Anthropogenic factors (definition and examples). Their influence on biotic and abiotic factors of the natural environment

anthropogenic soil degradation natural

Anthropogenic factors are changes in the natural environment that have occurred as a result of economic and other human activities. Trying to remake nature, in order to adapt it to his needs, man transforms the natural habitat of living organisms, influencing their life. Anthropogenic factors include the following types:

1. Chemical.

2. Physical.

3. Biological.

4. Social.

Chemical anthropogenic factors include the use of mineral fertilizers and toxic chemicals for the cultivation of fields, as well as the pollution of all earthly shells by transport and industrial waste. Physical factors include the use of nuclear energy, increased levels of noise and vibration as a result of human activities, in particular when using a variety of vehicles. Biological factors are food. They also include organisms that can inhabit the human body or those for which a person is potentially food. Social factors are determined by the coexistence of people in society and their relationships. Human impact on the environment can be direct, indirect and complex. The direct influence of anthropogenic factors is carried out with a strong short-term impact of any of them. For example, when arranging a highway or laying railway tracks through a forest, seasonal commercial hunting in a certain area, etc. Indirect impact is manifested by a change in natural landscapes due to human economic activity of low intensity over a long period of time. At the same time, the climate, the physical and chemical composition of water bodies are affected, the structure of soils, the structure of the Earth's surface, and the composition of fauna and flora change. This happens, for example, during the construction of a metallurgical plant near the railway without the use of the necessary treatment facilities, which leads to pollution of the environment with liquid and gaseous waste. In the future, trees in the nearby area die, animals are threatened with heavy metal poisoning, etc. The complex impact of direct and indirect factors entails the gradual appearance of pronounced changes in the environment, which may be due to rapid population growth, an increase in the number of livestock and animals living near human habitation (rats, cockroaches, crows, etc.), plowing of new lands, the ingress of harmful impurities into water bodies, etc. In such a situation, only those living organisms that are able to adapt to the new conditions of existence can survive in the changed landscape. In the 20th and 11th centuries, anthropogenic factors have become of great importance in changing climatic conditions, the structure of soils and the composition of atmospheric air, salt and fresh water bodies, in reducing the area of ​​\u200b\u200bforests, and in the extinction of many representatives of the flora and fauna. Biotic factors (in contrast to abiotic factors, covering all kinds of actions of inanimate nature), are a set of influences of the vital activity of some organisms on the vital activity of others, as well as on the inanimate habitat. In the latter case, we are talking about the ability of the organisms themselves to a certain extent influence the living conditions. For example, in the forest, under the influence of vegetation cover, a special microclimate or microenvironment is created, where, in comparison with an open habitat, its own temperature and humidity regime is created: in winter it is several degrees warmer, in summer it is cooler and wetter. A special microenvironment is also created in trees, in burrows, in caves, etc. It should be noted the conditions of the microenvironment under the snow cover, which already has a purely abiotic nature. As a result of the warming effect of snow, which is most effective when it is at least 50-70 cm thick, at its base, approximately in a 5-cm layer, small animals live in winter - rodents, because. temperature conditions for them are favorable here (from 0 ° to - 2 ° С). Thanks to the same effect, seedlings of winter cereals - rye, wheat - are preserved under the snow. Large animals - deer, elks, wolves, foxes, hares - also hide in the snow from severe frosts, lying down in the snow to rest. Abiotic factors (factors of inanimate nature) include:

The totality of the physical and chemical properties of the soil and inorganic substances (H20, CO2, O2) that participate in the cycle;

Organic compounds that bind the biotic and abiotic part, air and water environment;

Climatic factors (minimum and maximum temperatures at which organisms can exist, light, geographical latitude of continents, macroclimate, microclimate, relative humidity, atmospheric pressure).

Conclusion: Thus, it has been established that anthropogenic, abiotic and biotic factors of the natural environment are interrelated. Changes in one of the factors entail changes both in other environmental factors and in the ecological environment itself.

Environmental factors are all environmental factors acting on the body. They are divided into 3 groups:

The best value of a factor for an organism is called optimal(optimum point), for example, the optimum air temperature for a person is 22º.

