soil

soil

An organism as a habitat for another organism

Living Environments

Habitat

Ground-air

Ground-air

Aquatic life environment

All aquatic inhabitants, despite differences in lifestyle, must be adapted to the main features of their environment. These features are determined primarily by the physical properties of water: its density, thermal conductivity, and ability to dissolve salts and gases.

Physical properties of water

density

Thermal conductivity

Ability to dissolve gases and salts

Ground-air environment of life .

This environment has a different set of features. It is generally more complex and varied than aquatic. It has a lot of oxygen, a lot of light, sharper temperature changes in time and space, much weaker pressure drops, and often there is a moisture deficit.

Soil as a living environment .

The soil is a thin layer of the land surface, processed by the activities of living beings. Solid particles are permeated in the soil with pores and cavities, filled partly with water and partly with air, so small aquatic organisms can also inhabit the soil. The volume of small cavities in the soil is a very important characteristic of it. In loose soils, it can be up to 70%, and in dense soils - about 20%.

Living organisms as a living environment.

Examples and additional information

In the aquatic environment, the living conditions of its inhabitants vary greatly in different parts of the reservoir. Eternal darkness reigns in the depths of the oceans. There's a lot of pressure here. In deep depressions it is a thousand times greater than on the surface of the Earth. The bottom has a constant low temperature of about -2 °C and low oxygen content. Only microorganisms and some animals live here. In the upper layers of seas and oceans, the water is permeated with light, aerated, its temperature changes throughout the year, algae live in it and photosynthesis occurs.

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environmental factors. Basic living environments.

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Distribution of organisms among living environments. Water environment. Ground-air environment. Soil as a living environment. Living organisms as a living environment.

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In the process of the long historical development of living matter and the formation of more and more modern forms of living beings, organisms, mastering new habitats, were distributed on Earth according to its mineral shells and adapted to existence in strictly defined conditions.

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Water environment.

General characteristics. Hydrosphere - occupies up to 71% of the Earth's area. In terms of volume, water reserves are estimated at 1370 million km3. The main amount of water (98%) is concentrated in the seas and oceans, 1.24% is the ice of the polar regions, 0.45% is fresh water.

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About 150,000 species of animals (7% of the total number on Earth) and 10,000 species of plants (8%) live in the aquatic environment. The most diverse and rich flora and fauna of the seas and oceans of the equatorial and tropical regions.

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A characteristic feature of the aquatic environment is its mobility. The movement of water ensures the supply of aquatic organisms with oxygen and nutrients, leading to equalization of temperatures throughout the reservoir.

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Abiotic factors of the aquatic environment.

Temperature fluctuations in the World Ocean range from -2C to +36C. In fresh water bodies – from -0.9C to +25C. Exceptions are thermal springs up to +95C. Thermodynamic features of the aquatic environment, such as high specific heat capacity, high thermal conductivity and expansion during freezing, create particularly favorable conditions for life.

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Since the temperature regime of water bodies is characterized by great stability, the organisms living in them are characterized by a relative constancy of body temperature and have a narrow range of adaptability to fluctuations in environmental temperature.

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The density and viscosity of the aquatic environment is 800 times greater than that of air. In plants, these features are reflected in the fact that their mechanical tissue is poorly developed, so they are inherently buoyant and have the ability to be suspended in water. Animals have a streamlined body shape, covered with mucus.

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Light mode and water transparency. It depends on the season, and is also determined by the natural decrease in light with depth, due to the fact that water absorbs light, while rays of different wavelengths are absorbed unequally, red ones are the fastest, and blue-green ones penetrate much deeper.

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Salinity of water. It is an excellent solvent for many mineral compounds. Oxygen content is inversely proportional to temperature. As the temperature decreases, the solubility of oxygen and other gases increases.

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Hydrogen ion concentration. Freshwater pools: pH 3.7-4.7 – considered acidic; 6.95 – 7.3 – neutral; more than 7.8 – alkaline. Sea water is more alkaline, pH changes less, and decreases with depth.

