In ecosystems.
Progress:
1. Read about endangered, rare, and declining species of plants and animals in your region.
2. What kinds of plants and animals do you know that have disappeared in your area.
3. Give examples of human activities that are reducing species populations. Explain the reasons for the adverse effects of this activity, using knowledge of biology.
4. Make a conclusion: what types of human activities lead to changes in ecosystems.
Rare animals, plants listed in the Red Book (examples)
Human influence on the environment
Human impact on animals is expressed both in direct pursuit and disruption of the population structure, and in the change of their habitats. Recently, such a powerful factor as environmental pollution has been added to the general changes in habitat conditions. Very often, direct pursuit (hunting) was accompanied by a change in the landscape. A person, through his activities, strongly influences animal world, causing an increase in the number of some species, a decrease in others and the death of others. This impact can be direct or indirect. Game animals, which are hunted for fur, meat, fat, etc., are directly affected. As a result, their number is decreasing, certain types disappear. Also, the direct effects of humans on animals include their death from pesticides, and poisoning by emissions from industrial enterprises.
The indirect influence of humans on animals is manifested due to changes in the habitat during deforestation (black stork), plowing of steppes (steppe eagle, bustard and little bustard), drainage of swamps (Far Eastern stork), construction of dams (fish), construction of cities, application of pesticides ( red-footed stork), etc. In the XX century, direct pursuit caused the death of species in 28% of cases, and indirect in 72% of cases. The complete or almost complete extermination of animals as a result of immoderate and unregulated prey was quite widespread in the past. The first documented human victim of persecution was a giant dodo pigeon.
From this lesson, you will learn how, throughout its existence, man has influenced nature, destroying species of animals and plants, destroying biocenoses, irreversibly transforming landscapes and the entire appearance of the planet. Learn about the direct and indirect impact of human activities on the biodiversity of living things. Find out the consequences of such human influence on nature.
Homework
- What are the examples of direct human influence on species of living nature?
- What kinds of animals have been destroyed by humans?
- How did the industrial revolution affect biogeocegoses?
- What is the indirect (indirect) human influence on wildlife?
- Are there any examples of an increase in the number of living organisms under the influence of humans?
- Talk with friends and family about the need for conservation areas.
- Biological Dictionary ().
- All biology ().
- Internet portal Bio.fizteh.ru ().
- Biology ().
- Internet portal Sochineniya-referati.ru ().
Any species is adapted to its food. If its consumption increases, then natural reserves do not have time to recover. As a result, the amount of food begins to decrease. If, for example, a certain type of plant increases its nutrient intake, then the soil is depleted. Or some kind of animal eats favorite species of other animals or plants, then their number, respectively, decreases.
There is not enough food, the mortality rate is increasing. Fertility is declining and numbers are declining. From time immemorial, not only plants and animals, but also people have been exposed to this effect. When the primitive hunters depleted their hunting grounds, then famine ensued. In such a situation, the tribes reduced the birth rate and began to look for new fertile lands, but there they could be met by other tribes who were not going to share their hunting grounds.
In general, it should be noted that with the disappearance of the habitual food, the species switches to a new food. But he is less adapted to it physiologically, since its quality is much worse. An example of this is sea gulls. They used to feed on fish, but now they feed on garbage from ships. But the reason is not that they are easier to catch, but simply that there are fewer fish due to global fisheries.
Pollution is a form of environmental degradation. If natural environment balanced, the results of the vital activity of one species are eliminated by others. The manure is taken away by insects, processed by bacteria and fungi. And when the balance is disturbed, pollution accumulates. The same man has always polluted environment... But while there were few people, nature managed to destroy pollution.
However, modern mankind has increased the volume of pollution so much that nature no longer has time to cope with them. In addition, man began to produce pollutants that simply cannot be recycled. An example of this is radioactive waste. Therefore, the biosphere increasingly "refuses" to process the fruits of human activity, which can lead to a global catastrophe.
The decline in the number of species is facilitated by epidemics. For example, in rabbits, the number of which begins to increase rapidly, an epizootic (mass infection) occurs. As a result, the population size is reduced by hundreds and even thousands of times. That is, the epizootic acts as a population regulator. Humans have also been exposed to various epidemics over the centuries. So the plague that arose in the XIV century in 2 years reduced the population of Europe by half. Nowadays, well-known epidemics are successfully resisted by medicine. Therefore, the biosphere is looking for other ways to influence people.
Even 30 years ago, the first forecasts of the demographic collapse that awaits humanity appeared. And how can you avoid it? In nature, there are species that reduce the number in advance when it approaches the limit. At the same time, the biosphere assigns its own biological capacity to each species. It is thanks to her that the population density is formed.