Anthropogenic factors

Human influences change the environment too quickly. This leads to the fact that many species become rare and die out. Biodiversity is decreasing because of this.

For example, consequences of deforestation:

• The habitat for the inhabitants of the forest (animals, fungi, lichens, grasses) is being destroyed. They may disappear completely (decreased biodiversity).
• The forest with its roots holds the top fertile soil layer. Without support, the soil can be blown away by the wind (you get a desert) or water (you get ravines).
• The forest evaporates a lot of water from the surface of its leaves. If you remove the forest, then the air humidity in the area will decrease, and the soil moisture will increase (a swamp may form).

1. Choose three options. What anthropogenic factors influence the size of the wild boar population in the forest community?
1) increase in the number of predators
2) shooting animals
3) feeding animals
4) the spread of infectious diseases
5) cutting down trees
6) severe weather in winter

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2. Choose three correct answers from six and write down the numbers under which they are indicated. What anthropogenic factors influence the size of the May lily of the valley population in the forest community?
1) cutting down trees
2) increase in shading

4) collection of wild plants
5) low air temperature in winter
6) trampling the soil

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3. Choose three correct answers from six and write down the numbers under which they are indicated. What processes in nature are classified as anthropogenic factors?
1) ozone depletion
2) daily change in illumination
3) competition in the population
4) accumulation of herbicides in the soil
5) relationship between predators and their prey
6) increased greenhouse effect

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4. Choose three correct answers from six and write down the numbers under which they are indicated. What anthropogenic factors influence the number of plants listed in the Red Book?
1) destruction of their living environment
2) increase in shading
3) lack of moisture in summer
4) expansion of the areas of agrocenoses
5) sudden temperature changes
6) trampling the soil

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5. Choose three correct answers from six and write down the numbers under which they are indicated. Anthropogenic environmental factors include
1) application of organic fertilizers to the soil
2) decrease in illumination in reservoirs with depth
3) precipitation
4) thinning pine seedlings
5) cessation of volcanic activity
6) shallowing of rivers as a result of deforestation

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6. Choose three correct answers from six and write down the numbers under which they are indicated. What environmental disturbances in the biosphere are caused by anthropogenic interference?
1) the destruction of the ozone layer of the atmosphere
2) seasonal changes in the illumination of the land surface
3) decline in the number of cetaceans
4) the accumulation of heavy metals in the bodies of organisms near highways
5) accumulation of humus in the soil as a result of leaf fall
6) accumulation of sedimentary rocks in the depths of the oceans

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1. Establish a correspondence between the example and the group of environmental factors that it illustrates: 1) biotic, 2) abiotic
A) overgrowing of the pond with duckweed
B) increase in the number of fish fry
C) eating fish fry by a swimming beetle
D) ice formation
E) flushing into the river of mineral fertilizers

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2. Establish a correspondence between the process taking place in the forest biocenosis and the environmental factor that it characterizes: 1) biotic, 2) abiotic
A) the relationship between aphids and ladybugs
B) waterlogging of the soil
C) daily change in illumination
D) competition between species of thrushes
D) increase in air humidity
E) the effect of the tinder fungus on the birch

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3. Establish a correspondence between examples and environmental factors that are illustrated by these examples: 1) abiotic, 2) biotic. Write the numbers 1 and 2 in the correct order.
A) an increase in atmospheric air pressure
B) change in the topography of the ecosystem caused by an earthquake
C) a change in the population of hares as a result of an epidemic
D) interaction between wolves in a pack
D) competition for territory between pine trees in the forest

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4. Establish a correspondence between the characteristics of the environmental factor and its type: 1) biotic, 2) abiotic. Write the numbers 1 and 2 in the correct order.
A) ultraviolet rays
B) drying up of water bodies during a drought
C) animal migration
D) pollination of plants by bees
D) photoperiodism
E) a decrease in the number of squirrels in lean years

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6f. Establish a correspondence between examples and environmental factors that are illustrated by these examples: 1) abiotic, 2) biotic. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) an increase in soil acidity caused by a volcanic eruption
B) change in the relief of the biogeocenosis of the meadow after the flood
C) change in the population of wild boars as a result of the epidemic
D) interaction between aspens in the forest ecosystem
E) competition for territory between male tigers

