Form tasks Olympiad
Bibliography
Voronov A.G. Geobotany. Training Allowance for un-tov and ped. in-tov. Ed. 2nd M .: Higher. school., 1973. 384 p.
Stepanovsky A.S. General ecology: Textbook for universities. M .: UNITI, 2001. 510 p.
Zonn S.V. Vladimir Nikolaevich Sukachev: 1880-1967. M .: Science, 1987. 252 p.
Sukachev V.N. Basics of forest typology and biogeocenology. Fav. tr. L .: Science, 1972. T. 3. 543 p.
Program and methods of biogeocenological studies / Study of forest biogeocenoses / M .: Nauka, 1974. p. 281-317.
Shilov I.A. Ecology. M .: Higher School, 2003. 512 p.
Plavilschikov N.N. Homunculus M .: Detgiz, 1958. 431 p.
Questions
1. The period of factology, "naive ecology" - until the middle of the XIX century. (1-4 stages).
a) the birth of biocenology; dominance of autoecological research;
b) outstanding Russian scientists-biocenologists.
3. The period of biogeocenological studies - the dominance of synecological studies - from 1936 to the present day (stage 6).
4. V.N. Sukachev - the creator of the theory of biogeocenology.
5. Modern trends and objectives of biogeocenology (stage 7).
Biogeocenology, as an independent science, originated at the beginning of the 20th century. But the beginnings should be sought much earlier. To do this, turn to the history of the development of natural science, the history of environmental ideas, because nothing teaches as history teaches. These sciences - the sciences of nature - have evolved continuously, but unevenly throughout their history.
1. The period of factology, "naive ecology" - until the middle of the XIX century. (1-4 stages)
First stage - primitive knowledge, the accumulation of factual material. The fact that different types of animals are associated with certain conditions, that their numbers depend on the harvest of seeds and fruits, probably ancient hunters already knew 100-150 thousand years ago. The first farmers, many centuries before the new era (10-15 thousand years ago), knew about the dependence of plants on external conditions.
Crop rotation was used in Egypt, China and India 5 thousand years ago. In the ancient Indian tales "Mahabharata" (VI-II centuries. BC; information about the habits and lifestyles of 50 animals), in the manuscript books of China and Babylon (dates of sowing and gathering of wild and cultivated plants, methods of cultivating the earth, species of birds and animals).
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Ancient Rome: Pliny the Elder (23-79 years AD) in his multivoluted "Philosophy of Nature" considered many natural phenomena from a truly ecological position. The ancient scientists thought about a lot of things, and we are also thinking about it.
In the Middle Ages in Europe there was a reversal of human thought far back, the Church for several centuries was a brake on the development of all natural sciences. The relationship of the structure of organisms with the environment is entirely attributed to the will of God. Scientific information is contained in individual works and have an applied character; consist in the description of healing herbs, cultivated plants and animals. Famous scientists of this period: Razes (850-923), Avicenna (980-1037). But already in the late Middle Ages, new trends in science began - the beginnings of ecology. Albert the Great (Albert von Boltedt, ~ 1193-1280) in his works on plants attaches great importance to the conditions of growth, in particular to the light factor - "solar heat", considers the causes of "winter sleep". Information about distant countries appeared (Marco Polo (XIII century), Afanasy Nikitin (XV century) and his famous “Going beyond three seas”).
Karl Linney - the great Swedish scientist, the creator of the system of living organisms, the principles of which we use today |
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Contemporaries knew him as a witty, cheerful person. So in honor of the 3 Kommelin brothers, two of whom were well-known botanists, and the third was an unremarkable person, he called the genus Kommelin, whose flowers have 3 stamens: two long and one short. V.L. Komarov said about K. Linne: "Until civilization is erased from the face of the earth, the name of Linnaeus will live." The words are prophetic. More than 20 societies, two cities and a mountain in the USA, islands near Greenland, streets and squares in European cities, and other geographical objects carry the name of Linnaeus. In honor of C. Linnaeus, the genus is named Linnaeus with the only species - “L. North. "
The well-known English chemist R. Boyle (1627-1691) set the first ecological experiment on the effect of low atmospheric pressure on the development of animals, and F. Redi experimentally proved that it is impossible to self-generate complex animals. Anthony van Leeuwenhoek, who invented the microscope, was the first to study trophic chains and regulate the number of organisms.
A great contribution to the development of ecological ideas at that time was also made by Russian scientists such as M.V. Lomonosov (1711-1765), his associate S.P. Krasheninnikov (1711-1755), P.S. Pallas (1741-1811), I.I. Lepekhin (1740-1802). And this is not by chance, since Russia in the XVII century greatly expanded its borders, leaving its eastern frontiers on the coast of the Pacific Ocean.
Peter Simon Pallas in his work “Zoogeography” described the lifestyle of 151 mammals and 426 bird species and is considered one of the founders of the “ecology of animals”.
The great Russian natural scientist Mikhailo Lomonosov. In his theoretical constructions ahead of his contemporaries for 100-200 years |
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Fourth stage marked the beginning in the development of ecology. At the beginning of the XIX century. plant ecology and animal ecology stand out as independent branches. Scientists of this time analyzed the patterns of organisms and the environment, the relationship between organisms, adaptability and adaptability.
Professor of Moscow University Karl Frantsov Rulier (1814-1858) clearly formulated the idea that the development of the organic world is due to the impact of a changing external environment. It is believed that K.F. Rulie in his writings (160 works) laid the foundation for animal ecology, posed problems of adaptation, migration, variability, introduced the concept of “station”. He came closest to the evolutionary theory of Darwin, but he lived only 44 years.
A great role in the development of ecological ideas was played by the founder of biogeography and plant ecology, a German scientist, who laid the foundations of biogeography - A. Humboldt (1769-1859). He studied the influence of climate (temperature factor) on the distribution of plants. In the book "Ideas of plant geography" (1807), he introduced a number of scientific concepts that are used by ecologists today (ecobiomorph of plants, species association, vegetation formation, etc.).
The most important milestone in the development of ecological ideas about nature was the publication of the famous book by Charles Darwin (1809–1882) about the origin of species through natural selection and fierce competition.
(Before that, five years of traveling to the Beagle ship. Studied the geology of South America and other countries, studied the island fauna, gathered large collections of fauna and flora. The problem is why do individuals of the same species differ on different islands? Up to species - each island has its own species of mockingbirds, lizards, turtles ... Investigated beetles, pigeons, dogs, horses, weeds and cucumbers, studying the sundew, found that insectivorous plants feed on protein substances to produce nitrogen, on orchids studied the role of insects in pollination, etc. . All fit i. After the death of the money bequeathed to the publication of the list of plants around the globe. The manuscript list weighed 1 ton!).
This great discovery in biology was a powerful impetus for the development of natural science. Darwin had many followers. One of them is the German zoologist Ernst Haeckel (1834-1919). After the publication of the teachings of C. Darwin - in 1866, he proposed a term for the new science - "ecology", which later received universal recognition.
