Laureate of the competition of the Ministry of Education of the Russian Federation for the creation of textbooks of a new generation in general natural sciences (Moscow, 1999). The first Russian textbook on the discipline "Ecology" for university students studying technical sciences.
The textbook is written in accordance with the requirements of the current state educational standard and a program recommended by the Russian Ministry of Education. It consists of two parts - theoretical and applied. In its five sections, the main provisions of general ecology, the doctrine of the biosphere, and human ecology are considered; anthropogenic impacts on the biosphere, problems of ecological protection and environmental protection. In general, the textbook forms a new ecological, noospheric worldview among students.
Designed for students of higher educational institutions. The textbook is also recommended for teachers and students of secondary schools, lyceums and colleges. It is also necessary for a wide range of engineering and technical workers involved in environmental management and environmental protection.
Here is one of the textbooks of a new generation on the discipline "Ecology" for students of higher educational institutions studying technical directions and specialties of vocational education, written by well-known experts in the field of environmental sciences and passed through a difficult and long path of competitive selection.
This textbook is one of three winners in the discipline "Ecology" All-Russian competition textbooks of a new generation on general fundamental natural science disciplines. This competition is the first in history high school Russia in connection with the reform of the structure and content of higher education programs was initiated by the State Committee for Higher Education of Russia (hereinafter - the Ministry of Education of Russia) and carried out during 1995-1998. on the basis of the Peoples' Friendship University of Russia.
CONTENT
Dear reader! ten
Preface 11
Introduction. ECOLOGY. DEVELOPMENT SUMMARY 13
§ 1. Subject and tasks of ecology 13
§ 2. History of development of ecology 17
§ 3. Importance of environmental education 21
Part I. THEORETICAL ECOLOGY
Section one. GENERAL ECOLOGY 26
Chapter 1. Organism as a living integral system 26
§ 1. Levels of biological organization and ecology 26
§ 2. Development of an organism as a living integral system 32
§ 3. Systems of organisms and biota of the Earth? 6
Chapter 2. Interaction of the organism and the environment 43
§ 1. The concept of habitat and environmental factors 43
§ 2. Basic ideas about the adaptations of organisms 47
§ 3. Limiting factors 49
§ 4. The importance of physical and chemical environmental factors in the life of organisms 52
§ 5. Edaphic factors and their role in the life of plants and soil biota 70
§ 6. Resources of living beings as environmental factors 77
Chapter 3. Populations 86
§ 1. Static indicators of populations 86
§ 2. Dynamic indicators of populations 88
§ 3. Life expectancy 90
§ 4. Dynamics of population growth 94
§ 5. Ecological survival strategies 99
§ 6. Regulation of population density 100
Chapter 4 Biotic Communities 105
§ 1. Species structure of biocenosis 106
§ 2. Spatial structure of the biocenosis 110
§ 3. Ecological niche. The relationship of organisms in the biocenosis 111
Chapter 5 Ecological Systems 122
§ 1. Ecosystem concept 122
§ 2. Production and decomposition in nature 126
§ 3. Ecosystem homeostasis 128
§ 4. Ecosystem energy 130
§ 5. Biological productivity of ecosystems 134
§ 6. Ecosystem dynamics 139
§ 7. System approach and modeling in ecology 147
Section two. LEARNING ABOUT THE BIOSPHERE 155
Chapter 6. Biosphere - the global ecosystem of the earth 155
§ 1. The biosphere as one of the shells of the Earth 155
§ 2. Composition and boundaries of the biosphere 161
§ 3. The cycle of substances in nature 168
§ 4. Biogeochemical cycles of the most vital nutrients 172
Chapter 7. Natural ecosystems of the earth as chorological units of the biosphere 181
§ 1. Classification of natural ecosystems of the biosphere on a landscape basis 181
§ 2. Terrestrial biomes (ecosystems) 190
§ 3. Freshwater ecosystems 198
§ 4. Marine ecosystems 207
§ 5. The integrity of the biosphere as a global ecosystem 213
Chapter 8. The main directions of the evolution of the biosphere 217
§ 1. V. I. Vernadsky’s teaching about the biosphere 217
§ 2. Biodiversity of the biosphere as a result of its evolution 223
§ 3. 0 Regulatory impact of biota on environment 226
§ 4. Noosphere as a new stage in the evolution of the biosphere 230
Section three. HUMAN ECOLOGY 234
Chapter 9. Biosocial nature of man and ecology 234
§ 1. Man as a biological species 235
§ 2. Population characteristics of a person 243
§ 3. Natural resources of the Earth as a limiting factor in human survival 250
Chapter 10. Anthropogenic ecosystems 258
§ 1. Man and ecosystems 258
§ 2. Agricultural ecosystems (agroecosystems) 263
§ 3. Industrial-urban ecosystems 266
Chapter 11. Ecology and human health 271
§ 1. The influence of natural and environmental factors on human health 271
§ 2. The influence of social and environmental factors on human health 274
§ 3. Hygiene and human health 282
Part II. APPLIED ECOLOGY
Section four. ANTHROPOGENIC IMPACTS ON THE BIOSPHERE 286
Chapter 12. Main types of anthropogenic impacts on the biosphere 286
Chapter 13. Anthropogenic impacts on the atmosphere 295
§ 1. Air pollution 296
§ 2. Main sources of air pollution 299
§ 3. Ecological consequences of atmospheric pollution 302
§ 4. Ecological consequences of global atmospheric pollution 307
Chapter 14. Anthropogenic impacts on the hydrosphere 318
§ 1. Pollution of the hydrosphere 318
§ 2. Ecological consequences of pollution of the hydrosphere 326
§ 3. Depletion of underground and surface waters 331
Chapter 15. Anthropogenic impacts on the lithosphere 337
§ 1. Impacts on soils 338
§ 2. Impacts on rocks and their massifs 352
§ 3. Impacts on the subsoil 360
Chapter 16. Anthropogenic impacts on biotic communities 365
§ 1. The value of the forest in nature and human life 365
§ 2. Anthropogenic impacts on forests and other plant communities 369
§ 3. Environmental consequences of human impact on vegetable world 372
§ 4. The value of the animal world in the biosphere 377
§ 5. Human impact on animals and the causes of their extinction 379
Chapter 17. Special types of impact on the biosphere 385
§ 1. Pollution of the environment by production and consumption waste 385
§ 2 Noise exposure 390
§ 3. Biological pollution 393
§ 4. The impact of electromagnetic fields and radiation 395
Chapter 18. Extreme impacts on the biosphere 399
§ 1. Impact of weapons of mass destruction 400
§ 2. The impact of man-made environmental disasters 403
§ 3. Natural disasters 408
Section five. ENVIRONMENTAL PROTECTION AND PROTECTION 429
Chapter 19. Basic principles of environmental protection and rational nature management 429
Chapter 20. Engineering environmental protection 437
§ 1. Principal directions engineering protection environment 437
§ 2. Regulation of environmental quality 443
§ 3. Protection of the atmosphere 451
§ 4. Protection of the hydrosphere 458
§ 5. Protection of the lithosphere 471
§ 6. Protection of biotic communities 484
§ 7. Protection of the environment from special types of impacts 500
Chapter 21. Fundamentals of environmental law 516
§ 1. Sources of environmental law 516
§ 2. State authorities for environmental protection 520
§ 3. Environmental standardization and certification 522
§ 4. Ecological expertise and environmental impact assessment (EIA) 524
§ 5. Environmental management, audit and certification 526
§ 6. The concept of environmental risk 528
§ 7. Environmental monitoring (environmental monitoring) 531
§ 8. Environmental control and social environmental movements 537
§ 9. Environmental rights and duties of citizens 540
§ 10. Legal liability for environmental offenses 543
Chapter 22. Ecology and Economics 547
§ 1. Ecological and economic accounting natural resources and pollutants 549
§ 2. License, agreement and limits for the use of natural resources 550
§ 3. New mechanisms for financing environmental protection 552
§ 4. The concept of the concept of sustainable development 556
Chapter 23 public consciousness 560
§ 1. Anthropocentrism and ecocentrism. Formation of a new ecological consciousness 560
