The hydrosphere is water shell Earth that partially covers the solid surface of the earth.
According to scientists, the Hydrosphere was formed slowly, accelerating only during periods of tectonic activity.
Sometimes the Hydrosphere is also called the World Ocean. We will use the term Hydrosphere to avoid confusion. About the World Ocean, as part of the Hydrosphere, you can read in the article THE WORLD OCEAN AND ITS PARTS → .
For a better understanding of the essence of the term Hydrosphere, below are a few definitions.
Hydrosphere
Ecological dictionary
HYDROSPHERE (from hydro ... and Greek sphaira - ball) - intermittent water shell of the Earth. Closely interacts with the living shell of the Earth. The hydrosphere is the habitat of hydrobionts found throughout the entire water column - from the film surface tension water (epineuston) to maximum depths World Ocean (up to 11,000 m). The total volume of water on Earth in all its physical states- liquid, solid, gaseous - is 1454703.2 km3, of which 97% falls on the waters of the oceans. In terms of area, the hydrosphere occupies about 71% of the entire area of the planet. Total share water resources hydrosphere suitable for economic use without special measures - about 5–6 million km3, which is equal to 0.3–0.4% of the volume of the entire hydrosphere, i.e. the volume of all free water on Earth. The hydrosphere is the cradle of life on our planet. Living organisms play active role in the water cycle on Earth: the entire volume of the hydrosphere passes through living matter for 2 million years.
Ecological encyclopedic dictionary. - Chisinau: Main edition of the Moldavian Soviet Encyclopedia. I.I. Dedu 1989
Geological Encyclopedia
HYDROSPHERE - a discontinuous water shell of the Earth, one of the geospheres, located between the atmosphere and the lithosphere; the totality of oceans, seas, continental waters and ice sheets. The hydrosphere covers about 70.8% earth's surface. The volume of G. is 1370.3 million km3, which is approximately 1/800 of the volume of the planet. 98.3% of the mass of G. is concentrated in the World Ocean, 1.6% - in continental ice. The hydrosphere interacts with the atmosphere and lithosphere in a complex way. Most sediments are formed on the boundary between the lithosphere and the lithosphere. g.p. (see Modern sedimentation). The city is part of the biosphere and is entirely inhabited by living organisms that affect its composition. G.'s origin is associated with the long evolution of the planet and the differentiation of its matter.
Geological dictionary: in 2 volumes. - M.: Nedra. Edited by K. N. Paffengolts et al. 1978
Marine vocabulary
The hydrosphere is the totality of oceans, seas and land waters, as well as groundwater, glaciers and snow cover. Often, the hydrosphere refers only to the oceans and seas.
Edwart. Explanatory Naval Dictionary, 2010
Big Encyclopedic Dictionary
HYDROSPHERE (from hydro and sphere) - the totality of all water bodies the globe: oceans, seas, rivers, lakes, reservoirs, swamps, groundwater, glaciers and snow cover. Often, the hydrosphere refers only to the oceans and seas.
Large encyclopedic Dictionary. 2000
Explanatory dictionary of Ozhegov
HYDROSPHERE, -s, wives. (specialist.). The totality of all the waters of the globe: oceans, seas, rivers, lakes, reservoirs, swamps, groundwater, glaciers and snow cover.
| adj. hydrospheric, th, th.Explanatory dictionary of Ozhegov. S.I. Ozhegov, N.Yu. Shvedova. 1949-1992
Beginnings of modern natural science
Hydrosphere (from hydro and sphere) - one of the geospheres, the water shell of the Earth, the habitat of hydrobionts, the totality of oceans, seas, lakes, rivers, reservoirs, swamps, groundwater, glaciers and snow cover. The bulk of the water in the hydrosphere is concentrated in the seas and oceans (94%), the second place in terms of volume is occupied by groundwater (4%), the third is the ice and snow of the Arctic and Antarctic regions (2%). surface water land, atmospheric and biologically bound waters make up fractions (tenths and thousandths) of a percent of the total volume of water in the hydrosphere. Chemical composition hydrosphere approaches the average composition sea water. Participating in the complex natural cycle of substances on Earth, water decomposes every 10 million years and is formed again during photosynthesis and respiration.