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Plankton are free floating. - phytoplankton - zooplankton. Nekton - actively moving. Neuston - inhabitants of the upper film. Pelagos are inhabitants of the water column. Benthos are bottom dwellers.

Ecological groups of hydrobionts.

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Ecological plasticity of organisms.

Aquatic organisms have less ecological plasticity than terrestrial ones, because water is a more stable environment and its abiotic factors undergo minor fluctuations. The breadth of ecological plasticity of aquatic organisms is assessed in relation not only to the entire complex of factors, but also to one of them. Ecological plasticity serves as a regulator of the dispersal of organisms and depends on the age and phase of development of the organism.

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Ground-air environment.

General characteristics. Organisms are surrounded by air - a gaseous shell characterized by low humidity and density, but high oxygen content. The light is more intense, the temperature undergoes greater fluctuations, and the humidity varies depending on the geographical location, season and time of day.

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Environmental factors.

Air is characterized by a constant composition (oxygen – about 21% and carbon dioxide – 0.03%). Low density does not provide significant resistance to organisms when they move in the horizontal direction.

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Air has direct and indirect meaning.

Direct – has little environmental significance. Indirect - carried out through the winds (change humidity, temperature, have a mechanical effect, cause a change in the intensity of transpiration in plants, etc.)

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Precipitation. The amount of precipitation, its distribution throughout the year, the form in which it falls affect the water regime of the environment. Precipitation changes soil moisture, provides available moisture to plants, and provides drinking water to animals. The timing of rainfall, its frequency, duration and nature of rains are important.

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Ecoclimate and microclimate.

Ecoclimate is the climate of large areas, the surface layer of air. Microclimate is the climate of individual small areas.

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Geographical zoning.

The ground-air environment is characterized by a clearly defined zonality. In this case, the combination of vegetation cover and animal population corresponds to the morphological divisions of the geographical envelope of the Earth. Along with horizontal zonality, vertical zonality is clearly expressed.

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Soil environment.

General characteristics. It is a loose surface layer of land in contact with the air. Soil is a complex three-phase system in which solid particles are surrounded by air and water.

Ground-air habitat

The ground-air environment is of particular interest to us, since it is here - on the border of the two shells of the Earth - that the vast majority of animals and plants live. It is easy to notice that this environment is qualitatively different from water in its physical parameters. What problems did organisms encounter when exploring land and how did they learn to overcome them?

The ground-air environment is characterized by seven main abiotic factors. Let's consider each of them.

Low air density
It makes it difficult to maintain the shape of the body and therefore provokes the formation of a support system. Thus, aquatic plants do not have mechanical tissues: they appear only in terrestrial forms. Animals necessarily have a skeleton: a hydroskeleton (like roundworms, for example), or an external skeleton (in insects), or an internal skeleton (in mammals).
On the other hand, the low density of the environment facilitates the movement of animals. Many terrestrial species are capable of flight. These are mainly birds and insects, but among them there are also representatives of mammals, amphibians and reptiles. Flight is associated with searching for prey or settling. Land dwellers reproduce only on the Earth, which serves as their support and attachment point.

Due to active flight, such organisms have modified forelimbs and developed pectoral muscles, like bats, and in gliders (for example, flying squirrels and some tropical frogs) skin folds that stretch and play the role of a parachute

Mobility of air masses
Ensures the existence of aeroplankton. It includes pollen, seeds and fruits of plants, small insects and arachnids, spores of fungi, bacteria and lower plants. This ecological group of organisms adapted due to the large relative surface area of ​​their wings, outgrowths and even webs, or due to their very small sizes.

The oldest method of pollinating plants by wind - anemophily - is characteristic of the plants known to us in the middle zone: birch, spruce, pine, nettle, cereals and sedge. Some disperse with the help of the wind: poplar, birch, ash, linden, dandelions, etc. The seeds of these plants have parachutes (dandelions, cattails) or wings (maple, linden).

