Everything for summer residents and gardeners, tips and tricks. Morphological and ecological features in the population

Diatoms live everywhere. Many of them prefer reservoirs of a certain type, with the same physico-chemical regime; others live in very diverse bodies of water. Diatoms settle in raised bogs and moss pillows, on stones and rocks, in soils and on their surface, on snow and ice. Aquatic and out-of-water habitats are not the same both in species composition of diatoms and in their number. The number of species inhabiting out-of-water biotopes is small, and all of them are among the most widespread representatives of the department. Only soil communities are richer in terms of species. On snow and ice, diatoms can develop in mass, and then they turn them brown.

The aquatic environment is the main and primary habitat of diatoms; here they arose and went through a long path of evolution. They conquered all types of modern reservoirs and take part in the formation of various phytocenoses, prevailing qualitatively and quantitatively over other microscopic algae. They live in oceans, seas, brackish, salty and various types of fresh water bodies: stagnant - lakes, ponds, swamps, rice fields, etc. etc. - and flowing - rivers, streams, irrigation canals, etc., up to hot springs with temperatures above +50 ° C. In reservoirs, diatoms are included in various groups, the main ones being plankton and benthos.

Marine plankton is divided into coastal - neritic, living in the coastal strip at a depth of about 200 m, and remote from the coast - pelagic, inhabiting the open part of the sea. The neritic plankton is abundant and diverse in terms of species. Pelagic (or oceanic) plankton is poorer both in composition and quantity. Many neritic species live in the pelagic, and oceanic species are only occasionally found in neritic plankton: they are usually tender and cannot survive long in the coastal strip due to the damaging effects of the surf.

Marine planktonic species belong mainly to the group of centric diatoms, although some pennate forms are also mixed with them. In the plankton of freshwater reservoirs, on the contrary, pennate diatoms predominate. In neritic plankton, benthic species are often found raised by water from the bottom, some of them usually quickly sink to the bottom again, while others can remain in the water column for a long time (Table 13).

Benthos in a broad sense includes diatoms that live directly on the bottom and grow on various substrates rising above the bottom, including mobile ones (buoys, ships, animals, etc.). The life of these diatoms is necessarily connected with the substrate - they either attach to it or move along its surface. Benthic diatoms usually live at a depth of no more than 50 m. In marine and fresh water bodies, they are very abundant and systematically diverse (Table 14).

The fouling cenoses are the most diverse in species composition and number of diatoms. They consist of colonial and solitary forms. Representatives of the genera Licmophora, Grammatophora, Achnanthes, Mastogloia, Cocconeis, Synedra are common in the seas; in fresh water bodies - Gomphonema, Cymbella, Tabellaria, Diatoma, Rhopalodia, Cocconeis, etc. Plant growth is especially significant and diverse. The fouling of animals has not yet been studied enough. In particular, the case of mass fouling of the skin of Antarctic whales by diatoms Cocconeis ceticola is very interesting. Known diatoms living on cyclops, tintinids and some other animals.

The number of diatoms living at the bottom of water bodies depends on the nature of the soil and the degree of its illumination. On well-lit muddy ground they are numerous, and on sandy or moving ground they are much less. As a rule, benthic diatoms are solitary mobile forms that are able to move towards the light and thus get to the surface when silting. In the seas, these are species of the genera Diploneis, Amphora, Nitzschia, Surirella, Campylodiscus; in fresh waters there are also Pinnularia, Navicula, Gyrosigma.

The species composition of diatoms in water bodies is determined by a complex of physicochemical factors, of which water salinity is of great importance in the first place. In relation to salinity, all diatoms are divided into marine, brackish and freshwater. Their reaction to the content of common salt NaCl in water is especially clearly manifested, which makes it possible to distinguish three groups of species in them. The first is euhalobes, for the development of which the presence of chlorides is necessary. These include typically marine inhabitants (polyhalobes) and representatives of brackish waters (mesohalobes) living in inland seas and desalinated sea bays. The second group includes oligohalobes - inhabitants of fresh waters with a salinity of not more than 5 ° / ov. Among them, halophiles are distinguished, on which a slight increase in the content of NaCl in water has a stimulating effect (Cuclotella meneghiniana, Synedra pulchella, Bacillaria paradoxa, etc.), and indifferent - typical representatives of fresh water bodies, but capable of tolerating a slight presence of NaCl in water, although their development is suppressed in this case (Asterionella gracillima, Fragilaria pinnata and many species of the genera Cyclotella, Gomphonema, Cymatopleura, Surirella). The third group is real freshwater species, on which even a slight presence of NaCl in water has a detrimental effect (species of the genera Eunotia, Pinnularia, Cymbella, Frustulia). They are called halophobes.

There are quite a lot of such indicators of salinity, confined to certain salinity values, among diatoms, and their list is constantly being replenished. Many diatoms are so sensitive to the content of NaCl in the water that they cannot withstand even a slight change in salinity - these are the so-called stenohaline (narrow-salt) species, to which typical marine life belongs. However, there are species whose degree of sensitivity to NaCl is not so high, and they are able to exist in a wide range of changes in water salinity, from almost fresh to marine, these are euryhaline (wide-salt) species; they live in water bodies where the NaCl content fluctuates considerably.

An equally important environmental factor in the development of diatoms is temperature. In general, these algae vegetate in a wide temperature range - from 0 to +50 ° C, but still they are sensitive to temperature changes - this is reflected in seasonal dynamics and development peaks. True, in this respect, not all diatoms are the same. There are eurythermal species that can tolerate significant temperature fluctuations, and stenothermic species that live within narrow temperature limits. For the development of most diatoms, the optimum temperature is from +10 to +20 °C, but, in addition to them, there are warm-water species, the development of which is optimal at high temperatures, and cold-water species that prefer low temperatures. An intermediate position is occupied by moderately cold-water and moderately warm-water species.

The degree of illumination and the quality of light also have a significant impact on the development of diatoms in water bodies and determine the patterns of their distribution over depths. In turn, illumination depends on the transparency of water, and transparency in the oceans is always higher than in fresh water.

Diatoms inhabiting both water bodies and out-of-water biotopes are confined to certain geographical zones, that is, they have a certain range. Many marine species are strictly zoned, while others are widespread and even ubiquitous. Cosmopolitans are especially common among diatoms living in fresh continental waters. On the contrary, endemic species of diatoms are also known, living only in one or several reservoirs of one region. Some water bodies, such as lakes Baikal and Tanganyika, are very rich in endemics; a significant number of them have also been found in the southern seas of the USSR. Relic species also have limited ranges, now living in some ancient fresh water bodies - Baikal, Khubsugul, Elgygytgyn, lakes of the Kola Peninsula, African lakes, etc. Relics are known in the Black, Azov and Caspian Seas, preserved from the Upper Tertiary seas of the Black Sea basin.

The patterns of geographic distribution of diatoms are most clearly manifested in the waters of the oceans. If we accept the division of the World Ocean into geographical zones according to the temperature regime of the surface layers of water, then, as analysis shows, in two polar zones (Arctic and Antarctic), where low temperatures prevail with insignificant annual fluctuations (2-3 °), cold-loving stenothermic species diatoms. The temperate zones of both hemispheres - northern (boreal) and southern (notal) - are characterized by a wide range of temperatures, here annual fluctuations reach 15-20 ° C. These zones are characterized mainly by eurythermal, as well as moderately cold-water and moderately warm-water species of diatoms, which reach mass development in one season or another. In the tropical zone, where the surface water temperature does not fall below +15 °C, and annual temperature fluctuations are insignificant (about 2 °C on average), heat-loving stenothermic species live. Some species of diatoms can live in two adjacent zones - these are arctic-boreal and boreal-tropical species that have adapted to a wide temperature range.

The most rich in species composition and number of diatoms is the boreal zone, which is distinguished by the optimum temperature for their development (from +10 to +20 °C). Here they vegetate almost all year round, but develop especially abundantly in spring and autumn. In the Arctic and tropical zones, the vegetation of diatoms is short-term: in the Arctic seas, it is confined to a short summer period, since the autumn and spring blooms of diatoms here converge in time, in the tropical seas - to a colder winter period.

Subject: Ecological features of animals in relation to temperature.

Goals:

• Show the various adaptations of animals to temperature as an environmental factor.
• Learn to distinguish between cold-blooded and warm-blooded animals.
• Develop cognitive interests and logical thinking.
• Build a positive relationship with nature.

Equipment: map "Natural zones of the world", a multimedia projector for viewing the presentation, task cards, handouts.

During the classes

1. Organizational part.

-Hello guys! Sit down!

2. Communication of the topic and objectives of the lesson.

-In the past lessons of ecology, you have already learned what environmental factors are, how they affect living organisms, what features animals have in connection with the impact of these environmental factors. Look at the topic of our lesson. What associations do you have when you read it? What are we going to study today?

(STUDENT ANSWERS)

- You know a lot! And clearly, my friend,
What will be an important lesson for you now!