§ 2. Ecological education, upbringing and culture 567
Chapter 24. International cooperation in the field of ecology 572
§ 1 International objects of environmental protection 573
§ 2. Basic principles of international environmental cooperation 576
§ 3. Russia's participation in international environmental cooperation 580
Ecological manifesto (according to N. F. Reimers) (instead of a conclusion) 584
Basic concepts and definitions in the field of ecology, environmental protection and nature management 586
Index 591
RECOMMENDED READING 599
(Document)
n1.doc
Name:CD Ecology: electronic textbook. Textbook for universities
Year: 2009
Publisher: KnoRus
ISBN: 539000289X
ISBN-13(EAN): 9785390002896
the text is taken from the electronic textbook
Section I. General ecology
INTRODUCTION Ecology and a brief overview of its development
1. Subject and tasks of ecology
The most common definition of ecology as scientific discipline is the following: ecology science that studies the conditions of existence of living organisms and the relationship between organisms and their environment. The term "ecology" (from the Greek "oikos" - house, dwelling and "logos" - teaching) was first introduced into biological science by the German scientist E. Haeckel in 1866. Initially, ecology developed as an integral part biological science, in close connection with other natural sciences - chemistry, physics, geology, geography, soil science, mathematics.
The subject of ecology is the totality or structure of relationships between organisms and the environment. The main object of study in ecology ecosystems, i.e. uniform natural complexes formed by living organisms and the environment. In addition, her area of expertise includes the study certain types of organisms(organism level), their populations i.e. sets of individuals of the same species (population-species level), sets of populations, i.e. biotic communities biocenoses(biocenotic level) and biosphere in general (biospheric level).
The main, traditional, part of ecology as a biological science is general ecology, which studies the general laws of the relationship of any living organisms and the environment (including man as a biological being).
As part of the general ecology, the following main sections are distinguished:
autecology, investigating the individual relationships of an individual organism (species, individuals) with its environment;
population ecology(demoecology), whose task is to study the structure and dynamics of populations of individual species. Population ecology is also considered as a special branch of autecology;
synecology(biocenology), which studies the relationship of populations, communities and ecosystems with the environment.
For all these areas, the main thing is the study survival of living beings in the environment, and the tasks before them are mainly biological property study the patterns of adaptation of organisms and their communities to the environment, self-regulation, sustainability of ecosystems and the biosphere, etc.
In the above understanding, general ecology is often referred to as bioecology, when they want to emphasize its biocentricity.
From the point of view of the time factor, ecology is differentiated into historical and evolutionary.
In addition, ecology is classified according to specific objects and environments of study, i.e., they distinguish animal ecology, plant ecology and microbial ecology.
AT recent times the role and importance of the biosphere as an object of ecological analysis is continuously increasing. Particularly great importance in modern ecology is given to the problems of human interaction with the natural environment. The promotion of these sections in environmental science is associated with a sharp increase in mutual negative influence human and environment, the increased role of economic, social and moral aspects, in connection with the sharply negative consequences of scientific and technological progress.
Thus, modern ecology is not limited only to the framework of the biological discipline, which treats the relationship mainly of animals and plants with the environment, it turns into an interdisciplinary science that studies the most complex problems of human interaction with the environment. The urgency and versatility of this problem, caused by the aggravation of the ecological situation on a global scale, has led to the "greening" of many natural, technical and human sciences.
For example, at the intersection of ecology with other branches of knowledge, the development of such new areas as engineering ecology, geoecology, mathematical ecology, agricultural ecology, space ecology, etc. continues.
Accordingly, the term "ecology" itself received a broader interpretation, and the ecological approach in studying the interaction of human society and nature was recognized as fundamental.
The environmental problems of the Earth as a planet are being dealt with by an intensively developing global ecology, the main object of study of which is the biosphere as a global ecosystem. At present, there are also special disciplines, how social ecology, studying the relationship in the system " human society nature”, and its part human ecology(anthropoecology), which deals with the interaction of man as a biosocial being with the outside world.
Modern ecology is closely connected with politics, economics, law (including international law), psychology and pedagogy, since only in alliance with them is it possible to overcome the technocratic paradigm of thinking and develop a new type of ecological consciousness that radically changes people's behavior in relation to nature.
From a scientific and practical point of view, the division of ecology into theoretical and applied is quite justified.
Theoretical ecology reveals the general laws of the organization of life.
Applied Ecology studies the mechanisms of destruction of the biosphere by man, ways to prevent this process and develops principles for the rational use of natural resources. The scientific basis of applied ecology is a system of general environmental laws, rules and principles.
Based on the above concepts and directions, it follows that the tasks of ecology are very diverse.
In general terms, these include:
development general theory sustainability of ecological systems;
study of ecological mechanisms of adaptation to the environment;
study of population regulation;
study biodiversity and mechanisms for its maintenance;
study of production processes;
study of the processes taking place in the biosphere in order to maintain its stability;
modeling of the state of ecosystems and global biospheric processes.
The main applied tasks that ecology must solve at present are the following:
forecasting and assessment of possible negative consequences in the natural environment under the influence of human activity;
improving the quality of the environment;
optimization of engineering, economic, organizational, legal, social or other solutions to ensure environmentally safe sustainable development, primarily in the most environmentally endangered areas.
strategic objective ecology is considered to be the development of the theory of interaction between nature and society based on a new view that considers human society as an integral part of the biosphere.
At present, ecology is becoming one of the most important natural sciences, and, as many ecologists believe, the very existence of man on our planet will depend on its progress.
2. Brief review of the history of the development of ecology
In the history of the development of ecology, three main stages can be distinguished.
First stage the origin and formation of ecology as a science (until the 60s of the nineteenth century). At this stage, data were accumulated on the relationship of living organisms with their environment, and the first scientific generalizations were made.
In the XVII-XVIII centuries. ecological information accounted for a significant proportion in many biological descriptions (A. Réaumur, 1734; A. Tremblay, 1744, etc.). Elements of the ecological approach were contained in the studies of Russian scientists I. I. Lepekhin, A. F. Middendorf, S. P. Krashennikov, the French scientist J. Buffon, the Swedish naturalist C. Linnaeus, the German scientist G. Yeager, and others.
