The cycle of matter and the flow of energy
In ecosystems two transfer processes take place:
- Energy flow, open. Of the solar energy that reaches the Earth, most of it is reflected and absorbed by the atmosphere, the earth's surface and the seas. Only 2% of the solar energy that arrives is absorbed by plants and, from here, passes to the rest of living beings.
- Cycle of matter, closed.
The organism producing, by photosynthesis, manufacture their own organic matter (carbohydrates, lipids, proteins, etc.) from inorganic materials such as H2O, CO2, and mineral salts, using energy from the sun.
When a primary consumer feeds on a producer, or a secondary consumer feeds on a primary consumer, the energy contained in organic matter (carbohydrates, lipids, proteins, etc.) and the chemical elements that make up those substances are transferred, from one trophic level to a higher one.
All ecosystems need matter and energy to function. Energy, once solar energy is transformed by producers into chemical energy by making organic matter in photosynthesis, is transmitted along with matter.
The matter passes from the producers to the rest of the trophic levels, up to the decomposers, which will be the ones that end up with the recycling of the matter. Inorganic molecules (water and mineral salts) and organic (carbohydrates, lipids, proteins, etc.) are transformed when passing from one beings to others, but the chemical elements that constitute them (carbon, nitrogen, phosphorus, etc.) continue being the same.
In this way, matter passes from the environment to living beings, and from these, it is returned to the environment forming a closed cycle. We could think of a large spaceship called "Earth" that has a certain matter, in the form of atoms, that are passed from one being to another. The excrement and remains of living beings serve as food for the decomposers, which transform these substances by recycling them so that they can be used again by the producing organisms. It is, therefore, a closed cycle.
Matter, in addition to circulating through living beings, also does so through the inert medium (earth, water and air).
Interactive Activity: Organic or Inorganic?.
Interactive activity: Where do these chemical elements come from?.