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7f. Establish a correspondence between environmental factors and groups of factors: 1) biotic, 2) abiotic. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) daily fluctuations in air temperature
B) change in the length of the day
B) predator-prey relationship
D) symbiosis of algae and fungus in lichen
D) change in the humidity of the environment

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2. Match the examples with the environmental factors illustrated by these examples: 1) Biotic, 2) Abiotic, 3) Anthropogenic. Write the numbers 1, 2 and 3 in the correct order.
A) autumn leaves
B) Planting trees in the park
C) The formation of nitric acid in the soil during a thunderstorm
D) Illumination
E) The struggle for resources in the population
E) Freon emissions into the atmosphere

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3. Establish a correspondence between examples and environmental factors: 1) abiotic, 2) biotic, 3) anthropogenic. Write down the numbers 1-3 in the order corresponding to the letters.
A) change in the gas composition of the atmosphere
B) dispersal of plant seeds by animals
C) human draining of swamps
D) an increase in the number of consumers in the biocenosis
D) change of seasons
E) deforestation

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1. Choose three correct answers out of six and write them down in the numbers under which they are indicated. The following factors lead to a decrease in the number of squirrels in a coniferous forest:
1) reduction in the number of birds of prey and mammals
2) cutting down coniferous trees
3) harvest of spruce cones after a warm dry summer
4) increase in activity of predators
5) outbreak of epidemics
6) deep snow cover in winter

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Choose three correct answers from six and write down the numbers under which they are indicated. The destruction of forests in vast areas leads to
1) an increase in the amount of harmful nitrogen impurities in the atmosphere
2) violation of the ozone layer
3) violation of the water regime
4) change of biogeocenoses
5) violation of the direction of air flows
6) reduction in species diversity

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1. Choose three correct answers from six and write down the numbers under which they are indicated. Specify biotic factors among environmental factors.
1) flood
2) competition between individuals of the species
3) lowering the temperature
4) predation
5) lack of light
6) mycorrhiza formation

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2. Choose three correct answers from six and write down the numbers under which they are indicated. The biotic factors are
1) predation
2) forest fire
3) competition between individuals of different species
4) rise in temperature
5) mycorrhiza formation
6) lack of moisture

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1. Choose three correct answers out of six and write down the numbers under which they are indicated in the table. Which of the following environmental factors are abiotic?
1) air temperature
2) greenhouse gas pollution
3) the presence of non-recyclable garbage
4) the presence of a road
5) illumination
6) oxygen concentration

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2. Choose three correct answers out of six and write down the numbers under which they are indicated in the table. Abiotic factors include:
1) Seasonal bird migration
2) Volcanic eruption
3) The appearance of a tornado
4) Construction by beavers of platinum
5) The formation of ozone during a thunderstorm
6) Deforestation

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3. Choose three correct answers out of six and write down in the answer the numbers under which they are indicated. The abiotic components of the steppe ecosystem include:
1) herbaceous vegetation
2) wind erosion
3) the mineral composition of the soil
4) rainfall mode
5) species composition of microorganisms
6) seasonal livestock grazing

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Choose three correct answers from six and write down the numbers under which they are indicated. What environmental factors may be limiting for brook trout?
1) fresh water
2) oxygen content less than 1.6 mg/l
3) water temperature +29 degrees
4) water salinity
5) illumination of the reservoir
6) the speed of the river

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1. Establish a correspondence between the environmental factor and the group to which it belongs: 1) anthropogenic, 2) abiotic. Write the numbers 1 and 2 in the correct order.
A) artificial irrigation of land
B) meteorite fall
B) plowing virgin land
D) spring flood of waters
D) building a dam
E) movement of clouds

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2. Establish a correspondence between the characteristics of the environment and the environmental factor: 1) anthropogenic, 2) abiotic. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) deforestation
B) tropical showers
B) melting glaciers
D) forest plantations
D) draining swamps
E) an increase in the length of the day in spring

