Main groups of environmental factors. Abiotic, biotic and anthropogenic factors
ABIOTIC FACTORS, various factors not related to living organisms, both beneficial and harmful, found in the environment surrounding living organisms. These include, for example, the atmosphere, climate, geological structures, amount of light,... ... Scientific and technical encyclopedic dictionary
Environments, components and phenomena of inanimate, inorganic nature (climate, light, chemical elements and substances, temperature, pressure and movement of the environment, soil, etc.), directly or indirectly affecting organisms. Ecological encyclopedic... ... Ecological dictionary
abiotic factors- abiotiniai veiksniai statusas T sritis ekologija ir aplinkotyra apibrėžtis Fiziniai (temperatūra, aplinkos slėgis, klampumas, šviesos, jonizuojančioji spinduliuotė, grunto granulometrinės savybės) ir cheminiai (atmosferos, van dens, grunto cheminė… Ekologijos terminų aiškinamasis žodynas
Factors of inorganic nature affecting living organisms... Large medical dictionary
Abiotic factors- factors of the inorganic, or nonliving, environment in the group of environmental adaptation factors operating among biological species and their communities, divided into climatic (light, air, water, soil, humidity, wind), soil... ... The beginnings of modern natural science
ABIOTIC FACTORS- Factors of the inorganic environment affecting living organisms. These include: the composition of the atmosphere, sea and fresh waters, soil, climate, as well as zoohygienic conditions of livestock buildings... Terms and definitions used in breeding, genetics and reproduction of farm animals
ABIOTIC FACTORS- (from the Greek a negative prefix and biotikos vital, living), inorganic factors. environments affecting living organisms. K A. f. include the composition of the atmosphere, sea. and fresh water, soil, climate. characteristics (temperature pa, pressure, etc.). The totality... Agricultural encyclopedic dictionary
abiotic factors- (from the Greek a negative prefix and biōtikós vital, living), factors of the inorganic environment that affect living organisms. K A. f. include the composition of the atmosphere, sea and fresh waters, soil, climatic characteristics (temperature... Agriculture. Large encyclopedic dictionary
ABIOTIC FACTORS- environment, a set of conditions in the inorganic environment that affect the body. Chemical a.f.: chemical composition of the atmosphere, sea and fresh waters, soil or bottom sediments. Physical a.f.: temperature, light, barometric pressure, wind,... ... Veterinary encyclopedic dictionary
Environments, a set of conditions in the inorganic environment that affect organisms. A. f. are divided into chemical (chemical composition of the atmosphere, sea and fresh water, soil or bottom sediments) and physical, or climatic (temperature, ... ... Great Soviet Encyclopedia
Books
- Ecology. Textbook. RF Ministry of Defense stamp
- Ecology. Textbook. Grif Ministry of Defense of the Russian Federation, Potapov A.D.. The textbook examines the basic principles of ecology as a science about the interaction of living organisms with their habitat. The main principles of geoecology as a science about the main...
4. Abiotic environmental factors
Temperature. Most species are adapted to a fairly narrow temperature range. Some organisms, especially in the resting stage, are able to withstand very low temperatures. For example, microorganisms can withstand cooling down to -200°C. Certain types of bacteria and algae can live and reproduce in hot springs at temperatures of +80...88°C. The range of temperature fluctuations in water is much smaller than on land, and accordingly, the limits of tolerance to temperature fluctuations in aquatic organisms are narrower than in terrestrial ones. Although terrestrial organisms have adapted to significant fluctuations in environmental temperature, the optimal temperature for their life activity is within relatively narrow limits: 15-30°C.
There are organisms with variable body temperature and organisms with constant body temperature. The body temperature of the former depends on the ambient temperature. Its increase causes them to intensify their life processes and accelerate (within certain limits) development. These are fish, amphibians, and reptiles.
In nature, temperature is not constant. Sharp temperature fluctuations - severe frosts or heat - are also unfavorable for organisms. Various types of living organisms have developed many adaptations to combat cooling or overheating.
Animals with a constant body temperature - birds and mammals - depend to a much lesser extent on environmental temperature conditions. Aromorphic changes in structure allowed representatives of these two classes to remain active under very sharp temperature changes and colonize almost all habitats. However, even in mammals, some structural features are associated with temperature conditions. The mammoth, which lived in a harsh climate, had small ears, but the African elephant's ears serve as an organ of thermoregulation and therefore reach large sizes.
Light. Light in the form of solar radiation powers all life processes on Earth. For organisms, the wavelength of the perceived radiation, its intensity and the duration of exposure (day length, or photoperiod) are important. Ultraviolet rays with a wavelength greater than 0.3 microns account for approximately 10% of the radiant energy reaching the earth's surface. In small doses they are necessary for animals and humans. Under their influence, vitamin D is formed in the body. Insects visually distinguish ultraviolet rays and use this to navigate the area in cloudy weather. Visible light with a wavelength of 0.4-0.75 microns has the greatest effect on the body. Visible light energy accounts for about 45% of the total radiant energy striking the Earth. Visible light is least attenuated when passing through dense clouds and water. Therefore, photosynthesis can occur in cloudy weather and under a layer of water of a certain thickness.
Blue (0.4-0.5 µm) and red (0.6-0.7 µm) light is especially strongly absorbed by chlorophyll.
Depending on their living conditions, plants adapt to shade (shade-tolerant plants) or, on the contrary, to bright sun (light-loving plants). But even in light-loving plants, increasing the light intensity above the optimal one suppresses photosynthesis, so in the tropics it is difficult to obtain high yields of protein-rich crops.
An extremely important role in regulating the activity of living organisms and their development is played by the duration of exposure to light - the photoperiod. In temperate zones, above and below the equator, the development cycle of plants and animals is confined to the seasons of the year, and the signal for preparation for changes in temperature conditions is the length of daylight hours, which, unlike other seasonal factors, is always the same at a certain time of year in a given place . The photoperiod is like a trigger mechanism, including physiological processes that consistently lead to the growth and flowering of plants in the spring, fruiting in the summer and shedding leaves in the fall, as well as molting and accumulation of fat, migration and reproduction in birds and mammals, and the onset of the resting stage in insects . Changes in day length are perceived by the visual organs of animals or by special pigments in plant leaves.
Infrared radiation makes up 45% of the total amount of radiant energy falling on the Earth. Infrared rays increase the temperature of plant and animal tissues and are well absorbed by inanimate objects, including water. Since any surface with a temperature above zero emits long-wave heat rays, a plant or animal also perceives heat energy from surrounding objects.
Humidity. Water is a necessary component of the cell, so its quantity in certain habitats serves as a limiting factor for plants and animals and determines the nature of the flora and fauna in a given area. Excess water in the soil leads to the development of marsh vegetation. Depending on soil moisture (and annual precipitation), the species composition of plant communities changes. Broad-leaved forests to the south are replaced by small-leaved forests, which turn into forest-steppe. With a further increase in soil dryness, tall grass gives way to short grass. With annual precipitation of 250 mm or less, a desert landscape develops. Uneven distribution of precipitation across seasons is also an important limiting factor for organisms. In this case, plants and animals have to endure long droughts. During a short period of soil moisture, primary production for the community as a whole accumulates. It determines the size of the annual food supply for animals and saprophages - organisms that decompose organic remains.
Separates the quality of the biological form of matter movement from other manifestations. It helps to more fully understand the phenomenon of life and outline prospects for further research. 4. The inevitability of the transition of the biosphere into the noosphere The evolution of the biosphere is considered one of the most interesting issues from a philosophical point of view. IN AND. Vernadsky considered the volume and weight of “living matter”...
Life activity. The main specificity of the modern biosphere is clearly directed flows of energy and biogenic (associated with the activity of living beings) circulation of substances. (10) Developing the doctrine of the biosphere, V.I. Vernadsky came to the conclusion that the main transformer of cosmic energy is the green matter of plants. Only they are capable of absorbing the energy of solar radiation and...
Referred to the eradication of wars from the life of mankind. He paid great attention to solving the problems of democratic forms of organizing scientific work, education, and disseminating knowledge among the masses. 5. The transition of the biosphere to the noosphere: forecast and reality Vernadsky, analyzing the geological history of the Earth, argues that there is a transition of the biosphere to a new state - to the noosphere under the influence of a new...
We see the geological forces around us in action. This coincided, hardly by chance, with the penetration into scientific consciousness of the conviction about the geological significance of Homo sapiens, with the identification of a new state of the biosphere - the noosphere - and is one of the forms of its expression. It is connected, of course, primarily with the clarification of natural scientific work and thought within the biosphere, where living matter plays the main...
CHAPTER 5. GROUP OF ABIOTIC FACTORS
General information
The influence of climatic factors (temperature, air humidity, precipitation, wind, etc.) on the body is always cumulative. However, studying the impact of each individual climatic factor allows us to better understand its role in the life of certain species or crops and serves as a necessary prerequisite for studying the impact of the entire complex of climatic factors. When assessing climatic factors, one cannot attach exclusive importance to just one of them. Any of the above-mentioned climate components in specific conditions can be represented in different ways: not only quantitatively, but also qualitatively. For example, the amount of annual precipitation for a certain area may be quite high, but its distribution throughout the year is unfavorable. Therefore, in certain periods of the year (during growing seasons), moisture can act as a minimum factor and inhibit the growth and development of plants.
