All living organisms on our planet can be attributed to producers, consumers or reducers. What are these terms talking about? What are the characteristics of organisms belonging to a particular category? Based on what such a classification is proposed? This will be discussed in the article. In addition, the question of who such reducers will be revealed in more detail. Examples of these organisms will also be given below.
Description of the trophic (food) chain
All plants that inhabit the Earth, animals, microorganisms, fungi, etc., are included in peculiar relationships called by scientists the trophic chain (or food chain). Some of them eat others, due to which there is a transfer of energy from one link of an imaginary chain to another. Thus, there is a simple connection between them: "food is the consumer of food."
The first link in the food chain is the so-called producers, or autotrophs. These include most plants, algae. The producers have no predecessors, they are characterized by the conversion of inorganic substances to organic, due to which there is an accumulation of energy, and producers can be eaten by representatives of the next link. They are called consumers.
Consumers can be 1st, 2nd, 3rd and 4th order. Consumables of the 1st order are usually herbivores, the 2nd are predators who consume first-order consumers, etc.
Further in the food chain are located destructors, or reducers - organisms that process organics back into inorganic substances (or simple organic ones), thus ensuring the decomposition process and the cycle of substances in nature. This is the most important link - "orderlies". The following examples of reducers can be given: saprotrophic bacteria, actinomycetes, fungi (for example, the genus Penicillium).
The connection of living organisms in the food chain is not always linear. So, for example, there are plants - consumers of the 1st order, parasitic on other plants and not producing organic substances. One and the same animal can be the consumer of the 1st, 2nd, and 3rd order, if it, in addition to herbivores and other predators, eats herbs, berries, etc. For example, a brown bear, eating berries, is the primary consumer, hunting the rodent and eating it, the secondary, and eating the predatory salmon fish that feeds on herring, the third-order consumer. Therefore, scientists believe that in many cases it makes sense to talk not about a chain, but about a trophic network, quite ramified.
Ecosystem reducers
The role of these organisms in ecological systems is difficult to overestimate. Thanks to them, organic residues decompose without a trace, acquiring structure and form available for consumption by producers (autotrophs). Producer plants, consuming them, increase their green mass and serve as food for animals and people. A significant role in nature is played by reducing agents - soil-forming bacteria that decompose plant and animal organic remains, thereby contributing to their transformation into humus ( decaying bacteria), and it, in turn, into mineral salts.
The difference between reducers and scavengers
Some mistakenly believe that carrion animals and birds are among the reducers. But this is not so. The main difference between them and detritophages (scavengers) is that carrion-feeding organisms produce solid waste in the form of excrement. Similar waste products are absent in reducers. Their role is to destroy - the destruction of complex organic substances and turning them into more simple in structure (urea) or inorganic. Detritophages that produce solid waste are traditionally referred to as consumers.
Loss of energy in transitions from one level of the food chain to another
During the transition of energy from producers to consumers, a significant part of it is lost (up to 80-90%), most often in the form of heat. This is the reason why the length of the food chain is usually limited to 3-6 links.
The main causes of energy loss are as follows:
- Organisms move and spend energy on cellular respiration, providing their vital functions.
- Not all organics can be digested by animals, and part of it comes out in the form of excrement.
- Not all organisms of the previous level are eaten by representatives of the next. A significant part of them simply dies for various reasons.
- Excrement and dead organisms are processed by reducers into their energy.
The ratio of biomass at different levels
Given the above, it can be concluded that in order to maintain ecological balance, the number of living organisms at the previous level should significantly exceed that at the next. In other words, there should be more producers than consumers. At the same time, the number of predators at subsequent levels decreases, but they become larger. This law is called the rule of the ecological pyramid.
What about the reducers? The change of ecosystems does not matter here: reducers will still be present in it. It is their mutual dependence with consumers and producers that ensures that in any catastrophic circumstances the biogeocenosis will not be destroyed and the lost connections will be restored.
As for the ratio of reducers and other groups in nature, this is a rather complicated issue, because we are dealing with extremely small organisms. According to studies, neither their total biomass nor their numbers can speak of the degree of their productivity. The measurement of such biomass is difficult and also little informative. So, the number of microorganisms in the soil may remain the same, but under different conditions they will exhibit different activities.
It can be said that in productive ecosystems, the biomass of these microorganisms is approximately 10-100 g per square meter. If you look at the indicators in the tundra or desert, then they will be much less, as well as the activity of reducers. The ecosystem change in this example makes it possible to take into account different living conditions.
Finally
The article briefly described the structure of the food chain, and also described in more detail who such reducers are (with examples).
Interestingly, food chain links such as consumers were absent on Earth for about 2 billion years, when ecosystems consisted only of pre-nuclear organisms called prokaryotes. But without their reducers, their existence would be impossible, because someone must convert the organic substances produced even by the simplest microorganisms into inorganic ones again. Due to the vital activity of reducers, examples of which were given in the article, water and mineral salts return to the soil. Thus, the circle closes, and producing organisms (autotrophs) can again use beneficial substances.