Low pressure
Normally it is 760 mmHg (or 101,325 Pa). Pressure differences, compared to aquatic habitats, are very small; Thus, at an altitude of 5,800 m it is only half its normal value. Consequently, almost all inhabitants of land are sensitive to strong pressure changes, i.e. they are stenobionts in relation to this factor.

The upper limit of life for most vertebrates is about 6,000 m. This is explained by the fact that pressure drops with altitude, and therefore the solubility of oxygen in the blood decreases. To maintain a constant concentration of oxygen in the blood, the respiratory rate must increase. However, as you know, we exhale not only carbon dioxide, but also water vapor, so frequent breathing should invariably lead to dehydration of the body. This simple dependence is not typical only for rare species of organisms: birds and some invertebrates, ticks, spiders and springtails.

Gas composition
The land-air environment is characterized by a high oxygen content: it is more than 20 times higher than in the aquatic environment. This allows animals to have a very high metabolic rate. Therefore, only on land could homeothermy arise - the ability to maintain a constant body temperature, mainly due to internal energy. Thanks to homeothermy, birds and mammals can maintain vital activity in the harshest conditions

Soil and relief
Very important, first of all, for plants. Some of them are quite specialized. For example, saltworts (adapted specifically to salty soils, bananas prefer neutral soils rich in organic matter. For animals, the structure of the soil is more important than its chemical composition. For ungulates that make long migrations over dense soil, the adaptation is a reduction in the number of fingers and, consequently, a decrease in the surface area of ​​the support.Inhabitants of quick sand are characterized by an increase in the surface area of ​​the support, as in the fan-toed gecko, for example.

Soil density is also important for burrowing animals: prairie dogs, marmots, gerbils and others; some of them develop digging limbs.

Water shortage
A significant shortage of water on land provokes the development of various adaptations aimed at saving water in the body:
development of respiratory organs capable of absorbing oxygen from the air environment of the integument (lungs, trachea, pulmonary sacs)
development of waterproof covers
changes in the excretory system and metabolic products (urea and uric acid)
internal fertilization.

1. The concept of an organism’s habitat Environment is one of the basic ecological concepts, which means the entire spectrum of elements and conditions surrounding the organism in the part of space where the organism lives, everything among which it lives and with which it directly interacts. At the same time, organisms, having adapted to a certain set of specific conditions, in the process of life activity themselves gradually change these conditions, i.e., the environment of their existence.

2. Aquatic habitat (hydrosphere) The aquatic habitat is formed by the most important components of the Earth's hydrosphere and includes: the World Ocean, continental waters and groundwater. Continental waters include rivers, lakes and glaciers. The aquatic habitat is the starting point for all terrestrial life forms. The vast majority of organisms are primarily aquatic, that is, formed in an aquatic habitat. The permanent inhabitants of the hydrosphere are called hydrobionts.

Composition of the aquatic environment. Most of the Earth's surface (about 366 out of 510 million km 2, or 72%) is covered with water. The distribution and vital activity of organisms in the aquatic environment largely depend on its chemical composition. There is no shortage of water as a chemical substance in aquatic environments, except when water bodies dry out. However, water-related problems occur even in aquatic organisms.

First of all, aquatic organisms are divided into freshwater and marine, depending on the salinity of the water in which they live. The salinity of ocean water varies both in depth and in water area. In the Arctic Ocean it is below 30/00, and in the Red Sea it is above 420/00. The salt content in the Dead Sea water reaches 2627%, while the salt concentration in fresh water bodies is about 0.05%. Sea water is a complex saline solution with an average salinity of 35.2 g per 1 kg of water, i.e. 3.52% by weight, or 3.520/00.

Bental. The population of the bottom (Bentali) is called benthos ("deep"). Vertically, benthal is divided into a number of zones (only the main ones are listed): littoral - part of the coast, flooded during high tides (occupies an intermediate position between aquatic and ground-air habitats); sublittoral - continental shelf, or continental shelf - part of the benthic from the lower limit of the tides to a depth of about 200 m; bathial - an area of ​​a more or less steep continental slope to a depth of km; abyssal - an area of ​​the ocean floor with a depth of km.