Light
In crops that are especially light-demanding, such as rice, development is delayed when there is insufficient light. The formation of highly productive forest stands of many forest-forming species and fruit plantations is also largely determined by the intensity of solar energy. The sugar content of beets directly depends on the intensity of the sun's radiant energy during the growing season. It is known that flax (Linum usitatissimum) and hemp sativa (Cannabis sativa) under short daylight conditions, a significant amount of oil is synthesized in the tissues, and under long daylight conditions, the formation of bast fibers accelerates. The response of plants to the length of day and night is manifested in acceleration or delay of development. Consequently, the effect of light on a plant is selective and ambiguous. The importance of illumination as an environmental factor for the body is determined by the duration, intensity and wavelength of the light flux.
At the boundary of the earth's atmosphere with space, radiation ranges from 1.98 to 2 cal/cm 2 per minute; This value is called the solar constant. Under different weather conditions, 42...70% of the solar constant reaches the Earth's surface. Solar radiation, passing through the atmosphere, undergoes a number of changes not only in quantity, but also in composition. Short-wave radiation is absorbed by the ozone shield, located at an altitude of about 25 km, and by oxygen in the air. Infrared rays are absorbed in the atmosphere by water vapor and carbon dioxide. As a result, the air heats up. The rest of the radiant energy reaches the Earth's surface in the form of direct or diffuse radiation (Fig. 10). The combination of direct and diffuse solar radiation constitutes the total radiation. On clear days, diffuse radiation makes up 1/3 to 1/8 of the total radiation, while on cloudy days, diffuse radiation makes up 100%. At high latitudes, diffuse radiation predominates, while under the tropics, direct radiation predominates. Scattered radiation contains up to 60% of yellow-red rays at noon, direct radiation - 30...40%.
The amount of radiation reaching the Earth's surface is determined by the geographic latitude of the area, the length of the day, the transparency of the atmosphere and the angle of incidence of the sun's rays. On clear sunny days, the radiant energy reaching the Earth's surface consists of 45% visible light (380...720 nm) and 45% infrared radiation, only 10% is ultraviolet radiation. The dustiness of the atmosphere has a significant impact on the radiation regime. In some cities, due to its pollution, the illumination may be 15% or less of the illumination outside the city.
Illumination on the Earth's surface varies widely. It all depends on the height of the sun above the horizon, i.e. the angle of incidence of the sun's rays, the length of the day and weather conditions, and the transparency of the atmosphere. Light intensity also fluctuates depending on the season and time of day. The quality of light is also unequal in certain regions of the Earth, for example, the ratio of long-wave (red) and short-wave (blue and ultraviolet) rays. As is known, short-wave rays are absorbed and scattered by the atmosphere more than long-wave rays. Therefore, in mountainous areas there is always more short-wave solar radiation.
Rice. 10. The intensity of solar radiation falling on the Earth’s surface, according to W. Larcher
Since photosynthetically active radiation (PAR) is represented by a portion of the spectrum between wavelengths of 380 and 710 nm and is maximum in the region of orange-red rays (600...680 nm), it is natural that the coefficient of use of scattered radiation by plants is higher. Due to the increase in day length, light, even in high northern latitudes, does not limit the life activity of plants. L. Ivanov calculated that even on Spitsbergen there is enough solar radiation (20,000 kJ per 1 ha) to obtain some yield of dry plant mass.
Different types of plants and plant groups have different needs for light, in other words, for normal vegetation they also need different light supply (£,), i.e., the percentage of total PAR. This allows us to distinguish three ecological groups of plants in relation to the need for light:
· light plants, or heliophytes (from the Greek helios - sun + phyton), - L opt= 100%, £ min = 70%, these are plants of open spaces, for example feather grass (Stipa), most cultivated plants (sugar beets, potatoes, etc.);
· shade-tolerant plants, or hemiscyophytes, can grow at L = 100%, but also tolerate large shade; cocksfoot (Dactylis glomerata), for example, it is capable of vegetating in a range L from 100 to 2.5%;
· shade plants, or sciophytes (from the Greek skia - shadow), do not tolerate full light, their L max is always less than 100%, this is common oxalis (Oxalis acetosella), European seven-year-old (Trientalis europaea) and etc.; Due to the special structure of the leaves, sciophytes at low light intensity are able to assimilate carbon dioxide no less effectively than heliophyte leaves at L= 100 %.
Moscow plant grower A. Doyarenko found that for most agricultural herbaceous plants the coefficient of light use for photosynthesis is 2...2.5%, but there are exceptions:
· fodder beet - 1.91
· vika - 1.98
· clover - 2.18
· rye - 2.42
· potatoes - 2.48
· wheat - 2.68
· oats - 2.74
flax - 3.61
· lupine - 4.79
Of the plant communities, forest communities most actively transform the composition of sunlight, and a very small part of the initial solar radiation reaches the soil surface. It is known that the leaf surface of a tree stand absorbs about 80% of incident PAR, another 10% is reflected and only 10% penetrates under the forest canopy. Consequently, total radiation and radiation penetrating through the canopy of woody plants differs not only quantitatively, but also qualitatively.
Sciophytes and heliocyophytes, living under the canopy of other plants, are content with only a fraction of full illumination. Thus, if in wood sorrel the maximum intensity of photosynthesis is achieved at 1/10 of full daylight, then in light-loving species it occurs at approximately 1/2 of this illumination. Light plants are less adapted to exist in low light than shady and shade-tolerant plants. The lower limit at which forest green mosses can grow is 1/90 full daylight. In tropical rainforests there are even more sciophylic species that grow at 1/120 of full light. Some mosses are surprising in this regard: Schistostega pinnate (Schistostega pennaia) and others are plants of dark caves, vegetating at 1/2000 full illumination.
Each geographical area is characterized by a certain light regime. The most important elements of the light regime that determine the direction of plant adaptation are the intensity of radiation, the spectral composition of light, and the duration of illumination (length of day and night). The length of a solar day is constant only at the equator. Here day, like night, lasts 12 hours. The duration of a solar day during the summer period increases from the equator towards both poles; At the pole, as is known, the polar day lasts the whole summer, and the polar night lasts in winter. The plant's response to seasonal changes in the length of day and night is called photoperiodism.
Plant growers have long noticed that agricultural plants of different origins respond differently to daylength. Depending on this reaction, some species were identified as long-day plants, others as short-day plants, and others as not noticeably responding to day length. It is well known that in long day conditions a high yield of wheat, rye, and oats is formed (Avena sativa) and a number of fodder cereals; Long-day plants also include potatoes, citrus fruits and a number of other vegetable and fruit crops. Prolonged illumination of these plants causes a faster passage of the developmental phases of fruits and seeds. On the other hand, short-day plants such as millet (Panicum miliaceum), sorghum (Sorghum segpiit), rice, the speed of development stages slows down with prolonged illumination. Reducing development periods is achieved by shortening the lighting time.
These features must be taken into account when introducing agricultural plants. Low latitude species (southern plants) are often short-day plants. When introduced to high latitudes, i.e., under long-day conditions, they develop slowly, often do not ripen, and sometimes do not even bloom, like hemp, for example. Jerusalem artichoke can also be included in this group. (Helianthus tuberosus). Thus, the length of day and night can determine the boundaries of distribution and possible introduction of certain species: “southern” - to the north, “northern” - to the south. Neutral with respect to day length include tomato, grapes, buckwheat (Fagopyrum esculentum) and etc.
In the course of studying photoperiodism and photochemical reactions, it was found that the growth of long-day plants in the spring-summer period, when long daylight hours are observed in nature, clearly accelerates. However, in the second half of summer, when the sunny day decreases, growth processes clearly slow down. As a result, in cold climates, long-day plants do not always have time to form a complex of integumentary tissues, the periderm, before the onset of frost. Therefore, long-day perennial crops cultivated at high latitudes may lose winter hardiness, which must be kept in mind when selecting a range of plants for cultivation in these areas. In long-day conditions, it is preferable to introduce annual crops that do not require overwintering. The northward movement of some other crops, such as clovers, is hampered not by winter frosts, but by the nature of photoperiodic reactions. It is their character that can explain the paradoxical fact that the frost resistance of clovers and alfalfa is higher in the central zone of the European part of Russia than in the northern part.
Light has a formative effect on plants, which is manifested in the size, shape and structure (macro- and microscopic) of light and shadow leaves (Fig. 11), as well as in growth processes. The dependence of leaf (shoot) structure on light is not always direct; leaves (shoots) developing in the spring are formed in accordance with the lighting not of the current year, but of the past, i.e., when the buds were laid. I. Serebryakov (1962) believed that the light structure of a leaf is already determined in the bud. The leaves retain this structure quite stably even when the light shoots are transferred to shading. Great height, columnar shape of trunks, high arrangement of crowns (cleared of dry branches) characterize light-loving plants.
Rice. 11. Cross sections of lilac leaves (genus Syringa): a- light; b- shadow
One of the reactions of light-loving plants is to inhibit the growth of above-ground shoots, which in some cases leads to strong branching, in others to rosette. The plants of the mentioned group are also distinguished by a number of other structural changes: small leaves, increased thickness of the outer wall of the epidermis and its outgrowths (trichomes and emergents), cuticular layer, etc. (Fig. 12).
Rice. 12. Cross section of a leaf of the light-loving oleander plant (Nerium oleander):
1
- two-layer epidermis with cuticle; 2 - hypodermis; 3
- isopalisade mesophyll; 4
- depressions on the underside of the leaf (crypts) with stomata and hairs
One example of plant adaptation to light is the orientation of the leaf blade in relation to the sun's rays. There are three orientation methods:
· the leaf blade is oriented horizontally, i.e. perpendicular to the sun's rays; in this case, the rays are captured as much as possible when the sun is at its zenith;
· the leaf blade is oriented parallel to the sun's rays, that is, it is located more or less vertically, as a result the plant better absorbs the sun's rays in the morning and early evening;
· leaf blades are distributed diffusely along the shoot, like in corn - sometimes vertically, sometimes horizontally, so solar radiation is captured quite fully throughout the daylight hours.