In the same period, J. Lamarck (1744-1829) and T. Malthus (1766-1834) for the first time warned humanity about the possible negative consequences of human impact on nature.
Second phase registration of ecology as an independent branch of knowledge (after the 60s of the nineteenth century). The beginning of the stage was marked by the publication of works by Russian scientists K.F. Rulye (1814-1858), N.A. Severtsov (1827-1885), V.V. have lost their significance to the present day. It is no coincidence that the American ecologist Yu. Odum (1975) considers VV Dokuchaev one of the founders of ecology. At the end of the 70s. nineteenth century German hydrobiologist K. Möbius (1877) introduces the most important concept of biocenosis as a regular combination of organisms under certain environmental conditions.
An invaluable contribution to the development of the foundations of ecology was made by Charles Darwin (1809-1882), who revealed the main factors in the evolution of the organic world. What Ch. Darwin called the "struggle for existence" from evolutionary positions can be interpreted as the relationship of living beings with the external, abiotic environment and with each other, that is, with the biotic environment.
The German evolutionary biologist E. Haeckel (1834-1919) was the first to understand that this is an independent and very important area of biology, and called it ecology (1866). In his fundamental work “The General Morphology of Organisms”, he wrote: “By ecology we mean the sum of knowledge related to the economy of nature: the study of the totality of the relationship of an animal with its environment, both organic and inorganic, and above all its friendly or hostile relations with those animals and plants with which he directly or indirectly comes into contact. In a word, ecology is the study of all the complex relationships that Darwin called "the conditions that give rise to the struggle for existence."
As an independent science, ecology finally took shape in the early twentieth century. During this period, the American scientist C. Adams (1913) created the first summary of ecology, other important generalizations and reports were published (W. Shelford, 1913, 1929; C. Elton, 1927; R. Hesse, 1924; K. Raunker, 1929 and etc.). The largest Russian scientist of the twentieth century. V. I. Vernadsky creates a fundamental doctrine of the biosphere.
In the 30s and 40s. ecology has risen to a higher level as a result of a new approach to the study natural systems. First, A. Tensley (1935) put forward the concept of an ecosystem, and a little later, V. N. Sukachev (1940) substantiated a similar concept of biogeocenosis. It should be noted that the level of domestic ecology in the 20-40s. was one of the most advanced in the world, especially in the field of fundamental research. During this period, such prominent scientists as Academician V.I. Vernadsky and V.N. Sukachev, as well as prominent ecologists V.V. Stanchinsky, E.S. Bauer, G.G. Gauze, V.N. A. N. Formozov, D. N. Kashkarov and others.
In the second half of the twentieth century. In connection with environmental pollution and a sharp increase in human impact on nature, ecology is of particular importance.
Begins third stage(50s of the 20th century - up to the present) transformation of ecology into a complex science, including the sciences of the protection of natural and human environment environment. From a rigorous biological science, ecology is turning into "a significant cycle of knowledge, incorporating sections of geography, geology, chemistry, physics, sociology, cultural theory, economics ..." (Reimers, 1994).
The modern period of development of ecology is associated with the names of such major foreign scientists as J. Odum, J. M. Andersen, E. Pianka, R. Ricklefs, M. Bigon, A. Schweitzer, J. Harper, R. Whittaker, N. Borlaug , T. Miller, B. Nebel and others. Among domestic scientists, one should name I. P. Gerasimov, A. M. Gilyarov, V. G. Gorshkov, Yu. A. Israel, K. S. Losev, N. N. Moiseev, N. P. Naumov, N. F. Reimers, V. V. Rozanov, Yu. Yablokova, A. L. Yanshin and others.
The first environmental acts in Russia are known from the 9th-12th centuries. (for example, the code of laws of Yaroslav the Wise "Russian Truth", which established the rules for the protection of hunting and beekeeping lands). In the XIV-XVII centuries. on the southern borders of the Russian state, there were "cut forests", a kind of protected area, where economic felling was prohibited. History has preserved more than 60 environmental decrees of Peter I. Under him, the study of Russia's richest natural resources began. In 1805, a society of nature explorers was founded in Moscow. At the end of the nineteenth - beginning of the twentieth century. there was a movement for the protection of rare objects of nature. The works of prominent scientists V. V. Dokuchaev, K. M. Baer, G. A. Kozhevnikov, I. P. Borodin, D. N. Anuchin, S. V. Zavadsky and others scientific foundations nature conservation.
The beginning of the environmental protection activities of the Soviet state coincided with a number of first decrees, starting with the “Decree on Land” of October 26, 1917, which laid the foundations for nature management in the country.
It was during this period that the main type of environmental activity was born and received legislative expression Protection of Nature.
In the period of 30-40s, in connection with the exploitation of natural resources, caused mainly by the growth of industrialization in the country, nature protection began to be regarded as "a unified system of measures aimed at the protection, development, qualitative enrichment and rational use of natural funds countries" (from the resolution of the First All-Russian Congress on Nature Protection, 1929).
Thus, in Russia there is the new kind environmental activities rational use of natural resources.
In the 50s. the further development of the productive forces in the country, the strengthening of the negative impact of man on nature necessitated the creation of another form that regulates the interaction of society and nature, human habitat protection. During this period, republican laws on nature protection are adopted, which proclaim an integrated approach to nature not only as a source of natural resources, but also as a human habitat. Unfortunately, Lysenko's pseudoscience still triumphed, and IV Michurin's words about the need not to wait for mercy from nature were canonized.
In the 60s-80s. almost every year, government decrees were adopted to strengthen nature protection (on the protection of the Volga and Ural basins, the Azov and Black Seas, Lake Ladoga, Baikal, the industrial cities of Kuzbass and Donbass, the Arctic coast). The process of creating environmental legislation continued, and land, water, forest and other codes were issued.
These resolutions and the adopted laws, as the practice of their application showed, did not give the necessary results - the detrimental anthropogenic impact on nature continued.
3. Importance of environmental education
Environmental education not only provides scientific knowledge in the field of ecology, but is also an important link in the environmental education of future specialists. This implies instilling in them a high ecological culture, the ability to respect natural wealth and others. In other words, specialists, in our case of an engineering and technical profile, should form a new ecological consciousness and thinking, the essence of which is that a person is a part of nature and the conservation of nature is the preservation of a full-fledged human life.
Ecological knowledge is necessary for every person in order to fulfill the dream of many generations of thinkers about creating an environment worthy of a person, for which it is necessary to build beautiful cities, develop productive forces so perfect that they could ensure the harmony of man and nature. But this harmony is impossible if people are hostile to each other and, even more so, if there are wars, which, unfortunately, is the case. As the American ecologist B. Commoner rightly noted in the early 1970s: “Searching for the origins of any problem related to the environment leads to the indisputable truth that the root cause of the crisis lies not in how people interact with nature, but in how they interact with each other… and that, finally, peace between people and nature must be preceded by peace between people.”
At present, the spontaneous development of relationships with nature poses a danger to the existence of not only individual objects, territories of countries, etc., but also to all mankind.
This is explained by the fact that a person is closely connected with living nature, origin, material and spiritual needs, but, unlike other organisms, these connections have taken on such a scale and forms that this can lead (and is already leading!) To the almost complete involvement of living cover. planets (biospheres) into life support modern society by putting humanity on brink of ecological catastrophe.