Pelagial. The population of the pelagic (water column) is called pelagos. A collection of organisms floating in the water column and unable to move against the current is called plankton (“wandering”). There are phytoplankton (a set of photosynthetic planktonic organisms) and zooplankton (a set of planktonic organisms incapable of photosynthesis). Organisms capable of actively moving against the current are called nekton.

Vertically, the pelagic zone is divided into zones (only the main ones are listed): neustal - the surface layer of water bordering the atmosphere (the population of it is called neuston; organisms, part of the body of which is in the water, and part above its surface, are called pleiston); epipelagic – corresponds to the depth of the sublittoral; bathypelagic – corresponds to the depth of the bathyal; abyssopelagic – corresponds to the depth of the abyssal.

Features of the aquatic habitat and the adaptability of organisms to specific environmental factors: 1. Low content of dissolved oxygen. The O2 content in the atmosphere is 210 ml/l, the solubility of O2 in water depends on temperature: at 0°C it is 10.3 ml/l, and at 20°C – 6.6 ml/l. Thus, the oxygen content in water is approximately 20–30 times less than in the atmosphere. In this case, the actual oxygen content can decrease to 1 ml/l. Therefore, oxygen content is a limiting (limiting) factor for most aquatic organisms. The surface layers of water contain more oxygen, and oxygen can enter the deep layers either through diffusion (which occurs very slowly in water) or through vertical mixing of water masses.

2. High heat capacity and high thermal conductivity of water ensure equalization of temperatures. In relation to the temperature factor, all organisms are divided into poikilothermic (unable to regulate body temperature) and homeothermic (maintaining a constant body temperature). The direct effect of temperature on poikilothermic hydrobionts is a change in the nature of metabolism. The high thermal conductivity of water leads to the appearance of heat-insulating (fat) layers in homeothermic (warm-blooded) animals. Many hydrobionts protect themselves from ice formation in their cells by increasing the intracellular content of antifreeze (antifreeze is a substance that reduces the freezing point of water).

3. Relatively high viscosity of water. It has the greatest effect on planktonic organisms (reduces the speed of immersion and ensures their soaring in the water column) and on nektonic organisms moving at high speed (creates resistance). Plankton are characterized by an increase in body surface compared to body volume, which facilitates soaring. Nekton is characterized by a streamlined body shape, which facilitates active movement.

5. Intense absorption of light in water: the red part of the spectrum is absorbed by water, and the blue part is scattered; As a result, red rays reach only a depth of 10 m, and blue-green ones reach 160 m or more. Based on illumination, zones are distinguished: euphotic zone - favorable conditions for photosynthesis; disphotic, or twilight zone - unfavorable conditions for photosynthesis (mainly red algae and cyanobacteria live here); aphotic zone - photosynthesis is impossible.

6. Availability of water-soluble substances (Na+, K+, Cl–, NH4+, NO3– ions) and inaccessibility of water-insoluble substances (bound Ca2+ ions, heavy metal ions, phosphates). The availability of elements has the greatest impact on aquatic plants. The limiting factors for algae are the concentrations of nutrients: phosphates and nitrates. Based on the content of nutrients, they are distinguished: eutrophic waters - high content of nutrients; mesotrophic waters - moderate content of nutrients; oligotrophic waters - low content of nutrients; dystrophic waters - a high content of biogens in a bound state.

7. The overall salinity of the water has the greatest impact on animals. In salty waters (hypertonic environment), the problem of retaining water within the body arises. In unicellular animals, contractile vacuoles are less likely to contract; in multicellular animals, the distal (absorbent) parts of the renal tubules, nephridia and other excretory organs develop. In bony fish, excess salts are released through the gills.

Littoral. In the littoral zone, marine organisms are affected by environmental factors that have beneficial and unfavorable effects on the organisms. Favorable factors in the littoral zone include: high content of nutrients of terrigenous (continental) origin; high water aeration due to surf; high illumination.

Unfavorable (limiting) factors: periodic drying; destructive action of the surf; temperature changes (water and air temperatures often differ); changes in salinity (due to the flow of fresh water and evaporation of sea water in puddles); many aquatic and terrestrial predators.