Available scientific data suggest that plants at high latitudes, where low solstice prevails, more often have vertical leaf orientation. When organizing mixed crops, such as forage grasses, it is necessary to take into account the structure of the shoots of the crop components. A successful combination of forage grasses with different leaf orientations will provide a greater yield of phytomass.
As already noted, depending on the lack or excess of light, many plants are able to place leaves in planes perpendicular and parallel to the direction of the sun’s rays, forming a so-called leaf mosaic. A leaf mosaic is formed as a result of the rational placement of not only leaf blades of unequal size, but also petioles. A typical leaf mosaic can be observed in phytocenoses with the participation of Norway maple and small-leaved linden (Tilia cordata), smooth elm (Ulmus laevis), mountain elm (Ulmus glabra) and other tree species. The leaf mosaic is clearly visible in many plants with horizontal branches, for example in common ivy (Hedera helix) and many herbaceous plants (Fig. 13).
Rice. 13. Leaf mosaic near ivy (Hedera helix)
Compass plants clearly avoid strong light. Their leaf blade is not perpendicular to the sun's rays, like rosette plants, but parallel, like eucalyptus or wild lettuce (Lactuca serrtola), which protects the leaves from overheating in conditions of excess solar radiation. This ensures favorable photosynthesis and transpiration.
There are a number of other adaptive adaptations, both structural and physiological. Sometimes such adaptations are clearly seasonal in nature, which is well illustrated, for example, by the common duckweed (Aegopodium podagrata). In a typical habitat (oak forests), two “generations” of leaves are formed on the plant during the growing season. In the spring, when the tree buds have not yet blossomed and the forest canopy lets in a lot of light, a leaf rosette is formed, its leaves are clearly luminous in structure (micro- and macroscopic).
Later, when a dense forest canopy develops and only 3...4% of radiant energy reaches the soil surface, a second “generation” of leaves appears, clearly shady. It is often possible to observe both light and shadow leaves on one individual plant. Leaves of the lower tiers of the black mulberry crown (Morus nigra) large, lobed, while the upper tiers of the crown bear light leaves - smaller, devoid of blades. In forest-forming species, the periphery of the crown is formed in a similar way: in the upper tiers there are light leaves, inside the crown there are shadow leaves.
Temperature
Life activity of any species occurs in certain temperature ranges. At the same time, zones of optimum, minimum and maximum are traced. In the zone of minimum or maximum, the body’s activity attenuates. In the first case, low temperatures (cold), and in the second, high temperatures (heat) lead to disruption of its life processes. Beyond extreme temperatures lies the lethal zone, in which the irreversible process of plant death occurs. Therefore, temperatures determine the boundaries of life.
Due to their sedentary lifestyle, higher plants have developed greater tolerance to daily and seasonal (annual) temperature fluctuations. Many forest-forming species of our taiga - Siberian pine, Daurian larch (Larix dahurica) and others - can withstand temperature drops down to - 50 °C and below and summer heat up to 25 °C and above. The annual amplitude reaches 75 °C, and sometimes 85...90 °C. Plant species that can withstand large temperature changes are called eurythermic (from the Greek eurys + therme - heat) in contrast to stenothermic ones.
Heat differentiation on our planet is the basis of latitudinal zonality and altitudinal zonation of vegetation and soils. Due to the decrease in the height of the solstice and the angle of incidence of the rays from the equator to the poles, the amount of heat changes. Thus, the average annual temperature near the equator is 26.2 °C, near 30 °C. w. it is already equal to 20.3 ° C, and at 60 ° C. w. decreases to - 1 °C.
In addition to the average annual temperature of a given area, the highest and lowest temperatures (absolute maximum and absolute minimum) observed in a given climatic zone, as well as the average temperature of the warmest and coldest months, are important in the life of organisms. Thus, the duration of the growing season in the tundra (i.e. above 70° N) is only one and a half to two and a half months at an average temperature of 10...12 °C.
Taiga, otherwise the zone of coniferous forests, has a growing season of three to five months, an average temperature of 14.. L6 °C. In the southern part of the zone, where coniferous-deciduous forests predominate, the growing season lasts four to five months, the average temperature is 15... 16 °C. In the zone of broad-leaved forests (40...50° N), the growing season is five to six months, the average temperature is 16...18 °C. A sharp contrast to the described zones is the zone of tropical rainforests (0...15° N and S). The growing season here is year-round with an average temperature of 25...28 °C and is often not differentiated by seasons. An extremely important feature of tropical regions is that the difference between the average temperatures of the warmest and coldest months is less contrasting than the daily fluctuations.
Plant growth is directly related to temperature. The dependence of individual species on temperature varies widely. There is a clear distinction between thermophilic (from the Greek therme + philia - love) plants and their antipodes - cold-tolerant, or cryophilic (from the Greek kryos - cold). A. Decandolle (1885) distinguished groups of hekistothermic, microthermic, mesothermic and megathermic plants (from the Greek gekisto - cold, mikros - small, mesos - medium, megas - large).
The listed groups of plants in relation to temperature are complex; when identifying them, the relationship of plants to moisture is also taken into account. An addition to this classification can be considered the identification of cryophyte and psychrophyte plants (from the Greek psychros - cold + phyton) - hekistotherms and partially microtherms, requiring different moisture regimes. Cryophytes grow in cold, dry conditions, while psychrophytes are cold-tolerant plants in moist soils.
The influence of temperatures on the distribution of individual plant species and their groups is no less clear. The connection between the geographic distribution of individual species and isotherms has long been established. As you know, grapes ripen within an isotherm with an average temperature for six months (April - September) of 15 ° C. The distribution of English oak to the north is limited by the annual isotherm of 3 °C; The northern limit of date palm fruiting coincides with the annual isotherm of 18...19 °C.
In a number of cases, the distribution of plants is determined not only by temperatures. Thus, the 10 °C isotherm passes from west to east through Ireland, Germany (Karlsruhe), Austria (Vienna), Ukraine (Odessa). The named areas have a fairly different species composition of natural vegetation cover and provide the opportunity for the introduction and cultivation of a diverse set of crops. In Ireland, crops often fail to ripen. In Germany and Ireland, many pumpkins (watermelons - Citrullus vulgaris, melons), although camellias grow in open ground (Camella) and palm trees. In Karlsruhe, ivy and holly grow in open ground ( Ilex), sometimes the grapes also ripen. In the Odessa region, melons and watermelons are cultivated, but ivy and camellias cannot withstand low winter temperatures. Many such examples can be given.
Thus, average temperatures in isolation from other environmental factors cannot serve as a reliable indicator (indicator) of the possibility of introduction and cultivation of the crop of interest to us. The bottom line is that different types of plants are characterized by unequal lengths of the growing season. Therefore, with regard to temperature, it is necessary to take into account both the duration of the period of favorable temperatures for the normal development of plants, and the time of onset and duration of minimum temperatures (the same for maximum temperatures).
In the environmental and plant growing literature, the sum of active temperatures is widely used to estimate the thermal resources of the growing season. It serves as a good indicator for assessing the heat needs of plants and makes it possible to determine the area for cultivating a particular crop. The sum of active temperatures consists of the sum of positive average daily temperatures for the period when it is above 10 °C. In areas where the sum of active temperatures is 1000...1400 °C, early varieties of potatoes and root crops can be cultivated; where this amount reaches 1400...2200 °C, - cereals, potatoes, flax, etc.; the sum of active temperatures of 2200...3500 °C corresponds to the zone of intensive fruit growing; when the sum of these temperatures exceeds 4000 °C, the cultivation of subtropical perennials is successful.
Organisms whose vital activity and body temperature depend on heat coming from the environment are called poikilothermic (from the Greek poikilos - different). These include all plants, microorganisms, invertebrate animals and some groups of chordates. The body temperature of poikilothermic organisms depends on the external environment. That is why the ecological role of heat in the life of all systematic groups of plants and the named groups of animals is of paramount importance. Highly organized animals (birds and mammals) belong to the group of homeotherms (from the Greek homoios - identical), in which the body temperature is constant, since it is maintained by its own heat.
It is known that the protoplast of cells of living organisms is able to function normally in the temperature range 0...50 °C. Only organisms that have special adaptations can withstand these extreme temperatures for long periods of time. Physiologists have established optimal and critical temperatures for breathing and other functions. It turns out that the lower limit of the breathing temperature of wintering organs (buds, needles) is 20... - 25 °C. As the temperature rises, the breathing rate increases. Temperatures above 50 °C destroy the protein-lipid complex of the surface layer of the cytoplasm, which leads to the loss of osmotic properties by cells.
In some regions of Russia, mass death of plants from too low temperatures is periodically observed. The catastrophic effect of the latter has the greatest impact in winters with little snow, mainly on winter grains. Sudden cold snaps in the spring, when plants begin to grow (late spring frosts), are also destructive. Often, not only introduced evergreen trees, such as citrus fruits, but also deciduous plants die from the cold. N. Maksimov, studying the mechanism of action of low temperatures, came to the conclusion that the cause of plant death is explained by dehydration of the cytoplasm. Crystallization of water occurs in the intercellular spaces of the tissue. Ice crystals draw water from cells and mechanically damage cell organelles. The critical moment comes precisely with the appearance of ice crystals inside the cells.
