At the dawn of his emergence, man was a natural part of nature and did not have a significant impact on nature. But gradually its influence on the biosphere increased. Man more and more actively consumed what nature created, disrupting the established balance in existing ecosystems. To meet his growing needs, he began to create artificial ecosystems.
Artificial ecosystems created by humans to obtain agricultural products are called agrobiocenoses (agrocenoses).
Agrocenosis (Greek agros – “field”) is a community of organisms that live on agricultural lands occupied by crops or planting of cultivated plants.
Example: fields, vegetable gardens, orchards, parks, artificial pastures, flower beds, etc.
In the agrobiocenosis, the same food chains are formed as in the natural ecosystem:
- producers (cultivated plants, weeds),
- consumers (insects, birds, rodents, predators) and
- decomposers (bacteria and fungi).
Man is an indispensable link in this food chain. He creates conditions for his high productivity, and then uses the crop. People get more than 90% of food from agrocenoses.
But the irrational use of fertilizers and pesticides, violations of the technology of growing plants can lead to a decrease in soil fertility, its pollution and desertification of large areas. Deforestation for the expansion of agricultural lands negatively affects the state of the biosphere.
Comparison of natural ecosystems and agrobiocenoses
Agrobiocenoses and natural ecosystems have a number of important differences.
Natural communities are characterized by resilience.
The ecological sustainability of artificial ecosystems is negligible.
Example: without constant human intervention, fields sown with cereals or vegetables are overgrown with weeds within a year, orchards can exist for no more than 20 years.
Natural biocenoses receive energy only from the Sun.
Agrocenoses receive the energy of the Sun, as well as the energy that a person spends on cultivating the soil, feeding and weeding plants, protecting against diseases, etc.
In a natural ecosystem, the cycle of substances is complete and closed. All primary plant products are used by consumers and decomposers and are converted into minerals, which are again involved in a new cycle.
In agrobiocenosis, the circulation of substances is incomplete and unclosed, since a person withdraws the bulk of the production for his needs.
Agrobiocenosis cannot exist without constant human intervention in the form of soil cultivation, fertilization and disease control.