An ecosystem is a system made up of different groups of organisms and the physical environment in which it is related to each other and to the environment. In an ecosystem we find:
- Biotic factors : They are organisms, that is, living beings . They are from bacteria to animals and larger plants. They can be heterotrophs (they take their food from other living beings) or autotrophs (they generate their food from inorganic substances). They are related to each other by relations of predation , competition, parasitism, commensalism , cooperation or mutualism .
- Abiotic factors : They are all those that constitute the physical-chemical characteristics of an ecosystem. These factors are in constant relation with the biotic factors since they allow their survival and growth. For example: water, air, light.
Abiotic factors can be beneficial for some species and not for others. For example, an acidic pH (abiotic factor) is not favorable for the survival and reproduction of bacteria (biotic factor) but for fungi (biotic factor).
Biotic factors establish the conditions under which organisms can live in a given ecosystem. Therefore, some organisms develop adaptations to these conditions, that is, evolutionarily, living beings can be modified by biotic factors.
On the other hand, biotic factors also modify abiotic factors. For example, the presence of certain organisms (biotic factor) in the soil can change the acidity (abiotic factor) of the soil.
Examples of abiotic factors
- Water : The availability of water is one of the main factors that affect the presence of organisms in an ecosystem, since it is essential for the survival of all life forms. In places where there is no constant availability of water, organisms have developed adaptations that allow them to spend more time without contact with water. In addition, the presence of water affects the temperature and humidity of the air.
- Infrared light : It is a type of light invisible to the human eye.
- Ultraviolet radiation : It is electromagnetic radiation. It is not visible. The earth’s surface is protected from most of these rays by the atmosphere. However, UV-A rays (wavelength between 380 to 315 nm) reach the surface. These rays do little damage to the tissues of the various organisms. On the contrary, UV-B rays cause sunburn and skin cancer.
- Atmosphere : From what is said about ultraviolet radiation, it can be understood that the atmosphere and its characteristics affect the development of organisms.
- Temperature : Heat is used by plants during photosynthesis. In addition, for all organisms there is a maximum and minimum environmental temperature in which they can survive. That is why global changes in temperature result in the extinction of different species. The microorganisms called extremophiles can tolerate extreme temperatures.
- Air : The content of air affects the development and health of organisms. For example, if carbon monoxide is present in the air, it is harmful to all organisms, including humans. The wind also affects for example the growth of plants: trees that live in areas that have frequent winds in the same direction grow crooked.
- Visible light : It is essential for the life of plants, since it intervenes in the process of photosynthesis. Animals allow them to see around them to perform various activities such as looking for food or protect themselves.
- Calcium : It is an element found in the earth’s crust but also in seawater. It is an important element for the biotic factors: it allows the normal development of leaves, roots and fruits in the plants, and in the animals it is indispensable for the strength of the bones, among other functions.
- Copper : It is one of the few metals that can be found in nature in its pure state . It is absorbed in the form of a cation. In plants, participates in the process of photosynthesis. In animals, it is found in red blood cells, it participates in the maintenance of blood vessels, nerves, immune system and bones.
- Nitrogen : It forms 78% of the air. The legumes absorb it directly from the air. The bacteria convert it to nitrate. Nitrate is used by various organisms to make proteins .
- Oxygen : It is the most abundant chemical element in mass in the biosphere, that is, the sea, air and soil. It is an abiotic factor but is released by a biotic factor: plants and algae, thanks to the process of photosynthesis. Aerobic organisms are those that need oxygen to convert nutrients into energy. Human beings, for example, are aerobic organisms.
- Altitude : Geographically, the altitude of a place is measured taking into account its vertical distance with sea level. For this reason, when indicating the altitude, for example, 200 meters above sea level (meters above sea level) is indicated. The altitude affects both the temperature (decreases 0.65 degrees per 100 meters of altitude) and atmospheric pressure.