Natural groups of frost-resistant plants have been identified. These include coniferous evergreen trees and shrubs, as well as lingonberries (Vaccinium vitis-idea), heather, etc. Among herbaceous perennials, many frost-resistant plants have also been identified that can survive harsh winters. During winter dormancy, plants can withstand very low temperatures. So, black currant shoots (Ribes nigrum) with a slow decrease in temperature to - 253 ° C (temperature close to absolute zero) they can remain viable.
Most plant species have individual responses to temperature. Thus, in spring, germination of rye grains begins at 1...2 °C, meadow clover seeds (Trifolium pratense)- at 1 °C, yellow lupine (Lupinus luteus)- at 4...5, rice - at 10...12 °C. The optimal temperatures for ripening the seeds of these crops are 25, 30, 28, 30...32 °C, respectively.
For normal growth and development of plants, an appropriate ambient temperature is required for above-ground and underground organs. For example, flax develops normally at a temperature of the root approximately two times lower (10 °C) than that of the above-ground organs (22 °C). During ontogenesis, the need of plants for heat changes noticeably. The temperature of the plant body organs varies significantly depending on the location (soil, air) and orientation in relation to the sun's rays (Fig. 14). It has been experimentally established that the germination of rapeseed seeds (Brassica napus), rapeseed (V. campestrts), wheat, oats, barley, clover, alfalfa and other plants is observed at a temperature of 0...2 °C, while higher temperatures (3...5 °C) are required for the emergence of seedlings.
Rice. 14. Temperature (°C) of different plant organs: A - new versions (Novosiversia glacialis), according to B. Tikhomirov; B - Siberian scilla (Scilla sibiriati, according to T. Goryshina, A- bedding, b- the soil
Many types of continental plants are favorably affected by daily thermoperiodism, when the amplitude of night and day temperatures is 5... 15 ° C. Its essence lies in the fact that many plants develop more successfully at lower night temperatures. For example, tomatoes develop better if the daytime air temperature reaches 26° C, and the night temperature 17...18° C. Experimental data also indicate that plants in temperate latitudes also require low autumn temperatures - seasonal thermoperiodism - for normal ontogenetic development.
The temperature factor affects plants at all stages of their growth and development. Moreover, at different periods, each type of plant needs certain temperature conditions. For most annual plants, such as barley, oats and others, a general pattern can be traced: in the early stages of development, the temperature should be lower than in later stages.
Megathermal plants of tropical origin, such as sugarcane (Saccharum officinarum), need high temperatures throughout their lives. Plants in hot and dry regions - euxerophytes, as well as many succulents, such as Cactus and Crassulaceae - are characterized by the greatest tolerance to ultra-high temperatures. (Crassulaceae). This is also typical for plants in soils saline, especially with sulfides and chlorides. These species, as shown by X. Ludengaard (1925, 1937), remain viable even at 70 °C. Severely dehydrated seeds and fruits tolerate high temperatures well. It is on this property that the well-known method of combating the pathogen of loose smut of wheat is based. (Ustilago trtttci). When the affected seeds are heat treated, the fungus, being stenothermic, dies, while the grain embryo remains viable.
It is more difficult to resolve the issue of the influence of temperature on changes in the structure of the plant itself, its morphology. Observations in nature and experimental evidence provide various explanations. In fact, such an adaptation as the strong pubescence of the bud scales and leaves seems to be complex; it serves as protection not only from bright light, but also from high temperatures, as well as from excessive evaporation of moisture. The bright shine of glossy leaves, the parallel arrangement of the leaf blade to the sun's rays, felt pubescence - all this undoubtedly prevents overheating of the leaf, as well as excessive transpiration.
The founder of plant ecology, E. Warming (1895), clearly demonstrated the influence of temperature on the formation of squat and rosette forms of plants in the Arctic and in the highlands of the alpine and subnival zones, i.e., at the very border of eternal snow. We are talking not only about herbaceous stemless, rosette plants like elecampane (Inula rhizocephala), but also about woody life forms - dwarf birch, Turkestan juniper (Juniperus turcestanica), dwarf cedar, etc. Creeping and cushion forms of plants, for example arctic minuartia (Minuartia arctica), most adapted to living conditions at the very surface of the soil under the cover of snow cover. When there is no snow, the highest temperature remains in the ground layer of air at a height of up to 15...20 cm and the wind force is minimal. In addition, a special microclimate is created inside the “cushion” formed by the plant, and temperature fluctuations here are much less pronounced than outside it. The temperature factor can affect the development of squat forms both directly and indirectly - due to disruption of water supply and mineral nutrition.
The greatest role is played by the direct influence of temperature in the process of plant geophilization. Geophilization refers to the immersion of the lower (basal) part of the plant into the soil (first the hypocotyl, then the epicotyl, the first internode, etc.). This phenomenon is characteristic primarily of angiosperms. It was during their historical development that geophilization played a prominent role in the transformation of life forms from trees to grasses. As the base of the shoots is immersed in the soil, a system of adventitious roots, rhizomes, stolons and other organs of vegetative propagation intensively develops. Geophilization was a necessary prerequisite for the appearance of various underground plant organs, especially organs of vegetative reproduction. This gave angiosperms great advantages in the struggle for existence and dominance on the continents of the Earth.
In the ontogeny of many angiosperms, geophilization of plants is carried out with the help of special retractile (contractile) roots. Interesting experimental studies on geophilization were carried out by P. Lisitsyn. He found that the retraction of the basal part of the plant into the soil is much more widespread than previously thought (Fig. 15). For winter crops, geophilization improves wintering conditions; for spring crops, such as buckwheat, it improves water supply conditions.
Rice. 15. Geophilization (retraction into the soil) of the subcotyledon of meadow clover (Trifolium pratense), according to P. Lisitsin: A - soil surface; b - retraction depth
Water
All vital processes at the levels of cells, tissues, and organisms are unthinkable without sufficient water supply. Plant organs usually contain 50...90% water, and sometimes more. Water is an essential component of a living cell. Dehydration of the body entails a slowdown and then cessation of the life process. Maximum dehydration while maintaining life and reversibility of normal life processes is observed in spores and seeds. Here the water content drops to 10 and 12%, respectively. The cold resistance, as well as the heat resistance of plants, depends on the amount of water they contain. Soil nutrition of plants (the supply and transportation of nitrogenous and other mineral substances), photosynthesis, and enzymatic processes are also associated with water. Metabolic products are dissolved and transported in the plant body also with the help of water.
Water is one of the necessary conditions for the formation of plant mass. It has been established that 99.5% of the water transported from the root system to the leaves maintains turgor and only 0.5% of it is spent on the synthesis of organic matter. To obtain 1 g of dry plant mass, 250...400 g of water or more is required. The ratio of the above values is the transpiration coefficient. This indicator varies significantly among different species and even varieties of plants. There is a pattern: the value of the transpiration coefficient is directly proportional to the dryness of the climate. Therefore, the same variety may have different transpiration coefficients when grown in different ecological and geographical conditions.
The optimum water regime is observed in cases where the evaporation of water into the atmosphere does not exceed its entry into the plant body from the soil. During ontogenesis, a stage comes when the water supply determines all subsequent plant development and harvest. These developmental phases have been well studied in many cultivated plants. The critical stage of development in cereals is the formation of flowers and inflorescences. Under unfavorable water supply conditions, part of the tubercles of the growth cone degenerates. Since this process is irreversible, shortened, weakly branched inflorescences are formed, containing few flowers, and, consequently, caryopses.
Over millions of years of continuous evolution, organisms have adapted to different living conditions. Plants of arid regions, where the climate is extremely dry, have pronounced xeromorphic (from the Greek xeros - dry, morphe - shape) characteristics. They make it possible to reduce moisture loss, which mainly occurs as a result of transpiration through the stomatal apparatus, as well as through water stomata (the phenomenon of guttation - from the Latin gutta - drop). Significant moisture consumption also occurs through the cells of the epidermis (cuticular evaporation). Guttation is well expressed in seedlings of cereals, potatoes, buckwheat, and in many indoor plants, for example, alocasia (Alocasia macrorhiza) etc. Guttation is most common in plants of the humid tropics and subtropics.
Plants in arid conditions have a variety of adaptations to prevent water loss. In many cereals, the leaves are rolled into a tube, so that the stomata are inside. The leaves of xeromorphic plants often have a thick waxy coating or hairs. The transpiration organs (stomatal apparatus) in such plants are immersed in the mesophyll; their leaves are often reduced to scales or transformed into spines and thorns. With a strong reduction of leaves, the function of photosynthesis is taken over by the stem. Many crops, both herbaceous and woody, respond to a lack of soil moisture and groundwater by rapidly expanding their root systems.
The water balance of a plant is determined by the difference between the absorption and consumption of water by the body. The water balance is influenced by a whole series of environmental conditions: air humidity, the amount and distribution of precipitation, the abundance and height of groundwater, the direction and strength of the wind.
Water consumption by plants is largely determined by the relative humidity of the air. In a more humid climate, other things being equal, plants spend less moisture to form dry matter. In the temperate zone, transpiration productivity is about 3 g of dry matter at a consumption of 1 liter of water. With increasing air humidity, seeds, fruits and other plant organs contain less proteins, carbohydrates and mineral elements. In addition, the synthesis of chlorophyll in leaves and stems decreases, but at the same time growth increases and the aging process is inhibited. When the air is highly saturated with water vapor, bread ripens very slowly, and sometimes does not ripen at all. Air humidity has a great influence on the quantity and quality of crops and the operation of agricultural machines. At high air humidity, crop losses during threshing and harvesting increase, and the processes of post-harvest seed ripening slow down, which ultimately reduces their safety.