I'll prove! - E. Haeckel's motto. At the age of 8 I read Robinson Crusoe, dreamed for a long time with savages and adventures; punchy, who dreamed and achieved world fame, he successfully studied radiolarians for many years, drew well, but could draw conclusions that were not supported by facts and therefore were wrong; "General morphology", coined many different terms for the classification of departments of science; I have been searching for a single-celled organism for many years, which gave rise to all living things; I was looking for a general law that would explain all phenomena.
In 1895, the Danish scientist E. Warming (1841-1924) coined the term “ecology” into botany to denote an independent scientific discipline of plant ecology.
Thus, the accumulation and description of colossal factual material is common for the period of naive ecology, which lasted from the beginning of the development of civilization until 1986. At the same time - the lack of a systematic approach in its analysis.
2. The period of complex integration of knowledge, “factorial ecology” (5th stage - from the middle of the 19th century to the 40s of the 20th century)
Fifth stage - the autologous direction prevails, i.e. the period of factorial autoecology is the study of the natural totality of species and populations that are continuously reorganized in relation to changes in environmental conditions. At the same time, research began on the overorganism biosystems. This was facilitated by the formation of the concept of biocenoses as multiple-species communities.
a) the emergence of biocenology, the dominance of autologous research
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At the beginning of XX century - a surge of scientific thought! The development of complex sciences. In 1913–1920 different scientific societies and schools began to be created everywhere: botanists, phytocenologists, hydrobiologists, zoologists, etc., journals were produced, and in a number of universities they began to teach ecology. At the same time, many monographs and textbooks on plant geography, ecology of animals and plants were published.
First reports: a guide to the study of the ecology of animals by Charles Adams (1913), the book by V. Shelford on the communities of land animals (1913). 1916 - F. Clements showed the adaptability of biocenoses and the adaptive meaning of this, 1925 - A. Tinemann introduced the concept of "products", 1927 - C. Elton highlighted the originality of biocenotic processes, introduced the concept of ecological niche, formulated the rule of ecological pyramids. By the 1930s, various classifications of vegetation were created based on the morphological, ecological, morphological, and dynamic characteristics of the phytocenoses (C. Raunquier - Denmark, G. Di Ruye - Sweden, I. Braun-Blanke - Switzerland); the structure, productivity of communities were studied, ideas about environmental indicators were obtained (V. V. Alekhin, B. A. Keller, A. P. Shennikov). In the 30s-40s, new reports on the ecology of animals were compiled (K. Fredericks - 1930, F. Boldenheimer - 1938). A quantitative analysis of the phenomena and processes being studied associated with the names of A. Lotka (1925) and V. Volterra (1926) has been developed.
b) outstanding scientists-biocenologists of Russia (stage 5)
A prominent role in the development of biogeocenological ideas played Vladimir Vasilyevich Dokuchaev (1846-1903) - founder of scientific soil science, George F. Morozov (1867-1920) - classic forestry, and Vladimir Ivanovich Vernadsky (1863-1945) - the creator of the theory of the biosphere.
I. The merits of V.V. are exceptionally great. Dokuchaeva. By the end of the XIX century. He created the doctrine of natural zones and the doctrine of the soil as a special bio-axial body (system). Showed that the soil is an integral component of almost all the terrestrial ecosystems of our planet. In his work “The Doctrine of the Zones of Nature”, he wrote, “... that previously separate bodies, phenomena and elements — water, earth, but not their correlations — were not the same age-old genetic and always regular connection that exists between forces, bodies and phenomena , between dead and living nature, between plant, animal and mineral kingdoms on the one hand, by man, his way of life and even the spiritual world ... "
Ii. The idea of \u200b\u200bV.V. Dokuchaeva on the need to study not the individual components of biocenoses, but the connections existing between bodies, phenomena, and the environment (water, earth), between dead and living nature, between plants, animals, and the mineral kingdom, i.e. patterns of functioning of natural systems, was developed in the "Teaching about the forest" GF. Morozov. G.F. Morozov gave the first scientific definition of forest as a geographical factor — a global accumulator of solar energy that affects the climate, soil, and oxygen and carbon balance of the planet and regions.
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It may seem strange statement that VI. Vernadsky discovered the biosphere. What to open it? This is not a microbe of some kind. The biosphere is huge, and each of us constantly deals with it. We live, we constantly live in it. Yes, we live in it, but we think very little about the fact that this fragile house is unique in the Universe, that the mechanisms supporting it are very thin and can easily break not only from the fall of a large meteorite to Earth, but also from our irrational behavior.
“Matches for children are not a toy,” parents say and hide the matches away from children so that they do not make a fire and do not burn the house, and together with the house and themselves. Modern humanity in the biosphere is very similar to these silly playful children, who have come into the hands of "matches" - powerful mechanisms, advanced technologies. To hide away from the mischievous, these "matches" - but no one to do this. No parents at home, the children are left to themselves.
Having created the theory of the biosphere, V.I. Vernadsky contributed to the emergence of various trends in the study of the interactions and interactions of living organisms with inert natural bodies. Among them, four directions in the study of biospheric phenomena and processes stand out most clearly.
1. The study of landscapes, developed by L.S. Berg.
2. The doctrine of the physical-geographical shell, developed by A.A. Grigoriev.
3. The study of landscape biogeochemistry proposed by B. B. Polynov and developed V. A. Kovda.
4. The doctrine of biogeocenosis (biogeocenology), created by V.N. Sukachev.
Leonty G. Ramensky - the great Russian geobotanist, who formulated the law of the eeological individuality of species and created the theory of ecological continuum |
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All of them were united by the development of the vision of the permanent connection “between soils, on the one hand, and vegetative plants and animals (both higher and especially lower) organisms dwelling on them, on the other hand, proclaimed by V. V. Dokuchaev ...”
3. The period of biogeocenological studies - the dominance of synecological studies - from 1936 to the present day (stage 6)
Sixth stage - 40-70 years. XX century, reflects a new - systemic approach to the study of natural systems - it is based on the study of the processes of material and energy exchange. There is a development of quantitative methods and mathematical modeling.
In the early 40s of the last century, G. Gause pointed out the importance of trophic links as the main path for the flow of energy through natural systems. Following Gause, in 1935, the English botanist A. Tensley introduced the concept of ecosystem. The main achievement of A. Tensley is the successful attempt to integrate the biocenosis with a biotope at the level of a new functional unit - an ecosystem!