Beginnings modern natural science. Thesaurus. - Rostov-on-Don. V.N. Savchenko, V.P. Smagin. 2006
Hydrosphere (from Hydro ... and Sphere) - an intermittent water shell of the Earth, located between the atmosphere (See Atmosphere) and the solid earth's crust (lithosphere) and representing the totality of oceans, seas and surface waters of land. In more broad sense G. also includes groundwater, ice and snow of the Arctic and Antarctic, as well as atmospheric water and water contained in living organisms. The bulk of Georgia's water is concentrated in the seas and oceans; water masses occupied by groundwater, the third - ice and snow of the Arctic and Antarctic regions. Surface waters of land, atmospheric and biologically bound waters make up fractions of a percent of total volume G.'s water (see table). The chemical composition of G. approaches the average composition of sea water.
Surface waters, while occupying a relatively small proportion in the total mass of water, nevertheless play a role essential role in the life of our planet, being the main source of water supply, irrigation and irrigation. G.'s waters are in constant interaction with the atmosphere, the earth's crust, and the biosphere. The interaction of these waters and mutual transitions from one type of water to another constitute a complex water cycle on the globe. In G. for the first time life originated on Earth. Only at the beginning of the Paleozoic era began the gradual migration of animals and plant organisms on land.
Water types Name Volume, million km 3 To the total volume, % sea waters Maritime 1370 94 Groundwater (excluding groundwater) unpaved 61,4 4 Ice and snow Ice 24,0 2 Fresh surface waters of land Fresh 0,5 0,4 Atmospheric waters atmospheric 0,015 0,01 Water contained in living organisms biological 0,00005 0,0003 Great Soviet Encyclopedia. - M.: Soviet Encyclopedia. 1969-1978
For a better understanding, let us briefly formulate what we mean by the Hydrosphere within the framework of this material and within the framework of this site. By the hydrosphere we mean the shell globe, which unites all the waters of the globe, regardless of their condition and location.
In the hydrosphere, there is a continuous circulation of water between its various parts and the transition of water from one state to another - the so-called Water cycle in nature.
Parts of the hydrosphere
The hydrosphere interacts with all geospheres of the Earth. Conventionally, the hydrosphere can be divided into three parts:
- Water in the atmosphere;
- Water on the surface of the Earth;
- The groundwater.
The atmosphere contains 12.4 trillion tons of water in the form of water vapor. Water vapor is renewed 32 times a year or every 11 days. As a result of condensation or sublimation of water vapor on suspended particles present in the atmosphere, clouds or fogs are formed, while sufficient a large number of heat.
You can familiarize yourself with the waters on the surface of the Earth - the World Ocean in the article "".
Groundwater includes: groundwater, moisture in soils, pressure deep water, gravitational water of the upper layers earth's crust, water in related states in different rocks, mineral waters and juvenile waters…
Distribution of water in the hydrosphere
- Oceans - 97.47%;
- Ice caps and glaciers - 1,984;
- Groundwater - 0.592%;
- Lakes - 0.007%;
- Wet soils - 0.005%;
- Atmospheric Water vapor - 0.001%;
- Rivers - 0.0001%;
- Biota - 0.0001%.
Scientists have calculated that the mass of the hydrosphere is 1,460,000 trillion tons of water, which, however, is only 0.004% of the total mass of the Earth.
The hydrosphere is actively involved in the geological processes of the Earth. It largely provides the interconnection and interaction between different geospheres of the Earth.
Hydrosphere - the water shell of our planet, includes all water, chemically unbound, regardless of its state (liquid, gaseous, solid). The hydrosphere is one of the geospheres located between the atmosphere and the lithosphere. This discontinuous envelope includes all oceans, seas, continental fresh and salt water bodies, ice masses, atmospheric water, and water in living things.
Approximately 70% of the Earth's surface is covered by the hydrosphere. Its volume is about 1400 million cubic meters, which is 1/800 of the volume of the entire planet. 98% of the waters of the hydrosphere is the World Ocean, 1.6% is enclosed in continental ice, the rest of the hydrosphere falls on the share of fresh rivers, lakes, groundwater. Thus, the hydrosphere is divided into the World Ocean, groundwater and continental waters, and each group, in turn, includes subgroups of more low levels. So, in the atmosphere, water is in the stratosphere and troposphere, on the earth's surface the waters of the oceans, seas, rivers, lakes, glaciers are released, in the lithosphere - the waters of the sedimentary cover, the foundation.
Despite the fact that the bulk of water is concentrated in the oceans and seas, and only a small part of the hydrosphere (0.3%) accounts for surface water, it is they that play leading role in the existence of the Earth's biosphere. Surface water is the main source of water supply, watering and irrigation. In the water exchange zone, fresh groundwater is rapidly renewed in the course of the general water cycle, therefore, with rational exploitation, it can be used indefinitely.