Depending on their relationship to moisture, plants are divided into two ecological groups: poikihydride and homohydride. The former do not have special mechanisms for regulating the hydration (water content) of their body; in terms of the nature of moisture loss, they practically do not differ from wet cotton fabric. Poikilohydrides include lower plants, mosses, and many ferns. The vast majority of seed plants are homohydrid and have special mechanisms (stomatal apparatus, trichomes on leaves, etc.) to regulate the internal water regime. Poikihydridity among angiosperms is extremely rare and is most likely of secondary origin, i.e., it is a kind of adaptation to the xeric regime. A rare example of a poikihydrid angiosperm is the desert sedge, or silt. (Carex physoides).
Based on their characteristic water regime, homohydrid plants are divided into hydrophytes, helophytes, hygrophytes, mesophytes, xerophytes, and ultraxerophytes.
Hydrophytes (from the Greek hydor - water + phyton) are aquatic plants that freely float or take root at the bottom of a reservoir or are completely submerged in water (sometimes with leaves floating on the surface or inflorescences exposed above the water). Absorption of water and mineral salts is carried out by the entire surface of the plant. In floating hydrophytes, the root system is greatly reduced and sometimes loses its functions (for example, in duckweeds). The mesophyll of underwater leaves is not differentiated, there is no cuticle and stomata." Examples of hydrophytes are Vallisneria (Vallisneria spiralis), Elodea canadensis (Elodea canadensis), floating pondweed (Potamogeton natans), Aldrovanda vesiculata (Aldrovanda vesiculosa), white water lily (Nymphaea alba), yellow egg capsule (Nuphar luteum) etc. The listed species are characterized by a strong development of air-bearing tissue - aerenchyma, a large number of stomata in floating leaves, weak development of mechanical tissues, and sometimes diversity of leaves.
Helophytes (from the Greek helos - swamp) are aquatic-terrestrial plants growing both in water in shallow waters and along waterlogged banks of rivers and reservoirs; They can also live on abundantly moist soil away from water bodies. They are found only in conditions of constant and abundant water supply. Helophytes include common reed; plantain chastukha (Alisma plantago-aquaucd), arrowhead arrowhead (Saggitaria sagittifolia), umbrella susak (Butomus umbellatus) etc. Helophytes can withstand a lack of oxygen in the soil.
Hygrophytes (from the Greek hygros - wet) are terrestrial plants growing in conditions of high soil and air humidity. They are characterized by tissue saturation with water up to 80% and higher, and the presence of water stomata. There are two ecological groups of hygrophytes:
· shady, growing under the canopy of damp forests in different climatic zones, they are characterized by water stomata - hydathodes, which allow them to absorb water from the soil and transport mineral elements, even if the air is saturated with water vapor; Impatiens common are classified as shady hygrophytes (Impattens noli-tangere), Circe of Paris (Circaea lutetiana), wood sorrel;
· light, growing in open habitats, where the soil and air are constantly moist; these include papyrus (Cyperus papyrus), sundew rotundifolia (Drosera rotundifolia), marsh bedstraw (Galium palustre), rice, marsh marigold (Caltha palustrts).
Hygrophytes are characterized by poor adaptability to the regulation of tissue water content, therefore, picked plants of this group wither very quickly. Thus, hygrophytes from terrestrial homohydrid plants are closest to poikihydrid forms. Hydrophytes, helophytes and hygrophytes have a positive water balance.
Mesophytes (from the Greek mesos - average) are plants adapted to life in conditions of average water supply. They exhibit high viability in moderately warm conditions and average mineral nutrition. They can tolerate short-term, not very severe drought. The vast majority of cultivated crops, as well as plants of forests and meadows, belong to this group. At the same time, mesophytes are so diverse in their morphophysiological organization and adaptability to different habitats that it is difficult to give them a general definition. They constitute a diverse range of intermediate plants between hygrophytes and xerophytes. Depending on their distribution in different climatic zones, A. Shennikov (1950) identified the following five groups of mesophytes: evergreen mesophytes of tropical rainforests - trees and shrubs [*], growing all year round without a pronounced seasonal break; they are characterized by large leaves with hydathodes; often such leaves have a point at the end that drains water; leatheriness, drooping and dismembered leaves ensure their safety during rains (philodendron - Philodendron, ficus - Ficus elastica and etc.); the upper wide and dense leaves of the plants of the group are adapted to bright light, they are characterized by a thick cuticle, well-defined columnar parenchyma, a fairly developed conducting system and mechanical tissues;
winter-green woody mesophytes, or tropophytes (from the Greek tropos - turn), are also predominantly species of tropical and subtropical zones, but common not in rain forests, but in savannas; they shed their leaves and go into a dormant state during the dry summer period; have well-defined integumentary complexes - periderm and crust; a typical representative is the baobab;
summer-green woody mesophytes - plants of temperate climates, trees and shrubs that shed their leaves and go dormant in the cold season; these include most deciduous trees in cold and temperate zones; the fall of leaves in winter serves as an adaptation to reduce evaporation in the cold months, when the absorption of water from the soil is difficult; Integumentary complexes (periderm and crust), as well as devices for protecting the kidneys from water loss, are of great importance for this subgroup of mesophytes; nevertheless, in winter the plants lose a significant amount of moisture; evaporation occurs mainly through weakly protected leaf scars and buds;
summer-green herbaceous perennial mesophytes - plants of temperate climates, the above-ground parts of which usually die off in the winter, with the exception of protected renewal buds; very large group; the most typical representatives are perennial meadow grasses (meadow timothy grass - Phleum pratense, meadow clover, etc.) and forest herbs (fragrant woodruff - Asperula odorata, European hooffoot, etc.); the leaves are characterized by differentiated mesophyll, although in forest plants (sciophytes and hemiscyophytes) the palisade tissue is often not expressed; conductive elements are moderately developed; the epidermis is thin, the cuticle is not always present; mechanical tissues are moderately or poorly developed;
ephemerals and ephemeroids (from the Greek ephemeros - one-day) - annual (ephemeras) and bi- or perennial (ephemeroids) plants that, in dry conditions, grow for a short wet period and go into a dormant state during the dry season; for example, plants of deserts and dry steppes: ephemera - spring stonefly, small alyssum (Alissum minutum) and etc.; ephemeroids - viviparous bluegrass, or curly bluegrass (Poa bulbosa subsp. vMparum) different types of tulips (Tulipa), goose onions (Gagea) irises (Iris), ferul (Ferula) and etc.; characterized by a lack of structural adaptation to lack of moisture, but the seeds are able to tolerate severe drying and high temperatures; Bulbous and corm ephemeroids are characterized by contractile (retracting) roots, which ensure the retraction of the renewal bud under the soil during an unfavorable period.
It should be noted that not all scientists agree with the classification of desert ephemerals and ephemeroids to the group of mesophytes and classify them as xerophytes (understanding the latter term very broadly).
Xerophytes (from the Greek xeros) are plants adapted to life in conditions of low water supply. They tolerate soil and atmospheric drought, as they have various adaptations for living in hot climates with very little precipitation. The most important feature of xerophytes is the formation of morphophysiological adaptation to the destructive effects of atmospheric and soil drought. In most cases, xerophytes have adaptations that limit transpiration: leaflessness, small leaves, summer leaf fall, pubescence. Many of them are able to withstand quite severe dehydration for a long time, maintaining viability. Figure 12 showed a sheet with devices to limit evaporation.
Depending on the structural characteristics of organs and tissues and methods of regulating the water regime, the following three types of xerophytes are distinguished.
The first type is euxerophytes (from the Greek eu - real), or sclerophytes (from the Greek skleros - solid), or xerophytes themselves; In appearance these are dryish, tough plants. Even during the period of full water supply, the water content of their tissues is low. Sclerophytes are highly resistant to wilting - they can lose up to 25% of moisture without noticeable harm to themselves. Their cytoplasm remains alive even with such severe dehydration that would be fatal for other plants. Another feature of euxerophytes is the increased osmotic pressure of cell sap, which makes it possible to significantly increase the sucking force of the roots.
Previously, it was believed that the intensity of transpiration of sclerophytes, like other xerophytes, is very low, but the works of N. Maksimov (1926, 1944) showed that under favorable water supply conditions, these plants transpirate more intensively than mesophytes, especially in terms of unit of surface leaf. I. Kultiasov (1982) emphasized that, apparently, the main feature of xerophytes is their high drought resistance, depending on the properties of the cytoplasm, as well as the ability to effectively use moisture after rain. The characteristic “sclerophytic” morphology (strong development of mechanical and integumentary tissues, small leaves, etc.) has a protective value in case of difficulties in water supply.
The root system of euxerophytes is very branched, but shallow (less than 1 m). The group under consideration includes many plants of our steppes, semi-deserts and deserts: wormwood (white earth Artemisia terrae-albae, Lerha - A lerchlana etc.), gray-haired Veronica (Veronica Incana) and etc.
D. Kolpinov (1957) identified a special group of euxerophytes - stipaxerophytes (from the Latin stipa - feather grass). It includes narrow-leaved grasses such as feather grass, fescue (Festuca valesiaca). Plants of the group are distinguished by a powerful root system that uses the moisture of short-term showers. Stypaxerophytes are sensitive to dehydration and tolerate only short-term lack of moisture.
The second type of xerophytes - hemixerophytes (from the Greek hemi - half) have a deep root system that reaches the groundwater level (up to 10 m or more), i.e. they are phreatophytes (see below).
