We are all part of a living shell - the biosphere. This is a unique ecosystem not only of our planet, but of the galaxy as a whole. Of course, recent studies have confirmed that organic matter has been found both on Mars and on various asteroids, but such a variety of life forms is unique to Earth. If you are ready to expand your horizons a little and go beyond the school curriculum, it's time to talk in more detail about the characteristics of the biosphere, its structure and main functions.
The concept of the biosphere and its essence
The biosphere is a conditional shell of the Earth inhabited by living organisms. Why conditional? The fact is that other shells of the planet (terrestrial, water and air) frame the planet with a continuous layer. First comes the earth and oceanic crust (lithosphere), then the hydrosphere (it unites all water bodies), after - the atmosphere(air envelope smoothly passing into outer space). It is difficult to imagine the biosphere as a specific layer, because living organisms are evenly distributed over the entire surface of the Earth and can live in all three elements.
The essential characteristics of the biosphere go back to antiquity, but still it is the "youngest" shell of our planet. Life on Earth originated relatively recently, only 3.8 billion years ago, which, compared to the age of the planet, is a mere trifle. There are two concepts of the biosphere:
- The first defines the shell as the totality of all organic matter on the planet. It was it that served as the basis for the term, which is used to this day.
- The second concept was proposed by V. I. Vernadsky, he believed that the biosphere is an inseparable unity and interaction of animate and inanimate nature, in the broad sense of these definitions.
However, the main characteristics of the biosphere are determined precisely by its organic component. After all, this is its fundamental difference from other shells of the Earth.
The doctrine of the biosphere and the origin of the term
The concept of a living shell was proposed in the 19th century. Jean-Baptiste Lamarck gave a brief description of the biosphere, while the official name did not even exist yet. In 1875, the Austrian paleontologist and geologist Eduard Suess first coined the term "biosphere", which is still used today.
The Soviet philosopher and biogeochemist V. I. Vernadsky made a huge contribution to the study of all life on Earth, he became famous thanks to the creation of a holistic doctrine of the biosphere. ATin his writings, living organisms act as a powerful force that continuously participates in the transformation of the planet Earth.
Limits of living organisms
General description of the biosphere begins with a description of the boundaries within which living organisms can live. Some of them are quite tenacious, and can withstand even the most critical conditions.
Boundaries of the biosphere:
- Upper border. It is determined by the atmosphere, and specifically the ozone layer of the Earth, it is about 15-20 kilometers. The closer to the equator, the more powerful the protective screen of the planet. Above the ozone layer, life is simply impossible, because ultraviolet radiation is incompatible with the vital activity of organism cells. In addition, the amount of oxygen is significantly reduced with height, and this is also detrimental to living beings.
- Lower bound. Determined by the lithosphere, the maximum possible depth does not exceed 3.5 - 7.5 kilometers. It all depends on the critical increase in temperature at which denaturation of protein structures occurs. However, most of the living organisms are concentrated at a depth of only a few meters, this is the root system of plants, fungi, microorganisms, insects and animals that live in holes.
- Boundaries in the hydrosphere. Living organisms can exist in absolutely any part of the ocean: from the surface of the water (plankton, algae) to the bottom of deep-sea trenches. For example, scientists have proven that life exists even in the Mariana Trench at a depth of 11 kilometers.
Live shell structure
The main characteristics of the biosphere includeits structure. Vernadsky singled out several types of substances that make up the living shell. Moreover, they could have both organic and inorganic origin:
- Living substance. This includes everything that has a cellular structure. However, the mass of living matter in the structure of the biosphere is small and amounts to literally one millionth of the entire shell. The characteristic of the living matter of the biosphere is that it is the most important part of our planet. After all, it is living organisms that constantly influence the appearance of the Earth, changing the structure of its surface.
- Biogenic substance. These are structures that are created and processed by living organisms. Surprisingly, for millions of years, living beings have passed through the systems of their organs almost the entire world ocean, a huge amount of atmospheric gases and a large mass of minerals. These processes produce minerals of organic origin, such as oil, carbonate rocks and coal.
- Inert substance. These are products of inanimate nature, which were formed without the direct participation of living organisms. This includes rocks, minerals and the inorganic part of the soil.
- Bio-inert substance. We remember that living organisms constantly affect the planet. As a result, substances are formed that are products of the decay and destruction of inert structures. This group includes soil, weathering crust and sedimentary rocks of organic origin.
- Also, the structure of the biosphere can include substances that are instate of radioactive decay.
- A separate group consists of atoms that are continuously created in the process of ionization under the influence of cosmic radiation.
- Recently, substances of extraterrestrial (cosmic) origin have been included in the structure of the biosphere.