In the process of the development of the young Earth, the hydrosphere was formed during the formation of the lithosphere, which geological history our planet has allocated great amount water vapor and underground magmatic waters. The hydrosphere was formed during the long evolution of the Earth and its differentiation structural components. Life was born in the hydrosphere for the first time on Earth. Later, at the beginning of the Paleozoic era, the emergence of living organisms on land took place, and their gradual settlement on the continents began. Life without water is impossible. The tissues of all living organisms contain up to 70-80% water.
The waters of the hydrosphere constantly interact with the atmosphere, the earth's crust, the lithosphere, and the biosphere. At the boundary between the hydrosphere and the lithosphere, almost all sedimentary rocks that make up the sedimentary layer of the earth's crust. The hydrosphere can be considered as part of the biosphere, since it is completely populated by living organisms, which, in turn, affect the composition of the hydrosphere. The interaction of the waters of the hydrosphere, the transition of water from one state to another manifests itself as a complex water cycle in nature. All types of water cycle of various volumes represent a single hydrological cycle, during which the renewal of all types of water is carried out. The hydrosphere is an open system, the waters of which are closely interconnected, which determines the unity of the hydrosphere as natural system and mutual influence of the hydrosphere and other geospheres.
Related content:
Naturally, not only marine, but also fresh waters suffer from oil pollution. Wastewater oil refineries, oil changes in cars, oil leaks from crankcases, splashing of gasoline and diesel fuel at the time of refueling cars - all this leads to the pollution of water sources and aquifers. At the same time, not only and even not so much surface water as groundwater is polluted. Since gasoline penetrates the soil seven times faster than water and imparts an unpleasant taste to drinking water even at concentrations as low as 1 ppm, such contamination can render quite a significant amount of groundwater unsuitable for drinking.
3. Impact of oil products on aquatic ecosystems
Fuel oil, diesel fuel, kerosene (crude oil is much more easily subjected to biological and other degradation), covering water with a film, impairs gas and heat exchange in the ocean and atmosphere, and absorbs a significant part of the biologically active component of the solar spectrum.
The intensity of light in water under a layer of spilled oil is usually only 1% of the light intensity on the surface, at best 5-10%. In the daytime, a layer of dark-colored oil absorbs better solar energy, resulting in an increase in water temperature. In turn, the amount of dissolved oxygen in heated water decreases and the rate of respiration of plants and animals increases.
With a strong oil pollution the most obvious is its mechanical effect on the environment. Thus, the oil film formed in Indian Ocean as a result of the closure of the Suez Canal (the routes of all tankers with Arabian oil went through the Indian Ocean during this period), reduced the evaporation of water by 3 times. This led to a decrease in cloud cover over the ocean and the development of an arid climate in the surrounding areas.
An important factor is the biological effect of petroleum products: their direct toxicity to hydrobionts and semi-aquatic organisms.
Coastal communities can be ranked in increasing sensitivity to oil pollution in the following order:
Rocky shores, stone platforms, sandy beach, pebble beach, sheltered rocky shores, sheltered beaches, marshes and mangroves, coral reefs.
4. Polycyclic aromatic compounds: sources of ben (a) pyrene, ben (a) pyrene in water, bottom sediments, planktonic and benthic organisms, decomposition of ben (a) pyrene by marine organisms, consequences of pollution by ben (a) pyrene
Pollution by polycyclic aromatic hydrocarbons (PAHs) is now global. Their presence has been found in all elements of the natural environment (air, soil, water, biota) from the Arctic to Antarctica.
PAHs with pronounced toxic, mutagenic, and carcinogenic properties are numerous. Their number reaches 200. At the same time, PAHs distributed throughout the biosphere are no more than a few dozen. These are anthracene, fluoranthrene, pyrene, chrysene and some others.
The most characteristic and most common among PAHs is benzo(a)pyrene (BP):
BP is highly soluble in organic solvents, while it is extremely slightly soluble in water. The minimum effective concentration of benzo(a)pyrene is low. BP is transformed under the action of oxygenases. BP transformation products are end carcinogens.
Share of BP in total observed PAHs is low (1–20%). They make it significant:
Active circulation in the biosphere
High molecular stability
Significant pro-carcinogenic activity.
Since 1977 BP on international level is considered an indicator compound, the content of which is used to assess the degree of pollution of the environment with carcinogenic PAHs.
Sources of benz(a)pyrene
Various abiotic and biotic sources are involved in the formation of the natural background of benzo(a)pyrene.
Geological and astronomical sources. Since PAHs are synthesized during thermal transformations of simple organic structures, BP is found in:
meteorite material;
igneous rocks;
hydrothermal formations (1-4 µg kg -1);
Volcanic ash (up to 6 µg kg -1). The global flow of volcanic BP reaches 1.2 tons per year -1 (Israel, 1989).