The third type of xerophytes - succulents (from the Latin succulentus - juicy), unlike the xerophytes of the types described above, have well-developed water-storing parenchyma tissue. Depending on its location, leaf and stem succulents are distinguished. Examples of the former are agaves (Agava) aloe (Aloe), sedums (Sedum) etc. In stem succulents, the leaves are usually reduced, and these species store water in the stems (cacti and cactus-like euphorbias).
The root system of succulents is usually superficial. They are distinguished by their ability to store water when it is in excess in the environment, retain it for a long time and use it economically. Transpiration in succulents is extremely low. To reduce it, plants have a number of adaptive features in their structure, including the originality of the forms of the above-ground parts, demonstrating “knowledge” of the laws of geometry. It is known that spherical bodies (especially the ball) have the smallest surface-to-volume ratio. Thickening the leaves and stems, i.e., bringing them closer to a spherical or cylindrical shape, is a way to reduce the transpiration surface while maintaining the required mass. In many succulents, the epidermis is protected by a cuticle, a waxy coating, and pubescence. The stomata are few and usually closed during the day. The latter circumstance creates difficulties for photosynthesis, since the absorption of carbon dioxide by these plants can occur mainly at night: the access of CO 2 and light does not coincide in time. Therefore, succulents have developed a special path of photosynthesis - the so-called “CAM path”, in which the source of CO 2 is partially the products of respiration.
The response of the root system to water supply has been well studied in cultivated plants. Figure 16 shows the depth of penetration of the root system of winter wheat into the soil at different amounts of precipitation.
Rice. 16. Root system of winter wheat (genus Triticum):
1
- with large amounts of precipitation; 2
- at average; 3
- at low
There is a special classification of ecological groups of plants taking into account their use of ground moisture, i.e., according to the sources of moisture absorption from the substrate. It contains phreatophytes (from the Greek phreatos - well) - plants whose root system is constantly connected to the aquifers of soils and parent soil-forming rocks, ombrophytes (from the Greek ombros - rain) - plants that feed on the moisture of precipitation, and trichohydrophytes (from Greek trichos - hair) - plants associated with the capillary border of groundwater, which are in a state of constant mobility. Among phreatophytes, obligate and facultative ones are distinguished; the latter are quite close to trichohydrophytes. Phreatophytes are characterized by the development of deeply penetrating underground organs; at the camel thorn (Alchagi)- up to 15 m, in tree-like forms of black saxaul (Haloxylon aphyllum)- up to 25, in Central Asian tamarix (Tamarix)- 7, in North African tamarix - up to 30, in alfalfa (Medicago sativa)- up to 15 m. Ombrophytes have a shallow, but highly branched system of underground organs, capable of absorbing atmospheric moisture in a large volume of soil. Typical representatives of the group are ephemerals and desert ephemeroids. Trichohydrophytes are characterized by a root system of a universal type, which combines the features of phreatophytes and ombrophytes. Phreatophytes and trichohygrophytes are often classified as hemixerophytes.
Plants are supplied with water from two sources: precipitation and groundwater. Among atmospheric precipitations, rain and snow play the most important role. Hail, dew, fog, frost, and ice occupy a more modest share in the water balance of plants. Atmospheric precipitation for plants is not only a source of water supply. Solid precipitation, forming a snow cover, protects the soil, and consequently, above-ground and underground plant organs from low temperatures. In ecological terms, snow cover significantly affects the habitat of plants and animals - it creates a supply of soil moisture and significantly reduces the evaporation of moisture by plants. The distribution of precipitation by season, its form, amount and intensity of precipitation are important for agricultural plants, as well as for the productivity of pastures and hayfields.
Rains that produce a large amount of precipitation in a short time (more than 1...2 mm/min) are called torrential, or downpours. Rainfall is usually accompanied by strong winds and has a negative impact on agricultural land. The highest amount of precipitation in the Caucasus and Eastern Europe in general (up to 2500 mm per year) and heavy rainfall in particular occurs on the Black Sea coast of the Caucasus - Adjara and Abkhazia. However, heavy downpours (over 5 mm/min) have also been recorded in Ukraine. In general, as you move northward within the continent, the amount of precipitation first increases, reaching a maximum in the temperate zone, and then decreases (does not extend to coastal areas); There is a pattern in changes in other climatic indicators (Fig. 17).
Large differences (Fig. 18) in the amount of precipitation between individual regions of the Earth, along with the temperature regime, create a diversity of environmental conditions on the planet. The wettest areas are located in the upper reaches of the river. Amazon, on the islands of the Malay Archipelago.
Rice. 17. Schematic profile of the European part of Russia from north to south, according to G. Vysotsky
Rice. 18. Annual distribution of precipitation by continent
In the temperate climate zone, in places where frequent thaws are observed, the death of winter crops from the ice crust can be traced. After thaws, melted snow water accumulated in microdepressions in fields freezes and covers winter crops with an ice crust. In this case, mechanical pressure from ice occurs, which has a particularly detrimental effect on the tillering zones, and at the same time there is a lack of oxygen.
The thickness and density of snow cover are important for agriculture, forestry, and water management. Loose snow better protects plants overwintering in the soil from cooling. The density of snow is lowest when the snow cover is formed, then it constantly increases and becomes greatest during the period of snow melting. Therefore, by spring the protective effect of snow cover decreases. Parts of plants that are not covered with snow, especially in cold and windy winters, quickly lose moisture and die. At an air temperature of -21°C under snow on the soil surface it is only -5°C. If snow falls early and covers the soil in a thick enough layer, it does not freeze, and plants grow and develop normally. There are winters when under the snow cover you can find blooming saffrons (genus Crocus), Lyubka bifolia (Platanthera bifolia) and other plants.
In the harsh winter conditions of high northern latitudes, as well as in the mountains, special trellis and dwarf forms of woody plants are produced. Even large-trunked trees of the forest zone - Siberian spruce, Siberian larch and others - are transformed into creeping forms in the Arctic climate.
Atmospheric air
The ecological significance of atmospheric precipitation in the life of plants is also manifested in its participation as a solvent in feeding the lower tiers of woody and herbaceous plants with mineral substances. During rain, falling drops are saturated with volatile and vaporous substances in the air, the latter, together with the drop, fall on plant organs and the soil surface. Along with substances washed out of tree crowns and absorbed by volatile compounds emitted by plants, volatile and vaporous substances that are formed as a result of anthropogenic activities, as well as waste products of soil microflora, are dissolved and mixed in precipitation.
Herbaceous plants are not typical for these ecosystems, and tropical forest epiphytes belong to the subgroups of xeromesophytes or hygromesophytes. The features of their dislocation in tree crowns are determined by microclimatic conditions.
The thick layer of air (atmosphere) covering the Earth protects living organisms from powerful ultraviolet radiation and cosmic radiation, and prevents sudden temperature fluctuations. Ecologically, the gas composition of the atmosphere and the movement of air masses (wind and convection currents) are no less important.
When characterizing the gas composition of air, its constancy is usually emphasized. In almost all regions of the globe, the dry air of the troposphere (lower layer of the atmosphere) contains about 78.1% nitrogen, 21% oxygen, 0.032 % carbon dioxide, traces of hydrogen, small amounts of inert gases. Along with permanent components, the air contains gaseous components, the content of which varies depending on time and place: various industrial gases, ammonia, gaseous emissions of plants, etc.
The direct environmental impact of free nitrogen prevailing in the atmosphere is small; in this form, the specified chemical element lives up to its name, which translated from Greek means “not life-sustaining.” Fixed nitrogen is an essential and essential component of all biological systems. Free atmospheric oxygen not only supports life (respiration), but also has a biological origin (photosynthesis). Thus, the deterioration of the green world of our planet can significantly affect the reserves of free oxygen in the atmosphere.
About 21% of the oxygen released during photosynthesis and contained in the air is consumed by plants, animals and humans during respiration. An adult tree releases up to 180 liters of oxygen per day. A person consumes about 360 liters of oxygen per day in the absence of physical activity, and up to 900 liters during intensive work. A passenger car consumes the annual norm of oxygen consumed by a person per 1000 km, and a jet airliner consumes 35 tons of oxygen for a flight from Europe to America.
The content of carbon dioxide in the air depends even more on the life activity of various organisms. The most important natural sources of CO 2 are respiration, fermentation and decay - the total share of the listed processes accounts for 5.6.1% of CO 2 entering the atmosphere. About 38% of carbon dioxide enters the air from the soil ("soil respiration"); 0.1% - during volcanic eruptions. Quite a significant source of CO 2 are forest and steppe fires, as well as fuel combustion - up to 0.4%. The latter figure is constantly growing: in 1970, due to anthropogenic activity, 0.032% of the annual CO 2 intake entered the air; according to scientists, by the year 2000 the share of the source in question will increase to 0.038...0.04%.
Human activity also has a significant impact on the rate of carbon dioxide fixation in the biosphere. This is mainly due to excessive deforestation and pollution of the world's oceans. During photosynthesis, plants annually bind 6...7% of CO 2 from the air, and the process is most intense in forest ecosystems. The tropical rainforest records 1...2 kg of carbon dioxide per 1 m2 per year; in the tundra and deserts only 1% of this amount is recorded. In total, terrestrial ecosystems record 20...30 billion tons of CO 2 per year. Approximately the same amount is recorded by the phytoplankton of the World Ocean.