So in the pine forest there are few birds that nest in the hollows of trees, since hollows are almost never found in the pines. But if you hang the nest boxes, then this limiting factor will disappear. The number of birds nesting in hollows will begin to increase, but then it will stop, as it rests on the amount of food. For territorial species, fertility is established in this way. For people, at all times, the territory was also the main regulator of the number.
It is the consequence of territoriality that aggression is. When population density rises sharply and problems arise with food and a comfortable existence, aggressive behavior begins to prevail over other forms of communication. As a result, people begin to wage war with each other, which contributes to the rapid decline in numbers. In the animal kingdom, the situation is similar, since the program is turned off not to encroach on what belongs to others.
In nature, when the decline in the number of species becomes a vital necessity, an amazing mechanism is triggered. Its essence lies in the implementation of an alternative program of behavior. In animals in stressful condition, a generation is born that does not look like parents.
For example, locusts in normal conditions exist according to the territorial principle: each male has its own area. But when the population density increases, then males begin to invade foreign territories. And then the locust lays eggs, from which "marching" offspring appear. This generation has no territorial instinct. It gathers in a giant flock and begins to move somewhere. Sometimes he finds himself in places that are generally not suitable for life, and dies. In birds and mammals, the situation is similar, but not so pronounced. But the purpose of the movement is the same: to throw out extra individuals outside the biological capacity. Therefore, participants in mass movements become fearless and are not afraid to collectively perish.
Crowding affects the decline in the number of species. One of its forms is human urbanization. In huge metropolitan areas, the birth rate falls in the second generation so much that it does not ensure reproduction. Here, as an example, we can cite such cities as New York, Mexico City, Moscow, Tokyo, Singapore, etc. It is urbanization that can become the most painless way to reduce the population.
The biosphere is very resourceful when it comes to species decline. In animals, it can change marital relationships and attitudes towards offspring. When the number of individuals increases, the offspring ceases to be the main value for the entire population. Parents begin to avoid reproduction, lay eggs anywhere, reduce care for their offspring, and even devour them.
A similar phenomenon is observed in humans. One of its manifestations is the emancipation of women, through which many civilizations have gone. The consequence of emancipation is an increase in the proportion of single mothers. Such ladies have a minimum number of children, and fertility is half that of married women. During emancipation, the latter also try to have as few children as possible.
So, there is every reason to believe that in humans, as in animals, mechanisms of self-regulation of fertility operate in order to maintain it at a reasonable optimal level. If one child is born in a family, then every 35 years the number will begin to halve. This is a sufficient pace to move away from the ecological crisis associated with the overpopulation of the planet.
It should be said that the ecological crisis is already underway. And it goes globally, affecting the entire Earth. And therefore, the decline in the number of species has a very great importance for the biosphere. In the first place, of course, is the human community with a population of over 7 billion people. Such a mass of people contributes to the rapid degradation of the natural habitat. Therefore, the biosphere must protect itself. She has many ways, and there are both humane and cruel.
Human economic activity changes the living conditions of many species of plants and animals. For many of them, this entails a change in population size and can lead to the extinction of certain species.
Decline and disappearance of populations
Of the animals that were known to science in 1600, 65 species of mammals and 140 species of birds have now disappeared. Even in the last century in the steppes of Ukraine there was a wild gray horse - tarpan. The economic development of the steppes led to a rapid and sharp decrease in the number of this animal: the last tarpan was killed by a poacher in 1879, and the species ceased to exist.
At the same time, steppe antelopes - saigas lived in the Ukrainian steppes. By the beginning of this century, they were completely exterminated on the territory of Ukraine. Several dozen of these animals survived in the steppes east of the Caspian, and thanks to measures taken by the Soviet government, the species was saved. But many species of plants and animals are threatened with extinction.
Conservation measures for animal and plant populations
In this regard, the International Union for the Conservation of Nature in 1948 created a special commission that collected information about endangered, rare, organisms in need of protection, and entered the International Red Book of 248 species and 48 subspecies of mammals, 287 species of birds, 119 species and subspecies reptiles, 36 species of amphibians.
To the Red Book Soviet Union(1978) included animals disappearing on the territory of our country. It includes 62 species and subspecies of mammals, 63 species and subspecies of birds, 21 species of reptiles, 444 species of vascular plants. The Red Book of the Ukrainian SSR, approved in 1976 and published in 1980, includes: insects - 18 species, amphibians - 4, reptiles - 6, birds - 28, mammals - 29, plants - 110 species and subspecies.
As a result of the measures taken for the protection of animals and the reasonable management of the hunting economy in our country, the conditions for the reproduction of populations of many game animals have been restored and the number of elk, beavers, wild boars and many others has significantly increased. In Siberia, sable was on the verge of extinction. But at present, its number has reached the commercial size.