Abiotic synthesis of BP is possible during the combustion of organic materials during natural fires. During the burning of forest, grass cover, peat, up to 5 tons per year -1 is formed. Biotic synthesis of BP was found for a number of anaerobic bacteria capable of synthesizing BP from natural lipids in bottom sediments. The possibility of synthesizing BP and chlorella is shown.
In modern conditions, the increase in the concentration of benzo(a)pyrene is associated with anthropogenic origin. The main sources of BP are: domestic, industrial discharges, washouts, transport, accidents, long-distance transport. The anthropogenic flow of BP is approximately 30 t yr -1 .
In addition, an important source of BP entering the aquatic environment is oil transportation. In this case, about 10 t year -1 gets into the water.
Benz(a)pyrene in water
The highest pollution of BP is typical for bays, gulfs, closed and semi-enclosed sea basins subject to anthropogenic impact (Table 26). Most high levels BP pollution is currently noted for the North, Caspian, Mediterranean and Baltic Seas.
Benz(a)pyrene in bottom sediments
The entry of PAHs into marine environment in an amount exceeding the possibility of their dissolution, entails the sorption of these compounds on the particles of suspensions. Suspensions settle to the bottom and, consequently, BP accumulate in bottom sediments. In this case, the main zone of PAH accumulation is a layer of 1–5 cm.
PAHs in precipitation are often of natural origin. In these cases, they are confined to tectonic zones, areas of deep thermal impact, areas of scattering of gas-oil accumulations.
However, the highest concentrations of BP are found in zones of anthropogenic influence (Table 27).
Table 27
Average levels of marine environment pollution with benzo(a)pyrene μg l–1
Benz(a)pyrene in planktonic organisms
PAHs are not only sorbed on the surface of organisms, but also concentrated intracellularly. Planktonic organisms are characterized by a high level of PAH accumulation (Table 28).
The content of BP in plankton can vary from a few μg kg-1 to mg kg-1 dry weight. The most common content is (2-5) 10 2 µg kg -1 dry weight. For the Bering Sea, accumulation factors (the ratio of concentration in organisms to concentration in water) in plankton (Cp/Sw) range from 1.6 10 to 1.5 10 4 , accumulation factors in neuston (Cn/Sw) range from 3.5 10 2 to 3.6 10 3 (Israel, 1989).
Benz(a)pyrene in benthic organisms
Since the majority of benthic organisms feed on suspended organic matter and soil detritus, often containing PAHs in concentrations higher than in water, bentonts often accumulate BP in significant concentrations (Table 28). The accumulation of PAHs by polychaetes, mollusks, crustaceans, and macrophytes is known.
Table 28
BP accumulation coefficients in various ecosystem objects Baltic Sea(Israel, 1989)
Decomposition of benzo(a)pyrene by marine microorganisms
Since PAHs are naturally occurring substances, it is natural that there are microorganisms that can destroy them. So, in experiments in North Atlantic BP-oxidizing bacteria destroyed from 10-67% of the applied BP. In experiments in pacific ocean the ability of microflora to destroy 8-30% of the introduced BP was shown. In the Bering Sea, microorganisms destroyed 17-66% of the introduced BP, in the Baltic Sea - 35-87%.
On the basis of the experimental data, a model was constructed to assess the transformation of the BP in the Baltic Sea (Israel, 1989). It was shown that the bacteria of the upper layer of water (0-30 m) are able to decompose up to 15 tons of oil during the summer, and up to 0.5 tons during the winter. total weight BP in the Baltic Sea is estimated at 100 tons. If we assume that the microbial destruction of BP is the only mechanism for its elimination, then the time that will be spent on the destruction of the entire available stock of BP will be from 5 to 20 years.
Consequences of benzo(a)pyrene pollution
For BP, toxicity, carcinogenicity, mutagenicity, teratogenicity, and an effect on the reproductive ability of fish have been proven. In addition, like other hardly decomposable substances, BP is capable of bioaccumulation in food chains and, consequently, poses a danger to humans.
Lecture No. 18; The problem of increasing the acidity of water
Sources and distribution: anthropogenic emissions of sulfur and nitrogen oxides.
The effect of acid rain on environment: sensitivity of water bodies to increasing acidity, buffer capacity of lakes, rivers, swamps; effect of acidification on aquatic biota.
Fighting acidification: perspectives.