An increase in the content of carbon dioxide in the atmosphere has negative environmental consequences on a planetary scale and manifests itself in the form of the “greenhouse effect”. In general terms, this effect can be characterized as a constant warming of the climate, caused by the fact that, like a film in a greenhouse, accumulated in excessive amounts of CO 2 prevents the outflow of long-wave thermal radiation from the surface of the Earth, while freely transmitting the sun's rays. The specific manifestations of the “greenhouse effect” are different in different regions. In one case, these are unprecedented droughts, in the other, on the contrary, an increase in precipitation, unusually warm winters, etc.
Of the unstable components of atmospheric air, the most environmentally unfavorable for plants (both for humans and animals) are industrial gases - sulfur dioxide, fluorine, hydrogen fluoride, chlorides, nitrogen dioxide, ammonia, etc. The high vulnerability of plant organisms to “air poisons” is explained by the lack of special adaptation to the mentioned, relatively recently emerging factor. The relative resistance of some plants to industrial gases is associated with their pre-adaptation, that is, the presence of certain features that turned out to be useful in new conditions. Thus, deciduous trees tolerate air pollution more easily than coniferous trees, which is explained by the annual deciduous fall of the former, which gives them the opportunity to regularly remove toxic substances with litter. However, even in deciduous plants, when the gas composition of the atmosphere is unfavorable, the rhythm of seasonal development is disrupted: bud opening is delayed, and leaf fall occurs much earlier.
Abiotic factors are components of inanimate nature. These include: climatic (light, temperature, water, wind, atmosphere, etc.), acting on all habitats of living organisms: water, air, soil, the body of another organism. Their action is always cumulative.
Light- one of the most important biotic factors, it is the source of life for all life on earth. In the life of organisms, not only visible rays are important, but also others that reach the earth’s surface: ultraviolet, infrared, electromagnetic. The most important process that occurs in plants on Earth with the participation of solar energy: photosynthesis. On average, 1-5% of the light incident on a plant is used for photosynthesis and is transferred further along the food chain in the form of accumulated energy.
Photoperiodism– adaptation of plants and animals to a certain length of the day.
In plants: light-loving and shade-tolerant species are distinguished. Some species grow in illuminated areas (cereals, birch, sunflower), others with a lack of light (forest grasses, ferns), shade-tolerant species can grow in different conditions, but at the same time change their appearance. A pine tree that grows alone has a thick, wide crown; in a tree stand, the crown is formed in the upper part, and the trunk is bare. There are short-day and long-day plants.
Among animals, light is a means of orientation in space. Some are adapted to live in sunlight, while others are nocturnal or twilight. There are animals, such as moles, that do not require sunlight.
Temperature The temperature range at which life is possible is very small. For most organisms it is determined from 0 to +50C.
The temperature factor has pronounced seasonal and daily fluctuations. Temperature determines the speed of biochemical processes in the cell. It determines the appearance of the organism and the breadth of its geographical distribution. Organisms that can withstand a wide range of temperatures are called eurythermal. Stenothermic organisms live in a narrow range of temperatures.
Some organisms are better adapted to tolerate unfavorable (high or low) air temperatures, while others are better able to tolerate soil temperatures. There is a large group of warm-blooded organisms that are capable of
maintain body temperature at a stable level. The ability of organisms to suspend their vital functions at unfavorable temperatures is called suspended animation.
Water There are no living organisms on earth that do not contain water in their tissues. The water content in the body can reach 60-98%. The amount of water required for normal development varies depending on age. Organisms are especially sensitive to water deficiency during the breeding season.
In relation to the water regime, plants are divided into 3 large groups:
Hygrophytes– plants of damp places. They cannot tolerate water shortages.
Mesophytes– plants of moderately humid habitats. They are able to tolerate soil and air drought for a short period. These are the majority of agricultural crops and meadow grasses.
Xerophytes– plants of dry habitats. They are adapted to withstand a lack of water for a long time due to special devices. Leaves turn into spines or, for example, in succulents, the cells grow to enormous sizes, storing water. There is also a similar classification for animals. Only the ending of the phyta changes to phyla: hygrophiles, mesophylls, xerophiles.
Atmosphere The layered atmosphere covering the earth and the ozone layer, located at an altitude of 10-15 km, protect all living things from powerful ultraviolet radiation and cosmic radiation. The gas composition of the modern atmosphere is 78% nitrogen, 21% oxygen, 0.3-3% water vapor, 1% comes from other chemical elements.
Soil or edaphic factors. Soil is a bioinert natural body, formed under the influence of living and inanimate nature. She has fertility. Plants consume nitrogen, phosphorus, potassium, calcium, magnesium, boron and other microelements from soils. The growth, development and biological productivity of plants depends on the availability of nutrients in the soil. Both deficiency and excess of nutrients can become a limiting factor. Some plant species have adapted to an excess of an element, such as calcium, and are called calciumphylls.
The soil is characterized by a certain structure, which depends on humus - a product of the vital activity of microorganisms and fungi. Soil contains air and water, which interact with other elements of the biosphere.
When wind, water or other erosion occurs, the soil cover is destroyed, which leads to loss of soil fertility.
Orographic factors - terrain. Terrain is not a direct factor, but is of great ecological importance as an indirect factor that redistributes climatic and other abiotic factors. The most striking example of the influence of relief is the vertical zoning characteristic of mountainous regions.
There are:
nanorelief – these are heaps near animal burrows, hummocks in swamps, etc.;
microrelief – small funnels, dunes;
mesorelief – ravines, ravines, river valleys, hills, depressions;
macrorelief – plateaus, plains, mountain ranges, i.e. significant geographical boundaries that have a significant impact on the movement of air masses.
Biotic factors. Living organisms are influenced not only by abiotic factors, but also by the living organisms themselves. The group of these factors includes: phytogenic, zoogenic and anthropogenic.
The influence of biotic factors on the environment is very diverse. In one case, when different species influence each other, they have no effect (0); in another case, the effects are favorable (+) or unfavorable (-).
Types of species relationships
Neutralism (0,0) – species do not influence each other;
Competition (-,-) – each type has an adverse effect, suppressing the other and displacing the weaker one;
Mutualism (+,+) – one of the species can develop normally only in the presence of another species (symbiosis of plants and fungi);
Protocooperation (+,+) – cooperation, mutually beneficial influence, not as strict as with mutualism;
Commensalism (+, 0) one species benefits from coexistence;
Amensalism (0,-) – one species is oppressed, the other species is not oppressed;
Anthropogenic influence fits into this classification of species relationships. Among biotic factors, this is the most powerful. It can be direct or indirect, positive or negative. The anthropogenic impact on the abiotic and biotic environment is further discussed in the manual from the point of view of nature conservation.
3.1. Abiotic factors
Abiotic (from Greek - lifeless) factors are components and phenomena of inanimate, inorganic nature that directly or indirectly affect living organisms. In accordance with the existing classification, the following abiotic factors are distinguished: climatic, edaphic (soil), orographic or topographical, hydrographic (water environment), chemical (Table 1). Some of the most important abiotic factors are light, temperature, and humidity.
Table 1 – Classification of environmental environmental factors
Abiotic factors |
Biotic |
Anthropogenic |
Climatic: solar radiation, light and light conditions, temperature, humidity, precipitation, wind, pressure, etc. Edaphic: mechanical and chemical composition of the soil, moisture capacity, water, air and thermal conditions of the soil, groundwater level, etc. Orographic (topographic): relief (refers to indirectly acting environmental factors, since it does not directly affect the life of organisms); exposure (location of relief elements in relation to the cardinal points and prevailing winds bringing moisture); height above sea level. Hydrographic: factors of the aquatic environment. Chemical: gas composition of the atmosphere, salt composition of water. |
Phytogenic (influence of plants) Zoogenic (influence animals) biotic factors are divided into: competition, predation, |
with human activity |
Light. Solar radiation serves as the main source of energy for all processes occurring on Earth. In the spectrum of solar radiation, areas differing in biological action are distinguished: ultraviolet, visible and infrared. Ultraviolet rays with a wavelength of less than 0.290 microns are destructive to all living things. This radiation is delayed by the ozone layer of the atmosphere, and only a portion of ultraviolet rays (0.300–0.400 microns) reaches the Earth’s surface, which in small doses has a beneficial effect on organisms.
Visible rays have a wavelength of 0.400–0.750 microns and account for most of the solar radiation energy reaching the earth's surface. These rays are especially important for life on Earth. Green plants synthesize organic substances using the energy of this particular part of the solar spectrum. Infrared rays with a wavelength greater than 0.750 microns are not perceived by the human eye, but are perceived as heat and are an important source of internal energy. Light, therefore, has an ambiguous effect on organisms. On the one hand, it is the primary source of energy, without which life on Earth is impossible, on the other hand, it can have a negative effect on organisms.
Light mode . When passing through atmospheric air, sunlight (Figure 3.1) is reflected, scattered and absorbed. Each habitat is characterized by a certain light regime. It is established by the ratio of intensity (strength), quantity and quality of light. Indicators of the light regime are very variable and depend on the geographical location, terrain, altitude, atmospheric conditions, time of year and day, type of vegetation and other factors. Intensity, or luminous strength, is measured by the number of joules per 1 cm 2 of horizontal surface per minute. This indicator is most significantly influenced by the features of the relief: on the southern slopes the light intensity is greater than on the northern ones. Direct light is the most intense, but plants use diffused light more fully. The amount of light is an indicator that is determined by the total radiation. To determine the light regime, the amount of reflected light, the so-called albedo, is also taken into account. It is expressed as a percentage of total radiation. For example, the albedo of green maple leaves is 10%, and the albedo of yellowed autumn leaves is 28%. It should be emphasized that plants reflect mainly physiologically inactive rays.
