The food chain has a certain structure. It includes producers, consumers (of the first, second order, etc.) and decomposers. More about consumers will be discussed in the article. In order to thoroughly understand who the consumers of the 1st order, 2nd and beyond are, we first briefly consider the structure of the food chain.
Food chain structure
As you know, producers are located on the first step of the food chain, or on the first tier of the food pyramid. These are plants, the main feature of which is the ability to produce organic compounds from inorganic compounds, which can be absorbed by consumers of the 1st order during the nutrition process. Due to this feature, they are also called autotrophs (translated from Greek - self-feeding), in contrast to heterotrophs, which cannot synthesize organic substances. In fairness, it should be noted that they also include some representatives of the plant world, mainly parasitic plants. In general, the difference between them can be called rather conditional, because there are quite a few species that canuse one of the types of food depending on the conditions and situation.
The next link in the chain and, accordingly, the tier of the food pyramid are consumers (of several orders). This is the name of the organisms that the producers consume as food. They will be discussed in detail later.
And finally, decomposers - the final tier of the food pyramid, the last link in the chain - organisms-"orderlies". It is an integral and very important component of the ecosystem. They process and decompose high-molecular organic compounds to inorganic ones, which are then reused by autotrophs. Most of them are rather small organisms: insects, worms, microorganisms, etc.
Who are consumers
As mentioned above, consumers are located on the second tier of the food pyramid. These organisms, unlike producers, do not have the ability to photo- and chemosynthesis (the latter is understood as the process of obtaining by archaea and bacteria the energy necessary for the synthesis of organic substances from carbon dioxide). Therefore, they must feed on other organisms - those who have this ability, or their own kind - other consumers.
Animals - consumers of the 1st order
This link in the food chain includes heterotrophs, which, unlike decomposers, are not able to decompose organic substances into inorganic ones. The so-called primary consumers (1st order) are those that are directly fed by the biomass producers themselves, that is, the producers. They are primarily herbivores.the so-called phytophages.
This group includes both giant mammals, such as elephants, and small insects - locusts, aphids, etc. It is not difficult to give examples of consumers of the 1st order. These are almost all animals bred by man in agriculture: cattle, horses, rabbits, sheep.
Beaver belongs to phytophages among wild animals. As you know, he uses tree trunks to build dams, and eats their branches. Some species of fish, such as grass carp, also belong to herbivores.
Plants are first order consumers
Interestingly, scientists include not only those who eat green biomass in this group. Parasitic plants are also referred to consumers of the first order. And this is true, because they really feed on their fellows, sucking out nutritious juices from them. Examples of such plants are well known to everyone: this is dodder, popularly called bindweed. It wraps its long stem around the trunk of the producer plant and rises along it in height, feeding on it. Interestingly, in the course of evolution, this parasitic plant completely lost the ability to photosynthesize. The stem of the dodder is reddish or brown in color. It also lacks roots. Due to the system of haustoria (suckers), the dodder is attached to the host plant and sucks nutrients from it.
Like her, completely devoid of chlorophyll and parasitic plants of the genusOrobanche (broomrape). Their roots are turned into suckers, with which the broomrape attaches to the roots of the host. This plant causes great harm to agriculture, as it often parasitizes commercially cultivated legumes.
Another example is mistletoe, a well-known and, unfortunately, widespread parasitic plant that can be seen on trees. True, in this case it is not so easy to draw a clear line between producers and consumers. Indeed, in parallel with the fact that the mistletoe feeds on the sap of trees, the process of photosynthesis also proceeds in its cells. This is confirmed by the fact that the plant has a green color. But at the same time, mistletoe is also a first-order consumer, because it receives nutrition from other plants.
Summarizing, we can draw the following conclusion: consumers are organisms that feed on plants.
Consumers of the second order and beyond
From the above information, we can already conclude who the consumers of the 2nd, 3rd, 4th order are. These are primarily predatory animals (zoophages) that feed on herbivores (phytophages). This includes the wolf, and the fox, and the lynx, and the lion, and other well-known predators, as well as parasites-consumers of the 1st order.
In turn, consumers of the 3rd order - those who eat consumers of the previous order, that is, larger predators, 4th - those who eat consumers of the third. Above the fourth level, the food pyramid, as a rule, does not exist, since energy losses from the producer organism to the consumer at the previous levels are quite large. After all, theyare inevitable on each of its tiers.
It is also often difficult to draw a clear boundary between consumers of certain orders, and sometimes impossible. After all, some animals are simultaneously consumers of different levels.
Also, many of them are omnivorous, for example, a bear, that is, consumers of the first and second order at the same time. The same applies to a person who is an omnivore, although due to different views, traditions or living conditions, for example, he can eat food only of plant origin.
In closing
The article gave a brief description of the food chain (food pyramid) and characterized its main participants. Thus, it contains producers and consumers - the first two tiers (links). The third is decomposers, decomposing organic remains to inorganic ones. We hope that now there are no questions left about who the first-order consumers are: these are organisms that receive nutrition directly from producers, eating them or parasitizing them in various ways.