English geobotanist Tansley - one of the creators of the science of ecosystem x |
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4. V.N. Sukachev - creator of the theory of biogeocenology
Among the whole Pleiad of brilliant natural scientists of the XIX and XX centuries. (V.I. Vernadsky, K.K. Gedroyts, B. B. Polynov, I. P. Borodin, N. I. Vavilov, L. S. Berg, I. V. Tyurin, G. F. Morozov, A. .A. Grigoriev and others.) Vladimir Nikolaevich Sukachev occupies a special place. EAT. Lavrenko and V.D. Alexandrova (1975) wrote that “by the scope and, so to speak, the glow of scientific activity” by V.N. Sukachev can be compared only with V.V. Dokuchaev and N.I. Vavilov.
Vladimir Nikolaevich Sukachev one of the creators of the theory of biogeocenoses (ecosystems) |
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It can be argued that the creation of biogeocenology was largely, if not decisive, the result of the generalization of the extensive experimental work carried out by V.N. Sukachev in stationary and expeditionary research. All of them were most aimed at identifying the mechanisms of interaction of plants with each other, with individual components of the biogeocenosis as a special elemental natural system and were carried out for a long time. Biogeocenotic aspects V.N. Sukachevym formulated as a result of deep rethinking and reassessment of research in most areas of natural science.
Summarizing research on the quantitative expression of the interactions of all components in biogeocenoses led Sukachev to the statement that the exchange of matter and energy should be considered as a known resultant indicator of the vital activity of each individual and being in conjunction of biogeocenoses.
This exchange to the greatest extent in its properties and composition reflect the soil. The soil in its characteristics and properties reflects the development and evolution of biocenoses. In the soils, as in a mirror, both current instantaneous (dynamic) and secular (evolutionary) changes in biogeocenoses are focused (Sukachev, 1964). The biogeocenological understanding of the soil he introduced had a great influence on the identification of the role of vegetation, especially forest, in soil formation and soil evolution.
How did you manage to study all the sciences to the director of the leading Institute of Forests of the Academy of Sciences, chairman of the Biol. Science Academy of the USSR?
Vladimir Nikolaevich harmoniously developed his creative activity in all the listed directions.
S.V. Zonn, student and follower of VN In his book about the teacher, Sukachev tries to explain how V.N. Sukachev. He had his own, probably worked out by life experience, work system, his own schedule of studies for a particular branch of the sciences he developed.
Vladimir Nikolaevich was engaged in the Moscow period in questions of quaternary geology, which demanded departure to outcrops and other objects around Moscow and on the approaches to it. Mostly when he was tired of the current scientific and especially scientific and organizational activities at the Forest Institute, the Department of Biological Sciences of the USSR Academy of Sciences, etc. In such cases, he got into the car and left for one or three days to Rostov-Yaroslavsky, to Odintsovo and Rublevsky career and sometimes further.
Vladimir Nikolayevich was engaged in selection on an experimental plantation in the Serebrianobskoye forest area (Rublevo), stopping after visiting the Forest Institute. Here V.N. Sukachev grew willows, collected by himself, as well as by the staff of the Institute at his request in various regions of the country.
In the institute V.N. Sukachev, as a rule, himself worked with a microscope in his paleynological laboratory. VN working day Sukachev was painted by the hour. It consisted mainly in the management of the institute through its deputies, heads of departments and laboratories and in conversations with employees whose work Vladimir Nikolayevich for some reason attached particular importance to.
From the personal life ...
Creative activity Vladimir Nikolaevich concentrated both at home and in the country, where he worked mostly early in the morning and in the evenings. But very often winter evenings were devoted to the reception of visiting scientists and friends and the discussion of scientific problems with them. Evening discussions were always interesting, and Vladimir Nikolaevich often graciously invited many members of the Forest Institute to himself. This was done by Sukachev with a special approach, emphasizing a friendly, and by no means official or "directorship" attitude.
Here is one of his genuine invitations: “When you arrive in Moscow, now let me know by phone to my dacha ... I want to see you soon. We will agree on our meeting: either you will come to my dacha, or I will go to Uspenskoye or to Moscow. I imagine how many interesting things you can tell me! I have something to tell you. So, see you soon! Your V. Sukachev. This invitation was received by soil scientist S.V. Zonal after a long trip to the PRC.
Sukachev possessed tremendous diligence and the ability to write in any conditions, without waiting for the arrival of inspiration or attitude. However, his scientific work had a number of special features. To characterize Sukachev as an original encyclopaedist with a special attitude, this is very important. The expediency of such an analysis is vividly and figuratively formulated in the collective work “The Man of Science”.
It says: “The main thing in the biography is the disclosure of the impulses of scientific activity, the dynamics and results of the creative process, the psychology peculiar to one or another scientific way of thinking, the focus of his activities. Obsession with a scientific idea among great people is always combined with high criteria of honor and conscience, with an understanding of civil and humanistic duty. ”
Communication with GF probably contributed to the formation of high civil character traits of Vladimir Nikolaevich. Morozov, Principle in large and small, disinterestedness, responsiveness, sociability and actively convincing, not a commanding influence on the psychology of young people, “infecting” others with their diligence - these are the features acquired by V.N. Sukachev from their teachers.
What are the reasons that prompted V.N. Sukachev choose a scientific path?
The answer is very difficult. There were no scientists in his family. Therefore, one assumption remains that all his studies at school were accompanied by a display of interest in the knowledge of the unknown. This attitude is usually created by outstanding high school teachers. Did V.N. have such a coincidence of circumstances? Sukachev - unknown. But at the Forest Institute from the very first courses, it was undoubtedly greatly influenced by such outstanding institute professors of the time: the zoologist N.А. Kholodkovsky, soil scientists PS Kossovich, K.K. Gedroits, S.A. Zakharov, I.V. Tyurin, climatologist A.I. Voeikov and forestologists I.P. Borodin, and especially G.F. Morozov. Vladimir Nikolaevich kept the last handwritten works of George Fedorovich.
Hearing reports V.V. Dokuchaev in the Free Economic Society, the long-term performance of the duties of secretary at the beginning of the botanical and geographical subcommittee of the Soil Commission at the Free Economic Society, and then the Geobotanical Commission of the Dokuchaev Soil Committee, where I.P. Borodin - all this, of course, contributed to the formation of Sukachev and as a scientist.
The role of friends in the work of VN. Sukacheva
A special role in the life, scientific formation and creative path of Vladimir Nikolayevich belongs to friends, three prominent scientists: V.I. Edelstein, L.A. Ivanov and S.A. Yakovlev.
Vitaly Ivanovich Edelstein is the closest friend and comrade of Vladimir Nikolayevich. It was a touchingly kind and tender friendship, which lasted from the first year of undergraduate studies until the death of Edelstein. Vladimir Nikolaevich and Vitaly Ivanovich entered the Forest Institute in the same year. Together they began to work on the Faculty of Botany at prof. Borodin
Together they were arrested for political activities and in 1899, from 10.IV to 1.V (Art. Style), were in the Crosses, in one of the most stringent prisons of St. Petersburg. Then they parted: V.N. Sukachev lived in Leningrad, and V. I. Edelstein in Moscow. Nevertheless, all their life they shared their scientific problems and life circumstances. Such a bright friendship for over 65 years.
