Nutrients are basically required by all organisms for the overall growth, development, reproduction and to carry out various life processes. The interesting fact is that the nutrient amount is fixed in the environment. Thus, the nutrients are naturally recycled for the constant supply to the organisms. This movement of the nutrients through various components of the ecosystem is called nutrient cycling. Broadly, we have two types of nutrient cycling in nature:
- Gaseous cycling – This kind of cycling takes place for the gases and the atmosphere acts as the reservoir for these gases.
- Sedimentary cycling – This kind of cycling takes place for the nutrients that exist in their elemental form and the earth’s crust acts as the reservoir.
Here we will discuss two nutrient cycles – gaseous cycle – carbon cycle and sedimentary cycle – phosphorus cycle.
- Carbon cycle
Why is carbon so important to us? It is the second most abundant component in our body after water and constitutes almost 50 percent of the dry weight of our body. All the organic compounds consist of carbon. The largest portion of the available carbon in the environment is found in the oceans and this is where the atmospheric carbon is fixed. Apart from oceans, fossil fuels can also be considered as a reservoir of carbon in the environment.
The majority of the carbon is cycled as carbon dioxide by the plants in the process of photosynthesis, and in the process of respiration by the rest of the organisms.
The burning of a number of carbon compounds like fuels, woods, and other organic compounds also contribute to the carbon fixation in the atmosphere. However, the carbon cycle is now being disturbed by a number of human activities like pollution and deforestation.
- Phosphorus cycle
Phosphorus is a very important component of the living beings as they form a part of most of the biological membranes and genetic materials. It is also present in the structural components like bones, shells, and teeth.
Naturally found rocks serve as a reservoir for phosphorus in the phosphorus cycle. When the rocks are broken down naturally during the formation of soils, the phosphates present in the soil dissolve in water and are taken up by the plants through the roots. When these plants are eaten up by other organisms, the phosphorus is transferred to those organisms.
Phosphorus is also cycled by the detritus food chain as the microbes which decompose the dead organisms, release phosphorus into the atmosphere.
For more detailed information on all the nutrient cycles, visit BYJU’S.