All living creatures of the planet Earth come into close contact with each other and withenvironment, thereby forming ecosystems. These communities of interacting organisms are not isolated from each other. They are interrelated by various relationships, primarily food. The totality of ecosystems forms a single planetary ecosystem, called the biosphere. In this article we will consider the structure of the biosphere, her composition and main functions.
The science
This the concept was first introduced into the science of Zh. B. Lamarck at distant 1803 and meant the totality of all living organisms of the planet Earth. In the late nineteenth century, the term "biosphere" used G. Suse, which included the inanimate matter of sedimentary rocks in the structure of the biosphere. The doctrine of the biosphere appeared in 1926, when VI Vernadsky summarized a vast amount of scientific information, anyway illustrating the relationship between living and non-living matter. Scientist I was able to show that our planet is not onlyis populated by living organisms, but also actively transforms them. In addition, according to Vernadsky, the interference of people in the natural processes is so significant that it is possible to talk about the noosphere - a new phase of the development of the biosphere. To date, the science of the biosphere combines data from different fields of knowledge. Among them, we can mention biology, chemistry, geology, climatology, oceanology, soil science and others.
The structure of the biosphere is such that living organisms can independently maintain the necessary composition of soil, atmosphere and hydrosphere. They play a key environmental role. Based on this scientists hypothesis that the soil and air werecreated by living organisms themselves for hundreds of millions of years of evolution. Having studied the similarities in the structure of geological rocks lying deeper than the Cambrian rocks, with later rocks, Vernadsky suggested that in the form of the simplest organisms life on the planet existed almost from the very beginning. Later geologists proved the fallacy of this hypothesis.
Since the sun is the energy basis for the existence of all life on Earth, the biosphere can be regarded as a shell, the structure and composition of which are formed in the score joint activity of living organisms and are determined by the inflow of solar energy. Now let's get acquainted with the structure of the Earth's biosphere.
Living and Inanimate
Considering the composition and structure of the biosphere, it is first of all worth noting that it consists of living and non-living matter (inert matter). The bulk of living organisms is concentrated in three geological shells of the Earth: atmosphere (air layer), hydrosphere (oceans, seas, and so on) and the lithosphere (the upper layer of the rock).However, these shells are distributed unevenly in the largest ecosystem. So, the hydrosphere is represented in the biosphere's structure completely, and the lithosphere and atmosphere are partially (upper and lower layers, respectively).
The inanimate component of the biosphere consists of of:
- Biogenic substance, which is a product of life of living organisms. It includes: coal, oil, peat, natural limestone, gas and so on.
- Bio-nutrient substance, which is a joint result of the life of organisms and non-biological processes. This includes: soil, silt, water reservoirs and so on.
- A biogenic substance that enters the biological cycle, but is not a product of the vital activity of living organisms. This group includes: water salts of metals, atmospheric nitrogen and others.
Boundaries of the biosphere
Such concepts as the composition, structure and boundaries of the biosphere are closely related to each other. Despite what bacteria and spores were found at an altitude of up to 85 kilometers, what the upper limit of the biosphere is 20-25 km. At high altitudes, the concentration of living matter is negligible because of the strong effect of solar radiation.
In the hydrosphere, life is everywhere. And even in the Mariana Trench, whose depth is 11 km, scientist from France J. Picard observed not only invertebrates, but also fish. Under more than 400-meter thickness Antarctic ice live bacteria, algae, foraminifera and crustaceans. Bacteria are found under a kilometer layer of mud and in groundwater. However, less than the concentration of living creatures is observed at a depth of 3 km. Thus, the boundaries and structure of the biosphere in different parts of the planet can be different.
Atmosphere, lithosphere and hydrosphere
Atmosphere consists mainly of oxygen and nitrogen.In small quantities, it contains argon, carbon dioxide and ozone. From the state of the atmosphere depends the life of both land and water creatures. Oxygen is necessary for the breathing of living organisms and the mineralization of dying organic substances. Well, carbon dioxide is used by plants for photosynthesis.