Leonid Alekasandrovich Ivanov, an experimental botanist, was initially a teacher of Vladimir Nikolaevich, but they were equal friends, despite the fact that, by age, L.А. Ivanov was older than Vladimir Nikolaevich. Their friendship was boundless, sealed by time, scientific interests and everyday experiences, good and bad.
Sergey Alexandrovich Yakovlev was a geologist and soil scientist, for a long time he worked together with V.N. Sukachev in the Forestry Institute and lived in the same house with him, in the so-called director's house in the territory of the Forestry Institute. Each occupied half the house. Neighborhood contributed to the convergence of families, and the interest of Vladimir Nikolayevich to geology, especially to the geology of the Quaternary period, predetermined friendship on this basis. At that time, Quaternary geology experienced a period of rapid flourishing, many questions arose that required discussion.
There were many peat bogs around Lesnoye, and among them was one very famous - Shuvalov, or Shuvalov peat bog, studied by many, including Sukachev. The age of the marsh deposit, the stages of its formation and its differences from others, were undoubtedly the subject of discussion of Vladimir Nikolaevich with S.А. Yakovlev. S.A. At that time, Yakovlev was a well-known scientist, and communication with him was certainly very interesting and important for Vladimir Nikolayevich - to confirm or approve the problems of bog formation that he developed, as well as the formation, chronology and evolution of vegetation in the Quaternary.
As can be seen from the above, V.N. Sukachev was a natural scientist-encyclopedist, but, being very organized and striving for a deep knowledge of the factors and processes that determine the life of plants. Vladimir Nikolaevich purposefully limited his interests to those parties studying geology, soil science, breezing, genetics, breeding, which contributed to the expansion and deepening of knowledge about the relationship of plants with each other and with environmental factors of their existence in the past and present. In order to make predictions and conclusions. It is this quality that logically led to the creation of biogeocenology - a complex science aimed at the knowledge of biogeocenoses and their interactions, the science of our time.
5. Modern directions and tasks of biogeocenology
Seventh stage - from the second half of the 20th century to the present day. The meaning and essence of biogeocenology is revealed in the very definition of the central concept given by V. N. Sukachev: “Biogeocenosis is a combination of homogeneous natural phenomena (atmosphere, rock, vegetation, wildlife and microorganisms, soil and hydrological conditions) , which has its own specific specifics of the interactions of these components of its components and a certain type of exchange of matter and energy between them and with other natural phenomena, and which is an internal anti- orechivoe dialectical unity, is in constant motion and development "[Fundamentals of Forest biogeocenology, 1964, p. 23].
Thus, based on this definition, one can see that the main objectives of the study of biogeocenosis should be the study of its components, their interrelationship and connection with the environment, and at the same time study of the processes of exchange of matter and energy between them. The specific content of this concept also implies the need for an integrated approach to the study of biogeocenoses based on the organization of stationary, experimental studies.
In the modern biosphere, one of the most significant factors determining its condition has become the activity of Man. The science biogeocenology is becoming increasingly popular. Why is she?
It was only at the end of the twentieth century that there was an awareness that human activity often not only harms the environment, but also threatens the existence of humanity itself. At the same time, in changing the structure and dynamics of ecosystems, the role of random factors, often leading to disasters with numerous human losses, has dramatically increased. This was first officially announced at the Stockholm Ecological Conference in 1972 and this explains the wholesale greening of both science itself and other areas of human activity, the greening of all kinds of industries related to the consumption of natural resources.
The problems arising in connection with this go beyond the framework of private and many complex biological sciences, acquire a directed social and political character (green movements, the struggle for nature protection, putting environmental issues on the agenda of political organizations, etc.). Their solution should include all natural sciences, together with economic, social, political aspects.
Why is it so important and necessary to study nature at the level of ecosystems and, above all, biogeocenoses?
Only the biogeocenotic approach, i.e. The study of quantitative characteristics of interrelationships in complexes of living organisms, interrelationships of organisms with each other, as well as between the living component of natural complexes and inanimate nature, provides virtually unlimited possibilities for a systemic view of material and energy interrelations.
It allows you to compare different types of biogeocenoses, different landscapes, different systems, build common models and go to the highest - the biosphere level, solving problems of a global scale, not regional.
Knowing the laws of the formation and functioning of ecosystems, one can influence them, one can foresee and prevent their destruction as a result of negative factors affecting them, use natural resources rationally and take protective measures, and as a result save the human habitat as a species.
Examples of such research are the International Environmental Program IBE (International Biological Program) and the MAB (Human and Biosphere). Work on the IBE was conducted in the 60-80s. XX century., In the USSR - from the mid 70s.
Why was the IBE necessary?
At that time, the rapid development of scientific and technological progress had occurred;
An intensification of the anthropogenic press on nature began, which caused the rapid and irreversible destruction of natural systems (lunar landscapes, black storms, etc.);
In the sphere of urbanization, i.e. in the household. activity, biological resources were involved in such quantities that it caused alarm for their condition;
There was a need to predict the effects of the anthropogenic factor on the natural complexes in each region and on the planet as a whole;
The main thing! - even primitive assessments of biological resources were absent.
The IBE’s goal is to accumulate factual material on primary productivity for different types of ecosystems in different regions and in the biosphere as a whole.
1 - to develop common methods (in the USSR, under the leadership of VN Sukachev and NV Dylisa, the “Program and Methods of Biogeocenological Studies” was compiled, the main guide to this day ”, 1974);
3 - determination of reserves, fractional structure of plant mass, as the basis of all types of bio resources, specific biogeocenoses in different regions;
2 - the subsequent integration of the obtained data (there were a lot of reports, monographs on primary productivity);
4 - building models of production processes.
For several decades, research has been carried out on the MAB program - different areas of monitoring, modeling, stationary studies of various levels are expanding, etc.
Thus, we have identified eight stages in the formation and development of the natural sciences, and biogeocenology in particular:
First stage - reflects the primitive knowledge accumulated by people, including primitive, in the process of close communication with nature and natural economy. The period began many centuries before the new era and ended in the first centuries before the new faith.
Second phase - the accumulation of factual material, but already by ancient scholars, medieval stagnation. Period: I-III century BC - XIV century AD
Third stage - the continuation of the collection and the first attempts to systematize the colossal factual material accumulated since the beginning of the great geographical discoveries and the colonization of new countries - in the Renaissance. Period: from IV to XVIII century, inclusive.
Fourth stage - associated with major botanical and geographical discoveries, contributing to the development of environmental thinking and the deepening of environmental studies, systematization of accumulated material, the beginning of the study of relationships; plant ecology and animal ecology are highlighted; definition of "ecology" (1866). Period: from the end of the 18th century to the second half (1866) of the 19th century.
