Just as people live in houses and apartments, so in nature there are separate systems from others. They are isolated and, one might say, independent. They are called ecosystems and include many different organisms. In addition, they obey certain laws. In this article, we will examine what ecosystems are: the concept, structure, purpose. And also tell you what is included in them.
The concept
The set of organisms living together in a certain environment and interacting with each other in one way or another is denoted by the term "ecosystem". This concept was proposed in 1935 by the English scientist A. Tensley. He was engaged in research of interconnections of organisms and their joint development. By the way, he is considered one of the founders of such a science as ecology, which deals with the study of what an ecosystem is. The ecosystem structure is represented by two main components: biocenosis and biotope. The first refers to the organisms themselves and their relationships, and the second refers to the environment. As a rule, an entire set of living creatures is involved in an ecosystem: from bacteria to higher animals. And what is surprising, the whole community is in balance, which, being disturbed, is restored again, and each of its participants performs extremely important functions.
Biogeocenosis
The totality of some components that exchange energy and are capable of more or less autonomous existence is an ecosystem. The structure of the ecosystem assumes the presence of all the main organisms: bacteria, plants, animals, fungi. But some of them may be absent. In this situation, it makes sense to separate this concept from biogeocenosis. This term refers to a community in which there are all of the above components. Moreover, the biotic structure of an ecosystem can include only one participant, for example, only bacteria. This situation can be observed in communities formed, for example, on the basis of animal corpses. Thus, the ecosystem and biogeocenosis are not synonyms, because the latter is a broader concept. Despite this, they are often confused.
Classification and structuring
In addition to the fact that scientists share ecosystems among themselves according to some criteria, they are also interested in their internal structure. Various approaches and points of view in total give a fairly complete picture, which allows us to consider each element separately. It is not surprising that so many criteria are used in structuring: type of nutrition and function, species, location of participants. Of course, it is worth considering the most important of the factors in more detail, because the ecological structure of an ecosystem without talking, for example, about its composition, makes little sense.
As for the division of communities among themselves, as a rule, the main criterion is the prevailing environment. Another important feature is the naturalness of its origin and the ability to autonomously maintain functioning. Here we are talking primarily about interference in the nature of the human factor, which also makes sense to outline in more detail, but later.
By function
The trophic structure of the ecosystem delimits the organisms involved in it according to the type of nutrition. According to the cycle of substances in nature, nothing is taken from the void and cannot just disappear. Obviously, the only question is how these or those matters are transformed. And here two opposing groups of organisms come into play: autotrophs and heterotrophs. The latter are animals and mushrooms that consume organics. The first (plants and bacteria) do exactly the opposite. By the way, they, in turn, are divided into photosynthetics and chemosynthetics.
The functional structure of the ecosystem implies the same division, but under different names. Here we are talking about producers, reducers, consumers and destructors. These two approaches are closely related to the concept of food chains.
By hierarchy
Naturally, any system of this complexity is divided into several levels. The first and most comprehensive is the already mentioned biocenosis, which is the totality of all living organisms involved. Further, the hierarchical structure of ecosystems involves the division into phyto-, zoo-, myco-, and microbocenosis. Each of these individual groups contains a population called a population. Finally, the smallest unit is the individual (or individual), which is a separate instance.
There is also a functional hierarchy. The trophic structure of the ecosystem, as already mentioned, involves the division into producers, consumers, reducers and destructors. But here there are several levels. So, it all starts with green plants that receive minerals and water from the soil, as well as sunlight. Herbivores already belong to the consumers of the first level and consume greens for food. In turn, they serve as food for predators standing one step higher. So here you can see your own special hierarchy.
By type
Even within the limits of one type of organism some kind of diversity can be observed, and this is not surprising. The species structure of the ecosystem is its important indicator, reflecting the ratio of various plants, animals, fungi, microorganisms, etc. This characteristic depends on a large number of factors: geographical location, climatic zone, water regime, age of the community. Similar species compositions can be observed in thousands of kilometers from each other, if the main indicators are similar. In addition to the very presence of certain organisms, their number is important. The most common representatives of wildlife in a particular ecosystem are called environment-forming agents and, accordingly, perform key functions and create conditions for the survival of other species.