A person, thanks to the mind given to him by nature, seeks to provide himself with "comfortable" conditions of the environment, strives to be independent of it. physical factors, for example, from the climate, from the lack of food, to get rid of animals and plants harmful to him (but not at all "harmful" to the rest of the living world!) etc. Therefore, a person primarily differs from other species in that he interacts with nature through the culture, i.e., humanity as a whole, developing, creates a cultural environment on Earth thanks to the transfer from generation to generation of its labor and spiritual experience. But, as K. Marx noted, "culture, if it develops spontaneously, and is not directed consciously ... leaves behind a desert."
Only knowledge of how to manage them can stop the spontaneous development of events, and, in the case of ecology, this knowledge should “take possession of the masses”, according to at least, for the most part of society, which is possible only through the general environmental education of people from school to university.
Ecological knowledge makes it possible to realize the perniciousness of war and strife between people, because behind this lies not just the death of individuals and even civilizations, because this will lead to a general ecological disaster to the destruction of all mankind. This means that the most important of the ecological conditions for the survival of man and all living things is a peaceful life on Earth. This is what an environmentally educated person should and will strive for.
But it would be unfair to build the whole ecology "around" only man. The destruction of the natural environment entails detrimental consequences for human life. Ecological knowledge allows him to understand that man and nature are a single whole and ideas about his dominance over nature are rather illusory and primitive.
An ecologically educated person will not allow a spontaneous attitude to life around him. He will fight against ecological barbarism, and if such people become the majority in our country, they will ensure a normal life for their descendants, resolutely standing up for the protection of wildlife from the greedy offensive of the "wild" civilization, transforming and improving civilization itself, finding the best "environmentally friendly » options for the relationship between nature and society.
In Russia and the CIS countries, much attention is paid to environmental education. The Interparliamentary Assembly of the CIS Member States adopted the Recommendatory Legislative Act on the Environmental Education of the Population (1996) and other documents, including the Concept of Environmental Education.
Environmental education, as indicated in the preamble of the Concept, is intended to develop and consolidate more advanced stereotypes of people's behavior aimed at:
1) saving natural resources;
2) prevention of unjustified pollution of the environment;
3) widespread conservation of natural ecosystems;
4) respect for the norms of behavior and coexistence accepted by the international community;
5) formation of conscious readiness for active personal participation in ongoing environmental activities and their feasible financial support;
6) assistance in carrying out joint environmental actions and the implementation of a unified environmental policy in the CIS.
Currently, violation of environmental laws can only be stopped by raising to the proper height ecological culture each member of society, and this can be done, first of all, through education, through the study of the fundamentals of ecology, which is especially important for specialists in the field of technical sciences, primarily for civil engineers, engineers in the field of chemistry, petrochemistry, metallurgy, mechanical engineering, food and extractive industries, etc. This textbook is intended for a wide range of students studying in technical areas and specialties of universities. According to the authors' intention, it should give the main ideas in the main areas of theoretical and applied ecology and lay the foundations for the ecological culture of the future specialist, based on a deep understanding of the highest value - the harmonious development of man and nature.
test questions
1. What is ecology and what is the subject of its study?
2. What is the difference between the tasks of theoretical and applied ecology?
3. Stages of the historical development of ecology as a science. The role of domestic scientists in its formation and development.
4. What is environmental protection and what are its main types?
5. Why is it necessary for every member of society, including engineering and technical workers, environmental culture and environmental education?
Chapter 1
1.1. The main levels of life organization and ecology
Gene, cell, organ, organism, population, community (biocenosis) - the main levels of life organization. Ecology studies the levels of biological organization from organism to ecosystems. It is based, like all biology, on theory evolutionary development organic world of Ch. Darwin, based on ideas about natural selection. In a simplified form, it can be represented as follows: as a result of the struggle for existence, the most adapted organisms survive, which transmit beneficial traits that ensure survival to their offspring, which can develop them further, ensuring the stable existence of this type of organisms in given specific environmental conditions. If these conditions change, then organisms with traits that are more favorable for the new conditions, transmitted to them by inheritance, survive, etc.
Materialistic ideas about the origin of life and the evolutionary theory of Charles Darwin can only be explained from the standpoint of environmental science. Therefore, it is no coincidence that, following the discovery of Darwin (1859), the term "ecology" by E. Haeckel (1866) appeared. The role of the environment, i.e., physical factors, in the evolution and existence of organisms is beyond doubt. This environment was called abiotic, and its individual parts (air, water, etc.) and factors (temperature, etc.) are called abiotic components, Unlike biotic components represented by living matter. Interacting with the abiotic environment, i.e. with abiotic components, they form certain functional systems, where living components and the environment are “a single whole organism”.
On fig. 1.1 the above components are presented in the form levels of biological organization biological systems that differ in the principles of organization and the scale of phenomena. They reflect the hierarchy of natural systems, in which smaller subsystems make up large systems, which are themselves subsystems of larger systems.
Rice. 1.1. The spectrum of levels of biological organization (according to Yu. Odum, 1975)
The properties of each individual level are much more complex and diverse than the previous one. But this can be explained only partially on the basis of data on the properties of the previous level. In other words, the properties of each successive biological level cannot be predicted from the properties of the individual components of its lower levels, just as the properties of water cannot be predicted from the properties of oxygen and hydrogen. Such a phenomenon is called emergence the presence of a systemic whole of special properties that are not inherent in its subsystems and blocks, as well as the sum of other elements that are not united by backbone links.
Ecology studies the right side of the "spectrum" depicted in fig. 1.1, i.e. levels of biological organization from organisms to ecosystems. In ecology The body is viewed as a complete system interacting with the environment, both abiotic and biotic. In this case, our field of vision includes such a set as species, consisting of similar individuals, which, nevertheless, individuals differ from each other. They are just as different as one person is different from another, also belonging to the same species. But all of them are united by one for all gene pool , which ensures their ability to reproduce within the species. There can be no offspring from individuals of different species, even closely related, united in one genus, not to mention the family and larger taxa, uniting even more "distant relatives".
Since each individual (individual) has its own specific features, their attitude to the state of the environment, to the impact of its factors is different. For example, some individuals may not be able to withstand a rise in temperature and die, but the population of the entire species survives at the expense of other individuals that are more adapted to elevated temperatures.
population, in its most general form, is a collection of individuals of the same species. Geneticists usually add as a mandatory point the ability of this population to reproduce itself. Ecologists, taking into account both of these features, emphasize a certain isolation in space and time of similar populations of the same species (Gilyarov, 1990).
The spatial and temporal isolation of similar populations reflects the real natural structure of the biota. In a real natural environment, many species are scattered over vast areas, so it is necessary to study a certain species group within a certain territory. Some of the groupings adapt quite well to local conditions, forming the so-called ecotype. This one isn't even large group genetically related individuals can give rise to a large population, and very stable for quite a long time. This is facilitated by the adaptability of individuals to the abiotic environment, intraspecific competition, etc.
However, true single-species groups and settlements do not exist in nature, and we usually deal with groups consisting of many species. Such groupings are called biological communities, or biocenoses.