Epipelagic. Favorable factors in the epipelagic zone of the open ocean include: sufficiently high aeration; high illumination. The limiting factor is the low content of nutrients due to their migration into bottom waters. However, the concentration of nutrients can increase due to upwelling - the removal of deep waters to the surface, for example, in the polar zones. The main producers of the epipelagic zone are planktonic diatoms and peridinians (capable of mixotrophic nutrition) - about 1000 species. Due to the low nutrient content, the productivity of the open ocean is very low: 50 mg carbon/1 m2 day in the tropical zone and mg carbon/1 m2 day in high latitudes.

Abyssal and abyssopelagic. A favorable factor in the abyssal and abyssopelagic zone is the stability of living conditions. Limiting factors include: lack of light and impossibility of photosynthesis; high pressure. When illumination decreases, the visual organs in animals hypertrophy, but in the complete absence of light, the visual organs are completely reduced. The inhabitants of the depths are characterized by luminescence with the participation of symbiotic luminous bacteria.

3. Ground-air habitat (atmosphere) Ground-air habitat is the most complex in terms of environmental conditions. The emergence of different groups of organisms into the ground-air habitat turned out to be possible thanks to the emergence of specific adaptations, including those of an amorphous nature. The permanent inhabitants of the ground-air habitat are called aerobionts.

Features of the terrestrial-air habitat and the adaptability of organisms to specific environmental factors: 1. Lack of water is often a limiting factor for terrestrial organisms. 2. Low heat capacity and low thermal conductivity of air leads to significant temperature changes: when direct illumination changes, daily changes, seasonal changes (seasonality is typical for moderate and high latitudes). At the same time, the low heat capacity and thermal conductivity of air make it possible for birds and mammals to develop warm-bloodedness.

3. Low viscosity and low density of air allows for a variety of body shapes in animals. At the same time, gravity becomes the limiting factor. For flying animals, it is necessary to form a streamlined body and wings. For large animals, the formation of a skeleton is necessary. Plants require mechanical tissues and a certain crown shape. 4. Light absorption occurs due to topical interspecific interactions, which leads to the appearance of tiers. 5. High oxygen content with low air humidity leads to the appearance of various respiratory organs (trachea, lungs) in animals. 6. The uneven distribution of mineral nutrition elements affects, first of all, plants, which leads to mosaicism.

4. Soil as a habitat (lithosphere, or pedosphere) Soil, or pedosphere, is a loose surface layer of land that has fertility. Soil is a three-phase system in which solid particles are surrounded by air and water. The composition of the soil includes various types of matter: living matter (living organisms), biogenic matter (organic and inorganic substances, the origin of which is associated with the activities of living organisms), inert matter (rocks) and others. Therefore, soil is a special type of substance in the biosphere - bioinert substance.

Soil composition. Soil is a layer of substances lying on the surface of the earth's crust. It is a product of the physical, chemical and biological transformation of rocks and is a three-phase medium, including solid, liquid and gaseous components in the following ratios

5. Organism as a habitat Any organism (even the smallest) is a complex system that provides a variety of living conditions for other organisms. If organisms of one species use an organism of another species as a habitat, then various biotic interactions arise between them.

The positive aspects of the organism as a habitat lead to degeneration of the body of endosymbionts (a striking example is the gradual reduction of organ systems in flukes and tapeworms); as a rule, gigantism is observed - endosymbiont forms are much larger than their related free-living forms.

At the same time, the organism as a habitat also has negative aspects: limited living space, lack of oxygen, difficulties in spreading from one host individual to another, defensive reactions of the host organism, lack of light for photoautotrophic organisms.

Test questions and assignments 1. What is habitat? 2. What habitats do you know? 3. How is the land-air habitat characterized? 4. What are the features of organisms inhabiting aquatic habitats? 5. What is the importance of soil? What characteristics does this relate to? 6. What are the adaptations of living organisms that inhabit the internal environment of other organisms?