However, this does not mean that small participants are not very important. On the contrary, in some cases, the particular biotic structure of ecosystems can provide very accurate information about its state. The presence of rare instances of plants and animals can make it possible to understand, for example, how pure water and air are.
Spatial feature
At first glance, the division of ecosystems associated with their location is quite obvious. The steppe, forest, desert, tundra, seabed - the set of organisms living here, without a doubt, will be completely different. But such a classification is appropriate only if it comes to comparing several systems and the differences between them.
On the other hand, each individual community will have its own physical hierarchy. The spatial structure of the ecosystem in the forest, for example, is easily noticeable; it is divided into several levels. Nightingales make nests on taller trees, and wagtails prefer to stay closer to the ground. And among the vegetation, the inequality is obvious: trees, shrubs, grass and moss are located at completely different levels. Scientists call these characteristics a combination of stories, or number of storeys.
Terrestrial ecosystem
The structure of the ecosystem located on land can be very different, but almost always extremely interesting. They are everywhere: in forests, steppes, deserts, high in the mountains, and each of them is curious in its own way. All of them are united by a land-air habitat. Meanwhile, the differences in them may be even greater than the total. For example, the structure of the forest ecosystem in the tropics will be completely different from what is observed in central Russia. Moreover, the green massif in South America will be very different from the picture in Southwest Asia. As already mentioned, the climate zone is one of the main, but not the only factor affecting how the ecosystem is formed. The ecosystem structure is too complex and multidimensional, and therefore delightful and mysterious.
Water
Freshwater and marine organisms, algae, plankton, jellyfish, deep-sea fish - the species structure of the ecosystem located in the oceans is no less interesting than the earth. Often, it can be even more complicated. The structure of the aquatic ecosystem in some ways may resemble the terrestrial, for example, there is also a tiered structure. But there is a very important difference. It consists in the fact that the pyramid of biomass is upside down here. This means that primary producers (here it is a diverse plankton) are much more numerous and multiply faster than consumers, or consumers. This primarily concerns the deep sea and ocean, but the same situation can be observed in freshwater communities. The most interesting thing is that the structure of the aquatic ecosystem includes both one of the smallest organisms and the largest. And they all live peacefully in the neighborhood of each other.
Value
The importance of ecosystems is hard to overestimate. Firstly, they are all interconnected by the cycle of substances in nature. Elements from some systems fall into others, so that they are also interdependent. Secondly, they allow more or less to preserve biodiversity - each community of organisms is unique, surprising and beautiful in its own way. Finally, all the natural resources that a person receives without hesitation - clean water, agricultural land, fertile soil, fresh air - give him this or that ecosystem. The structure of the ecosystem, as well as the entire biosphere, is rather fragile, so you should not forget about its role and sometimes you should think about the fact that the planet is worth saving its wealth for posterity.
Anthropogenic factor
A person through his activities in one way or another affects almost all ecosystems. But if the influence on some of them is indirect, then others experience it directly. Deforestation, pollution of air, soil and water, capture of fish and animals - all this becomes a serious test to maintain the natural balance.
By the way, people continue to learn to model stably functioning ecosystems on their own, and also try to manage existing ones. As a rule, the life cycle of artificially created communities is not too large, and stability raises a lot of questions. Nevertheless, it would be very useful to learn how to manage ecosystems, because in this way it would be possible to achieve greater agricultural productivity, as well as try to restore the destroyed. Unfortunately, while the influence of man on nature is evaluated extremely negatively, his actions cause a lot of consequences, in particular:
- decrease in biological diversity ;
- climate change due to a shift in the gas composition of the atmosphere;
- reduction of forest areas;
- changing and destroying unique communities and conditions;
- depletion of natural resources;
- desertification and soil erosion ;
- accumulation of household waste and environmental pollution;
- change in ecosystem structure;
- thinning of the ozone layer.
It is worth considering the consumer attitude of mankind to the planet and pondering whether nature can be preserved in its magnificent variety. After all, it is not so difficult to destroy, but will it be possible to create?