Biocenosis- a set of cohabiting populations of different types of microorganisms, plants and animals. The term "biocenosis" was first used by Möbius (1877) when studying a group of organisms in an oyster bank, i.e., from the very beginning, this community of organisms was limited by a certain "geographical" space, in this case, the boundaries of a shoal. This area was later named biotope which refers to the environmental conditions in a certain area: air, water, soils and underlying rocks. It is in this environment that the vegetation, fauna and microorganisms that make up the biocenosis exist.
It is clear that the components of the biotope do not just exist side by side, but actively interact with each other, creating a certain biological system, which Academician V.N. Sukachev called biogeocenosis. In this system, the totality of abiotic and biotic components has "... its own, special specificity of interactions" and "a certain type of exchange of matter and energy between themselves and other natural phenomena and representing an internal contradictory dialectical unity, which is in constant motion, development" (Sukachev, 1971). The scheme of biogeocenosis is shown in fig. 1.2. This well-known scheme of V. N. Sukachev was corrected by G. A. Novikov (1979).
Rice. 1.2. Scheme of biogeocenosis according to G. A. Novikov (1979)
The term "biogeocenosis" was proposed by V.N. Sukachev in the late 30s. Sukachev's ideas later formed the basis biogeocenology a whole scientific direction in biology, dealing with the problems of the interaction of living organisms with each other and with their abiotic environment.
However, a little earlier, in 1935, the English botanist A. Tensley introduced the term "ecosystem". Ecosystem, according to A. Tensley, "a set of complexes of organisms with a complex of physical factors of its environment, i.e., habitat factors in the broad sense." Other well-known ecologists have similar definitions - Y. Odum, K. Willy, R. Whittaker, K. Watt.
A number of supporters of the ecosystem approach in the West consider the terms "biogeocenosis" and "ecosystem" to be synonymous, in particular Yu. Odum (1975, 1986).
However, a number of Russian scientists do not share this opinion, seeing certain differences. Nevertheless, many do not consider these differences significant and put an equal sign between these concepts. This is all the more necessary because the term "ecosystem" is widely used in related sciences, especially environmental content.
Of particular importance for the allocation of ecosystems are trophic, i.e., the nutritional relationships of organisms that regulate the entire energy of biotic communities and the entire ecosystem as a whole.
First of all, all organisms are divided into two large groups - autotrophs and heterotrophs.
autotrophic organisms use inorganic sources for their existence, thereby creating organic matter from inorganic matter. Such organisms include photosynthetic green plants of land and aquatic environment, blue-green algae, some bacteria due to chemosynthesis, etc.
Since organisms are quite diverse in types and forms of nutrition, they enter into complex trophic interactions with each other, thereby performing the most important ecological functions in biotic communities. Some of them produce products, others consume, others convert it into an inorganic form. They are called respectively: producers, consumers and decomposers.
Producers producers of products that all other organisms then feed on these are terrestrial green plants, microscopic marine and freshwater algae that produce organic substances from inorganic compounds.
Consumers These are consumers of organic substances. Among them there are animals that consume only plant foods herbivores(cow) or eating only the meat of other animals carnivores(predators), as well as those who use both "omnivorous"(man, bear).
decomposers (destructors)) reducing agents. They return substances from dead organisms back to inanimate nature, decomposing organic matter into simple inorganic compounds and elements (for example, into CO 2 , NO 2 and H 2 O). By returning nutrients to the soil or aquatic environment, they complete the biochemical cycle. This is done mainly by bacteria, most other microorganisms and fungi. Functionally, decomposers are the same consumers, so they are often called microconsumers.
A. G. Bannikov (1977) believes that insects also play an important role in the processes of decomposition of dead organic matter and in soil-forming processes.
Microorganisms, bacteria and other more complex forms, depending on the habitat, are divided into aerobic, i.e. living in the presence of oxygen, and anaerobic living in an oxygen-free environment.
1.2. The body as a living holistic system
An organism is any living being. It differs from inanimate nature a certain set of properties inherent only in living matter: cellular organization; metabolism in the leading role of proteins and nucleic acids, providing homeostasis organism self-renewal and maintenance of the constancy of its internal environment. Living organisms are characterized by movement, irritability, growth, development, reproduction and heredity, as well as adaptability to the conditions of existence adaptation.
Interacting with the abiotic environment, the organism acts as complete system, which includes all lower levels of biological organization (the left side of the "spectrum", see Fig. 1.1). All these parts of the body (genes, cells, cellular tissues, whole organs and their systems) are components of the pre-organismal level. A change in some parts and functions of the body inevitably entails a change in its other parts and functions. So, in the changing conditions of existence, as a result of natural selection, certain organs receive priority development. For example, a powerful root system in plants of the arid zone (feather grass) or "blindness" as a result of eye reduction in animals that exist in the dark (mole).
Living organisms have a metabolism, or metabolism many chemical reactions take place. An example of such reactions is breath, which even Lavoise and Laplace considered a kind of combustion, or photosynthesis, through which green plants bind solar energy, and as a result of further metabolic processes it is used by the whole plant, etc.
As you know, in the process of photosynthesis, in addition to solar energy, carbon dioxide and water are used. total chemical equation photosynthesis looks like this:
where C 6 H 12 O 6 is an energy-rich glucose molecule.
Almost all carbon dioxide (CO 2 ) comes from the atmosphere and during the day its movement is directed downward to plants, where photosynthesis takes place and oxygen is released. Respiration is the reverse process, the movement of CO 2 at night is directed upwards and oxygen is being absorbed.
Some organisms, bacteria, are able to create organic compounds at the expense of other components, for example, due to sulfur compounds. Such processes are called chemosynthesis.
Metabolism in the body occurs only with the participation of special macromolecular protein substances enzymes acting as catalysts. Each biochemical reaction during the life of an organism is controlled by a specific enzyme, which in turn is controlled by a single gene. A gene change called mutation, leads to a change in the biochemical reaction due to a change in the enzyme, and in the case of a shortage of the latter, then to the loss of the corresponding stage of the metabolic reaction.
However, not only enzymes regulate metabolic processes. They are helped coenzymes large molecules, of which vitamins are a part. vitamins special substances that are necessary for the metabolism of all organisms bacteria, green plants, animals and humans. The lack of vitamins leads to diseases, since the necessary coenzymes are not formed and metabolism is disturbed.
Finally, a number of metabolic processes require specific chemicals called hormones, which are produced in various places (organs) of the body and delivered to other places by blood or by diffusion. Hormones carry out in any organism the general chemical coordination of metabolism and help in this matter, for example, nervous system animals and humans.
At the molecular genetic level, the impact of pollutants, ionizing and ultraviolet radiation is especially sensitive. They cause a violation of genetic systems, cell structure and inhibit the action of enzyme systems. All this leads to diseases of humans, animals and plants, oppression and even destruction of species of organisms.
Metabolic processes proceed with varying intensity throughout the life of the organism, the entire path of its individual development. This path from birth to the end of life is called ontogeny. Ontogenesis is a set of successive morphological, physiological and biochemical transformations undergone by the body over the entire period of life.