Living matter in other shells of the Earth
If we dwell in detail on the characteristics and composition of the biosphere, then one cannot but consider the features of the vital activity of living organisms in other shells of the planet:
Aerosphere. Living organisms cannot be suspended in the atmospheric layers, microscopic water drops serve as a substrate for the life of aerobionts, and solar activity and aerosols act as a source of inexhaustible energy. Organisms living in the atmosphere are divided into three groups. Trobobionts - are active in space from the tops of trees to cumulus clouds. Altobionts are organisms that can survive in thin air. Parabionts - accidentally fall into the highest layers of the atmosphere. At this altitude, they lose their ability to reproduce, and their life cycle is significantly reduced
Geobiosphere. The Earth's crust serves as a substrate and habitat for geobionts. This shell also includes several levels on which specific life forms live. Terrabionts are organisms that live directly on the land surface. In turn, the terrabiosphere is divided into several more shells: the phytosphere (the zone from the tops of trees tosurface of the earth) and the ipedosphere (soil layer and weathering crust). Aeolian zone - high- altitude areas, to which life is impossible even for higher plants. Eolobionts are typical representatives of this zone. Lithobiosphere - deep layers of the earth's crust. This zone is divided into the hypoterrabiosphere (a place where aerobic (oxygen-requiring) life forms can live) and the tellurobiosphere (only anaerobic (oxygen-free) organisms can survive here). In addition, lithobionts can be found in the lithobiosphere, which live in groundwater and rock pores
Hydrobiosphere. This area covers all water bodies (except groundwater and atmospheric moisture) of our planet, including glaciers. The inhabitants of the seas and oceans are called hydrobionts, which in turn are divided into: Aquabionts - inhabitants of continental waters. Marinobionts are living organisms of the seas and oceans. Three levels of life are distinguished in the water column, depending on the amount of sunlight that penetrates inside: The photosphere is the most illuminated zone. The disphotosphere is always the twilight region of the ocean (no more than 1% of insolation). Aphotosphere - a zone of absolute darkness
From tundra to tropical forests. Classification of planet biomes
Characteristics of the biosphere is inextricably linked with the concept of biome. This term refers to large biological systems that have a certain predominant type of vegetation or specific landscape features. There are nine in total. Below is a brief description of the mainbiomes biosphere:
- Tundra. A vast treeless expanse that occupies the northern parts of Eurasia and North America. The vegetation of this zone is not rich, mainly lichens, seasonal grasses and mosses. The fauna is more diverse, especially during the warmer months of the year, when the migration season of many species of birds and animals begins.
- Taiga. The main type of vegetation in this area is coniferous forests. The biome occupies about 11% of the entire land area. Despite the harsh weather conditions, the taiga has an extremely diverse flora and fauna.
- Decidated forests. located in the temperate zone. The seasonality of the climate and a sufficient amount of moisture allowed the development of a certain type of vegetation in this biome. These are mainly broad-leaved tree species. In addition, these forests are home to many mammals, birds and fungi, not to mention insects and microorganisms.
- Steppes. This biome is represented by the Asian steppes and the classic prairies of North America. Most often, these are treeless open spaces, as a significant moisture deficit affects. But the animal world is still diverse.
- Mediterranean zone. The area around the sea of the same name is characterized by hot and rather dry summers and very comfortable cool winters. Typical vegetation is represented by hard-leaved forests, thorny bushes and grasses.
- Deserts. Unfortunately, more than 30% of the land is occupied by areas that are not at all favorable for the habitation of living organisms. Desert zones are found alongthroughout Africa and Australia, in South America, as well as in the South, Southwest and in the Center of Eurasia. The flora and fauna of these regions is rather scarce.
- Savannas. This biome is an open space that is completely covered with grass and single trees. Despite the fact that these are rather poor soils, the fauna of this zone is striking in its diversity. Savannahs are characteristic of Africa, South America and Australia.
- Prickly (tropical) woodlands. This zone is distinguished by bizarre forms of thorny bushes and centuries-old trees - baobabs. Due to the uneven distribution of rainfall, the vegetation of this biome is quite sparse. Tropical woodlands can be found in Southwest Asia and Africa.
Tropical forests. This is the wettest area of our planet. The vegetation of this biome is striking in its scale and diversity. Broad-leaved rainforests are located in the basins of large full-flowing rivers, such as the Amazon, Orinoco, Niger, Zambezi, Congo. They also cover the peninsulas and archipelagos of Southeast Asia
Basic functions of a live shell in nature
It's time to consider the main functions of the biosphere and their characteristics:
- Energy. This function is carried out by plants that participate in the process of photosynthesis. By accumulating solar energy, they either distribute it between other components of the living shell, or accumulate it in dead organic particles. This is how combustible minerals (coal, peat, oil) appear.
- Gas. Living organisms are involved in the ongoing gas exchange.
- Concentration. Some life forms have the ability to selectively accumulate biogenic elements from the external environment. Subsequently, they can serve as a source of these substances.
- Destructive. Living organisms constantly affect the environment, decomposing and processing its surface. This is how inert and bio-inert matter is formed.
- Environment-forming. The biosphere maintains a balance of favorable and unfavorable environmental conditions, which are necessary for the full life of organisms.
Properties of the biosphere
Since the living shell is a very complex system, the characteristics of the biosphere cannot do without the basic properties that determine its specificity:
- Centralization. All processes in the living shell are concentrated around living organisms, they occupy a central place in the doctrine of the biosphere.
- Openness. The biosphere can only exist due to energy from outside, in this case it is solar activity.
- Self-adjustment. The biosphere is a "whole organism", which, like a living being, has the ability to homeostasis.
- Variety. A huge number of animals, plants, microorganisms and fungi live on earth.
- Ensuring the circulation of substances. It is due to living organisms that photosynthesis and the circulation of substances are carried out. In the characteristics of the biosphere, these two processes occupy one of the main places.
Evolution and historydevelopment of the living shell of the Earth
If we characterize the biosphere from the point of view of evolution, we can say that this is the only shell that is continuously developing and improving. It's all about living matter, it is it that is constantly evolving. The inorganic part of the living shell does not have the ability to develop. If we talk about the characteristics of the biosphere in the future, then everything is a little more complicated. The shell is becoming more and more unstable, and it is very difficult to predict further developments.
Artificial biosphere
A person cannot exist outside of a living shell, it is very difficult to reproduce all that it can give us. The characteristics of the biosphere are so unique that humanity still cannot fully recreate its conditions in an artificial environment. However, science does not stand still and, perhaps, in the future, scientists will achieve some success in this direction.