Fifth stage - the dominance of research in the autecological direction - the study of the natural totality of species that are continuously rearranged in relation to changes in environmental factors, i.e. factorial autoecology; definition of the concept of "biocenosis" (1877), "ecosystem" (1936) and "biogeocenosis" (1942). Period: from the second half (1866) of the XIX to the middle (1936) of the XX century.
Sixth stage reflects the new - systemic, approach to the study of natural systems, the formation of biogeocenology and general ecology, as independent fundamental biological sciences, the dominance of the synecological direction; the study of the processes of material and energy exchange, the development of quantitative methods and mathematical modeling. Period: 40-70 years. XX century.
The specificity of this stage is the opinion about the primacy of competitive relations in biocenoses and the depreciation of the significance of evolutionary factors, the dominance of the discretionary paradigm.
Seventh stage - "greening" of all branches of science; the development of environmental sciences, taking into account the activities of man, i.e. social and political orientation. Increased interest in the study of populations (demecology), the dynamics of biogeocenosis formation due to anthropogenic disturbances; reducing descriptive and expanding integrated inpatient research. One of the main directions is the organization of long-term environmental monitoring at various levels (ground, regional, global, etc.). Period: from the 80s of the XX century to the present.
Specificity of the 7th stage - rejection of the primacy of competitive relations in the cenosis; in phytocenology, the change of the discreteness paradigm to the continuity paradigm; development of methods and theory of environmental monitoring.
In the past decade, a number of recent trends have merged. Scientists recognize both continuality and discreteness of vegetation cover - in nature there is both this and that, a new paradigm is being formed - biological diversity.
The biosphere is the upper shell of the planet, owing its origin to living organisms.
Tests on the topic "Ecological Systems"
Discipline Human Hygiene and Ecology1. The author of the term "ecological system":
А) V.N.SukachevB) A.TensliV) E.HeckelG) B.Commoner2. The scientist who introduced the concept of “biogeocenosis” into science: A) V.N.SukachevB) A.TensliV) E.HekkelG) B.Commoner3. Find the correct statement:
A) biocenosis + biotope \u003d ecosystem
B) biocenosis + ecosystem \u003d biotope
B) consumers + decomposers \u003d ecosystem
D) biocenosis \u003d ecosystem
4. Find the wrong statement:
A) ecosystem - the main functional unit in ecology
B) ecosystem - self-organizing system
C) under the ecosystem is understood as the totality of living organisms (communities)
D) Agroecosystem - artificially created human ecosystem
5. What are the names of living organisms that create organic matter in the ecosystem:
6. What are the names of predatory animals in the ecosystem structure:
A) consumersB) ReducersB) DetritusG) Producers
7. Vegetarians are:
A) first-order concessions
B) second-order consumer goods
B) third-order consumer
D) there is no right answer
8. What is the function of the consumers in the ecosystem:
A) form organic matter using solar energy during photosynthesis
B) consume organic matter
B) decompose organic matter to mineral components
D) decompose animal feces
9. Who does not belong to the reductionists: A) a centipede
B) bacteria
C) worms
D) kelp
10. Find a properly constructed sequence of ecosystem structures:
A) decomposers, producers, consumers B) producers, decomposers, consumers B) producers, consumers, decomposers G) consumers, decomposers, producers
11. What type of ecosystem does the home aquarium ecosystem relate to:
A) Mezoecosystem; B) Micro Ecosystem; Macro Ecosystem; G) Natural Ecosystem
12. Choose an example of a food chain:
A) rat, deer, wolf
B) aphid, ladybug, spider-cross
C) mushrooms, ticks, man
D) lake, fish, man
13. With the transfer of matter and energy in the food chain at each part of the energy is lost, which is:
A) 10%
B) 50%
C) 75%
D) 90%
14. The collection of interconnected food chains in an ecosystem is called:
A) food web
B) food pyramid
B) trophic level
D) environmental factor
15. The set of populations of species of living organisms that live in a certain area, characterized by certain relationships (food chains, symbiosis, etc.) and adapted to environmental conditions is called:
A) phytocenosis
B) microbiocenosis B) zoocenosis
D) biocenosis
16. The condition for a long-term ecosystem is a sufficient amount:
A) decomposers and consumers B) producers and consumers B) producers, consumers, decomposers
D) producers
17. Which of the following organisms can be called succession pioneers?
A) mosses and ferns
B) shrubs
C) mosses and lichens
D) herbs
18. The greater the diversity of species of organisms, the longer the ecosystem exists, which is a manifestation of:
A) self-regulationB) integrity
C) self-reproduction
D) sustainability
19. An important property of ecosystems is the ability to change ecosystems, which is called
A) self-regulationB) ecosystem integrity
C) self-reproduction
D) succession
20. Within the limits of an ecosystem, a natural extinction of a species as a result of eating by other individuals cannot occur. This is a manifestation of such an ecosystem property as: A) self-regulationB) sustainability
C) self-reproduction
D) integrity
The concept of biogeocenosis was introduced into scientific use in 1942 by Academician Vladimir Nikolaevich Sukachev (1880-1967). According to his ideas, biogeocoenosis is a combination of homogeneous natural phenomena (atmosphere, rocks, vegetation, animal world and microorganisms, soil and hydrological conditions) over a known length of the earth’s surface, which has the specific interaction of these components and a certain type of matter and energy exchange. them between themselves and other phenomena of nature.
Biogeocenosis is an open bio-axial (i.e., consisting of living and non-living matter) system, the main source of external energy for which is solar radiation. This system consists of two main blocks. The first unit, ecotope, combines all the factors of inanimate nature (abiotic environment). This inert part of the system is formed by an aerotop - a combination of factors of the above-ground environment (heat, light, humidity, etc.) and an edaphotop - a combination of the physical and chemical properties of the soil-soil environment. The second unit, the biocenosis, is a collection of all types of organisms. Functionally, the biocenosis consists of autotrophs — organisms capable of creating organic matter from inorganic matter based on the use of solar energy, and heterotrophs — organisms that use organic matter created by autotrophs as a source of matter and energy.
Diazotrophs, prokaryotic nitrogen-fixing organisms, are a very important functional group. They determine the sufficient autonomy of most natural biogeocenoses in providing plants with available nitrogen compounds. This includes both autotrophic and heterotrophic bacteria, cyanobacteria and actinomycetes.
In the literature, especially foreign, instead of the term biogeocenosis or along with it, the concept of an ecosystem proposed by the English geobotanist Arthur Tansley and the German hydrobiologist Volterek is used. The ecosystem and biogeocenosis are essentially identical. However, an ecosystem is understood as a dimensionless formation. As an ecosystem, for example, consider a rotting stump in the forest, individual trees, forest phytocenosis, in which these trees and stump are located; forest, which includes a number of phytocenoses; the forest zone, etc. But the biogeocenosis is always understood as a chorological (topographic) unit, which has definite boundaries, defined by the boundaries of the phytocenosis included in its composition. “Biogeocenosis is an ecosystem within the boundaries of the phytocenosis” - aphorism of one of the like-minded people V.N. Sukachev. Ecosystem is a broader concept than biogeocenosis. An ecosystem can be not only a biogeocenosis, but also biokosny systems that depend on biogeocenoses, in which organisms are represented only by heterotrophs, as well as such bio-axial systems created by humans, such as a granary, an aquarium, a ship with organisms inhabiting it, etc.