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Choose three correct answers from six and write down the numbers under which they are indicated. The following anthropogenic factors can change the number of producers in an ecosystem:
1) collection of flowering plants
2) increase in the number of consumers of the first order
3) trampling of plants by tourists
4) decrease in soil moisture
5) cutting down hollow trees
6) increase in the number of consumers of the second and third orders

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Read the text. Choose three sentences that describe abiotic factors. Write down the numbers under which they are indicated. (1) The main source of light on Earth is the Sun. (2) In photophilous plants, as a rule, strongly dissected leaf blades, a large number of stomata in the epidermis. (3) The humidity of the environment is an important condition for the existence of living organisms. (4) Plants evolved adaptations to maintain the body's water balance. (5) The content of carbon dioxide in the atmosphere is essential for living organisms.

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Choose three correct answers from six and write down the numbers under which they are indicated. With a sharp decrease in the number of pollinating insects in the meadow over time
1) the number of insect pollinated plants is reduced
2) the number of birds of prey is increasing
3) the number of herbivores is increasing
4) the number of wind-pollinated plants increases
5) the water horizon of the soil changes
6) the number of insectivorous birds is decreasing

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© D.V. Pozdnyakov, 2009-2019

The currently most significant group of factors that intensively change the environment is directly related to the versatile human activity.

Human development on the planet has always been associated with environmental impact, but today this process has accelerated significantly.

Anthropogenic factors include any impact (both direct and indirect) of a person on the environment - organisms, biogeocenoses, landscapes,.

By reshaping nature and adapting it to his needs, man changes the habitat of animals and plants, thereby influencing their life. The impact can be direct, indirect and accidental.

Direct impact directed directly at living organisms. For example, unsustainable fishing and hunting have drastically reduced the number of species. The growing strength and accelerated pace of human change in nature necessitate its protection.

Indirect Impact is carried out by changing the landscapes, climate, physical condition and chemistry of the atmosphere and water bodies, the structure of the earth's surface, soils, vegetation and wildlife. A person consciously and unconsciously exterminates or displaces some species of plants and animals, spreads others or creates favorable conditions for them. For cultivated plants and domestic animals, man has created a largely new environment, multiplying the productivity of developed lands. But this ruled out the possibility of the existence of many wild species.

In fairness, it should be said that many species of animals and plants disappeared from the face of the Earth even without human intervention. Each species, like an individual organism, has its own youth, flowering, old age and death - a natural process. But in nature, this happens slowly, and usually leaving species have time to be replaced by new ones, more adapted to living conditions. Man, on the other hand, accelerated the process of extinction to such a pace that evolution gave way to revolutionary, irreversible transformations.

Anthropogenic factors is a set of influences of human economic activity on the natural environment as a habitat for other species.

Natural ecosystems have considerable resilience and resilience, which helps to endure periodic disturbances and often recover quite well after many periodic anthropogenic disturbances. Ecosystems are naturally adapted to such impacts.

However, chronic (permanent) violations can lead to pronounced and persistent negative consequences, especially in the case of pollution of atmospheric air, natural waters and soils with hazardous chemicals. In such cases, the evolutionary history of adaptation no longer helps organisms and anthropogenic stress can be a major limiting factor for them.

Anthropogenic stress of ecosystems is divided into two groups:

- acute stress , which is characterized by a sudden onset, rapid intensity and short duration of disturbances;

- chronic stress , in which violations of low intensity continue for a long time or often recur, i.e. it is a "constantly disturbing" effect.

Natural ecosystems have a significant ability to cope with or recover from acute stress. The degree of stability of ecosystems is different and depends on the severity of the impact and on the effectiveness of internal mechanisms. There are two types of stability:

Resistant stability – the ability to remain stable under load.

Elastic stability - the ability to recover quickly.

The chronic impact of anthropogenic factors causes significant changes in the structure and functioning of ecosystems, which can have catastrophic consequences. The effects of chronic stress are harder to assess—sometimes it may take years for the effects of stress to show up. Thus, it took years to establish a link between cancer and smoking or chronic, weak ionizing radiation.

If humanity does not make efforts to curb the process of environmental degradation in the coming decades, then pollutants may well become a limiting factor for industrial civilization.

