Deciduous forests of temperate latitudes climate. Forest types of biomes. Ecological role of hydrothermal factors. Current state. Deciduous forests of North America

Forests temperate zone are forests growing in regions with temperate climate e.g. east side North America, Western and Central Europe and Northeast Asia. Temperate forests are found at latitudes between approximately 25° and 50° in both hemispheres. They have a temperate climate and a growing season that lasts 140 to 200 days a year. Precipitation in temperate forests tends to be evenly distributed throughout the year. The temperate forest canopy is primarily composed of broadleaf trees. In the polar regions, temperate forests give way.

Temperate forests first appeared about 65 million years ago, during the beginning cenozoic era. At that time, global temperatures dropped and forests sprang up in more temperate regions above the equator. In these regions, the temperature was not only cooler, but also showed seasonal fluctuations. Plants evolved and adapted to climate change.

Today, in temperate forests that are closer to the tropics (where the climate has not changed so much), trees and other plant species are more reminiscent of vegetation from. Temperate evergreen forests can be found in these regions. In areas where climate change has been more intense, deciduous trees have evolved (they shed their leaves each year when the weather turns cold as an adaptation, allowing the trees to withstand seasonal temperature fluctuations in these regions).

Main characteristics of temperate forests

The following are the main characteristics of temperate forests:

• grow in temperate regions (at latitudes between about 25°-50° in both hemispheres);
• experiences distinct seasons, with a growing season that lasts 140 to 200 days;
• the forest canopy consists mainly of deciduous trees.

Classification of temperate forests

Temperate forests are divided into the following habitats:

• Moderate deciduous forests- grow in eastern North America, Central Europe and parts of Asia. They are characterized by temperature fluctuations from -30° to +30° C throughout the year. They receive about 750-1500 mm of precipitation per year. Vegetation deciduous forests includes a variety of broad-leaved tree species (eg oak, beech, maple, hickory, etc.) as well as various shrubs, perennial grasses, mosses and mushrooms. Temperate deciduous forests are found in mid-latitudes, between the polar regions and the tropics.
• Temperate evergreen forests - consist mainly of evergreen trees that renew their foliage throughout the year. Temperate evergreen forests are found in eastern North America and the basin mediterranean sea. They also include subtropical broadleaf evergreen forests in the Southeastern United States, southern China, and eastern Brazil.

Some of the animals that inhabit temperate forests include:

• The Eastern Chipmunk (Tamias striatus) is a species of chipmunk that lives in the deciduous forests of eastern North America. Oriental chipmunks are small rodents with red-brown fur adorned with dark, light and brown stripes that run along the back of the animal.
• The white-tailed deer (Odocoileus virginianus) is a species of deer that inhabits deciduous forests in eastern North America. White-tailed deer have a brown coat and a tail that is white on the back.
• The American black bear (Ursus americanus) is one of three species of bears that live in North America, the other two are and. Of these species, black bears are the smallest and timid.
• Robin (Erithacus rebecula) is a small bird from the flycatcher family (muscicapidae). The range of habitation of robins is quite extensive and includes: Northwest Africa from Morocco to eastern Tunisia and the Mediterranean coast, as well as most of the Eurasian continent.

If you find an error, please highlight a piece of text and click Ctrl+Enter.

Broad-leaved forests are common in areas natural landscape which are characterized by an optimal ratio of heat and moisture. Geographic map Earth captures significant areas of their natural growth in the temperate zone of Europe, Manchuria, Far East, Japan, Eastern China, North America. Small areas are occupied by deciduous forests in Central Asia, in southern South America. In Russia, broad-leaved forests replace mixed ones and occupy a territory in the form of a triangle, the base of which is located at the western border of the state, and the top rests on Ural mountains. AT Western Siberia a narrow strip of birch and aspen forests separates the taiga from the forest-steppe.

Characteristics of the natural zone of broad-leaved forests.