We have several tasks ahead of us! It is necessary to find out what temperature conditions are on our planet, what groups of animals are distinguished in connection with the influence of temperature, and most importantly, how animals adapt to different temperatures.

Open your notebooks and write down the date and the topic of the lesson.

III. Learning new material.

1. Teacher's story with elements of conversation.

– So what are the temperature conditions on our planet?

Mountains, deserts, savannas, forests,
Rivers, lakes, fields and seas.
How huge you are my planet!
How mysterious you are our Earth!

– Look at the map “Natural areas of the world”. From the lessons of geography, you already know what different natural areas distinguish. Think about the criteria by which they are distinguished?

(STUDENT ANSWERS)

- They are shown in different colors. The hottest territories are located near the equator - these are the tropics and subtropics.

What color is it shown on the map?

(ORANGE)

- Right. But this color in the visual arts are referred to as warm colors!

- And here are shown coldest zones – near the poles are subpolar regions. What color is used here?

(VIOLET)

- Correctly! It belongs to the group of cold colors!

- And between them lie temperate areas. They are shown to us in green.

The planet is huge!
Where it's humid, where it's hot!
Where the cold is terrible
And severe frost.
And there is no corner on a huge planet
Where someone could not survive at all!

(IN THE PROCEDURE OF READING THE POEM I DEMONSTRATE TYPES OF NATURE)

– Animals live in almost the entire temperature range that is represented on the planet. Shell amoeba are found at + 58 °C, the larvae of many Diptera can live at a temperature of about + 50 °C. The bristletails, springtails and mites living high in the mountains survive perfectly at night temperatures of about -10 ° C. Science knows a flightless mosquito - a twitch that lives on the slopes of the Himalayas. It remains active even at -16°C. The body of an animal is constantly undergoing metabolism. Its intensity depends on the body temperature of the animal. At the same time, metabolism provides the animal with energy. The temperature of the environment affects the body temperature of animals. With too much heat or too much cold, the animal dies.

2. Work with the textbook.

- Temperature, as an environmental factor, of course, affects living organisms, and depending on this, two groups of animals are distinguished: cold-blooded and warm-blooded.

(I FORM A SCHEME ON THE BOARD)

Guys, write down the diagram in your notebook.

– COLD BLOODED… WARM BLOODED

- These are complex adjectives formed by adding 2 roots: cold and blood, warm and blood.

– What do these terms mean?

(STUDENT ANSWERS)

–And as it is said in textbook nike?

- Open your textbooks. Find § 12 on page 31 4 paragraph above. Read the definition.

(STUDENT ANSWERS)

- Right. The cold-blooded group includes all invertebrates, fish, amphibians and reptiles.

- Turn the page of the textbook and find the 2nd paragraph from the bottom. Read the definition in italics. (STUDENT ANSWERS)

The group of warm-blooded animals includes only birds and mammals. (DURING THE EXPLANATION, I SUPPLEMENT THE PREVIOUSLY FORMED SCHEME). Write this down in your notebook.

- Pay attention to the diagram. Why do I use blue for cold-blooded animals and red for warm-blooded animals?

(STUDENT ANSWERS)

– That's right, today in the lesson we will use blue for low temperatures and cold-blooded animals, and red for high temperatures and warm-blooded animals.

Take pencils and highlight the terms in your notebook.

- Name the animals that we can classify as warm-blooded.

What about animals that can be classified as cold-blooded?

3. Work in small groups.

- Guys, I suggest uniting in groups of 5 people. To do this, the guys from the third desks will have to change seats. You have packages with tasks on the tables. You need to determine which group these animals belong to. There are 5 cards, like you, and there are also 5 circles near the animal. Everyone fills in 1 circle and passes it on to the next. Write your names on the package and remember the serial number. Everyone paints only a circle with its serial number. We use colors for warm-blooded - red, and cold-blooded - blue. Based on the results, you will make the only right decision. In addition, you need to think about where this animal lives. The work needs to be done quickly! I give you a minute to discuss! Get started! Time has gone!

(INCLUDING MUSIC AND NATURE VIDEOS)

- The group that finishes the work, raise your hand.

(DISCUSSION OF THE RESULTS OF THE WORK)

“Ah, now let’s place our animals on the map.

(GUYS NAME THE ANIMAL, SAY TO WHICH GROUP IT IS RELATED TO, CALL THE PLACE OF ITS HABITATION AND POSITION THEM ON THE MAP).

Look at the map now guys! Both warm-blooded and cold-blooded live in zones with low temperatures. And in areas with high temperatures, representatives of these two groups also live.

4. Working with a multimedia projector.

How do animals adapt to life in different conditions?

STEP 1.

An image of a lizard appears on the screen.

What kind of animal is shown here? To which group does it belong?

(STUDENT ANSWERS)

- The desert iguana is painted in darker colors in the morning, when it is not yet hot, and as the sun heats up, it turns pale. Why do you think this is happening?

(DARK COLOR IS HELPING TO ABSORB EXTERNAL HEAT, AND LIGHT TONE REFLECTS SOLAR RADIATION.)

– Thus, by changing color during the day, the turtle has adapted to tolerate changes in temperature. The desert tortoise uses the same device.

An inscription appears on the screen: Change in body color.

STEP 2.

An image of a frog and a crocodile appears on the screen.

Who is on the screen? What group do these animals belong to?

(STUDENT ANSWERS)

- Where do these animals live? Since these animals are cold-blooded, they also have to adapt to temperature changes during the day. They do this by changing their physical activity. As the temperature drops, cold-blooded animals become more active.

(STUDENT ANSWERS)

An inscription appears on the screen: Change in motor activity during temperature fluctuations during the day.

STEP 3.

An image of a turtle appears on the screen.

-This is a desert tortoise. With a strong increase in air temperature, the separation of saliva sharply increases in her. Flowing out of the mouth, it wets the lower part of the head, neck and limbs - this is how the turtle cools. Many animals, in order to avoid overheating, burrow into the sand, or vice versa, try to find some kind of hill and climb it, because. the sand gets very hot. Thus, behavioral maneuvers come to the rescue here.

The display reads: Behavioral Maneuvers.

STEP 4.

An image of a grape snail and a bear appears on the screen.

– Look at this image, what can unite such different animals? And the whole point is to avoid unfavorable temperatures for them, they fall into hibernation and stupor. In addition to mollusks, fish and amphibians can fall into a stupor. And what animals living in our area are able to hibernate in winter? ( Hedgehogs, shrews, badgers, ground squirrels, etc.)

On the screen appears the inscription: Hibernation, torpor due to seasonal changes in temperature.

STEP 5.

An image of a group of penguins appears on the screen.

- Look at the image. These are penguins.

(STUDENT ANSWERS)

- Now I need 10 of the most daring helpers. Please, guys, come to the blackboard!

(A GROUP OF CHILDREN COMES OUT, I GIVE THEM HATS AND WE ALL TRY TO DEMONSTRATE THE MOVEMENTS OF THE PENGUINS).

- We will now depict with you the behavior in a group of penguins.

The guys stand close to each other and form an outer and inner circle.

This is how penguins are built. So they stand for some time, shifting from foot to foot. Then they move in a circle, stepping left or right. Later, those penguins that were inside the group go to the outer circle, and those are inside the group. And again they stand and mark time, and again after a certain time they change places. That's how they get warm.

- What conclusion can be drawn, what kind of device is this?

(STUDENT ANSWERS)

An inscription appears on the screen: Formation of groups of animals when the temperature drops.

STEP 6.

An image of a polar bear and a brown bear appears on the screen, and immediately the inscription: The hotter the climate, the lower the body weight.

– Here you see representatives of the same class and even the same detachment, but they live in different conditions. This, of course, is reflected in their appearance. These features were formulated as follows: The hotter the climate, the less body weight! In ecology, this is called the Bergmann rule, after the name of the scientist who formulated it.

STEP 7.

An image of foxes and an arctic fox appears on the screen, and immediately an inscription appears: The colder the climate, the shorter the protruding parts of the body (ears, tail, paws). Allen's rule.

There is a rule here too, but which one? Let's imagine ourselves for a moment as research scientists and try to formulate this rule. Shown here are the Fennec fox, the common fox and the arctic fox. They live in various climatic conditions. I CALL THE TEMPERATURE LIMITS,

- What can be said about the distinctive features of the appearance of these animals?

(STUDENT ANSWERS)

- Guys, does the Bergman rule apply in this case?

STEP 8.

An image of a bird, a bear, a walrus appears on the screen.

-Maybe someone guessed why these animals are united here? Look at the background. it is blue, which means we are considering adaptation to low temperatures here.

(STUDENT ANSWERS)

On the screen appears the inscription: The presence of a protective cover.

STEP 9.

An image of a dog appears on the screen.

-Guys, what usually happens to you when you run cross country?

(STUDENT ANSWERS)

- That's right, you sweat, and dogs, due to their physiological characteristics, do not have sweat glands. How do they get out? What adaptations do they have to endure high temperatures?

