Transpiration in Water Cycle

We are aware that water is essential to sustain life on Earth.

The water cycle helps to maintain the water level on Earth

Evaporation and Transpiration are two methods by which water-vapor is released into the atmosphere.

We will discuss about the process of transpiration

Transpiration is the process where plants release excess water through leaves

Plants absorb water through the roots and then give off water vapor through pores in their leaves.

The way we release excess moisture when we exhale, plants also do the same.

Roots grow deep into the soil to draw water and nutrients into the stems and leaves. Some of this water is returned to the air by transpiration.

Let us see a practical demonstration of transpiration

If a plastic bag is wrapped around a part of a plant, the inside of the bag becomes misty with transpired water vapor.

Generally, transpiration is an invisible process. However, when we wrap a plastic bag, we can see the transpired water.

Water also evaporates directly into the atmosphere from soil in the vicinity of the plant.

Transpiration releases water vapor into the atmosphere similar to evaporation

Let us discuss transpiration with respect to the water cycle

Water transpires from plants and enters the atmosphere as water vapor, similar to evaporation of water cycle.

Transpiration is a relatively slower process compared to evaporation from open water bodies.

30% of water from land is converted to water vapor. Out of this one-third is by transpiration.

Moving on, let us see how transpiration is an alternate way of water-vapor transfer

The water-vapor that is released from plants go into the atmosphere along with the evaporated water to form clouds.

From the sky, the water comes back to the land via rainfall.

Thus, apart from evaporation, transpiration is also an alternate step in converting water to water vapour for the water cycle.

Now let us discuss the factors affecting transpiration

Soil, water, and plant activity have roles in controlling the rate of transpiration of a plant.

Temperature is one of the factors affecting transpiration. Transpiration rates go up as the temperature goes up

Soil-moisture availability is another factor. When moisture is lacking, plants can begin to sense and transpire less water.

As the relative humidity rises the transpiration rate falls

Increased movement of the air around a plant causes higher transpiration rate.

Wind moves the air around, so that the humid air close to the leaf is replaced by drier air.

Different types of plant transpires differently

Some plants, such as cacti , conserve water by transpiring less than other plants.

Revision

Transpiration is a step in the water cycle.

Transpiration is the process by which groundwater is converted into water vapor.

Plant takes up ground water via roots and release excess water by “transpiring”.

Transpiration is an alternate to evaporation.

The water-vapor gas moves up into the sky to form clouds.

Factors affecting transpiration are temperature, type of plant, humidity, water content in soil, and wind speed.

The End