Ontogeny includes growth organism, i.e., an increase in body weight and size, and differentiation, i.e., the emergence of differences between homogeneous cells and tissues, leading them to specialization in performing various functions in the body. In organisms with sexual reproduction, ontogenesis begins with a fertilized cell (zygote). With asexual reproduction - with the formation of a new organism by dividing the maternal body or a specialized cell, by budding, as well as from a rhizome, tuber, bulb, etc.
Each organism in ontogeny goes through a series of stages of development. For sexually reproducing organisms, there are germinal(embryonic), post-embryonic(postembryonic) and period of development adult organism. The embryonic period ends with the release of the embryo from the egg membranes, and in viviparous birth. Important environmental significance for animals has an initial stage of post-embryonic development, proceeding according to the type direct development or by type metamorphosis passing through the larval stage. In the first case, there is a gradual development into an adult form (chicken - chicken, etc.), in the second - development occurs first in the form larvae, which exists and feeds on its own before turning into an adult (tadpole - frog). In a number of insects, the larval stage allows you to survive the unfavorable season (low temperatures, drought, etc.)
In plant ontogenesis, there are growth, development(the adult organism is formed) and aging(weakening of the biosynthesis of all physiological functions and death). The main feature of the ontogenesis of higher plants and most algae is the alternation of asexual (sporophyte) and sexual (hematophyte) generations.
Processes and phenomena taking place at the ontogenetic level, i.e. at the level of an individual (individual), are a necessary and very essential link in the functioning of all living things. The processes of ontogeny can be disturbed at any stage by the action of chemical, light and thermal pollution of the environment and can lead to the appearance of malformations or even death of individuals at the postnatal stage of ontogeny.
The modern ontogeny of organisms has developed over a long evolution, as a result of their historical development phylogenesis. It is no coincidence that this term was introduced by E. Haeckel in 1866, since for the purposes of ecology it is necessary to reconstruct the evolutionary transformations of animals, plants and microorganisms. This is done by science - phylogenetics, which is based on the data of three sciences - morphology, embryology and paleontology.
The relationship between the development of the living in the historical evolutionary plan and the individual development of the organism was formulated by E. Haeckel in the form biogenetic law
: the ontogenesis of any organism is a brief and concise repetition of the phylogenesis of a given species. In other words, first in the womb (in mammals, etc.), and then, having been born, individual in its development repeats in abbreviated form historical development of its kind.
1.3. General characteristics of the Earth's biota
Currently, there are more than 2.2 million species of organisms on Earth. Their taxonomy is becoming more and more complicated, although its basic skeleton has remained almost unchanged since its creation by the eminent Swedish scientist Carl Linnaeus in the middle of the 17th century.
Table 1.1
Higher Taxa of the Cytematics of the Empire of Cellular Organisms
It turned out that on Earth there are two large groups of organisms, the differences between which are much deeper than between higher plants and higher animals, and, therefore, rightfully, two kingdoms were distinguished among the cellular: prokaryotes - low organized pre-nuclear and eukaryotes - highly organized nuclear. prokaryotes(Procaryota) are represented by the kingdom of the so-called shotgun, which include bacteria and blue-green algae, in the cells of which there is no nucleus and the DNA in them is not separated from the cytoplasm by any membrane. eukaryotes(Eucaryota) are represented by three kingdoms: animals, mushroomsand plants , whose cells contain a nucleus and DNA is separated from the cytoplasm by a nuclear membrane, since it is located in the nucleus itself. Fungi are singled out in a separate kingdom, since it turned out that not only do they not belong to plants, but they probably originate from amoeboid biflagellated protozoa, that is, they have a closer connection with the animal world.
However, such a division of living organisms into four kingdoms has not yet formed the basis of reference and educational literature, therefore, in the further presentation of the material, we adhere to the traditional classifications, according to which bacteria, blue-green algae and fungi are divisions of lower plants.
The whole set of plant organisms of a given territory of the planet of any detail (region, district, etc.) is called flora, and the totality of animal organisms fauna.
The flora and fauna of this area together make up biota. But these terms have a much wider application. For example, they say flora of flowering plants, flora of microorganisms (microflora), soil microflora, etc. The term “fauna” is used similarly: mammalian fauna, bird fauna (avifauna), microfauna, etc. The term “biota” is used when they want evaluate the interaction of all living organisms and the environment, or, say, the influence of "soil biota" on the processes of soil formation, etc. Below is a general description of the fauna and flora in accordance with the classification (see Table 1.1).
prokaryotes are the oldest organisms in the history of the Earth, traces of their vital activity were found in the deposits of the Precambrian, that is, about a billion years ago. Currently, about 5000 species are known.
The most common among shotguns are bacteria , and are currently the most common microorganisms in the biosphere. Their sizes range from tenths to two or three micrometers.
Bacteria are ubiquitous, but most of all in soils - hundreds of millions per gram of soil, and in chernozems more than two billion.
Soil microflora is very diverse. Here, bacteria perform various functions and are divided into the following physiological groups: decay bacteria, nitrifying, nitrogen-fixing, sulfur bacteria, etc. Among them there are aerobic and anaerobic forms.
As a result of soil erosion, bacteria enter water bodies. In the coastal part, there are up to 300 thousand of them per 1 ml, with distance from the coast and with depth, their number decreases to 100–200 individuals per 1 ml.
There are much fewer bacteria in the atmospheric air.
Bacteria are widespread in the lithosphere below the soil horizon. Under the soil layer, they are only an order of magnitude smaller than in the soil. Bacteria spread hundreds of meters deep earth's crust and even found at a depth of two or more thousand meters.
blue green algae similar in structure to bacterial cells, are photosynthetic autotrophs. They live mainly in the surface layer of freshwater reservoirs, although there are also in the seas. The products of their metabolism are nitrogenous compounds that promote the development of other planktonic algae, which under certain conditions can lead to "blooming" of water and its pollution, including in plumbing systems.
eukaryotes These are all other organisms on Earth. The most common among them are plants, of which there are about 300 thousand species.
Plants they are practically the only organisms that create organic matter due to physical (non-living) resources solar insolation and chemical elements extracted from soils (complex biogenic elements). Everyone else eats ready-made organic food. Therefore, plants, as it were, create, produce food for the rest of the animal world, that is, they are producers.
All unicellular and multicellular forms of plants, as a rule, have autotrophic nutrition due to the processes of photosynthesis.
Seaweed This is a large group of plants living in the water, where they can either swim freely or attach themselves to the substrate. Algae are the first photosynthetic organisms on Earth, to which we owe the appearance of oxygen in its atmosphere. In addition, they are able to absorb nitrogen, sulfur, phosphorus, potassium and other components directly from the water, and not from the soil.
The rest, more highly organized plants land dwellers. They receive nutrients from the soil through the root system, which are transported through the stem to the leaves, where photosynthesis begins. Lichens, mosses, ferns, gymnosperms and angiosperms (flowering) are one of the most important elements of the geographical landscape, dominated there are more than 250,000 flowering species here. Land vegetation is the main generator of oxygen entering the atmosphere, and its thoughtless destruction will not only leave animals and humans without food, but also without oxygen.
Lower soil fungi play a major role in soil formation processes.
