Affect Transpiration

Several factors affect transpiration, including temperature, humidity, light intensity, wind speed and soil moisture content. High temperature, low humidity and high light intensity increase transpiration rates, while low temperature, high humidity and low light intensity decrease transpiration rates. Wind speed also affects transpiration; high wind speeds increase transpiration rates by removing the layer of humid air that forms around leaves, whereas low wind speeds have the opposite effect.

Measuring Transpiration

There are several methods for measuring transpiration. One such method is by using a potometer, which measures the rate of water uptake by plants. Another method is by using a lysimeter, which measures the amount of water lost through the soil from a planted container. Scientists also use C13 isotopes to measure transpiration. In this method, plants are exposed to a C13 labeled CO2 atmosphere, and the ratio of C12 to C13 in the plant tissue is measured to calculate transpiration rates.

In Conclusion

In summary, transpiration is the loss of water from plants to the atmosphere through pores called stomata. Transpiration is important for regulating the temperature of plants and for transporting minerals and nutrients from the soil up to the leaves. There are three main types of transpiration: cuticular, lenticular and stomatal. Several factors affect transpiration rates including temperature, humidity, light intensity, wind speed and soil moisture content. Scientists use several methods to measure transpiration including potometers, lysimeters and C13 isotopes.