Consortia as structural and functional units of biocenoses
The concept of consortia in the modern understanding of them as structural and functional elements of biocenoses was formed in the early 50s of the 20th century. Russian scientists - zoologist Vladimir Nikolayevich Beklemishev and geobotanist Leonty Grigorievich Ramensky.
Consortia of populations of certain plant species may consist of many tens or even hundreds of plant, animal, fungi and prokaryote species. In the composition of only the first three concentrates in a consortium of wart birch (Betula verrucosa) more than 900 species of organisms are known.
General characteristics of natural communities and their structure
The basic unit of natural communities is the biocenosis. Biocenosis is a community of plants, animals, fungi and other organisms inhabiting the same territory, mutually connected in the food chain and exerting a certain influence on each other.
Biocenosis consists of the plant community and organisms accompanying this community.
The plant community is a collection of plants growing in a given territory, forming the basis of a specific biocenosis.
The plant community is formed by autotrophic photosynthetic organisms, which are the food source for heterotrophic organisms (phytophages and detritophages).
Based on the ecological role, organisms that form a biocenosis are divided into producers, consumers, decomposers and detritophages of various orders.
The concept of "biogeocenosis" is closely associated with the concept of "biocenosis". The existence of an organism is impossible without its habitat, therefore, the composition of the flora and fauna of a given community of organisms is greatly influenced by the substrate (its composition), climate, terrain features of this particular area, etc. All this makes it necessary to introduce the concept of “biogeocenosis”.
Biogeocenosis is a stable self-regulating ecological system located in this particular territory, in which organic components are closely and inextricably linked with inorganic ones.
Biogeocenoses are diverse, they are interconnected in a certain way, they can be stable for a long time, however, under the influence of changing external conditions or as a result of human activity, they can change, die, and be replaced by other communities of organisms.
Biogeocenosis consists of two components: biota and biotope.
A biotope is a relatively homogeneous space according to abiotic factors, occupied by a biogeocenosis (biota) (sometimes a biotope is understood as the habitat of a species or its individual population).
Biota is a collection of various organisms inhabiting a given territory and forming part of a given biogeocenosis. It is formed by two groups of organisms differing in the way of feeding - autotrophs and heterotrophs.
Autotrophic organisms (autotrophs) refer to such organisms that are able to absorb energy that comes from the outside as individual portions (quanta) using chlorophyll or other substances, and these organisms synthesize organic substances from inorganic compounds.
Among autotrophs, phototrophs and chemotrophs are distinguished: the first include plants, the second are chemosynthetic bacteria, for example, sulfur bacteria.
Heterotrophic organisms (heterotrophs) are organisms that feed on ready-made organic substances, while the latter are both a source of energy (it is released during their oxidation) and a source of chemical compounds for the synthesis of its own organic substances.
Biogeocenosis is a concept that combines three fundamentals: “bios” (life), “geo” (earth), and “koinos” (common). Proceeding from this, the floor by the word “biogeocenosis” is understood as a concrete developing system in which living organisms and objects of inanimate nature constantly interact. They are links of one food chain and are united by one energy flow. This concerns, first of all, the place of contact between animate and inanimate nature. For the first time, VN spoke about biogeocenosis. Sukachev, the famous Soviet scientist and thinker. In 1940, he deciphered this concept in one of his articles, and this term became widely used in Russian science.
Biogeocenosis and ecosystem
The term “biogeocenosis” is a term that is used only by Russian scientists and their colleagues in their CIS countries. In the West, there is an analogue of the term, the author of which is the English botanist A. Tensley. He introduced the word “ecosystem” in 1935 and by the beginning of the 1940s it had become generally accepted and discussed. At the same time, the concept of “ecosystem” has a broader meaning than “biogeocenosis”. To some extent, we can say that biogeocenosis is a class of ecosystem. So what is an ecosystem? This combination of all types of organisms and their habitats into one single system, which is in balance and harmony, lives and develops according to its own laws and principles. At the same time, the ecosystem, in contrast to biogeocenosis, is not limited to a plot of land. Therefore, biogeocenosis is part of the ecosystem, but not vice versa. An ecosystem can contain several types of biogeocenosis at once. Suppose the belt ecosystem includes a continental biogeocenosis and an ocean biogeocenosis.
Biogeocenosis structure
The structure of biogeocenosis is a very broad concept that is devoid of certain indicators. This is explained by the fact that its basis is made up of various organisms, populations, objects of the surrounding world, which can be divided into biotic (living organisms) and abiotic (environment) components.
The abiotic part also consists of several groups:
- inorganic compounds and substances (oxygen, hydrogen, nitrogen, water, hydrogen sulfide, carbon dioxide);
- organic compounds that serve as food for biotic organisms;
- climate and microclimate, which determines the conditions of life for all systems that are in it.
What is an ecosystem? What scientist introduced the concept of "ecosystem"? List the components of the ecosystem. What is the biological productivity of an ecosystem? What is the structure of the ecosystem. Give the definition of biocenosis, biogeocenosis, biotope. What is the trophic and species structure of ecosystems.
Ecosystem (1935) (from the Greek. Oikos - housing, location and systema - combination, association) - a collection of all populations of different species living in a common area along with the surrounding non-living environment.
Biogeocenosis (1942) - the area is homogeneous in environmental conditions and occupied by a single biocenosis.
Ecosystem features
Open (there are incoming and outgoing energy flows)
Autonomous. If you isolate it and ensure the flow of energy, then it can exist for almost an unlimited time.
Shows ability to self-regulation and self-maintenance, i.e. it has a buffer.
Has homeostasis - relative stability in time and space.
Blurred boundaries, both vertically and horizontally.
Can exist without any component. For example, in wetland ecosystems there is no soil, in the underground (cave) there is no influx of light energy.
Ecotone - boundary between ecosystems (biogeocenoses). Ecotone always has a higher species diversity and population density in relation to the central part of the biogeocenosis. For example, the edge of the forest is always more saturated with species of woody, grassy and shrubby vegetation, in relation to the areas located in the depths of the forest
Ecosystem classification
In size
Macro ecosystem. For example, sea, ocean, continent ...
Meso ecosystems. For example, a forest site, field, meadow, river, lake. ... Such ecosystems are usually called biogeocenoses.
Micro ecosystems (edge, meadow, puddle ...).
By origin:
Natural - formed spontaneously (tundra, steppe, forest ...).