Acidification of the environment by the accumulation of strong acids, or substances that form strong acids, has a strong impact on the chemical regime and biota of tens of thousands of lakes, rivers, watersheds in Northern Europe, in northeastern North America, parts of East Asia, and elsewhere, although to a lesser extent. Water acidification is determined by a decrease in neutralization capacity (acid neutralizing capacity - ANC). Acidified waters undergo chemical and biological changes, changing species structure biocenoses, biodiversity is declining, etc. A high concentration of H+ leads to the release of metals from soils, with their subsequent transport to lakes and swamps. A high concentration of H+ in watercourses also leads to the release of metals, including toxic ones, from river sediments.
Two groups of reservoirs:
l Standing
l Fluid
Reservoirs - watercourses:
l Natural (lake rivers)
l Artificial (pond, reservoir)
By degree of salinity:
1. fresh (groundwater, rivers)
2. brackish
3. salty
4. bitter-salty
RIVERS
Watercourses in which water moves from the source to the mouth under the influence of gravity
Two groups of rivers:
l main (flow directly into the oceans, seas, lakes)
l tributaries (flow into the main river)
First
Second
third order
Catchment area- the area with which main river collects tributaries
Bed - where the river flows
floodplain- part of the land that is flooded with water during floods
RIVER + FLOODPLAIN + TERRACE = VALLEY
Ripal- part of the water adjacent to the shore
Strezhen– sections of the river with faster movement of water
Medial- the middle of the river (deeper)
Riverbed from source to mouth:
l upstream(higher speed, rocky bottom, no sedimentary soils)
l the average(slows down; deposition of particles sedimentation; soil formation; more full-flowing)
l bottom(smooth flow, sandy soils, thick sedimentary deposits, full flow)
2 mouth shapes:
l delta(vast shallow waters)
l estuaries(deep sea sea bays)
Reobionts organisms that inhabit rivers
Rheoplankton:
l bacteria
l algae (green, diatoms)
l protozoa
l small crustaceans
Reobenthos:
l Rheozoobenthos
Sirton- the inhabitants of the benthos, who ended up in the water column.
l Econosirton- came up voluntarily
l Evrysirton- washed with a stream of water
Biostock- demolition of organisms
Lithophiles- inhabitants of stony soils (larvae of caddisflies, leeches)
Argyllophiles– on clay soils (padenki, caddisflies)
psammophiles– in sandy soils (nematodes, molluscs, crayfish)
Pelophiles– silty soils (mollusks, protozoa)
Reonekton:
Reoneiston: very poor due to water flow
Periphyton: - substrate foulers (Bening)
LAKES
Continental body of water, the basin of which is filled with water.
Genesis classification:
1. Relic (remains of vast other seas; Tethys Balkhash Island)
2. Tectonic (movement of plates, faults; Lake Baikal)
3. Floodplain (remains of the former riverbed)
4. Marine (remains of the laced sea; lagoon, estuaries)
5. Thermokarst (thawing glaciers; in Karelia)
Parts of the lake
1 - littoral - coastal shallow water
2 - sublittoral - decrease to the bottom
3 - profundal - deep-water part
Classification of lakes by the presence of organic matter (Tineman):
1. Oligotrophic (a lot of oxygen, deep-sea, rocky bottom, little organic matter)
2. Euphorphic (they warm up more, more organic matter, there are sedimentary soils)
Sedimentary soils: autochthonous (image in the very bottom)
allochthonous (transferred from land)
3. Mesotrophic (intermediate properties m / y 1 and 2)
4. Dystrophic (a lot of humic substances, acidic pH, a lot of organics, little oxygen)
Classification of lakes by salinity:
1. fresh (less than 0.5% o)
2. brackish (16% o)
3. salty (up to 47% o)
4. bitter-salted (more than 47% o)
Sapropel– autochthonous layer of organic minerals
Limnobionts organisms that inhabit lakes
l Limnoplankton (algae, bacteria, protozoa)
Limnobenthos (rich in the littoral, sublittoral; Macrophytes- semi-submersible rast.)
l Limnoneuston (insects, bugs)
l Limnonekton (fish, pinnipeds)
THE GROUNDWATER
3 groups:
l Cave (large cavities)
l Friatic
l Interstitial (voids in sandy soils)
Conditions:
l Darkness (aphotic, oligophotic, euphotic)
l Water hardness
Troglobionts- inhabitants of underground waters. Ancient, little changed forms.
Reduction of the organs of vision; No bright coloration.
l Protozoa
l Bacteria (chemosynthetics)
l Algae (in the aphotic zone)
l Phytophages (crustaceans - heliophobes)
Arid ecosystems: steppes, deserts, savannas.