Lithosphere has a thickness of 50 to 200 km, nevertheless the main number of species of living organisms is concentrated in her the top layer several tens thickcentimeters. The spread of life deep into the lithosphere is limited due to a number of factors, the main of which are: lack of light, high density of the medium and high temperature. Thus, the lower limit of the spread of life in the lithosphere is a depth of 3 km, at which were detected some types of bacteria. It is fair to say that they did not live in the ground, but in underground waters and oil-bearing horizons. The value of the lithosphere is that it gives plant life, nourishing their all necessary substances.
Hydrosphere is an important component of the biosphere. About 90 % The water reserves are in the World Ocean, which occupies 70 % surface of the planet. It contains 1.3 billion km3, and the rivers and lakes - 0.2 million km3 water. The most important factor in the vital activity of the body is the content of oxygen and carbon dioxide in the water.
Fascinating figures
And the composition, structure and functions of the biosphere are surprisingtheir scale. We will get acquainted with some interesting facts. The water contains 660 times more carbon dioxide than in the air. On land, the diversity of the plant world predominates, and in the sea - the animal. 92 percent The total biomass on land is green plants. In the ocean, however, 94 % are microorganisms and animals.
On average, once every eight years the biomass of the Earth is renewed. Plants of land for this need 14 years, the ocean - 33 days. To ensure that all the water of the globe passes through living organisms, it will take 3000 years, oxygen to 5000 years, and carbon dioxide - 6 years. In nitrogen, carbon and phosphorus, these cycles yet longer. The biological cycle is not closed - about 10 % living matter goes into sediment and disposal.
The biosphere accounts for only 0.05 % from the masses of our planet. It takes about 0.4 % from volume Of the earth. The mass of living beings is only 0.01-0,02 % however, they play a very significant role in geochemical processes.
200 billion tons of dry weight produced annuallyorganics, and in the process of photosynthesis is absorbed 170 billion tons of carbon dioxide. In the process of vital activity of microorganisms, 6 billion tons of nitrogen and 2 billion tons of phosphorus are involved in the nutrient cycle every year, as well as a huge amount of iron, magnesium, sulfur, calcium and other elements. During this time, mankind extracts about 100 billion tons of minerals.
In the course of their vital activity, organisms make a significant contribution to the circulation of substances, stabilizing and transforming the biosphere, the properties and structure of which make one think about the presence of higher forces.
Energy function
Acquainted with the structure and composition of the biosphere, go to her functions. Let's start with energy. As you know, plants absorb solar radiation and saturate the biosphere with vital energy. About 10 % captured light producers use for their needs (mainly for cellular respiration). Everything else through food chains spreads through all ecosystems of the biosphere. Part of the energy canned in the bowels of the earth, saturating them with its power (coal, oil, etc.).
Even considering the functions and structure of the biosphereBriefly, they always release the redox function as an energy subspecies. Being producers, chemosynthesizing bacteria can extract energy from the reactions of oxidation and reduction of inorganic compounds. In the process of hydrogen sulfide oxidation, sulfur bacteria are fed with energy, and iron (from 2valence in 3-valent) - iron bacteria.Nitrifying also do not sit idle. They oxidize ammonium compounds to nitrates and nitrites. For this purpose, farmers fertilize their fields with ammonium compounds, which are not digested by the plants themselves. When soil is fertilized directly with nitrates, the plant storage tissues are supersaturated with water, which leads to their deterioration taste and increase the risk of diseases of the digestive system in those who eat them.