Animals represented by a wide variety of shapes and sizes, there are more than 1.7 million species. The entire animal kingdom is heterotrophic organisms, consumers.
The largest number of species and the largest number of individuals in arthropods. There are so many insects, for example, that there are more than 200 million of them for each person. In second place in terms of the number of species is the class shellfish, but their numbers are much smaller than insects. In third place in terms of the number of species are vertebrates, among which mammals occupy about a tenth, and half of all species account for fish.
Means, most of species of vertebrates was formed in water conditions, and insects are purely land animals.
Insects developed on land in close connection with flowering plants, being their pollinators. These plants appeared later than other species, but more than half of the species of all plants are flowering. Speciation in these two classes of organisms was and is now in close relationship.
If we compare the number of species land organisms and water, then this ratio will be approximately the same for both plants and animals the number of species on land 92-93%, in water 7-8%, which means that the release of organisms on land gave a powerful impetus to the evolutionary process in the direction of increasing species diversity, which leads to an increase in the stability of natural communities of organisms and ecosystems as a whole.
1.4. About habitat and environmental factors
The habitat of an organism is the totality of the abiotic and biotic levels of its life. The properties of the environment are constantly changing and any creature, in order to survive, adapts to these changes.
The impact of the environment is perceived by organisms through environmental factors called environmental.
Environmental factors These are certain conditions and elements of the environment that have a specific effect on the body. They are divided into abiotic, biotic and anthropogenic (Fig. 1.3).
Rice. 1.3. Classification of environmental factors
Abiotic factors called the whole set of factors of the inorganic environment that affect the life and distribution of animals and plants. Among them are physical, chemical and edaphic. It seems to us that the ecological role of natural geophysical fields should not be underestimated.
Physical factors these are those whose source is a physical state or phenomenon (mechanical, wave, etc.). For example, the temperature - if it is high, there will be a burn, if it is very low - frostbite. Other factors can also affect the effect of temperature: in water - current, on land - wind and humidity, etc.
Chemical Factors These are those that come from the chemical composition of the environment. For example, the salinity of water, if it is high, life in the reservoir may be completely absent (Dead Sea), but at the same time, in fresh water most marine organisms cannot live. The life of animals on land and in water depends on the adequacy of the oxygen content, etc.
Edaphic factors, i.e. soil, this is a combination of chemical, physical and mechanical properties of soils and rocks that affect both the organisms living in them, i.e., for which they are the habitat, and the root system of plants. The effects of chemical components (biogenic elements), temperature, humidity, soil structure, humus content, etc., on the growth and development of plants are well known.
Natural geophysical fields have a global ecological impact on the biota of the Earth and humans. The ecological significance of, for example, the magnetic, electromagnetic, radioactive and other fields of the Earth is well known.
Geophysical fields are also physical factors, but they are of a lithospheric nature, moreover, it can be reasonably assumed that edaphic factors are predominantly of a lithospheric nature, since the environment for their occurrence and action is soil, which is formed from rocks of the surface part of the lithosphere, therefore we combined them into one group (see Fig. 1.3).
However, not only abiotic factors affect organisms. Organisms form communities where they have to fight for food resources, for the possession of certain pastures or hunting territory, i.e., to compete with each other both at the intraspecific and, especially, at the interspecific level. These are already living nature factors, or biotic factors.
Biotic factors the totality of the influences of the life activity of some organisms on the life activity of others, as well as on the non-living environment (Khrustalev et al., 1996). In the latter case, we are talking about the ability of the organisms themselves to a certain extent influence the living conditions. For example, in a forest, under the influence of vegetation cover, a special microclimate, or microenvironment, where, in comparison with open habitat, its own temperature and humidity regime is created: in winter it is several degrees warmer, in summer it is cooler and wetter. A special microenvironment is also created in tree hollows, burrows, caves, etc.
Of particular note are the conditions of the microenvironment under the snow cover, which already has a purely abiotic nature. As a result of the warming effect of snow, which is most effective when it is at least 50–70 cm thick, small rodent animals live in its base, approximately in a 5 cm layer, in winter, since the temperature conditions for them are favorable here (from 0 to minus 2 С). Thanks to the same effect, seedlings of winter cereals - rye, wheat - remain under the snow. Large animals also hide in the snow from severe frosts - deer, elk, wolves, foxes, hares, etc., lying down in the snow to rest.
Intraspecific interactions between individuals of the same species are made up of group and mass effects and intraspecific competition. Group and mass effects - terms proposed by Grasset (1944), denote the association of animals of the same species in groups of two or more individuals and the effect caused by overpopulation of the environment. Currently, these effects are most commonly referred to as demographic factors. They characterize the dynamics of the number and density of groups of organisms at the population level, which is based on intraspecific competition, which is fundamentally different from interspecies. It manifests itself mainly in the territorial behavior of animals that protect their nesting sites and a known area in the area. So do many birds and fish.
Interspecies relationships much more diverse (see Fig. 1.3). Two species living side by side may not influence each other at all, they may influence both favorably and unfavorably. Possible types of combinations and reflect different types of relationships:
neutralism both types are independent and have no effect on each other;
competition each of the species has an adverse effect on the other;
mutualism species cannot exist without each other;
proto-operation(commonwealth) both species form a community, but can exist separately, although the community benefits both of them;
commensalism one species, the commensal, benefits from cohabitation, and the other species the owner has no benefit (mutual tolerance);
amensalism one species, amensal, experiences inhibition of growth and reproduction from another;
predation The predatory species feeds on its prey.
Interspecific relations underlie the existence of biotic communities (biocenoses).
Anthropogenic factors factors generated by man and affecting the environment (pollution, soil erosion, deforestation, etc.) are considered in applied ecology (see "Part II" of this textbook).
Among the abiotic factors, one often singles out climatic(temperature, air humidity, wind, etc.) and hydrographic factors of the aquatic environment (water, flow, salinity, etc.).
Most factors, qualitatively and quantitatively, change over time. For example, climatic during the day, season, by year (temperature, illumination, etc.).
Factors that change regularly over time are called periodic. These include not only climatic, but also some hydrographic - ebbs and flows, some ocean currents. Factors that arise unexpectedly (volcanic eruption, predator attack, etc.) are called non-periodic.
The division of factors into periodic and non-periodic (Monchadsky, 1958) is of great importance in studying the adaptability of organisms to living conditions.
1.5. On adaptations of organisms to the environment
Adaptation (lat. adaptation) adaptation of organisms to the environment. This process covers the structure and functions of organisms (individuals, species, populations) and their organs. Adaptation always develops under the influence of three main factors variation, heredity and natural selection(as well as artificial, carried out by man).
The main adaptations of organisms to environmental factors are hereditarily determined. They were formed on the historical and evolutionary path of the biota and changed along with the variability of environmental factors. Organisms are adapted to constantly acting periodic factors, but among them it is important to distinguish between primary and secondary.
Primary these are the factors that existed on Earth even before the emergence of life: temperature, illumination, tides, ebbs, etc. The adaptation of organisms to these factors is the most ancient and most perfect.
Secondary periodic factors are the result of changes in the primary ones: air humidity, depending on temperature; plant food, depending on the cyclicity in the development of plants; a number of biotic factors of intraspecific influence, etc. They arose later than the primary ones, and adaptation to them is not always clearly expressed.