Artificial - formed as a result of human activity
Ecosystem components
Biocenosis is a biotic component
Biotope - abiotic component
Ecosystem hierarchy
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Heterotrophic Organismsuse to build their bodies and as a source of energy ready-made organic matter created by autotrophs. Heterotrophs are mainly represented by animals that receive organic matter from food, as well as bacteria and fungi that receive energy through the absorption of substances in the process of decomposition of dead organic matter. The inorganic compounds formed during the vital activity of heterotrophs are assimilated by autotrophs.
According to the role in the transfer of energy through the ecosystem and in the circulation of substances, there are three ecological-functional groups of organisms.
Producers - these are autotrophic organisms that synthesize organic matter from inorganic components using external energy sources. Thus, producers are producers of organic matter in natural communities, while they convert the energy of solar radiation into the “stored” energy of chemical bonds of organic substances and involve elements of inanimate nature into circulation, including them in the composition of tissues of organisms.
Reducers - heterotrophic organisms that use dead organic matter as food and in the process of metabolism (a set of biochemical reactions that ensure the vital activity of the organism) decompose it into inorganic constituents. Fungi and bacteria are decomposers in ecosystems.
The process of decomposition of dead organic matter begins with the destruction of its special group of consumers - saprophagous. Large saprophages (for example, arthropods) mechanically destroy dead tissues, preparing the substance for the effects of decomposers - bacteria and fungi that carry out the process of mineralization.
As a result of the interaction of producers, consumers and decomposers in the ecosystem, energy transfer and the circulation of matter take place (Fig. 3).
Organic substances synthesized by autotrophic organisms undergo numerous chemical transformations and ultimately return to the environment in the form of inorganic waste products, which are again involved in the circulation.
Functionally, all the species that make up the ecosystem are divided into several groups depending on their place in the general cycle of matter and energy flow. Equivalent species in this sense form separate trophic (food) levelsrelated system food (trophic) chains according to the principle of food - the consumer.
Trophic chains represented by producers and consumers are defined as pasture food chains. Food chains in which the processes of destruction and mineralization of organic substances are carried out are defined as detrital food chains.
The flow of organic matter in the ecosystem at the level of consuments is divided: living matter follows the digging chains, the dead one goes along the decomposition chains.
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What is ecosystem homeostasis. The functioning and dynamics of the ecosystem. Energy and productivity of the ecosystem. Succession
Ecological Successions
Ecological succession is the sequential change of biocenoses within a single biotope.
The law of succession substitution: natural biotic communities consistently form a regular series of ecosystems, leading to the most stable under given conditions (climax)
Climax (climax community) - the final stable stage of ecosystem development
The main stages of succession
First settlers (pioneer species) → series of successions → climax community
Types of Ecological Successions
1. By the nature of the biotope
Primary succession. Succession in areas first mastered by organisms.
Secondary successions. Community develops in a place where a well-developed ecosystem previously existed
2. At the final stage
Progressive - the indigenous biotic community that existed at this place, which for some reason was removed (logging) is fully restored
Regressive - do not end with a final menopause, the indigenous ecosystem disappears completely (eg desertification)
3. For success reasons
Exogenous successions - associated with the action of external factors
Climatic
Soil.
Geological
Anthropogenic
Endogenous successions - associated with the internal processes of the ecosystem
Examples of Ecological Successions
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An example of succession in an aquatic ecosystem
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Ecosystem Homeostasis
Homeostasis - the ability of an ecosystem to maintain a state of mobile equilibrium, despite the external impact.
Homeostasis — the ability of biological systems — the organism, the population, and ecosystems — to resist change and maintain balance.
The functioning and dynamics of the ecosystem:
Cyclicity - the daily, seasonal and long-term periodicity of external conditions and the manifestation of the internal (endogenous) rhythms of organisms.
Daily cycles are most pronounced in high continental climate conditions, where there is a significant difference between day and night temperatures.
Seasonal cyclicality - for a certain period, groups of animals and even entire populations that fall into hibernation, in the period of diapause or stupor, fall out of the biocenosis, with the disappearance of annual grasses, leaf litter, and so on.
Long-term cyclicality due to climate fluctuations. The long-term periodicity in the change in the number of biocenosis, caused by sharply uneven rainfall over the years, with periodic recurrence of droughts, and so on.
Ecosystem Energy
Energy can transfer from one form (light energy) to another (potential energy of food), but it never creates again and does not disappear without a trace.
Energy maximization law:
in rivalry with other ecosystems, one of them is preserved that best contributes to the flow of energy and uses its maximum amount in the most efficient way.
Ecosystem productivity
Biological productivity - the rate of creation of organic matter in ecosystems.
Biomass is the body mass of living organisms.
The primary production of a community is the organic mass produced by plants per unit of time. And the production of animals or other consumers - secondary.
The product pyramid rule: at each previous trophic level, the amount of biomass generated per unit of time is greater than at the next.
If the predator-prey relationship, then the rule of the pyramid of numbers: the total number of individuals that participate in the food chains, with each subsequent link decreases.
Succession is a consistent irreversible change of biocenoses, successively occurring on the same territory as a result of the influence of natural factors or human influence.
The primary source of energy for ecosystems is the sun. The earth receives ~ 1, KJ / m2. year of solar energy. About 40% of it is reflected from clouds, atmospheric dust and from the surface of the Earth, ~ 15% is absorbed by the atmosphere (in particular, the ozone layer) and is converted into heat, or spent on the evaporation of water. The rest of the energy is absorbed by the earth’s surface and plants, with most of the absorbed energy being re-emitted by the earth’s surface and heating the atmosphere, and only a small part (~ KJ / m2. Year) enters the biotic component of ecosystems through producers. The biomass of organic matter synthesized in the ecosystem by autotroph producers is defined as primary production. The total amount of biomass is considered as gross primary production (Runway). A significant part of the energy accumulated in the form of gross primary production of the ecosystem is spent on respiration and photorespiration of plants. The part of the biomass that determines the growth in the ecosystem is considered as pure primary production (NWP). The difference between gross and net primary production is determined by the expenditure of energy on the vital activity of organisms. The net primary production accumulated in the form of biomass of autotrophic organisms serves as a source of food (substance and energy) for the following trophic levels. Typically, net primary production is not more than 20% of the gross primary production. The substance and energy contained in food, when eaten by some organisms by others, passes from one trophic level to the next. The undigested portion of food containing some energy is excreted with excrement. Organic waste from the metabolism (excreta) also contains some energy. Finally, some of the energy is lost to animals by breathing. The energy remaining after these losses, goes to growth, maintenance and reproduction of organisms. The amount of energy accumulated by heterotrophic organisms at each trophic level is secondary products (VP) of this level.