Medium-forming function
Living organisms form the soil, and also regulate the composition of the air and water membranes of the earth. If a would there was no photosynthesis on the planet, the supply of atmospheric oxygen was would spent for 2000 years old. In addition, literally in one century, due to the increasing concentration of carbon dioxide in the air, the organisms would begin to die. In one day the forest can to swallow from a 50-meter layer of air up to 25 % carbon dioxide. A medium sized tree can provide oxygen four person. One hectare of deciduous forest located near the city annually retains about 100 tons of dust. Lake Baikal, which famous for its crystalline purity, is due to the small crustaceans, which three times a year "filter" it. And these are just a few examples of how living organisms regulate the composition of substances in the biosphere.
Concentration function
Living beings, and especially microorganisms, are capable of concentrating many chemical elements found in the biosphere. Almost 90 % soil nitrogen are the result of activity blue green seaweed Bacteria can concentrate iron (for example, by oxidizing bicarbonate, soluble in water, to hydroxide deposited in their habitat), manganese, and even silver. This amazing feature allowed to scientists to believe that it is thanks to microorganisms that there are so many metal deposits on earth.
In some countries, elements such as germanium and selenium extracted from plants. Fucus algae can accumulate 10 thousand times more titanium than is contained in the surrounding her sea water. Each ton of brown algae contains several kilograms of iodine. Australian oak accumulates aluminum, pine - beryllium, Birch tree - barium and strontium, larch - niobium and manganese, and thorium concentrated in aspen, bird cherry and fir. In addition, some plants even “collect” precious metals. So, in 1 ton of ash of wormwood can be up to 85 grams of gold!
Destructive function
Chemical structure of the Earth’s biosphere and her environment implies not only creative,but also destructive processes. However, they also play a large role in the regulation of substances on the planet. With the active life of living organisms, the mineralization of organic residues and the weathering of rocks occur. Bacteria, fungi, blue green algae and lichen can destroy solid breeds for score extraction of carbonic, nitrous and sulfuric acids. Corrosive compounds also secrete the roots of trees. There are bacteria that can even destroy glass and gold.
Transport function
Considering the structure and functions of the biosphere, one cannot lose sight of the mass transfer of matter. The tree raises the water from the ground into the atmosphere, the mole throws the earth up, the fish swimming against the current, a flock of locusts migrates - all this is a manifestation of the transport function of the biosphere.
Living matter can perform tremendous geological work, forming a new image of the biosphere and actively participating in all her processes.
Separately, it is worth noting the process of formation of sedimentary rocks. The first stage of this process is weathering - destruction of the upper layers lithosphere under the action of air, sun, water and microorganisms. Being introduced into the breed, the roots of plants can destroy her. Water that seeps into cracksformed by the roots, dissolves and carries away the substance. This is due to corrosive components of the plant. Especially abundantly organic acids secrete lichens. Thus, physical weathering occurs along with chemical weathering.
Due to the death of plankton organisms at the bottomoceans deposited annually to 100 million tons of limestone. Many of them are of chemical origin, being, for example, in the contact area of acid and alkaline groundwater. With the death of unicellular algae and radiolarians are formed silicon silts that cover hundreds of thousands of kilometers2 seabed.
Soil forming function
The properties and structure of the biosphere are so comprehensive that all her functions are closely related. So, soil formation is one of the branches of mass exchange and medium formation, but is considered separately by virtue of his of importance.With the destruction and further processing of rocks by microorganisms, a loose productive shell of the earth is formed, called the soil. The roots of large plants extract mineral elements from deep horizons, enriching the upper layers of the soil and increasing their fruitfulness. The soil gets organic compounds from the dead the roots and stems of plants, as well as animal excrement and carcasses. These compounds are food for soil organisms that mineralize organic, produce carbon dioxide, organic acids and ammonia.
Invertebrates, insects, and theirlarvae play the most important structural role. They make the soil loose and suitable for plant life. Vertebrates (moles, shrews, etc.) loosen the ground, contributing to the successful growth of shrubs in it. At night, penetrates the earth cooled compressed air, which is necessary for respiration of roots and microorganisms.
Such is the amazing structure of the biosphere.
