The importance of plants on Earth
A plant is a living organism like trees, shrubs, flowers, grasses etc…
Vegetation describes all the plants growing in a defined area.
For example, oak trees, ryegrass and daisies are all plants individually. In a park, you may say the vegetation is made up of oak trees, ryegrass and daisies.
Plants play an extremely important role in limiting the amount of carbon dioxide (CO2), a greenhouse gas, in the Earth’s atmosphere.
What is plants' role?
Plants absorb carbon dioxide (CO2) from the atmosphere, water (H2O) from the soil and light and transform them into dioxygen (O2), releasing it. This process is called photosynthesis.
Photosynthesis occurs in 2 major steps inside the plant’s chloroplasts (organelles, specialised subunits within plant cells).
Image: ChemBAM
A bit of science...
Firstly, the light reaction takes place in the thylakoids, which contain chlorophyll. The layer that surrounds the thylakoids, called thylakoid membrane, is composed of two photosystems, Photosystem I and Photosystem II. These photosystems are made up of multiple proteins and chlorophyll, absorbing light and exciting electrons, which travel through electron transport chains. This process splits water to form ATP and NADPH, both energy molecules, as well as oxygen.
The second step, the dark reaction, also called the Calvin cycle, uses the formed ATP and NADPH in order to transform carbon dioxide from the atmosphere into glucose. This step takes place in the stroma, the fluid surrounding the thylakoids. The glucose formed is then used as energy by the plant.
Image: TinyTap
Image: CK12-Foundation
The chloroplasts contain chlorophyll, a pigment leading to the green colour of plants. Chlorophyll absorbs light, mainly issued by the Sun. This light powers the plant taking in carbon dioxide (CO2) from the air and water (H2O) from the soil. Within the plant cell, carbon dioxide and water are broken down and respectively transformed into glucose and oxygen. The plant then releases the oxygen back into the air, and stores energy within the glucose molecules.
Why does it matter?
Plants provide us with the air we breathe, the food we consume, and essential materials used for shelter and clothing.
Combat climate change
Through photosynthesis, plants release oxygen into the atmosphere, allowing the respiration of all living organisms, including humans. As carbon dioxide is a greenhouse gas mostly produced by humans, it contributes massively to climate change. Reducing the amount of carbon dioxide in the atmosphere would mitigate global warming and its devastating effects.
Ensure worldwide food security
Plants are also a primary source of food: fruits, vegetables, grains all originate from plants.
In addition, they play a vital role in the food chain as a food source for other organisms and are used as habitats by countless organisms. The food chain collapsing would result in mass species death and therefore food instability.
Contribute to social development
Roots bind the soil, essential for maintaining solid fertility and as a result agriculture, not only ensuring a global food supply, but also creating employment opportunities in the agricultural sector and assuring economic stability.
Summary
-
Plants perform photosynthesis, a process which transforms water from the soil and carbon dioxide from the air into oxygen and glucose through the absorption of light.
-
The oxygen formed is released into the atmosphere.
-
The glucose formed is used as energy by the plant.
-
Reducing the amount of carbon dioxide in the atmosphere would mitigate global warming and its devastating effects.
-
Plants disappearing would result in mass species death and therefore food and economic instability.