(TONGUE OUT)

The display shows: Evaporation increase with temperature increase.

STEP 10.

- So, having considered the adaptations of animals to various temperature conditions, we formulated the following conclusions:

All abstracts are displayed on the screen.

- So we coped with all the tasks set at the beginning of the lesson.

There were many tasks
But everything is settled!
But how much more do you have ahead of you?
So much to know!!!
What do you know - do not be lazy.
Always strive to know the world!

IV. Consolidation of new material.

– And now let's check the results of our joint work!

-Remind me what color we used today to designate warm-blooded animals and cold-blooded animals.

- Look at the screen. Determine who is superfluous here and why?

- You have cards with the names of animals on your tables, underline the warm-blooded ones in red, and the cold-blooded ones in blue.

V. Summary of the lesson.

(PLANET LIGHTS AND MUSIC PLAYS)

How beautiful is our world!
Forests and gardens, a brook murmurs,
The waters of a quiet river!
Silent villages, roads, fields,
And sleeps in the cradle of the Universe Earth.
Do not be, my friend, you are cruel to the planet,
Take care of any flower and leaf,
Protect her, help her with labor ...
Earth among the stars is our only home.

So guys, our lesson is coming to an end. Look again at the map and remember that the temperature regime of our planet is very diverse, look at the diagram in your notebook and remember which animals we classify as warm-blooded and cold-blooded, and finally, remember what various adaptations animals have in order to endure exposure various temperatures.

VI. Homework:§12.

Grading.

_________________________ worked well in class today.

Ecological characteristic

An ecological characteristic is the attitude of an organism to a complex of environmental factors, or environmental conditions. Ecological factors themselves can be defined as dynamic elements of the natural or environmental environment that affect the activity of living organisms, their vital activity. In other words, without the presence of any environmental factor, the normal life of the organism, up to and including death, is impossible; so that environmental factors are the conditions of life of plants, animals and humans.
The set of environmental factors for plants includes the following groups: cosmic (the Sun was discussed at the beginning of the book), abiotic and biotic factors. Abiotic factors include climatic (light, heat, moisture, air), soil, orographic (determined by relief). Biotic factors are associated with the impact of living organisms on each other: the influence of human activities on plants (mowing in meadows, logging, treatment of crops with drugs, etc.), animals on plants (on pastures, the influence of pollinating insects, plant pests, etc.) . It is believed that all environmental factors are equivalent for organisms, including plants. This is fundamentally so, since each factor will determine the possibility of life. If we take into account the time during which the organism can survive without a single factor, then a certain difference appears in the significance of the factors. So, without light, the plant can be but several hours a day (at night), but without heat (when frozen) - only a few minutes or even seconds (with a strong drop in temperature); some plants endure water deficiency for days (and in deserts - almost during the entire growing season), while others - only for a few hours. Estimates of the significance of factors also differ in the animal world.

For example, without air, they can live only minutes or even seconds, without enough heat - hours, and sometimes only seconds (but some animals in hibernation spend several months, having adapted to a special thermal regime), without water and food - several days. In general, a complex of environmental factors is vital for organisms, in particular, cosmic, all climatic and soil factors are extremely important for plants.
It should be noted the indispensability of environmental factors. For example, an additional supply of water cannot compensate for the deficiency of one or another nutrient element in the soil or lack of heat, etc. At the same time, some improvement in plant growth conditions is still observed if, with a deficiency of some factors or one factor, others are provided to the plant in enough full, without deficit. And yet, a complete replacement of one environmental factor with another cannot be achieved.
The variety of necessary levels of environmental factors, their combination, deficit and surplus are reflected in one of the main, generalizing all such indicators, the law of ecology, formulated by the American ecologist W. Shelford in the works of 1911-1915. This law is called Shelford's law, or the law of tolerance. Its essence is as follows: the absence or impossibility of the prosperity of any organism is determined by the lack or excess in qualitative and quantitative sense (indicators) of any of the factors, the level of which may be close to the limits of tolerance, that is, to the limits tolerated by this organism (from lat. Shegapye - "patience").
The adaptability of organisms to certain conditions in which their life cycle is possible is expressed by the difference between the minimum and maximum indicators for each environmental factor. Such a range, or zone, between the levels of factors acceptable for life is called the limits of tolerance, that is, the boundaries of the conditions in which the organism goes through the entire development cycle and can survive. For each species of organisms (plants, animals, humans), the ranges are individual and differ from the ranges of other organisms (although in some species such zones may be similar, in some cases almost identical).
Note that not only representatives of different species have individual ecological characteristics, but also forms of organisms within the same species, for example, different varieties of a particular plant species (varietal agricultural techniques of cultivation are also based on these differences). This can also be illustrated by the example of people with different levels of health and fitness: some can tolerate factor deficits and overloads that are very difficult for ordinary people to tolerate. Everyone can easily imagine the difference between the limits of tolerance of a weak, sickly person and a trained, hardened athlete or astronaut, tester. After earthquakes, weak women, and sometimes old men, were found under the rubble as survivors after many days. But these are the individual characteristics of people and the specifics of circumstances.
And more explanations to the basic law: any of the factors approaching the limits of tolerance in terms of level (it does not matter - to the ecological maximum or minimum), limits the conditions for the normal development of the organism and is called the limiting factor. The quantitative indicator of the factor at which the organism develops normally and "thrives" is called the optimal level (from the Latin oritt - "the best").
It is very important that there is a range of indicators according to the optimum for each environmental factor, and the wider it is for a particular organism (plant or animal), the more adapted the organism to changing conditions. So, the optimum -r is not a certain point on the scale of indicators, but a zone, the optimal conditions under which nature provides the body with the opportunity to develop normally. In the absence of a range of optimal conditions, living organisms would die at the slightest deviation of conditions from the optimal level.
The optimal levels of each factor for the same organism may vary ("optimal bias"). This means a change in the organism's requirements for conditions both in different periods of development (in different growth phases) and depending on competitive relationships with other organisms, but especially on the level of other environmental factors: with a favorable combination of factors (when each of them is close to optimal level, non-deficient) all of them are used by the body most efficiently and economically. This is very important, in particular, for the practice of plant cultivation: by applying agronomic methods, it is possible to achieve the most rational use of environmental conditions by plants in crops, which always leads to an increase in yield. This is the ecological essence of agronomy: the plant must be provided with optimal levels of all environmental factors throughout the entire period of development of this plant. It is clear that in order to achieve the best result, it is absolutely necessary to know the ecological characteristics of cultivated plants and their changes during the entire life cycle of the plant.
I also emphasize that the quality of a factor (its qualitative characteristic) is determined not only by the internal essence and characteristics of this factor (the composition of light, air, water, soil), but also by the uniformity of its supply: plants require no deficiency throughout the entire period of active vegetation. In this regard, fluctuations in weather conditions (periods with the return of cold weather, periods with no precipitation, etc.) and uneven supply of plants with nutrients (if scientific recommendations on the correct use of fertilizers are not followed) have a significant negative effect on plants.
To get a visual idea of ​​the law of tolerance, it is convenient to consider a diagram that shows the effect of this law for different organisms.
The scheme shows in the form of sectors the main environmental factors for plants. A short explanation is required here. Due to the presence of mineral compounds in the soil, plants are nourished. Therefore, each of the elements necessary for plants (nitrogen, phosphorus, potassium, calcium, sulfur, and a number of others) is an environmental factor, as well as each physical property of the soil (moisture content, air content, bulk density, etc.), since each of these factors affects the conditions of plant life in the soil. So, all the chemical and physical properties of the soil are ecological soil factors.
The difference between plants and animals (II) and humans (III) is obvious: these organisms do not receive food from the soil and air, like plants, but use plants and animals (organic substances) as food.
Here it is appropriate to give two more ecological terms: ecological niche and food chains. An ecological niche is understood as a complex of environmental factors between the minimum and maximum indicators for a particular organism. In other words, more generally, it is a set of characteristics that shows the position of a species in an ecosystem. It is within its individual ecological niche that any species develops, multiplies and lives.

Ecology is the science that studies the life of various organisms in their natural habitat, or environment. The environment is everything living and non-living around us. Your own environment is everything you see and much of what you don't see around you (such as what you breathe). It is basically unchanged, but its individual details are constantly changing. Your body is also, in a sense, the environment for many thousands of tiny creatures - bacteria that help you digest food. Your body is their natural habitat.

General characteristics of ecology as a section of general biology and complex science

At the present stage of development of civilization, ecology is a complex complex discipline based on various areas of human knowledge: biology, chemistry, physics, sociology, environmental protection, various types of technology, etc.

For the first time, the concept of "ecology" was introduced into science by the German biologist E. Haeckel (1886). This concept was originally purely biological. Literally translated, "ecology" means "the science of housing" and meant the study of the relationship between various organisms in natural conditions. At present, this concept has become very complicated and different scientists put different meanings into this concept. Let's consider some of the proposed concepts.