3.4. Ecological Valence of Species and Limiting Factors

The amplitude of the fluctuation of a factor at which organisms can exist is called species ecological valence . Organisms with broad ecological valence are called eurybiont, with a narrow stenobiont.

Figure 2. Comparison of relative tolerance limits of stenothermic and eurythermal organisms

(according to Y. Odum, 1986)

In stenothermic species, the minimum, optimum, and maximum are close (Fig. 2). Stenobiontness and eurybiontness characterize various types of adaptation of organisms for survival. So, in relation to temperature, eury- and stenothermal organisms are distinguished, in relation to the salt content - eury- and stenohaline, in relation to light - eury- and stenophotic, in relation to food - eury- and stenophageous.

The ecological valency of a species is the wider, the more diverse the conditions it lives in. Thus, coastal forms are more eurythermal and euryhaline than marine forms, where the temperature and salinity of the water are more constant.

Thus, organisms can be characterized as ecological minimum , so ecological maximum . The range between these two values ​​is called limit of tolerance .

Any condition approaching or exceeding the tolerance limit is called a limiting condition or limiting factor. A limiting factor is an environmental factor that goes beyond the endurance of the organism. The limiting factor limits any manifestation of the organism's vital activity. With the help of limiting factors, the state of organisms and ecosystems is regulated.

The limiting factor there may be not only a deficiency, but also an excess of some factors, for example, such as heat, light and water. In a stationary state, the limiting substance will be that vital substance, the available quantities of which are closest to the required minimum. This concept is known as « Liebig's Law of the Minimum .

In 1840, the German chemist J. Liebig first concluded that the endurance of an organism is determined by the weakest link in the chain of its environmental needs. This conclusion was made as a result of studying the influence of various factors on plant growth. It has been found that plants are often limited not by those nutrients that are required in large quantities (for example, CO 2 and water, which are in excess), but by those that are required in negligible amounts (for example, zinc), but which are also found in the environment. very little.

Liebig's law of the "minimum" has two auxiliary principle :

1. Restrictive – the law is strictly applicable only under stationary conditions, i.e. when the inflow and outflow of energy and substances are balanced. When the equilibrium is disturbed, the rate of supply of substances changes and the ecosystem also begins to depend on other factors.

2. Interaction of factors - high concentration or availability of one substance or factor can change the rate of consumption of a nutrient contained in a minimum amount. Sometimes an organism is able to replace, at least partially, a deficient element with another chemically close one.

Studying the various limiting effects of environmental factors (such as light, heat, water), the American zoologist Victor Ernest Shelford in 1913 came to the conclusion that not only a deficiency, but also an excess of factors can be a limiting factor. In ecology, the concept of the limiting influence of the maximum along with the minimum is known as "law of tolerance" W. Shelford .

Organisms can have a wide range of tolerance for one factor and a narrow range for another. Organisms with a wide range of tolerance for all environmental factors are usually the most widely distributed.

The importance of the concept of limiting factors is that it provides the ecologist with a starting point for dealing with complex situations. In the study of ecosystems, the researcher must first of all pay attention to those factors that are functionally most important.

 Anthropogenic factors - it is a combination of various human influences on inanimate and living nature. Human action in nature is enormous and extremely diverse. Human impact can be direct and indirect. The most obvious manifestation of anthropogenic impact on the biosphere is environmental pollution.

Influence anthropogenic factor in nature can be conscious , so random or unconscious .

To conscious include - plowing of virgin lands, the creation of agrocenoses (agricultural land), the resettlement of animals, environmental pollution.

To random include impacts that occur in nature under the influence of human activity, but were not foreseen and planned by him in advance - the spread of various pests, the accidental importation of organisms, unforeseen consequences caused by conscious actions (draining swamps, building dams, etc.).

Other classifications of anthropogenic factors have also been proposed. : changing regularly, periodically and changing without any patterns.

There are other approaches to the classification of environmental factors:

in order(primary and secondary);

by time(evolutionary and historical);

by origin(cosmic, abiotic, biogenic, biotic, biological, natural-anthropogenic);

according to the environment of origin(atmospheric, water, geomorphological, edaphic, physiological, genetic, population, biocenotic, ecosystem, biospheric);

by degree of impact(lethal - leading a living organism to death, extreme, limiting, disturbing, mutagenic, teratogenic - leading to deformities in the course of individual development).