Steppes
The herbaceous type of vegetation, xerophytic in nature, occupies significant spaces in temperate zone northern hemisphere.
Treeless communities of perennial xerophytic grasses (cereal associations). Forest groups are found only along the valleys of large rivers, as well as on the sands of floodplain terraces ( Pinery). The northern steppes of the CIS are characterized by the predominance of herbs and high species richness. The southern plant groups are characterized by the predominance of cereals and sparse grass cover.
Virgin steppes only in reserves:
Askania-Nova
Streltsy steppe
Khamutovskaya steppe
Steppes of the Naurzum Reserve in northern Kazakhstan
In North America, cereal ecosystems are called prairie(South Canada to Mexican Highlands)
Perennials (feather grass, wheatgrass). Currently it is arable/pasture.
Pampas and Pampas.
The cereal ecosystems of South America are distinguished by the absence of -t in winter.
Analogues of the steppes of South Africa - velds.
Environmental conditions in the steppes of Eurasia:
1. continental climate(hot summers and cold winters with little snow)
2. insignificant amount of precipitation (250-450 mm/year and unstable regime)
3. constant winds (dry winds in summer)
Plant adaptations:
l dominated by the life form - hemicryptophytes
Perennials > 60%
Annuals 15%
Hamefites 10%
Phanerophytes<1%
l narrow-leaved, xeromorphic, sod grasses (fescue) are widespread
l Xerophytes with different adaptations predominate (pubescence, wax coating)
l variety of geophytes (terraphytes) - these are ephemeral bulbous tulip plants
Animal adaptations:
The fauna is diverse: vipers, rodents, lizards, etc. predominate.
Pampas - fox, Patogonian weasel
Prairies - coets, antelopes, prairie dogs.
l Long distance running
l Predominance of foleobionts
l Estivation (marmots)
l Twilight, nocturnal lifestyle
desert
Arid territory, which is characterized by sparse vegetation or its complete absence due to low rainfall or soil aridity.
Drought- the main feature of the desert. A climatic or soil phenomenon characterized by a prolonged absence of atmospheric precipitation at high temperatures and insolation (solar radiation) leading to a drop in relative air humidity to 30% or less and soil moisture< 50% от наименьшей влагоемкости, к повышению концентрации почв.р-ра до токсической величины.
35% of the land is occupied.
According to the nature of the seasonal distribution of precipitation, 4 types of deserts:
1. with precipitation in winter (Mediterranean type)
– Karakum
North of the Arabian Peninsula
Victoria Desert in Australia
Deserts of Iran
2. with precipitation in summer
Thar - Pakistan
mexican deserts
3. with irregular precipitation (extraarid)
Center of the Sahara
Taklamakan - center. Asia
Atacama - Chile
- "deserts of mists" - moisture from fogs, no rain - Namib
4. deserts without a distinct rainy season
Classification of deserts according to the characteristics of soils and underlying rocks: lithoedaphic, 1973 - Petrov:
1. sandy on loose deposits of ancient alluvial plains
2. sand-gpal and pebble on Tertiary and Cretaceous structural plateaus
3. gravelly gypsum on Tertiary plateaus
4. gravel on foothill plains
5. rocky in the lowlands and hilly areas
6. loamy on slightly carbonate mantle loams
7. loess on foothill plains
8. clayey takyr on foothill plains and in river deltas
9. saline soils in saline depressions and along sea coasts
Desert environmental conditions:
1. dry climate (atmospheric precipitation<250 мм/год или их полное отсутст;высок.испоряемость)
2. high T in summer; max + 58С; low T in winter in the temperate zone.
3. hyperinsolation
4. sharp drop in daily T
5. deep groundwater
6. overheating of the upper soil horizons up to + 87.8С
7. mobility and salinity of the substrate
8. constant winds: Sahara - sirocco
Middle Asia - sanum
Egypt - khamsin
The level of extremeness of the environment- a combination of all factors limiting the vital activity and distribution of organisms.