1. According to V. A. Radkevich: “Ecology is a science that studies the patterns of life of organisms (in any of its manifestations, at all levels of integration) in their natural habitat, taking into account the changes introduced into the environment by human activity.” This concept corresponds to biological science and cannot be recognized as fully corresponding to the field of knowledge that ecology studies.

2. According to N. F. Reimers: “Ecology (universal,“ large ”) is a scientific direction that considers a certain set of natural and partly social (for humans) phenomena and objects that is significant for the central member of the analysis (subject, living object) from the point of view view of the interests (in quotation marks or without quotation marks) of this central subject or living object. This concept is universal, but it is difficult to perceive and reproduce. It shows the diversity and complexity of environmental science at the present stage.

Currently, ecology is divided into several areas and scientific disciplines. Let's consider some of them.

1. Bioecology - a branch of biological science that studies the relationship of organisms with each other; habitat and the impact of human activities on these organisms and their habitats.

2. Population ecology (demographic ecology) - a section of ecology that studies the patterns of functioning of populations of organisms in their habitat.

3. Autecology (autoecology) - a section of ecology that studies the relationship of an organism (individual, species) with the environment.

4. Synecology - a section of ecology that studies the relationship of populations, communities and ecosystems with the environment.

5. Human ecology is a complex science that studies the general laws of the relationship between the biosphere and the anthroposystem, the influence of the natural environment (including the social one) on an individual and groups of people. This is the most complete definition of human ecology; it can be attributed both to the ecology of an individual and to the ecology of human populations, in particular, to the ecology of various ethnic groups (peoples, nationalities). Social ecology plays an important role in human ecology.

6. Social ecology is a multi-valued concept, one of which is the following: a branch of ecology that studies the interactions and relationships of human society with the natural environment, develops the scientific foundations for rational environmental management, involving the protection of nature and optimization of the human living environment.

There are also applied, industrial, chemical, oncological (carcinogenic), historical, evolutionary ecology, ecology of microorganisms, fungi, animals, plants, etc.

All of the above shows that ecology is a complex of scientific disciplines that have Nature as an object of study, taking into account the interconnection and interaction of individual components of the living world in the form of individuals, populations, individual species, the relationship of ecosystems, the role of individuals and humanity as a whole, as well as ways and means of rational nature management, measures for the protection of Nature.

Relationships

Ecology is the study of how plants and animals, including humans, live together and influence each other and their environment. Let's start with you. Consider how you are connected to the environment. What do you eat? Where do you throw waste and garbage? What plants and animals live near you. The way you impact the environment has a rebound effect on you and on everyone who lives near you. The relationships between you and them form a complex and extensive network.

Habitat

The natural environment of a group of plants and animals is called a habitat, and the group itself living in it is called a community. Turn the stone over and see if the floor above it lives. Nice little communities are always part of larger communities. So, a stone can be part of a stream if it lies on its bank, and a stream can be part of the forest in which it flows. Each large habitat is home to a variety of plants and animals. Try to find several different types of habitat around you. Look around: up, down - in all directions. But do not forget that life must be left as you found it.

The current state of environmental science

For the first time the term "ecology" was used in 1866 in the work of the German biologist E. Haeckel "General morphology of organisms". An original evolutionary biologist, physician, botanist, zoologist-morphologist, supporter and propagandist of Charles Darwin's teachings, he not only introduced a new term into scientific use, but also applied all his strength and knowledge to form a new scientific direction. The scientist believed that "ecology is the science of the relationship of organisms to the environment." Speaking at the opening of the Faculty of Philosophy of the University of Jena with a lecture “The Path of Development and the Tasks of Zoology” in 1869, E. Haeckel noted that ecology “explores the general attitude of animals to both their organic and inorganic environments, their friendly and hostile relations with others animals and plants with which they enter into direct and indirect contacts, or, in a word, all those intricate interactions that Ch. Darwin conditionally designated as the struggle for existence. Under the environment, he understood the conditions created by inorganic and organic nature. Haeckel attributed the physical and chemical features of the habitats of living organisms to inorganic conditions: climate (warmth, humidity, illumination), composition and soil, features, as well as inorganic food (minerals and chemical compounds). Under organic conditions, the scientist meant the relationship between organisms that exist within the same community or ecological niche. The name of ecological science comes from two Greek words: "eco" - house, dwelling, habitat and "logos" - word, teaching.

It should be noted that E. Haeckel and many of his followers used the term "ecology" not to describe the changing environmental conditions and the relationships between organisms and the environment that change over time, but only to fix the existing unchanged conditions and environmental phenomena. According to S. V. Klubov and L. L. Prozorov (1993), in fact, the physiological mechanism of the relationship of living organisms was studied, their relationship to the environment was singled out exclusively within the framework of physiological reactions.

Within the framework of biological science, ecology existed until the middle of the 20th century. The emphasis in it was placed on the study of living matter, the laws of its functioning, depending on environmental factors.

In the modern era, the ecological paradigm is based on the concept of ecosystems. As you know, this term was introduced into science by A. Tansley in 1935. An ecosystem is understood as a functional unity formed by a biotope, i.e. set of abiotic conditions, and the organisms inhabiting it. The ecosystem is the main object of study of general ecology. The subject of its knowledge is not only the laws of formation of the structure, functioning, development and death of ecosystems, but also the state of integrity of systems, in particular their stability, productivity, circulation of substances and energy balance.

Thus, within the framework of biological science, general ecology took shape and finally stood out as an independent science, which is based on the study of the properties of the whole, which is not reducible to a simple sum of the properties of its parts. Consequently, ecology in the biological content of this term means the science of the relationship of plant and animal organisms and the communities they form with each other and with the environment. The objects of bioecology can be genes, cells, individuals, populations of organisms, species, communities, ecosystems and the biosphere as a whole.

The formulated laws of general ecology are widely used in so-called particular ecologies. In the same way as in biology, peculiar taxonomic directions are developing in general ecology. The ecology of animals and plants, the ecology of individual representatives of the flora and fauna (algae, diatoms, certain genera of algae), the ecology of the inhabitants of the World Ocean, the ecology of communities of individual seas and water bodies, the ecology of certain parts of water bodies, the ecology of animals and plants of land, the ecology of freshwater communities of individual rivers and reservoirs (lakes and reservoirs), the ecology of the inhabitants of mountains and uplands, the ecology of communities of individual landscape units, etc.

Ecology of individuals (autoecology), ecology of populations (demecology), ecology of associations, ecology of biocenoses, and ecology of communities (synecology) are generally distinguished depending on the level of organization of the living matter of ecosystems.

When considering the levels of organization of living matter, many scientists believe that its lowest ranks - genome, cell, tissue, organ - are studied by purely biological sciences - molecular genetics, cytology, histology, physiology, and the highest ranks - organism (individual), species, population , association and biocenosis - both biology and physiology, and ecology. Only in one case, the morphology and systematics of individual individuals and the communities they compose are considered, and in the other, their relationship with each other and with the environment.

To date, the ecological direction has covered almost all existing areas of scientific knowledge. Not only the sciences of the natural profile, but also the purely humanities, when studying their objects, began to widely use environmental terminology and, most importantly, research methods. Many "ecologies" emerged (environmental geochemistry, ecological geophysics, ecological soil science, geoecology, ecological geology, physical and radiation ecology, medical ecology, and many others). In this regard, a certain structuring was carried out. So, in his works (1990-1994) N. F. Reimers made an attempt to present the structure of modern ecology.

The structure of Ecological Science looks simpler from other methodological positions. The structuring is based on the division of ecology into four major and at the same time fundamental areas: bioecology, human ecology, geoecology and applied ecology. All of these areas use almost the same methods and methodological foundations of a unified environmental science. In this case, we can talk about analytical ecology with its corresponding divisions into physical, chemical, geological, geographical, geochemical, radiation and mathematical, or systemic, ecology.

Within the framework of bioecology, two equivalent and most important areas are distinguished: endoecology and exoecology. According to N.F. Reimers (1990), endoecology includes genetic, molecular, morphological and physiological ecologies. Exoecology includes the following areas: autoecology, or the ecology of individuals and organisms as representatives of a particular species; de-ecology, or the ecology of individual groupings; population ecology, which studies behavior and relationships within a particular population (species ecology); synecology, or the ecology of organic communities; ecology of biocenoses, which considers the relationship of communities or populations of organisms that make up a biocenosis with each other and with the environment. The highest rank of the exoecological direction is the doctrine of ecosystems, the doctrine of the biosphere and global ecology. The latter covers all areas of the existence of living organisms - from the soil cover to the troposphere inclusive.

Human ecology is an independent direction of ecological research. In fact, if one strictly adheres to the rules of hierarchy, this direction should be an integral part of bioecology, in particular, as an analogue of autoecology within the framework of animal ecology. However, given the huge role that humanity plays in the life of the modern biosphere, this direction is singled out as an independent one. In human ecology, it is advisable to single out the evolutionary ecology of man, archeoecology, which considers the relationship of man with the environment since the time of primitive society, the ecology of ethnosocial groups, social ecology, ecological demography, the ecology of cultural landscapes and medical ecology.