Rational use of species from the wild requires regulation of their populations. Deforestation can only be carried out taking into account its renewal. The same applies to fishing and hunting. This is also provided for by the law on the protection and use of wildlife, adopted by the Supreme Soviet of the USSR in 1980.
Human influence
It should be noted that human economic activity can not only maintain the number of certain species, but also contribute to an increase in the number of populations of those animals that feed on plants raised by humans. As a result of plowing virgin lands in the East of the USSR, many species of insects that fed on plants specific for virgin lands died. But some species that previously lived on wild grains have switched to wheat crops. As a result, the abundance of wheat thrips and gray grain moth increased sharply.
Often, populations of plants and animals, voluntarily or involuntarily introduced by humans to new territories, where their competitors and enemies are absent, reach mass numbers. There is a well-known story with a wild, European rabbit brought to Australia, intensively multiplying there and threatening agricultural crops. The ragweed weed penetrated the territory of the Soviet Union during the Second World War and, having no enemies here, more and more litters the fields.
Struggle for existence
An instructive example of the influence of human activity on changes in the number of natural populations is given by Darwin. On the island of Jamaica, the first European colonizers received bountiful harvests. But along with the colonialists, rats also entered the island. Lacking enemies, the rodents multiplied intensively and jeopardized the preservation of the harvest.
To fight rats, a predatory animal, the mongoose, was brought to the island. Due to the abundance of food, the mongoose population has increased dramatically. The rat population dropped rapidly. Then the predator switched to feeding on wild and domestic birds.
These complex relationships that develop in nature between organisms belonging to different types, Darwin called the struggle for existence. It is this that leads to the survival of the fittest.
. (A1. Science studies 1) the structure of cells 2) the functions of the body and individual organs 4) intrauterine development of a person a3. the flexibility of the spine is provided by the vertebrae connected by 1) by fusion 2) bone suture 3) cartilaginous discs
4) movably a4. the vital capacity of the lungs is 1) the amount of air inhaled at rest 2) the amount of air exhaled during rest 3) the maximum amount of air exhaled after the deepest inhalation 4)
the amount of exhaled air after maximum exhalation a5. what happens with chest when inhaling? 1) rises, volume decreases 2) falls, volume decreases 3) rises, volume increases
4) it goes down, the volume increases a6. Subcutaneous fatty tissue 1) gives the skin 2) softens the skin 3) participates in sweating 4) protects the body from cooling and overheating a7. protective function liver in the body
man? 1) forms bile, which is involved in the process of digestion 2) neutralizes toxic substances that blood brings to it 3) converts glucose into animal starch - glycogen 4) converts proteins into other organic
substance a8. in the large intestine there is an intensive absorption of 1) glucose 2) amino acids 3) carbohydrates 4) water a9. at the breakdown of which substances not only a lot of energy is released, but also 1) proteins 2) fats 3) carbohydrates
4) vitamins a10. Primary urine is formed in 1) renal capsule 2) urinary bladder 3) convoluted tubules 4) renal artery a11. In which part of the human brain is the center of respiratory reflexes located? 1) in the middle 2) on average
brain 3) in the medulla oblongata 4) in the diencephalon a12. somatic nervous system regulates the activity of 1) heart, stomach 2) endocrine glands 3) skeletal muscles 4) smooth muscles a13. platelet function is
1) protection against microbes 2) blood clotting 3) gas transport 4) neuro-humoral regulation a14. Passive immunity arises after the introduction of 1) serum 2) vaccine 3) antibiotic 4) donor blood a15. The highest blood flow rate in
1) veins 2) arteries 3) capillaries 4) aorta a16. Theory conditioned reflexes created 1) and. m. Sechenov 2) and. p. pavlov 3) and. and. mechnikov 4) a. a. Ukhtomsky V. 1. with myopia (choose three correct answers) 1) eyeball 2) image
focuses in front of the retina 3) glasses with biconvex lenses must be worn 4) the eyeball is elongated 5) the image is focused behind the retina 6) glasses with diffusing lenses are recommended c2.
correspondence between the function of the tissue and its type of function of the tissue type of tissue a) forms the mucous membranes of all internal organs 1) epithelial b) protects against mechanical damage 2) connective c) carries out movement
substances in the body d) performs a supporting function e) protects the body from the ingress of microbes c 3. Establish a correspondence between the reflex sign and its type reflex sign Reflex type a) acquired during life
1) unconditional b) congenital 2) conditional c) not inherited d) typical for all individuals of the species e) individual for each individual c 4. establish the sequence of air movement through the airways a) nasopharynx b) nasal
cavity c) trachea d) larynx e) bronchi).