Indices for assessing the extremeness of the environment:
1. "Annual evaporation" (with open water surface)
l Dry steppes / semi-deserts 75-120 cm
l Desert dead belts 120-175 cm
l Desert subtropics 175-225 cm
J = R / Q where R is the radiation balance
Q - the amount of heat required for the evaporation of years of precipitation
n/deserts 2.3 – 3.4
desert > 3.4
Plant adaptations:
There are adaptive dilemmas: having opened. stomata to absorb CO2 they lose moisture through transpiration. By substituting leaves to absorb light, overheating is possible.
l Annuals (bloom during rains, fast seed maturation)
l Ephimeroids - heliophytes, geophytes, terraphytes
l Psammophytes - adapted from falling asleep with sand
l Perennials with aboveground permanent organs. The leaves are reduced to spines.
l Low shrubs ( chamephites) during the period of active growth during the wet season. In the dry season, the leaves die off in an acropetal sequence (from the top of the shoot to the base of the name. Drought-leaved - wormwood)
l Shrubs with reduced scaly leaves (saxaul)
l Cereals - leaves in a tube and root s-ma to a great depth
l Plants with complete absence of leaves (photosynthesis in stems - sand ephedra)
l Sparsity of vegetative cover - low projective cover
l Succulents (aloe, cactus)
l Protection against overheating by reflecting solar radiation (fine hairs, wax deposits)
Animal adaptations:
l Water supply: - rarely drink animals (camel, saiga)
The predominance of phytophages (gerbil)
l Overheat protection:
Termination of activity
Night-twilight lifestyle
Long legs on insects
Eggs and other b / call. can remain in the soil for several years until rain (ephimers)
Pale feathers of birds and light hair of mammals
Long thin limbs, long neck increased. surface area of the body, from which
can radiate heat
Aestivation
Storing seeds during the rainy season
Rapid breathing, sweating, fur licking
l Nutritional: reduced nutritional selectivity polyphagia
Savannah
Tropical grass-tree communities with a pronounced seasonal rhythm of development.
Africa up to 40%
South America - llanos
N-In Australia
Rainfall 500 - 1500 mm/year
3 types of savannas by duration of drought:
l Wet (drought 2.5 - 5 months; height of hard-leaved grasses 2-5 m - baobab, acacia)
l Dry (drought up to 7.5 months; lower tree height; no continuous grass cover; deciduous trees)
l Prickly (drought up to 10 months; sparse herbage combined with stunted trees and shrubs - blackthorn, cactus)
Savannas by genesis:
l Climatic (indigenous)
l Secondary (at the site of fires and clearings of tropical forests)
l Edaphic (on hardened laterites where tree roots cannot reach aquifers)
Plant adaptations:
l Leaf shedding during dry periods
l Leaves turn into thorns
l Characteristic succulents (baobab, bottle tree)
Animal adaptations:
l Migration and nomadism in the savanna during the dry season.
44. Ecosystems of temperate and high latitudes (taiga, tundra)
Tundra
Zonal type of vegetation. It occupies the northern outskirts of Eurasia and North America. The southern borders coincide with the July isotherm + 10С
1. Low T air
2. short growing season (60 days)
3. permafrost
4. low amount of atmospheric precipitation 200-400 mm
5. gley-marsh soils
Classification from north to south:
1. Polar deserts (Arctic tundra)
l Franz Josef Islands
l North Earth
l Svalbard
l Greenland
l northern part of the Taimyr peninsula
Terrestrial glaciation. Polar night - day. Sparse vegetation (moss, lichen)
2. Moss-lichen tundra
Mosses and lichens need snow protection from strong winds. Among the mosses, cheonophiles (moss moss) predominate. Among the mosses there are grasses, sedges, dwarf birch and polar willow.
3. Shrub tundra
Dwarf birch, blueberry, bilberry, some types of willow. The role of mosses and lichens is reduced - they do not form a continuous cover. Shrubs form a dense closed layer of 30-50 cm, which contributes to the retention of snow.
4. Forest tundra
Classification of tundra plant communities based on 3 main features:
1. Characteristics of vegetation
l Lichen
l Moss
l Grass-moss
2. Substrate characteristics
Clayey
Loams
Stony
3. Relief characteristics
· Lumpy
· hummocky
polygonal
Plant adaptations:
1. flora is relatively poor< 500 видов
2. in Eurasia, 2 tundra annuals - kenigia, gentian. The absence of annuals is due to the short growing season.
3. common plants - centenarians
l arctic willow 200 years
l dwarf birch 80 years old
l wild rosemary 95-100 years old
4. Many tundra plants begin their phenological cycle with the vegetation under snow.
5. winter hardiness (rhizomes up to -60С, ground parts up to -50С)
6. 2 life forms of plants prevail: creeping and pillow-shaped
7. superficial root system
8. trees (phanerophytes) penetrate only into the southernmost parts of the tundra. The branches of the trees are located. In the direction of the prevailing winds (flag shape)
9. plant communities are characterized by low layering
10. sparse nature of vegetation
Taiga
Boreal coniferous forests of the temperate zone of the northern hemisphere (Eurasia and North America)
The floristic composition of tree species is poor:
Siberia - 2 types of larch
2 types of spruce (Siberian, Alyan)
2 fir (Siberian, Far Eastern)
2 pines (Siberian, Cedar)
The reason for the monotony: Quaternary glaciation that destroyed Tertiary forests
Environment characteristic:
l temperate (barreal) climate
l widespread permafrost
l short frost-free period
l cold winter with stable snow cover
l significant average annual precipitation up to 800 mm.