Population L-3

Term "population" was first introduced in 1903 by Johansen.

Population - this is an elementary grouping of organisms of a certain species, which has all the necessary conditions for maintaining its numbers for an indefinitely long time in constantly changing environmental conditions.

population - This is a group of individuals of the same species that has a common gene pool and occupies a certain territory.

View - it is a complex biological system consisting of groupings of organisms - populations.

Population structure characterized by its constituent individuals and their distribution in space. Functions populations - growth, development, the ability to maintain existence in constantly changing conditions.

Depending on the area occupied allocate three types of populations :

elementary (micropopulation)- is a collection of individuals of a species occupying some small area of ​​​​a homogeneous area. The composition includes genetically homogeneous individuals;

ecological - is formed as a set of elementary populations. Basically, these are intraspecific groups, slightly isolated from other ecological populations. Revealing the properties of individual ecological populations is an important task in understanding the properties of a species in determining its role in a particular habitat;

geographic - cover a group of individuals inhabiting a territory with geographically homogeneous living conditions. Geographical populations cover a relatively large area, are quite demarcated and relatively isolated. They differ in fertility, size of individuals, a number of ecological, physiological, behavioral, and other features.

The population has biological features(characteristic of all its constituent organisms) and group features(serve as unique characteristics of the group).

To biological features includes the presence of the life cycle of the population, its ability to grow, differentiate and self-maintain.

To group features include fertility, mortality, age, sex structure of the population and genetic adaptability (this group of traits applies only to the population).

The following types of spatial distribution of individuals in populations are distinguished:

1. uniform (regular) - characterized by an equal distance of each individual from all neighboring ones; the value of the distance between individuals corresponds to the threshold beyond which mutual oppression begins ,

2. diffuse (random) - occurs in nature more often - individuals are distributed unevenly in space, randomly,

aggregated (group, mosaic) - expressed in the formation of groups of individuals, between which there are sufficiently large uninhabited territories .

The population is the elementary unit of the evolutionary process, and the species is its qualitative stage. The most important are quantitative characteristics.

There are two groups quantitative indicators :

static – characterize the state of the population at this stage;

dynamic – characterize the processes occurring in a population over a certain period (interval) of time.

To statistics populations include:

number,

density,

structure indicators.

Population size is the total number of individuals in a given area or in a given volume.

The number is never constant and depends on the ratio of the intensity of reproduction and mortality. In the process of reproduction, the population grows, mortality leads to a decrease in its number.

population density determined by the number of individuals or biomass per unit area or volume.

Distinguish :

average density is the abundance or biomass per unit of the entire space;

specific or environmental density- abundance or biomass per unit of habitable space.

The most important condition for the existence of a population or its ecotype is their tolerance to environmental factors (conditions). Tolerance in different individuals and to different parts of the spectrum is different, therefore population tolerance is much wider than that of individual individuals.

Population dynamics - these are the processes of changes in its main biological indicators over time.

Main dynamic indicators (characteristics) of populations are:

fertility,

mortality,

population growth rate.

Fertility - the ability of a population to increase in numbers through reproduction.

Distinguish the following types of births:

maximum;

ecological.

Maximum, or absolute, physiological fertility - the appearance of the theoretically maximum possible number of new individuals under individual conditions, i.e., in the absence of limiting factors. This indicator is a constant value for a given population.

Ecological, or realizable, fertility denotes an increase in a population under actual, or specific, environmental conditions. It depends on composition, population size, and actual environmental conditions.

Mortality - characterizes the death of individuals of populations for a certain period of time.

Distinguish:

specific mortality - the number of deaths in relation to the number of individuals that make up the population;

environmental or marketable, mortality - the death of individuals in specific environmental conditions (the value is not constant, it changes depending on the state of the natural environment and the state of the population).

Any population is capable of unlimited population growth if it is not limited by environmental factors of abiotic and biotic origin.

This dynamic is described A. Lotka's equation : d N / d t ≈ r N

N– number of individuals;t- time;r- biotic potential