In the middle of the XX century. in connection with the ongoing deep studies of the human environment and the organic world, scientific directions of ecological orientation arose, closely related to the geographical and geological sciences. Their goal is not to study the organisms themselves, but only their response to changing environmental conditions and to trace the reverse impact of the activities of human society and the biosphere on the environment. These studies were combined within the framework of geoecology, which was given a purely geographical direction. However, it seems appropriate to single out at least four independent areas within both geological and geographic ecologies - landscape ecology, ecological geography, ecological geology, and space (planetary) ecology. At the same time, it should be emphasized that not all scientists agree with such a division.

Within the framework of applied ecology, as its name implies, multidimensional environmental issues related to purely practical problems are considered. It includes commercial ecology, i.e., environmental research related to the extraction of certain biological resources (valuable species of animals or wood), agricultural ecology, and engineering ecology. The last branch of ecology has many aspects. The objects of study of engineering ecology are the state of urbanized systems, agglomerations of cities and towns, cultural landscapes, technological systems, the ecological state of megacities, science cities and individual cities.

The concept of system ecology arose during the intensive development of experimental and theoretical research in the field of ecology in the 20s and 30s of the XX century. These studies have shown the need for an integrated approach to the study of biocenosis and biotope. The need for such an approach was first formulated by the English geobotanist A. Tensley (1935), who introduced the term "ecosystem" into ecology. The main significance of the ecosystem approach for ecological theory lies in the mandatory presence of relationships, interdependence and cause-and-effect relationships, i.e., the unification of individual components into a functional whole.

A certain logical completeness of the concept of ecosystems is expressed by the quantitative level of their study. An outstanding role in the study of ecosystems belongs to the Austrian theoretical biologist L. Bertalanffy (1901-1972). He developed a general theory that allows using the mathematical apparatus to describe systems of various types. The basis of the ecosystem concept is the axiom of systemic integrity.

With all the completeness and depth of coverage in the classification heading of environmental studies, which includes all modern aspects of the life of human society, there is no such important link of knowledge as historical ecology. After all, when studying the current state of the ecological situation, the researcher, in order to determine the patterns of development and forecast environmental conditions on a global or regional scale, needs to compare the existing environmental situations with the state of the environment of the historical and geological past. This information is concentrated in historical ecology, which, within the framework of ecological geology, makes it possible, using geological and paleogeographic methods, to determine the physical and geographical conditions of the geological and historical past and trace their development and change up to the present era.

Starting with the studies of E. Haeckel, the terms "ecology" and "environmental science" have become widely used in scientific research. In the second half of the XX century. ecology was divided into two areas: purely biological (general and system ecology) and geological and geographical (geoecology and ecological geology).

ecological soil science

Ecological soil science arose in the 1920s. Soil scientists began to use the terms "soil ecology" and "pedoecology" in separate works. However, the essence of the terms, as well as the main direction of ecological research in soil science, have been revealed only in recent decades. G. V. Dobrovolsky and E. D. Nikitin (1990) introduced the concepts of “ecological soil science” and “ecological functions of large geospheres” into the scientific literature. The latter direction is interpreted by the authors in relation to soils and is considered as the doctrine of the ecological functions of soils. This implies the role and significance of the soil cover and soil processes in the emergence, preservation and evolution of ecosystems and the biosphere. Considering the ecological role and functions of soils, the authors consider it logical and necessary to identify and characterize the ecological functions of other shells, as well as the biosphere as a whole. This will provide an opportunity to consider the unity of the human environment and the entire existing biota, to better understand the inseparability and irreplaceability of individual components of the biosphere. Throughout the geological history of the Earth, the fates of these components have been strongly intertwined. They have penetrated each other and interact through the cycles of matter and energy, which determines their development.

Applied aspects of ecological soil science are also being developed, mainly related to the protection and control of the state of the soil cover. The authors of works in this direction seek to show the principles of conservation and creation of such soil properties that determine their high, stable and high-quality fertility that does not damage the associated components of the biosphere (G.V. Dobrovolsky, N.N. Grishina, 1985).

At present, some higher educational institutions offer special courses on "Soil Ecology" or "Ecological Soil Science". In this case, we are talking about science, which examines the patterns of functional relationships between the soil and the environment. Soil-forming processes, the processes of accumulation of plant matter and humus formation are studied from an ecological standpoint. However, soils are considered as the "center of the geosystem". The applied value of ecological soil science is reduced to the development of measures for the rational use of land resources.

flowing pond

A pond is an example of a larger habitat ideal for observing an ecosystem. It is home to a large community of various plants and animals. The pond, its communities and the inanimate nature around it form the so-called ecological system. The depths of the pond are a good environment for studying the communities of its inhabitants. Gently move the net in different parts of the pond. Write down everything that will be in the net when you pull it out. Put the most interesting finds in a jar to study them in more detail. Use any manual that describes the life of the inhabitants of the pond to determine the names of the organisms you find. And when you finish the experiments, do not forget to release the living beings back into the pond. You can buy a net or make your own. Take a piece of thick wire and bend it into a ring, and stick the ends into one of the edges of a long bamboo stick. Then sheathe the wire ring with a nylon stocking and tie it at the bottom with a knot. Today, ponds are much less common than forty years ago. Many of them have become shallow and overgrown. This adversely affected the life of the inhabitants of the ponds: only a few of them managed to survive. When the pond dries up, its last inhabitants also perish.

Make your own pond

By digging a pond, you can arrange a corner of the wild nature. This will attract many species of animals to it and will not become a burden for you. However, the pond will need to be constantly maintained in good condition. It will take a lot of time and effort to create it, but when various animals settle in it, you can study them at any time. A homemade snorkel for underwater observations will allow you to get to know the life of the inhabitants of the pond better. Carefully cut off the neck and bottom of the plastic bottle. Place a clear plastic bag at one end and secure with a rubber band. Now through this tube you can observe the life of the inhabitants of the pond. For safety, the free edge of the tube is best pasted over with adhesive tape.

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The active role of organisms in their interactions with the environment was noted above. Therefore, it is necessary to consider the ecological features of animals and plants.

Abiotic and biotic factors acting in unity on a living organism in any conditions are characterized by a certain natural manifestation in various environments of life. But each species, being a qualitatively defined state of living nature, is distinguished by its requirements. medium. At the same time, groups of species that have ecological similarities in one way or another can be distinguished.

Ecology of microorganisms. Although microbes are essentially plants, they are so peculiar in a number of their properties that they are usually distinguished into a special group of organisms, and the science that studies them - microbiology - has long been isolated into an independent biological discipline.

Bacteria are the smallest, invisible to the naked eye plants, consisting of one or more cells. Bacteria are not achromatinobionts, "primitive cytodes" in Haeckel's sense. A peculiar feature of bacteria, as relatively primitive organic beings, is the constant presence of nucleic substances in the cell.

The size of microbes ranges from 100 to 2-5 microns, while for viruses it is calculated in millimicrons (Peterson, 1953). The shape of the bacteria are divided into three main groups: rod-shaped - bacilli, spherical - cocci ("chains" - streptococci) and corkscrew-shaped - spirilla ("commas" - vibrios).

Bacteria are found in large numbers in air, water, soil, on the surface and inside organisms. The number of bacteria in different media is characterized by the following numbers: air 0.01 ind. / cm 3 water 10-20 million / cm 3 soil 100 thousand - 1 billion / cm 3

Bacteria reproduce by division. Under favorable temperature conditions and the presence of food, division can occur every 0.5 hours. As a result of such a progression of reproduction, one copy in a day gives 115,000 billion bacteria. Bacteria reproduce as fast as any other living being.

Substances produced by bacteria can be harmful (toxins) or beneficial to humans (enzymes). Bacteriology and immunology are developing problems of protecting organisms from bacteria, and a number of industries (food, leather, etc.) and agriculture use the beneficial activity of bacteria.

The role of bacteria in the cycle of substances that takes place in nature is huge. Green plants, or producers, synthesize from mineral salts (soil and water) and carbon dioxide (air, water), with the participation of solar energy, complex organic substances - proteins, fats and carbohydrates. Consumers, i.e., various herbivores and carnivores, convert these primary products into intermediate and final products. After the death of plants and animals, their corpses undergo a process of decay and fermentation with the participation of bacteria, or decomposers.

As a result, mineral salts and gases are formed again, which, during the decomposition of organisms, return to inorganic nature. Thus, bacteria are a necessary link in the general circulation of substances, making possible the existence and development of real plant and animal life on Earth. The importance of microorganisms as a factor in plant productivity is known.

Soil fertility depends not only on minerals, but also on microflora, which takes an active part in all the most important processes occurring in the soil and creating favorable conditions for plant nutrition. Microorganisms are involved in the preparation of food for plants, in creating conditions for its assimilation by plants, and, finally, are directly involved in supplying plants with nutrients.

