Abiotic Factors (Meaning and Explanation)

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

floor — Soils are part of the abiotic components of an ecosystem.

What are the abiotic factors?

Abiotic factors are all those elements of a physical or chemical nature that intervene in the characterization of a specific biotope or ecosystem. They are distinguished from biotic factors in that they do not have to do with life or living beings, but with inanimate and environmental factors, such as climate, water, light, temperature or the nature of the soil.

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

A given ecosystem is made up of the sum of these two types of factors: the biotic ones (considered in the biocenosis) and abiotics (considered in the biotope). The interaction between both types of factors lies in the fact that abiotics model the course of evolution of biotics. This occurs through processes of adaptation or natural selection. On the other hand, biotic factors also alter the nature of abiotics.

For example: The level of salinity of sea waters can affect the creatures that live there, allowing those capable of adapting to proliferate. On the other hand, those that are not able to adapt to changes in salinity levels will migrate to other regions or become extinct.

Physical abiotic factors

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

Sunlight. The main natural source of energy on the planet is sunlight. This is a form of electromagnetic emission of light waves (visible), infrared (IR) and ultraviolet (UV), which affect the temperature of large masses of water, air and land, which heat and expand during the day, and They cool and contract at night.
The 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, as water freezes and forms large fragments of ice or permafrost (frozen ground) 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 its development. For example, the pressure that water exerts on the creatures that inhabit marine niches is immense, much greater than that which exists on the surface.
The weather. The climatic region in which an ecosystem is located has a lot of relevance in the processes that occur within it. If the region is warm and tropical, for example, there will be plenty of rainfall, therefore, lots of humidity and great plant growth. On the other hand, in desert regions plant life is scarce, due to the oppressive heat.
The relief Another important physical abiotic factor is the relief of the region, since altitude affects both temperature and atmospheric pressure (the higher the altitude, the lower the pressure and the lower the temperature).

Chemical abiotic factors

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. Some may be:

pH pH is a chemical property of media, such as water or soil. This factor allows us to determine its level of acidity or alkalinity, that is, the amount of hydrogen ions dissolved in the different media. A very acidic or very alkaline environment is corrosive and, therefore, unfavorable for the development of organic life.
Soil chemistry. The amount and type of chemical elements that predominate in a type of soil are decisive when it comes to explaining properties such as fertility and water absorption.
Chemistry of air. Life and most biotic processes have to do with gas exchange. For example, in animal respiration oxygen is taken in and CO2 is produced, while in plant photosynthesis the opposite occurs. Therefore, the characteristics of the air can facilitate or impede the development of an ecosystem, or subject it to specific conditions.
Chemistry of water. Elements such as salinity, the concentration of nutrients or oxygen and any contaminants determine the quality of the water to sustain life and, therefore, the type of ecosystem that takes place in it.

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