Biogeochemical cycles: what are they, types and importance

The biogeochemical cycles or cycles BGQ are processes that guarantee the constant recycling, to a greater or lesser speed, those elements which are absolutely necessary for life and survival (nutrients), by converting the organic state to the mineral and vice versa.

In these cycles of nature , macronutrients and micronutrients that constitute the inorganic matter present in our environment (air, water or soil), are incorporated into organisms as organic matter , through metabolic processes and, later, return to the natural environment. in its inorganic form.

Macronutrients (C, H, O, N, P, S) constitute more than 95% of the biomass of all living beings and are those elements that our body requires in large quantities for its development, maintenance and reproduction.

Although they are also essential, unlike macronutrients, micronutrients are less present in the body. Some examples of biogeochemical cycles in micronutrients are: iron (Fe), copper (Cu), zinc (Zn), chlorine (Cl) and iodine (I).

The classification of biogeochemical cycles can be established according to their complexity and mobility.

Considering the complexity of the BGQ cycles , these can be:

• Simple cycles: where the elements are more influenced by physical-chemical forces than by biological ones. Eg: salts and trace elements.
• Intermediate cycles: made up of elements of organic matter (OM) that can be easily released (C, H, O, P).
• Complex cycles: associated with elements of OM that require specialized microorganisms in their complex transformations (N and S).

In terms of mobility , we can distinguish:

• Global cycles: are those that have gas phases, which allows their distribution on a global scale.
• Local cycles: they are less mobile, more sedimentary cycles, which end up being transported by water, accumulating in sediments, which gives rise to a more regional or local distribution (P, K, Ca).

There are also three types of interconnected biogeochemical cycles :

• Gaseous: macro and micronutrients are quickly recycled and circulate between the atmosphere and living beings. The oxygen, carbon and nitrogen cycle stand out.
• Sedimentary – Elements (eg phosphorus and sulfur) circulate between the earth’s crust, hydrosphere, and organisms and are recycled at a slower rate than the gas cycle.
• Hydrological or water cycle. In this other post you can learn about What is the water cycle .

The carbon cycle is essential because it makes up organic matter and represents the exchanges between organisms and the environment, as a consequence of the processes of respiration and photosynthesis .

Generally, carbon is recycled quickly , but can remain in ways not available for long periods. In hot and humid ecosystems (rainforest), production and decomposition rates are high, and C (carbon) circulates rapidly through the ecosystem. On the contrary, in cold and dry ecosystems the process is slower.

Learn more about what the carbon cycle is, how it works and its importance with this other article.

This element has sedimentary and gaseous phases .

• On the one hand, in the sedimentary, the sulfur that is immobilized in organic and inorganic deposits is released by wear and tear and by decomposition processes until it is transported to terrestrial ecosystems in the form of saline solution.
• On the other hand, the gaseous phase of the biogeochemical cycle of sulfur allows its circulation on a global scale.

The biogeochemical cycle of phosphorus does not present a significant atmospheric reservoir, since it is found in mineral deposits and marine sediments, in unavailable forms.

It is released to terrestrial ecosystems and aquatic ecosystems by rock erosion and mining extraction, mainly.

The importance of biogeochemical cycles is given by the benefits they report and by their characteristics:

• In the first place, these cycles allow life on Earth , maintaining optimal conditions. This means that biogeochemical cycles regulate the climate, the distribution of nutrients …
• They also make possible the exchanges of matter between living beings and the natural environment and access to the vital elements (nutrients) that we need.

In this other article you can read more about the Characteristics of planet Earth that make life possible .

Below are examples of biogeochemical cycles altered by human activities :

• Deforestation alters the water cycle leading to the desertification of ecosystems.
• Wastewater discharges , intensive agriculture and the use of fertilizers (eutrophication) modify the nitrogen and sulfur cycles, favoring acid rain .
• Large-scale fishing activities alter the bacterioplankton, being able to modify the C, N, O and P cycles, which it regulates.
• Industrial activities and the burning of fossil fuels modify, among others (such as the S) the carbon cycle, causing global warming .

If you want to read more articles similar to Biogeochemical cycles: what they are, types and importance , we recommend that you enter our Biology category .