In relation to light, the following ecological groups of plants are distinguished: photophilous(light), shade-loving(shadow), shade-tolerant. Light-loving species live in the forest zone in open places and are rare. They form a sparse and low vegetation cover so as not to shade each other. Shade-loving plants do not tolerate strong light and live under the forest canopy in constant shade. These are mainly forest herbs. Shade-tolerant plants can live in good light, but can easily tolerate some shading. These include most forest plants. Due to this specific habitat, these groups of plants are characterized by certain adaptive features. In the forest, shade-tolerant plants form densely closed stands. Shade-tolerant trees and shrubs can grow under their canopy, and even more shade-tolerant and shade-loving shrubs and herbs can grow below them.
Figure 3.1 – Balance of solar radiation on the surface
Earth in the daytime (according to N. I. Nikolaikin, 2004)
Light is a condition for the orientation of animals. Animals are divided into diurnal, nocturnal and crepuscular species. The light regime also affects the geographical distribution of animals. Thus, certain species of birds and mammals settle in high latitudes with long polar days in the summer, and in the fall, when the day shortens, they migrate or migrate south.
One of the most important environmental factors, an irreplaceable and universal factor, is temperature . It determines the level of activity of organisms, affects metabolic processes, reproduction, development, and other aspects of their life. The distribution of organisms depends on it. It should be noted that depending on body temperature, poikilothermic and homeothermic organisms are distinguished. Poikilothermic organisms (from the Greek - various and heat) are cold-blooded animals with an unstable internal body temperature, varying depending on the ambient temperature. These include all invertebrates, and vertebrates include fish, amphibians and reptiles. Their body temperature, as a rule, is 1–2° C higher than the external temperature or equal to it. When the environmental temperature increases or decreases beyond optimal values, these organisms fall into torpor or die. The lack of perfect thermoregulatory mechanisms in poikilothermic animals is due to the relatively weak development of the nervous system and low level of metabolism compared to homeothermic organisms. Homeothermic organisms are warm-blooded animals whose temperature is more or less constant and, as a rule, does not depend on the ambient temperature. These include mammals and birds, in which the constancy of temperature is associated with a higher level of metabolism compared to poikilothermic organisms. In addition, they have a thermal insulating layer (feather, fur, fat layer). Their temperature is relatively high: in mammals it is 36–37° C, and in birds at rest – up to 40–41° C.
Thermal mode . As noted, temperature is an important environmental factor that affects the existence, development and distribution of organisms. At the same time, not only the absolute amount of heat matters, but also its distribution over time, that is, the thermal regime. The thermal regime of plants consists of temperature conditions, which are characterized by one or another duration and change in a certain sequence in combination with other factors. In animals, it also, in combination with a number of other factors, determines their daily and seasonal activity. The thermal regime is relatively constant throughout the year only in tropical zones. To the north and south, daily and seasonal temperature variations increase with distance from the equator. Plants and animals, adapting to them, show different needs for heat in different periods. For example, seed germination occurs at lower temperatures than their subsequent growth; the flowering period requires more heat than the period of fruit ripening. In different organisms, biological processes at optimal temperatures obey van't Hoff's rule, according to which the rate of chemical reactions increases 2–3 times with every 10° C increase in temperature. For plants, like animals, the total amount of heat that they can receive from the environment is important. Temperatures that lie above the lower threshold of development and do not go beyond the upper threshold are called effective temperatures. The amount of heat required for development is determined by the sum of effective temperatures, or sum of heat. The effective temperature can be easily determined by knowing the lower development threshold and the observed temperature. For example, if the lower threshold for the development of an organism is 10° C, and the current temperature is 25° C, then the effective temperature will be 15° C (25–10° C). The sum of effective temperatures for each species of plants and poikilothermic animals is a relatively constant value.
Plants have various anatomical, morphological and physiological adaptations that smooth out the harmful effects of high and low temperatures: the intensity of transpiration (as the temperature decreases, the evaporation of water through the stomata occurs less intensely and, as a result, heat transfer decreases and, vice versa); accumulation of salts in cells that change the temperature of plasma coagulation, the property of chlorophyll to prevent the penetration of the hottest sunlight. The accumulation of sugar and other substances in the cells of frost-resistant plants that increase the concentration of cell sap makes the plant more resilient and is of great importance for their thermoregulation. The influence of thermal conditions can also be seen in animals. As we move away from the poles to the equator, the sizes of systematically similar animals with unstable body temperatures increase, and with constant ones they decrease. This provision reflects Bergman's rule. One of the reasons for this phenomenon is an increase in temperature in the tropics and subtropics. In small forms, the relative surface area of the body increases and heat transfer increases, which has a negative effect in temperate and high latitudes, primarily on animals with unstable body temperature. The body temperature of organisms has a significant shape-forming effect. Under the influence of the thermal factor, they form such morphological characteristics as a reflective surface; fat deposits, down, feathers and fur in birds and mammals. In the Arctic, high in the mountains, most insects are dark in color, which enhances the absorption of sunlight. In animals with a constant body temperature in cold climatic zones, there is a tendency to reduce the area of protruding parts of the body - Allen's rule, since they release the greatest amount of heat into the environment (Figure 3.2). In mammals, at low temperatures, the size of the tail, limbs, and ears is relatively reduced, and hair develops better. Thus, the size of the ears of the arctic fox (an inhabitant of the tundra) is small; they increase in the fox, typical of temperate latitudes, and become quite large in the fennec fox (an inhabitant of the deserts of Africa). In general, in relation to temperature, anatomical and morphological changes in both plants and animals are primarily aimed at regulating the level of heat loss. In the course of long historical development, adapting to periodic changes in temperature conditions, organisms, including those living in forests, have developed different needs for heat at different periods of life.
Figure 3.2 – Differences in ear length among three species of foxes,
living in different geographical areas
(according to A. S. Stepanovskikh, 2003)
Thermal conditions also affect the distribution of plants and animals around the globe. They are historically adapted to certain thermal conditions. Therefore, the temperature factor is directly related to the distribution of plants and animals. To one degree or another, it determines the population of different natural zones by organisms. In 1918, A. Holkins formulated bioclimatic law. He established that there is a natural, rather close connection between the development of phenological phenomena and latitude, longitude and altitude. The essence of this law is that as you move north, east and into the mountains, the time of onset of periodic phenomena (such as flowering, fruiting, shedding of leaves) in the life activity of organisms is delayed by 4 days for each degree of latitude, 5 degrees of longitude and approximately 100 m height. There is a connection between the boundaries of distribution of plants and animals with the number of days per year with a certain average temperature. For example, isolines with average daily temperatures above 7° C for more than 225 days a year coincide with the distribution limit of beech in Europe. However, it is not the average daily temperatures that are of great importance, but their fluctuations in combination with other environmental factors, ecoclimatic and microclimatic conditions.
Heat distribution is associated with various factors: the presence of bodies of water (near them the amplitude of temperature fluctuations is smaller); features of the relief, topography of the area. Thus, on the northern and southern slopes of hills and ravines, quite large temperature differences are observed. The terrain, determining the exposure of the slopes, affects the degree of their heating. This leads to the formation of slightly different plant associations and animal groups on the southern and northern slopes. In the south of the tundra, forest vegetation is found on slopes in river valleys, in floodplains or on hills in the middle of the plain, since these are the places that warm up the most.
As the air temperature changes, the soil temperature also changes. Different soils warm up differently depending on color, structure, moisture, and exposure. Heating, as well as cooling, of the soil surface is prevented by vegetation cover. During the day, the air temperature under the forest canopy is always lower than in open spaces, and at night it is warmer in the forest than in the field. This affects the species composition of animals: even in the same area they are often different.
Important environmental factors include humidity (water) . Water is necessary for any protoplasm. All physiological processes occur with the participation of water. Living organisms use aqueous solutions (such as blood and digestive juices) to maintain their physiological processes. It limits the growth and development of plants more often than other environmental factors. From an ecological point of view, water serves as a limiting factor both in terrestrial habitats and in aquatic ones, where its quantity is subject to strong fluctuations. It should be noted that terrestrial organisms constantly lose water and need regular replenishment. In the process of evolution, they have developed numerous adaptations that regulate water metabolism. The need of plants for water at different periods of development is not the same, especially among different species. It varies depending on climate and soil type. For each phase of growth and stage of development of any type of plant, a critical period is distinguished when the lack of water has a particularly negative effect on its life. Almost everywhere, except in the humid tropics, terrestrial plants experience drought, a temporary lack of water. Moisture deficiency reduces plant growth and causes short stature and infertility due to underdevelopment of generative organs. Atmospheric drought is strongly manifested at high summer temperatures, soil drought - with a decrease in soil moisture. At the same time, there are plants that are sensitive to one or another deficiency. Beech can live in relatively dry soil, but is very sensitive to air humidity. Forest plants require a high content of water vapor in the air. Air humidity determines the frequency of active life of organisms, the seasonal dynamics of life cycles, and affects the duration of their development, fertility, and mortality.
As you can see, each of these factors plays a major role in the life of organisms. But the combined action of light, temperature, and humidity is also important for them. Atmospheric gases (oxygen, carbon dioxide, hydrogen), nutrients (phosphorus, nitrogen), calcium, sulfur, magnesium, copper, cobalt, iron, zinc, boron, silicon; currents and pressure, salinity, and other environmental abiotic factors influence organisms. Summarized data on the main abiotic environmental factors, rhythm and scope of their action are presented in Table 2.
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