The average efficiency of energy transfer to producers is ~ 1%; energy transfer from plants to phytophages is ~ 10%, and energy transfer from animal to animal is 10–20%. Energy lost through breathing is not transferred to other organisms. The energy contained in excreta and excreta, on the contrary, is not lost for ecosystems, since it is transmitted detritophages(organisms that feed on detritus) and decomposers. If the ecosystem is stable, there is no increase in biomass ( productivity - biomass accumulation rate is equal to zero).
The main feature of the ecological balance of the ecosystem is its mobility. Any ecosystem, adapting to changes in the external environment, is in a state of dynamics. Distinguish between cyclical and directional dynamics. An example of cyclical dynamics is a seasonal change in the activity of the vital activity of organisms, or a periodic change in the number of individual species in a long-term series. Directional dynamics is the progressive development of ecosystems. This type of dynamics is characterized either by the introduction of new species into ecosystems, or the replacement of some species by others, which ultimately leads to a change in biocenoses and ecosystems as a whole. The change in species structure and biocenotic processes in an ecosystem is called succession.ecosystems. Thus, succession is a process of consecutive change of ecosystems proceeding in time with a gradual directional change of environmental conditions.
Succession due to external factors, called exogenous,Such successions can be caused, for example, by climate change in one direction (cooling or warming) and other changes in abiotic conditions. Such shifts can occur over centuries and millennia and are called centuries-old successions. If, as a result of changing environmental conditions, some species die out, while others change under the influence of natural selection, this process is considered as evolutionary succession.
If succession occurs due to internal interactions, it is called endogenetic.. Endogenetic successions are observed in nature when, in the course of their development, a community changes the environment so that it becomes more favorable for another community. The emerging new community in turn makes the environment even more unfavorable to the former community. There is a process of changing ecosystems, going through several stages, until the final population equilibrium is reached. The succession ends with the formation of a community adapted to climatic conditions, able to sustain itself indefinitely, the internal components of which are balanced with each other and with the environment. The final succession community — sustainable, self-renewing, and in balance with the environment — is called climax community.
The process of development and change of ecosystems, which begins on a new, previously uninhabited site, is defined as primary succession. A typical example is the settling of rock outcrops. First, lichens appear on the rocks and algae form a complex of microscopic species of algae, protozoa, nematodes, some insects and ticks, which promotes the formation of the primary soil. Later, there are other forms of lichen, specialized species of mosses, then vascular plants settle and the fauna is enriched.
Restoration of a damaged ecosystem that previously existed in a given area is called secondary succession. Such successions occur, for example, after deforestation or forest fires, with the overgrowing of areas that were previously under agricultural land. Secondary successions develop on a substrate already enriched with organic matter, they. begin with intermediate stages and occur much faster than primary successions.
The general patterns of endogenetic successions are an increase in species diversity, increased links between populations of different species of organisms, a decrease in the number of free ecological niches, an increase in the productivity of ecosystems, and ultimately, the formation of climax biocenosis. Moreover, each succession and at each stage is characterized by a set of species that are characteristic of this region and are most adapted to one or another of its stages.
How quickly the ecosystems change depends on the degree of shift in their equilibrium. Successions are a natural process of ecosystem development. During succession, changes occur slowly and gradually. At all stages of the process of replacing some species with others, the system is quite balanced. In the process of succession, the formation of more and more complex biocenoses and ecosystems, increasing their productivity.
In the case of sudden drastic changes causing a “population explosion” of some species due to the death of most other species, they talk about environmental violation.
Violations may occur during the invasion of introduced species or when the human has a rash effect on nature. In modern conditions, a constant increase in anthropogenic pressure on natural ecosystems (draining wetlands, excessive loads on forests, for example, as a result of recreation of the population, fires, increased cattle grazing, chemical pollution of the environment) often leads to a relatively rapid change in their structure. Human impacts often lead to the simplification of ecosystems. Such phenomena are commonly referred to as digressions (for example, pasture, recreational and other digressions). When the disturbances are so great that almost no component of the ecosystem is preserved, it is said doom. After the destruction of the ecosystem in the vacated area may begin a new succession.
What is an ecological niche? Give a definition of the law of competitive exclusion (Gause rule)
The ecological niche is the place of the species in nature, mainly in the biocenosis, including both its position in space and its functional role in the community, its relation to the abiotic conditions of existence.
There are no two different species that occupy the same ecological niche, but there are closely related species, often so similar that they require essentially the same niche. In this case, when the niches partially overlap, there is a particularly tough competition, but in the end, the niche takes one look. The phenomenon of ecological dissociation of closely related (or similar in other ways) species has been called the principle of competitive exclusion, or the Gauze principle, in honor of the scientist who proved it experimentally.
What is a population? Population indicators
A population is an elementary grouping of organisms of a certain species, possessing all the necessary conditions for maintaining its abundance for an immeasurably long time in constantly changing environmental conditions.
Static indicators:
Abundance - the total number of individuals in a designated area or in a given volume;
Density is the average number of individuals (or biomass) per unit area or volume of space occupied by a population.
Dynamic performance:
Fertility (fertility) - the number of new individuals that appeared per unit of time as a result of reproduction;
Mortality - the number of dead in the population of individuals in a certain period of time;
Population growth - the difference between fertility and mortality;
The growth rate of the population - the average increase per unit time.
Populations in nature do not exist in isolation. Populations of different species that make up the communities are interconnected and are in close unity with the environment.
The number of individuals and the mechanisms of its regulation are among the most important properties of populations.
In each ecosystem there is a sum of external and internal factors, under the influence of which the number of each species is established at some average level corresponding to the suitability and capabilities of the environment. Any deviation of the population size from the optimum is associated with negative consequences for its existence. In this regard, populations usually have adaptation mechanisms that contribute to the decline in numbers, if it significantly exceeds the optimal, and its recovery, if it decreases below the optimal values.
Each population has its own so-called biotic potential, which is understood to be the theoretically possible offspring from one pair of individuals in the absence of factors limiting the growth of numbers. The biotic potential is usually higher, the lower the level of organization of living beings.
The factors determining the growth of a population include: fertility, the ability to settle and seize new habitats, protective mechanisms, the ability to withstand adverse environmental conditions.
The rate of increase in numbers, in the absence of limiting factors, is characterized graphically by an exponential curve (1) in the coordinates “number - time” (Fig. 2). This is the so-called “biotic potential curve”. Such a change in numbers is largely realized only in individual cases and for short periods of time (for example, during the development of fast-growing organisms in a nutrient-rich environment where there is no competition).
For most populations and species, survival is characterized by a curve (2) of a different type (S-shaped or logistic), which reflects the high mortality of juveniles or buds (Fig. 2). The population size in this case asymptotically tends to a limit representing the maximum population size that the environment can support.
The resistance of the environment to population growth increases with increasing numbers, and for each population is characterized by the area between the curves (1) and (2) on the graph (Fig. 2).
For the human population, the current type of population growth is close to exponential, which is caused by overcoming the action of many environmental resistance factors, primarily lack of food and disease, and a sharp decrease in mortality in childhood.