Plant adaptations:
1. Dominant position in tree species that can remain dormant for a long time with minimal expenditure on respiration and evaporation
2. Low T soils due to permafrost (one of the f-s limiting the geographical distribution of conifers)
3. A clear advantage of permafrost areas in trees with lateral roots.
Animal adaptations:
Diverse fauna: 90 species of mammals; 250 species of birds in Russia
Dendrophiles and bloodsuckers
l Hypernation (hibernation)
l Migration and nomadism
l Adaptation to extreme winter conditions (to snow, food storage, heat-insulating covers, transition to a social lifestyle - wolves)
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Deposits of continental waters are much rarer than those of oceanic basins.
Pollution of continental waters and the World Ocean is growing rapidly with industrial effluents, municipal farms, fertilizers and pesticides washed off the fields, as well as oil and its residues discharged from tankers after unloading. As a result of pollution, fish and other living creatures die. Reine in 1910, 175 thousand pieces were caught.
The hydrosphere, as noted above, is the discontinuous water shell of the Earth, the totality of oceans, seas, continental waters (including groundwater) and ice sheets. Seas and oceans occupy about 71% of the earth's surface, they contain about 1 4 10 hours of water, which is 96 5% of the total volume of the hydrosphere. The total area of all inland water bodies of land is less than 3% of its area. Glaciers account for 1-6% of water reserves in the hydrosphere, and their area is about 10% of the area of the continents.
The hydrosphere, as noted above, is the discontinuous water shell of the Earth, the totality of oceans, seas, continental waters (including groundwater) and ice sheets. Seas and oceans occupy about 71% of the earth's surface, they contain about 14109 km3 of water, which is 965% of the total volume of the hydrosphere. The total area of all inland water bodies of land is less than 3% of its area. Glaciers account for 1-6% of water reserves in the hydrosphere, and their area is about 10% of the area of the continents.
The fact that the tritium content of precipitation in the Chicago area at that time was only 20 (Table 50) shows that atmospheric water vapor consists of two-thirds sea water and one-third re-evaporated continental water. Libby goes on to make an interesting conclusion about the water balance of North America, which we cannot discuss in detail here, but which describes the potential use of tritium as a tracer in meteorology and hydrology.
Green algae constitute the most diverse group of classical oxygenic phototrophic organisms. They dominate both on land and in continental waters. The successive series of morphological complication with the same type of exchange can be traced here with the greatest obviousness.
In the tropical latitudes of the Earth, they then rain down, and in temperate regions, depending on the season, they fall in the form of rain or snow. This moisture then falls out with precipitation: 420 thousand km3 on the surface of the oceans, and 100 thousand km3 on land, but the excess of continental waters is transferred to the ocean by rivers. If we move to a time period less than a year, it turns out that 1 km3, or 1 billion tons, of water evaporates in one minute, and each gram of steam carries 537 calories of solar energy into the atmosphere.
Differences in the composition and productivity of algae are no less significant in two other large biotopes of the seas, delimited in the latitudinal direction - the oceanic and nerite areas, especially if all inland seas are included in the latter. The special features of oceanic plankton are listed above. Although they are different in tropical and subpolar waters, they generally reflect the characteristic features of marine phytoplankton. Oceanic plankton, and only it, consists exclusively of those species that complete their entire life cycle in the water column - in the pelagic zone of the reservoir, without contact with the ground. In the neritic plankton, such species are already much less numerous, and in the plankton of continental waters they can occur only as an exception.
Seaside lakes (for example, the largest ones: Sasyk-Sivash - 71 km2 and Donuzlav - 47 km to Crimea) arise from lagoons. The study of the hydrological balance of the Crimean lakes showed that they are mainly fed by surface and underground runoff of groundwater, as well as atmospheric precipitation. Only from 2 to 11% of the total water balance falls on the filtration of sea water through the barrage. However, the main mass of salts in lakes comes from the sea (at concentrations of 1-8% salts in sea water and 0 03 - 0 05% salts in continental waters) [6, p. Therefore, coastal lakes usually retain the hydrochemical features of the sea. Some of them (for example, Dzhaksy-Klych in the Aral Sea region, 72 KMZ) are periodically fed by the sea through dry channels or when barrier barriers break through.
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