Under normal conditions, only periodic factors should act in the habitat, non-periodic ones should be absent.
The source of adaptation is genetic changes in the body mutations arising both under the influence of natural factors at the historical and evolutionary stage, and as a result of artificial influence on the body. Mutations are diverse and their accumulation can even lead to disintegration phenomena, but thanks to selection mutations and their combination acquire the significance of “the leading creative factor in the adaptive organization of living forms” (TSB, 1970, vol. 1).
On the historical-evolutionary path of development, abiotic and biotic factors in combination act on organisms. Both successful adaptations of organisms to this complex of factors are known, as well as "unsuccessful", i.e., instead of adaptation, the species dies out.
An excellent example of successful adaptation is the evolution of the horse over a period of about 60 million years from a short ancestor to a modern and beautiful swift animal with a height of up to 1.6 m at the withers. An opposite example of this is the relatively recent (tens of thousands of years ago) extinction of mammoths. The highly arid, subarctic climate of the last glaciation led to the disappearance of the vegetation that these animals fed on, which, by the way, are well adapted to low temperatures (Velichko, 1970). In addition, opinions are expressed that primitive man was also “guilty” of the disappearance of the mammoth, who also had to survive: he used mammoth meat as food, and the skin saved him from the cold.
In the mammoth example above, the lack of plant food initially limited the number of mammoths, and its disappearance led to their death. Plant foods acted here as a limiting factor. These factors play essential role in the survival and adaptation of organisms.
1.6. Limiting environmental factors
For the first time, the German agricultural chemist J. Liebig pointed out the importance of limiting factors in the middle of the 19th century. He installed law of the minimum: yield (production) depends on the factor that is at a minimum. If in the soil useful components as a whole represent a balanced system and only some substance, for example, phosphorus, is contained in quantities close to a minimum, then this can reduce the yield. But it turned out that even the same minerals, which are very useful when they are optimally contained in the soil, reduce the yield if they are in excess. This means that the factors can be limiting, being at the maximum.
In this way, limiting environmental factors one should name such factors that limit the development of organisms due to their lack or excess compared to the need (optimal content). They are sometimes called limiting factors.
As for the law of the minimum by J. Liebig, it has a limited effect and only at the level of chemicals. R. Mitcherlich showed that the yield depends on the combined action of all factors of plant life, including temperature, humidity, light, etc.
Differences in cumulative and isolated actions are related to other factors. For example, on the one hand, the effect of negative temperatures is enhanced by wind and high air humidity, but on the other hand, high humidity weakens the effect of high temperatures, etc. But despite the mutual influence of factors, they still cannot replace each other, which is found reflection in the law of independence of factors by V. R. Williams: the conditions of life are equivalent, none of the factors of life can be replaced by another. For example, the action of humidity (water) cannot be replaced by the action carbon dioxide or sunlight etc.
Most fully and in the most general form, the complexity of the influence of environmental factors on the body reflects W. Shelford's law of tolerance: the absence or impossibility of prosperity is determined by a deficiency (in a qualitative or quantitative sense) or, conversely, an excess of any of a number of factors, the level of which may be close to the limits tolerated by a given organism. These two limits are called outside tolerance.
Regarding the action of one factor, this law can be illustrated as follows: a certain organism is able to exist at a temperature from minus 5 to plus 25 0 C, i.e. range of tolerance lies within these temperatures. Organisms whose life requires conditions limited by a narrow range of tolerance in terms of temperature are called stenothermal(“wall” narrow), and able to live in a wide temperature range eurythermal("evry" wide) (Fig. 1.4).
Rice. 1.4. Comparison of relative tolerance limits of stenothermal and
eurythermal organisms (according to F. Ruttner, 1953)
Other limiting factors act like temperature, and organisms, in relation to the nature of their influence, are called, respectively, stenobionts and eurybionts. For example, they say that an organism is stenobiontic in relation to humidity or eurybiontic in relation to climatic factors, etc. Organisms that are eurybiontic in relation to the main climatic factors are the most widespread on Earth.
The range of tolerance of an organism does not remain constant; for example, it narrows if any of the factors is close to any limit or during reproduction of the organism, when many factors become limiting. This means that the nature of the action of environmental factors under certain conditions may change, i.e., it may or may not be limiting. At the same time, we must not forget that organisms themselves are able to reduce the limiting effect of factors by creating, for example, a certain microclimate (microenvironment). Here there is a kind factor compensation, which is most effective at the community level, less often at the species level.
This compensation of factors usually creates conditions for physiological acclimatization eurybiote species, which has a wide distribution, which, acclimatizing in this particular place, creates a kind of population, which is called ecotype, the tolerance limits of which correspond to local conditions. With deeper adaptation processes, there may also appear here genetic races.
So in natural conditions organisms depend on the state of critical physical factors, on the content of necessary substances and from tolerance range organisms themselves to these and other components of the environment.
test questions
1. What are the levels of biological organization of life? Which of them are objects of study of ecology?
2. What is biogeocenosis and ecosystem?
3. How are organisms divided according to the nature of the food source? By ecological functions in biotic communities?
4. What is a living organism and how does it differ from inanimate nature?
5. What is the mechanism of adaptation during the interaction of the organism as an integral system with the environment?
6. What is plant respiration and photosynthesis? What is the significance of the metabolic processes of autotrophs for the biota of the Earth?
7. What is the essence of the biogenetic law?
8. What are the features of the modern classification of organisms?
9. What is the habitat of an organism? Concepts about ecological factors.
10. What is the name of the set of factors of the inorganic environment? Give the name and define these factors.
11. What is the name of the totality of factors of the living organic environment? Give the name and give a definition of the influence of the vital activity of some organisms on the vital activity of others at the intraspecific and interspecific levels.
12. What is the essence of adaptations? What is the significance of periodic and non-periodic factors in adaptation processes?.
13. What are the environmental factors that limit the development of an organism called? Laws of the minimum by J. Liebig and tolerance by W. Shelford.
14. What is the essence of the isolated and cumulative effect of environmental factors? The law of V. R. Williams.
15. What is meant by the tolerance range of an organism and how are they subdivided depending on the size of this range?
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Lev Dmitrievich Peredelsky- a prominent figure in the field of local history.
L.D. Peredelsky was born on October 27, 1922 in Karachev. In 1940 he graduated from the Karachev Pedagogical College and was appointed director of a rural school. In the same year he was drafted into the Red Army. He went through the entire war in the air defense forces, was a participant in the battle for Moscow, was awarded a military order and medals. After the war, he graduated from the Moscow Pedagogical Institute with a degree in History. He worked as an inspector of the Karachevsky RONO, director of rural schools, and since 1959 - director of the secondary school named after. M.A. Gorky in the city of Karachev. "Excellent student public education”, “Honored teacher of the RSFSR”.
Actively engaged in local history work. Collected and systematized rich material characterizing the glorious path ancient city, heroism and self-sacrifice of the Karachevites at all stages of its more than 850-year history.
The book "Karachev" went through two editions (1969,1995). Lev Dmitrievich is an honorary citizen of the city of Karachev.
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