The weight of bodies of microbial, mainly bacterial, mass in the surface layer of 1 hectare of fertile soil is about 5-7 tons, and if we take into account the continuous reproduction and renewal of this population, then during the growing season its weight will reach tens of tons per hectare (Samoilov, 1957).

Bacteria play a large role in the biological productivity of water bodies. This has been established for the Northern Caspian, which is important in terms of fishing (Osnitskaya, 1954; Zhukova, 1955, etc.) and other basins. Stoke river The Volga is reflected in the distribution, abundance and biomass of bacteria in the sea. In the deltaic part of the sea, the number of bacteria reaches 2-2.5 million per 1 ml of water, and as it moves to the open sea, it drops to 100-300 thousand per 1 ml. The biomass of bacteria: in the area of ​​the Volga delta is 470-600 mg per 1 m 3.

The number of bacteria per 1 g of soil in the Northern Caspian ranges from hundreds of millions to several billion. The bacterial biomass reached its greatest value in the deltas of the Volga and Ural rivers, and immediately after the 1951 flood it was 50–52 g/m2 of the bottom in a layer 1 cm thick.

On the question of the type and relationship of microbes with the environment in microbiology, there are two opposite directions: monomorphism and pleomorphism.

The theories of monomorphism and pleomorphism treat questions of speciation and variability of organisms one-sidedly and idealistically. The dominance of conservative ideas in microbiology hindered the development of this science. However, already from the end of the last century, materials began to accumulate on the variability of microbes, which made it possible to overcome the one-sidedness of these opposing concepts.

L. Pasteur showed the possibility of a directed change in the properties of microorganisms and, on this basis, developed methods for preparing vaccines. N. F. Gamaleya in 1888 discovered significant variability in the Mechnikov vibrio discovered by him. Paying great attention to the problem of variability and speciation, Gamaleya was one of the first to prove the possibility of transformation of one microbial species into another. II Mechnikov found out the significance of microbial associations, their symbiosis and antagonism. In 1909, he wrote: "It was in the field of microbiology that the possibility of changing the nature of bacteria by changing external conditions was proved, and stable changes transmitted by inheritance can be achieved." Similar statements are found in the works of S. N. Vinogradsky, L. S. Tsenkovsky, D. I. Ivanovsky, V. L. Omelyansky and other domestic microbiologists, but only after the victory in biology of the views of I. V. Michurin did a genuine restructuring of microbiology begin on dialectical materialistic basis.

The recent work carried out by microbiologists made it possible to identify a number of regularities and causes that determine the processes of variability and speciation, and to draw some generalizing conclusions on this problem. Of great importance in this regard is the conference on directional variability and selection of microorganisms, held by the Russian Academy of Sciences at the end of 1951.

A. A. Imshenetsky (1952) convincingly shows that the failure of the old and modern bourgeois microbiology is rooted in the underestimation of the significance of the fundamental law of biology. New forms of microbes were studied morphologically, but no attention was paid to their physiology, their requirements for certain living conditions (the latter remained unified in the laboratory).

The heredity and variability of microbes are characterized by a number of features that distinguish them from higher plants. The most important are the following (according to Imshenetsky):

1. The overwhelming majority of microorganisms, including bacteria and practically important yeast-like and mold fungi, do not have a sexual process. There is a vegetative reproduction of organisms in which it is possible to change the properties using processes close to vegetative hybridization.

2. Heredity in microorganisms is no less stable than in higher plants, and since most bacteria are completely devoid of a nucleus and chromosomes, this fact in itself is an excellent illustration of the failure of the chromosome theory of heredity.

3. Exceptional reproduction rate allows multiple exposure

change the external conditions on young cells and makes it possible to obtain a large number of generations in a short time (important for selection).

4. There is exceptionally close contact between the cells of microorganisms and the external environment. Due to the small size of the microbial cell, it is more exposed to the external environment than a multicellular organism. The great adaptability of microorganisms has led to the emergence of forms adapted in nature to a variety of external factors.

Most of all, the facts of variability have been established in microbes that cause gastrointestinal diseases in humans and animals, since most studies have been carried out on these microbes (Muromtsev, 1952). It has been repeatedly shown that, for example, the properties of typhoid microbes can change so profoundly in tap water that these microbes become indistinguishable from Escherichia coli or an alkali-forming agent, some strains even acquire properties that take them beyond the enteric typhoid group.

From the cultures of the plague pathogen, a microbe was obtained that has all the properties of the pathogen of false tuberculosis in rodents. At the same time, plague and pseudotuberculous microbes are independent species, differing in morphological, cultural and enzymatic properties, and interspecific competition is observed in the relationship between them.

Species variability of dysenteric microbes was indisputably shown under experimental conditions by G. P. Kalina, who received a paratyphoid microbe.

Many researchers have described the mutual transitions of pneumococci, hemolytic and green streptococci both in experiments with artificial media and in experiments on animals.

As V. D. Timakov (1953) points out, when cultivating microorganisms of the enteric typhoid group under conditions when their source of nutrition is the decay products of other related bacteria, it is possible to obtain cultures that almost fully possess the properties of the culture on whose decay products it was grown. The author comes to the conclusion that "in the world of microorganisms, it is possible to purposefully change and create new forms and types of bacteria that are useful for humans." S. N. Muromtsev (1952) writes: “It is necessary to recognize as unscientific the idea widespread among microbiologists that the existing types of microorganisms arose only in the deepest antiquity and do not arise again under modern conditions. Speciation in microorganisms also occurs under modern conditions.

As we pointed out above, the existence of bacteria is closely connected with plants and animals. In nature, you can not find places where there would be other organisms, but bacteria would be absent. In any biocenosis, microorganisms are always present as an integral element. But there may be biotopes in which the existence of animals and plants is impossible, and bacteria are the only representatives of living beings (for example, in the hydrogen sulfide zone of the Black Sea).

An idea of ​​the microbial life of the ocean depths is provided by recent studies of the Kuril-Kamchatka Basin of the Pacific Ocean (Kriss and Biryuzova, 1955). Samples were taken to a depth of 9000 m. It turned out that the bulk of heterotrophic microbes are represented by non-spore-bearing rods, then by spore-bearing rods and cocci, as well as yeasts; actinomycetes are rare. At a depth of 0-250 m, more than 10,000 cells per 1 ml were found; in the zone of pronounced photosynthesis - up to 100,000 cells; at a depth of 300-400 m - thousands and hundreds of cells in 1 ml, and in the deepest places - tens of cells. Biomass of microorganisms: 10-80 mg per 1 m 3 of water in a layer of 0-25 m; 1-10 mg - up to 300 m depth; below 400 m - tenths and hundredths, and in the near-bottom areas - thousandths of a milligram. Dozens, hundreds and thousands, more rarely more than 10,000 cells per 1 g of silt, were found in the ocean soil. The distribution of the microbial population in the soil does not depend on the depth of the ocean and, obviously, is associated with the distribution of assimilable organic matter in the soil and in the water above it.

The evolution of microbes went and goes in different directions and is associated with the occupation of all possible habitats by them.

Ecology of plants. Plants are (together with bacteria) one of the two great divisions of living nature. Modern botany divides the entire plant world into two trunks: lower (Sloevtsy) and higher (leafy) plants.

Representatives of lower plants (bacteria, algae, fungi, lichens) in most of the main types remain in the original aquatic environment, where many have retained the features of a primitive organization to this day. In the past, the lower plants were at first the only, then the predominant representatives of the plant world, but now they occupy a subordinate position in comparison with the higher ones.

Higher plants (mosses, ferns, horsetails, club mosses, gymnosperms, angiosperms) are represented by approximately 300,000 species. Most of them live on land (use air and soil), a smaller part - in the water.

Among the flowering plants there are several hundred secondary aquatic species (in different systematic groups). An aquatic lifestyle causes increased growth, compared with terrestrial plants, and the replacement of sexual reproduction by vegetative (elodea, duckweed, telorez). In many aquatic plants, the roots lose their importance as organs of absorption of nutrients, since this process occurs directly through the integuments. As a result, wood is underdeveloped in the vascular bundles of aquatic plants. Protection of the body from leaching due to excess water occurs due to mucus, which abundantly covers the underwater parts. Mechanical tissue in aquatic plants does not develop, since water itself - a dense medium - is a good body support for them. Few species of aquatic plants are annuals, overwintering in the form of seeds (shelnik, small naiad, etc.). Most, due to the preservation of positive temperatures under the ice in winter, overwinter in the form of certain vegetative parts - rhizomes (water lilies, capsules), tubers (arrowhead, combed pondweed), wintering buds (pemphigus, watercress) or entirely (duckweed, swamp , some pondweeds).

In the course of plant evolution, various adaptations to the conditions of existence - abiotic and biotic - took place. For example, the evolution from lower to higher plants was associated with the transition from an aquatic to aerial way of life, but then among the higher ones a process of reconquest of the hydrosphere is noticed.

