Question

What is the importance of different Biogeochemical cycles in nature? (ASI)

Answer 1

Hint: Energy flows directionally through Earth’s ecosystems, entering in the form of sunlight and exiting in the form of heat. This needs to be recycled and reused.

Complete answer:
1. Biogeochemical cycles are natural cycles, in which conserved matter moves through the living and nonliving parts of an ecosystem.
2. ‘Biogeochemical cycle' can be easily broken down into ‘Bio'- the biotic system, ‘geo'- the geological component, and ‘chemical’- the elements that are moved through a “cycle”.
3. The main chemical elements that are cycled are carbon (C), hydrogen (H), nitrogen (N), oxygen (O), phosphorus (P), and sulfur (S).
4. These elements are circulated through the biotic components, which are the living parts of an ecosystem, and the abiotic components, which are the nonliving parts.
5. The abiotic components can be subdivided into three categories: the hydrosphere (water), the atmosphere (air), and the lithosphere (rock).
6. Importance of different cycles are:
Nitrogen cycle- It includes nitrification, ammonification, and denitrification by bacteria and regulation of atmospheric nitrogen which is needed for our DNA, RNA, and proteins and is critical to human agriculture.
Phosphorus cycle- Phosphorus is also needed for our DNA, RNA, pesticides, and agriculture.
Sulfur cycle- It is the key to the structure of a protein and is produced by the burning of fossil fuels.
Carbon cycle- Carbon dioxide from the atmosphere is taken up by photosynthetic organisms and used to make organic molecules, which travel through food chains and is finally released in respiration as $CO_2$. Carbon is an exclusively important element of a cell, sugars, and various other chemicals of our body.
Geological processes like weathering of rocks, erosion, water drainage, the exchange between atmosphere and organisms all contribute to the regulation of biogeochemical cycles.

Note:
1. The newly studied biogeochemical cycles include-
The human-regulated cycle of PCBs (Polychlorinated Biphenyls).
Mercury cycle.
2. The chemicals are sometimes held for long periods of time in one place. This place is called a reservoir, for example, coal is a reservoir for carbon. When chemicals are held for only short periods of time, they are being held in exchange pools. Examples of exchange pools include plants and animals.