What are the abiotic factors?

We explain what are the abiotic factors, both physical and chemical, in an ecosystem. Difference with biotics, examples.

1. What are the abiotic factors?

Abiotic factors are all those elements of a physical or chemical nature that are involved in the characterization of a particular biotope or ecosystem . They differ from biotic factors in that they have nothing to do with life or living beings , but with inanimate and environmental factors, such as climate or the nature of soils.

The abiotic term, in fact, is used in biology and ecology to designate everything that is not part or product of organic life as we know it. These elements present in the environment are also called inert factors, such as geological or geographical.

A given ecosystem is composed of the sum of these two types of factors: biotics (contemplated in biocenosis ) and abiotic (contemplated in the biotope ). Both types of factors, however, can be differentiated for study purposes, but they have dense and varied relationships in reality : abiotic factors affect biotics and shape the course of their evolution (through adaptation processes , for example, or natural selection) and in turn the biotic factors alter the nature of the former.

For example : The salinity level of sea waters can affect creatures that inhabit it, allowing those capable of adapting to proliferate and those that do not become extinct or migrate to other regions. Similarly, the proliferation of certain types of microorganisms can increase or decrease the concentration of certain substances in the water, modifying their chemical constitution.

2. Physical abiotic factors

Abiotic factors of a physical nature are those linked to the forces acting on ecosystems on Earth, for example:

• Sunlight . The main natural source of energy on the planet is sunlight, a form of electromagnetic emission of light waves (visible), infrared and ultraviolet (UV), which affects the temperature of large bodies of water, air and earth, which They warm and dilate during the day and cool and contract at night.
• Temperature . The temperature levels of any medium, be it aquatic, gaseous or terrestrial, affect the possible development of life and the type of relationships of a biotope. For example, in frozen Arctic regions, life is scarcer and adapted to the cold, since water freezes and forms large pieces of ice or permafrost (frozen soil) for much of the year.
• Atmospheric pressure . The pressure exerted by the mass of gas in the atmosphere on the different elements of an ecosystem is also a determining factor. For example, the pressure exerted by water on the creatures that inhabit marine niches is immense, much greater than what exists on the surface.
• Climate . The climatic region in which an ecosystem is located is very relevant in the processes that occur within it. If the region is warm and tropical, for example, there will be an abundant margin of rainfall, therefore a lot of humidity and great plant growth. On the other hand, in the desert regions there is a shortage of plant life, despite the overwhelming heat.
• The relief . Another important physical factor is the relief of the region, since the height affects both the temperature and the atmospheric pressure (at a higher height, less pressure and lower temperature).

3. Chemical abiotic factors

The chemical abiotic factors, on the other hand, have to do with the constitution of matter and the different reactions that take place with it within a given ecosystem, such as:

• pH . The pH is a chemical property of the media, such as water or soil , and that points to its level of acidity or alkalinity, that is, the amount of hydrogen ions dissolved in them. A very acidic or very alkaline medium is corrosive and contrary to organic life.
• Soil chemistry . The quantity and type of chemical elements that predominate in a type of soil are decisive when explaining attributes such as fertility, water absorption, etc.
• Chemistry of the air . Life and most biotic processes are concerned with the exchange of gases breathing animal takes oxygen and produces CO ₂ , while photosynthesis opposite. Therefore, the characteristics of the air can facilitate or prevent the development of an ecosystem, or subject it to demanding conditions.
• Water chemistry . Elements such as salinity, the concentration of nutrients or oxygen, any contaminants, etc. they determine the quality of water to house life and therefore the type of ecosystem that takes place in it.