Algae differentiate into solitary and colonial forms (Volvox). In algae, as in mosses, there is a complex alternation of generations, characterized by a change in the requirements for living conditions at individual stages of individual development.

Many fungi have taken a very peculiar place in nature, having adapted to mutually beneficial symbiosis with other organisms. Thanks to "mutual assistance", lichens (mushroom and algae) are able to live on the most barren soils and bare rocks, where neither fungus nor algae can live separately. The settlement of fungi on the roots of higher plants forms mycorrhiza, which contributes to a more complete absorption of soil nutrients by the plant. Heather growing in sandy areas does not even develop an embryo without mycorrhiza.

The flowering of seed plants is associated with their complete conquest of the land and the gradual liberation from the participation of the aquatic environment in the process of sexual reproduction. The embryo in the seed is abundantly supplied with food material and is able to withstand both dryness and cold for a long time. Therefore, only flowering plants could become true land organisms, while mosses and ferns still remained amphibious.

The vital advantage of angiosperms over gymnosperms is the formation of fruits, which more fully ensure the maturation and dispersal of seeds (with the participation of animals). The microspores of gymnosperms are adapted to be carried by the wind. Most angiosperms have developed adaptations for pollinating flowers with the assistance of insects (bright perianths, secretion of nectar and aroma, sticky pollen). This method of pollination better provides cross-fertilization, biologically useful.

Thus, an important factor in the evolution of angiosperms is their relationship with the animal world with pollinating insects, with birds and mammals that contribute to the spread of seeds. As we can see, as evolution proceeds, the connection between plants and animals is strengthened. At the same time, they not only mutually serve each other in the process of nutrition, but plants, providing animals with shelter, often include them in their development conditions.

As B. A. Keller (1938) rightly notes, in plants, relations with the environment have peculiar features, special qualities associated with the mode of nutrition typical of these organisms. Green plants take advantage of the food that is around them in an extremely rarefied form. For example, in the air this food is carbon dioxide, which is only 0.03% there, in the soil - nutritious mineral salts, usually in a weak solution. In addition, leaves, as a source of energy in the process of nutrition, capture sunlight. In this regard, the evolutionary development of plants, in general, proceeded along the path of strong dissection outwards, the development of a very rich external absorbing surface (leaf and root). As a result, plants are especially closely related to their environment, which determines their increased intraspecific variability.

The role of plants as producers in individual living environments is different. In water, the main mass of autotrophs is algae, and on land, higher plants.

The attached way of life of plants determines the vertical layering in their distribution. Closeness is observed only in plants, as a result of population density (duckweed in a pond, forest, etc.) under favorable conditions.

In combination with climate and soils, vegetation forms characteristic vertical belts in mountainous areas and latitudinal landscape zones within the northern and southern hemispheres (from the equator to the poles), an integral element of which are representatives of the animal world characteristic of them.

The value of the annual growth of above-ground plant mass, according to the studies of E. M. Lavrenko, for the tundra, steppe and desert regions ranges from 4 to 56 centners / ha. The gross stock (biomass) of above-ground plant mass reaches the highest values ​​in forest communities (900 centner/ha in the northern taiga, 1300 centner/ha in the middle taiga, 2600 centner/ha in broad-leaved forests). In the tundra, this figure is 6-32 c/ha, in the forest-tundra 73 c/ha. For the steppes, the annual growth (production) of plant mass is almost equal to its gross stock (biomass) due to the annual death of above-ground parts. Desert steppes and semi-shrub communities. deserts give the smallest value of the gross stock (5-10 q/ha).

We are not talking about the factors necessary in the life of plants: each species, depending on the environment and living conditions, “at each stage of its ontogenesis needs special conditions for existence and development. Manuals on plant ecology contain relevant material, although they are far from complete coverage of the issue.

Animal ecology. Animals, represented by more than 1.2 million species, are very diverse in terms of the height of their organization and live in all environments of life.

As J. Lamarck pointed out, the effect of the environment on animals is much more complicated than on plants. If plants directly experience the influence of external conditions, then in highly organized animals this influence is more indirect than direct. The difference here is not in how the environment acts, but in how the organism reacts to these actions.

An immobile plant dies or remains under the action of a new factor; in the latter case, a change occurs, the organism adapts to the corresponding external influence. The mobile animal organism is in a more advantageous position, since it does not face a dilemma: to die or to change. For him, a third response to the corresponding impact is possible - migration, leaving for more favorable conditions. In addition, the nervous system is of paramount importance as a condition for the connection of the organism with the environment in animals. As IP Pavlov showed, animals have historically developed constant responses of the body to external influences (unconditioned reflexes, instincts) and temporary connections (conditioned reactions), which are of great importance in establishing connections with the environment.

Due to the diversity of types of the nervous system in animals and the general differences in organization and metabolism, ecologically animals are very different. There are differences both in the environments of life and in systematic groups.

Like plants, in the animal world, the environment determined the direction and course of evolution.

The development of an outer chitinous cover in aquatic arthropods, which delayed evaporation, made it possible for some groups of these small animals to leave the aquatic environment on land and fully master the conditions of terrestrial existence.

The abundance of species (up to 1 million) and the wide distribution of arthropods in all environments of life testify to the prosperity of this group at the present time. As a result of the high development of the nervous system and the phenomena of special adaptation to the conditions of life associated with it, the type of arthropods formed one of the two peaks of the entire animal world.

Only higher vertebrates, along with spiders, centipedes and insects, were able to fully master the air environment and acquire similar adaptations for movement on land (legs that bend at the joints) and in the air (wings for flight). Only in the higher arthropods and higher vertebrates do we encounter such a far-reaching differentiation of various parts and organs of the body, and, finally, in both of them, their neuro-brain activity (instincts, etc.) turns out to be the most developed.

In the evolution of animals, a fundamentally important stage is associated with the divergence of protostomes and deuterostomes, which gave rise to two large branches of the animal world. The beginning of the divergence of these groups is due to the fact that one went along the line of adaptation to the bottom way of life (protostomes - worms, mollusks, arthropods), and the other gave rise to forms that can swim freely in water (deuterostomes - echinoderms and chordates).

In the evolution of lower vertebrates, adaptation to nutrition played an important role, in connection with which two lines of development were outlined: jawless (which gave rise to armored and cyclostomes) and jawed (a progressive branch that led from real fish to mammals).

The arid conditions that prevailed over vast areas in the Devonian gave life advantages to such freshwater fish, which showed the ability to do without gill breathing and, in the event of water damage or a temporary drying up of a reservoir, use atmospheric air for breathing. These "lungfish" belonged to two different groups, the lungfish and the lobefin. By the end of the Devonian, amphibians, the stegocephals, had their beginnings from the ancient crossopterygians, the heyday of which was Carboniferous, which was distinguished by a humid climate.

The new climate change to reduce humidity has given a vital advantage to those modified descendants of ancient amphibians who developed horn formations on their skin and did not need water to reproduce. Thus, the development of reptiles began with the arid Permian, and in the Jurassic they reached great diversity and occupied a leading position on land.

At the end of the Mesozoic, two trunks separated from reptiles - birds and mammals, independently of each other developed a similar adaptation - a complete separation of arterial and venous blood flows. This anatomical feature, due to the development of a larger respiratory surface in the lungs, provides a more vigorous respiratory exchange and creates the possibility of maintaining a constant body temperature.

The development of both groups of "warm-blooded" animals proceeded almost simultaneously and without mutual interference: they diverged into two different ecological niches and each took its own special place in nature. Birds moved from a climbing arboreal lifestyle (the Jurassic first birds) to aerial locomotion and related methods of obtaining food. In mammals, evolution has gone mainly in the direction of various possibilities of existence and movement on the surface of the land.

Mammals switched from oviposition to live birth, which ensured significantly greater survival of the offspring.

Thus, the evolution of animals, which took place in connection with a change in living conditions, can only be understood through an ecological analysis of the origin of certain adaptations. And the modern process of speciation, which is characterized by a certain specificity in individual groups of animals, can also be correctly understood only through an ecological analysis of the material.

Let us dwell on the consideration of some ecological features of vertebrates.

Ecologically, fish are quite noticeably different from other vertebrates. As you know, fish make up the richest (about 20,000 species) class of vertebrates. Fishes are highly characterized by intraspecific variability, which required the use of a particularly differentiated system of taxonomic units. In almost every reservoir we can find local forms of certain fish species.

What are the reasons for this increased variability in fish?

There are several of them, but the main reason is the exceptional dynamism of the aquatic environment and the action in it of a number of factors that terrestrial vertebrates do not experience (large fluctuations in pressure, light and oxygen regimes, the influence of the reaction of the environment, various mineralization, etc.). The specified variety of conditions of existence in the aquatic environment contributes to the adaptive radiation of fish, causing the existing diversity of species and the process of formation of local forms that is intensively continuing at the present time.

