Do you know what unites a field of wheat, a bed of potatoes and a garden of fruit trees? All these are agrocenoses. In our article, we will get acquainted with the main characteristics of this concept.
Communities of organisms
Under natural conditions, different types of living beings do not live separately. As a result, various communities are formed. One of them is biocenosis. Its structure includes populations of various species living in a site with homogeneous conditions. The basis of such a community is phytocenosis.
But living organisms are connected not only with each other. The environmental conditions also have a certain influence on them. Therefore, ecologists call another structure - biogeocenosis. This is a territory with approximately the same conditions, in which populations of various species are united among themselves and the physical environment through the circulation of matter and energy.
Agrocenosis is also a community of organisms, but it differs significantly from all the others. What is the difference? Let's find out.
Biogeocenosis and agrocenosis
Agrocenosis is a community of organisms created by man. It may includeplants, animals, fungi and microorganisms. The purpose of its creation is to obtain agricultural products. But most often an artificial plant community is called an agrocenosis. This is a field, vegetable garden, orchard or garden bed.
Biogeocenosis is a natural, self-developing structure.
The almost complete absence of self-regulation also belongs to the characteristics of agrocenosis. All processes in this community are controlled by a person. When its activity ceases, the agrocenosis ceases to exist.
Biogeocenosis uses only solar energy for its development. There are additional reserves in the agrocenosis. This is the energy that a person contributes when irrigating, plowing land, using fertilizers, special feeds, chemicals to control weeds and rodents.
Signs of agrocenosis
Agrocenoses are characterized by low species diversity. Since these communities are created with the aim of obtaining certain agricultural products, they include one or two representatives of the organic world. As a result, the number of other species inhabiting the area is decreasing.
Agrocenosis is a weakly stable structure. Its development occurs only under the influence of a person in artificially recreated conditions. Therefore, the ability to withstand fluctuations in the intensity of environmental factors without abrupt changes in the structure and functions of agrocenosis is almost impossible.
Trophic connections
For any natural communitycharacterized by the presence of power circuits. Agrocenosis is no exception. Its food webs are very poorly branched. This is due to the depleted species diversity.
In the biogeocenosis there is a continuous circulation of substances and energy. For example, plant products are consumed by other organisms, after which they are returned to the natural system in an altered form. It can be water, carbon dioxide or mineral elements.
This does not happen in the chains of agrocenosis. Receiving a crop, a person simply withdraws it from circulation. Trophic bonds are broken. To compensate for such losses, it is necessary to systematically apply fertilizers.
Development conditions
To increase the yield and productivity of agrocenoses, man uses artificial selection. During this process, a person selects individuals with the most useful qualities, capable of producing viable and prolific offspring. This kind of selection is faster and more efficient than natural selection.
On the other hand, it leads to an inability to self-regulate and self-renew. If a person stops his activity, the agrocenosis is destroyed. It won't happen right away. Thus, perennial herbaceous cultivated plants will last about 4 years, and trees - several dozen.
To maintain the development of agrocenoses, a person must constantly prevent the processes of succession. This term means the destruction or replacement of some natural communities by others. For example, if weeds are not removed, they will first become the dominant species. Withover time, they will completely replace the culture. The fact is that weeds have a number of adaptations that help to successfully survive adverse conditions. This is the presence of underground modified shoots - rhizomes, bulbs, a large number of seeds, a variety of methods of distribution and vegetative reproduction.
The value of agrocenoses
Thanks to agrocenoses, a person receives agricultural products, which he uses as food and the basis for the food industry. The advantage of artificial communities is their manageability and unlimited ability to increase productivity. But human activity also leads to negative consequences. Plowing of land, deforestation and other manifestations of irrational nature management lead to an imbalance. Therefore, when creating agrocenoses, it is necessary to take into account the links between wild and cultivated species.
So, agrocenosis is an artificial biogeocenosis. Man creates it to obtain various types of products. To do this, he selects productive plant varieties, animal breeds, fungal species or microorganism strains. The main characteristics of agrocenosis include: poorly branched trophic chains, lack of cycling of substances and energy, low species diversity and constant human control.