The isolation factor affects fish (especially non-aquatic ones) to a much greater extent than land animals. To confirm this, it suffices to recall that the number of lakes that differ in regime on the globe is many times greater than the number of islands with different living conditions. It is not difficult to point out two adjacent lakes, which differ in the conditions of aquatic life, but neighboring islands are usually similar in the nature of land life. To this it should be added that terrestrial animals have a much greater variety of means in overcoming mechanical barriers than fish.

The isolation factor has a dual effect - on the reservoir and on the fish. In an isolated reservoir, a special mode of life is quickly established, which is composed of the physical and geographical conditions characteristic of the reservoir, its relationship with the surrounding landscape, and depends on the complex of hydrobionts that have fallen into it. On the earth's surface it is impossible to find two completely identical reservoirs, even in the same locality, in the neighborhood of each other. The isolation of water bodies leads to the development of a specific regime, which ultimately increases the diversity of aquatic life conditions.

On the other hand, the isolation of fish (populations) contributes to the preservation of all those deviations (local forms) that have the opportunity to develop in these various water bodies and which would be leveled when they communicate with each other. Isolation contributes to the preservation of forms that could be destroyed in the interspecific struggle for existence with an open connection between different water bodies. Finally, prolonged isolation leads to a deterioration in heredity and degeneration, as a result of the lack of free crossing of individuals developed under different conditions.

The increased variability of fish depends, further, on their considerable "subordination" to the aquatic environment. The internal environment of terrestrial vertebrates, which was formed in the past, possibly with the participation of the external aquatic environment, now differs sharply from it (air). On the contrary, the internal environment of fish (liquid) remains similar and even in some cases close to their external environment. The gaseous and liquid environments of life are sharply different in their physicochemical properties, and this, of course, creates a fundamental difference between fish and terrestrial vertebrates and cannot but affect the features of their variability.

Separate groups of fish in the process of evolution have developed a different degree of isolation from the external environment, but, nevertheless, in them, due to the similar nature of the external and internal environments, changes in the first should find a greater response in the second, compared with terrestrial animals.

Finally, the variability of fish cannot but be reflected in the fact that they are apparently the only animals among animals characterized by growth throughout their entire life. It is known that organisms have significant plasticity during the period of formation and growth. Adult organisms that have reached the limit of growth are the most enduring and therefore less subject to the transforming influence of the conditions of existence.

The growth of fish throughout life is undoubtedly a factor that increases variability. In growing terrestrial vertebrates, one can distinguish between size and age variability, but after they reach their definitive (final) sizes, only age variability remains (in addition to sexual and seasonal). As a result, a taxonomist can operate with absolute measurement data for birds and mammals, but for fish, he must necessarily convert them into comparable relative indices. This circumstance, by the way, is indirect proof of the need to distinguish between age and size variability in fish.

Depending on the living conditions, the growth of fish in individual water bodies fluctuates extremely strongly.

The ecological features of birds and mammals were first examined in detail by D. N. Kashkarov and V. V. Stanchinsky (1929). In subsequent years, a large amount of factual material was accumulated in this area. The book by S. I. Ognev “Essays on the Ecology of Mammals” (1951) is of great value, but it is far from a general summary, since a number of environmental factors that determine the life of mammals are not covered in it.

D. N. Kashkarov and V. V. Stanchinsky, characterizing the dependence of birds and mammals on environmental conditions, consider climatic, ecotopic and biocenotic factors.

Climatic factors are divided by these authors into heat, light, pressure and humidity. Birds are quite sensitive to all factors. Being warm-blooded animals, birds are able to endure different temperature conditions and live wherever there is food. Eurythermal are: crows, jackdaws, tits, etc., remaining with us for the winter; inhabitants of areas with a pronounced continental climate, such as sandgrouse, saji, mountain turkeys; rising when flying to great heights - vultures and eagles.

The stenothermic forms include birds from tropical countries with an even maritime climate and migratory birds from the temperate zone. To protect the body from cooling, a cover of feathers and down is used. The role of the cooling apparatus, in the absence of sweat glands, is taken over by the respiratory organs, which evaporate water.

In relation to the light factor, birds are divided into diurnal (most) and nocturnal (owls, etc.). In relation to moisture, birds can be divided into three groups: hydrophiles (water-loving - inhabitants of water basins and their shores), hygrophiles (moisture-loving - for example, waders) and xerophiles (dry-loving - inhabitants of deserts).

As for ecotopic factors, the following characteristic habitats can be distinguished in relation to birds: air (for swifts, swallows, terns, etc., feeding exclusively on flying animals in the air), water (petrels, gulls, etc.), swamps (waders , herons, storks, cranes, etc.), open spaces - meadows, steppes, deserts (ostriches), woody vegetation (woodpeckers, nuthatches).

The biocenotic relationships of birds are very versatile, due to the high development of various instincts.

Kashkarov and Stanchineky characterize the ecology of mammals in a similar way, S.I. Ognev approaches this issue differently. According to the last author, there are 360 ​​species of mammals in the fauna of Russia. In ecological terms, they have been studied very unevenly and completely insufficiently, given the great practical importance of many species.

S. I. Ognev focuses on the consideration of adaptations in mammals to various living conditions - underground and in open spaces (fast running), on trees (climbing, fluttering) and in the air (flight), in water and on mountains. He then describes burrows and nests, hibernation, molting, migrations, reproduction, feeding, and population fluctuations. Unfortunately, the author does not evaluate natural factors from the point of view of their significance in the life of mammals as conditions for existence and development.

N. I. Kalabukhov (1951) considers temperature, light, thermal and ultraviolet rays, humidity, precipitation, gas composition of the atmosphere and pressure to be the conditions for the existence of terrestrial vertebrates. Thus, this author speaks only of abiotic factors, without touching on biotic ones. Undoubtedly, with all the importance of the former, the existence of animals without food is still completely impossible, and therefore biotic factors play an equally important role.

Thus, we have to state that the development of general issues of animal ecology from the standpoint of creative Darwinism is extremely lagging behind, although there are a number of good ecological studies of individual species, due to their practical significance (acclimatization, hunting, extermination). Most ecological works are devoted to the study of adaptations (morphological, physiological, ecological) that are developed in individual species under the influence of specific conditions of existence.

But now this is no longer enough. Michurin's teaching does not require that the adaptive value of the mole's paw to the conditions of underground life be shown again and again or that the wing of a bat be described as an adaptation to flight. Namely, this is how S.I. Ognev describes ecology. It is required to show what factors are necessary for the existence and development of the mole, bat and other animals and what effect other environmental conditions have on them. With the appropriate knowledge, ecology will become an effective science.

Individual scientists, in particular animal breeders, are trying to find ways of research in this direction. Work on the creation of the Kostroma breed of cattle and others carried out by Soviet livestock specialists on the basis of the achievements of the Michurin teaching are examples of deeply scientific ecological research. The work on creating a new breed of animal consists of two parts: 1) selection of producers and crossing (one or more) in order to loosen heredity and strengthen the desired properties, 2) an expedient mode of education and feeding. If the first part of the work is genetic, then the second is ecological. Knowledge of the best conditions for the temperature regime, exercise, nutrition, etc., in which young animals should be brought up in order to develop new breed qualities, makes it possible to create highly productive breeds of farm animals in a planned and short time.

But no less important practical importance is the exact knowledge of the ecological characteristics of animals, also when carrying out work on the acclimatization of valuable species or the extermination of harmful ones, on the rational exploitation of stocks in hunting and fisheries and other industries.

There are significant differences in the relationship of plants and animals with the environment and in the nature of the development of adaptability to living conditions.

First, the life forms of plants are much less diverse than the diversity of animal biomorphs. In plants, convergence is quite common. This is explained by the more monotonous way of life of plants (fixed rooting in the soil) and their more similar vital needs (light, carbon dioxide, water, soil mineral salts). In the animal world, the vital requirements of various species are more diverse and complex, their methods of obtaining food and protecting themselves from enemies are very different; differences in the methods of movement are very strongly reflected in their structure and appearance.

Secondly, in plant organisms, natural selection has developed a very wide morpho-physiological plasticity in response to changes in external conditions, that is, a hereditary ability to produce changes of an adaptive nature. It is clear that when plant organisms are immobile, this ability is of great vital importance for them: plants deprived of this plasticity would inevitably die if external conditions change, since they do not have the ability to actively hide.

Rice. 1. Dandelion grown in the lowlands.

In animals, plasticity of this nature is developed incomparably less, and adaptability to changes in the life situation is achieved in a different way - by the development of mobility, the complication of the nervous system and sensory organs. When external conditions change, the animal responds to it not so much by a change in its organization, but by a rapid change in its behavior and in a very large number of cases it can adapt to new conditions rather quickly. Natural selection advances to the highest levels in the animal world such organisms in which, along with a general increase in the type of organization, there was also a progressive development of their mental activity.

Thus, the interaction of plants and animals with the environment, while having much in common, at the same time differs significantly.

Used literature: Fundamentals of Ecology: Proc. lit./B. G. Johansen
Under. editor: A. V. Kovalenok, -
T .: Printing house No. 1, -58

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