To the necessary conditions for the development of these forest ecosystems includes the complex interaction of relief, soil, climate, and water. The temperate climate is characterized by warm, long summers and mild winters. The annual amount of precipitation, evenly distributed throughout the year, is somewhat higher than evaporation, which significantly reduces the level of waterlogging of soils. Main tree species broad-leaved forests are oak, linden, elm, maple, ash, beech, hornbeam. Most of these forests are multi-layered systems: high tree layer, undergrowth, shrub, several herbaceous of varying heights. The ground layer is formed by mosses and lichens. There are also forests in which high and dense crowns of trees exclude undergrowth, grassy cover. The soil in them is densely covered with a layer of old leaves. Decaying, organic residues form humus, contribute to the formation of stable organo-mineral compounds, since the leaves are rich in ash, calcium, potassium, and silicon. In smaller quantities they contain magnesium, aluminum, phosphorus, manganese, iron, sodium, chlorine.

Broad leaf blades are not suitable for adverse conditions cold period of the year, so they fall off. Falling leaves, thick bark of trunks and branches, resinous, dense scaly buds - all this is a defense against excessive winter evaporation. A stable snow cover during the melting period strikes at the soil due to active leaching. Broad-leaved forests are characterized by sod-podzolic, gray, brown forest soil, less often there are varieties of chernozem.

In temperate latitudes, large seasonal differences in radiation conditions are observed. In summer, the radiation balance of the underlying surface is high and in areas with little cloudiness it approaches the conditions of tropical latitudes, while on the continents it is negative in winter.

The temperate latitudes are also the scene of the most intense cyclonic activity on the polar and arctic fronts, so the weather regime here is very variable. Frequent intrusions air masses, both from polar and from subtropical latitudes, and hence also drastic changes temperature.

In the Northern Hemisphere, there are great differences in the circulation conditions on the continents and oceans, which cause pronounced types of maritime and continental climates.
In predominantly oceanic southern hemisphere the continental type of climate in temperate latitudes is practically absent.

Very significant differences in climate exist on the western and eastern margins of temperate continents. The climate of the western shores, subject to the predominant influence of marine air masses, is transitional from maritime to continental; it is often referred to simply as the sea. On the eastern shores there is a monsoon type of climate, especially in Asia.

In the temperate zone B.P. Alisov distinguishes the following four types of climate: continental, maritime climate of the western parts of the continents, monsoon climate eastern parts of the continents and oceanic.

Continental climate of temperate latitudes. This type of climate is found on the continents of Eurasia and North America. It is characterized warm summer and cold winter with stable snow cover. The annual temperature amplitude is large and increases with the distance to the interior of the mainland. Moisture conditions change in the direction both from south to north and from west to east.

In the southern part of the temperate latitudes of Eurasia, the winter regime is dominated by high pressure.
On climatological maps, it is in these latitudes that the center of the famous Asian winter anticyclone with a spur directed to southern part Europe. Therefore, winter precipitation here is small and decreases with distance into the interior of the mainland. For this reason, the snow cover is not high, and in Transbaikalia, near the center of the anticyclone, it reaches negligible values, despite the very severe winter.

In summer, in the southern part of the temperate latitudes of Eurasia, anticyclones of a subtropical type are also not uncommon, contributing to hot and dry weather. Summer precipitation is greater, but even they are insufficient due to high evaporation at high summer temperatures, so humidification in the southern part of temperate latitudes is insufficient. In general, 200–450 mm of precipitation falls here annually. As a result, starting from Moldova, through Ukraine, the southern part European territory Russia and further beyond the Urals, up to and including Mongolia, steppes stretch, in which dry conditions are often created in summer. AT Caspian lowland steppes turn into a semi-desert, and beyond the Urals, in the northern part of the Turan lowland (Kazakhstan), even into a desert, i.e. in an area with a permanently dry (arid) climate. In Kherson (46.6°N, 32.6°E) average temperature July +23°С, January –4°С; the annual amount of precipitation is 380 mm. In Akhtuba (48.3°N, 46°E) in July +25°С, in January -9°С; precipitation per year 240 mm. In Balkhash (46.9°N, 75.0°E) in July +24°С,
in January -15°С; precipitation for the year 127 mm. Over the same latitude, with distance to the east, winter temperatures decrease and precipitation decreases, landscapes change: from the steppe through the semi-desert to the desert.

In the higher latitudes of the temperate zone of Eurasia, summers are less hot, but still very warm, winters are more severe (for any given longitude), large annual precipitation totals
(300–600 mm). Continentality also increases from west to east (mainly due to a decrease in winter temperatures): annual temperature amplitudes increase and precipitation decreases. The snow cover here is higher and lasts longer. This is a zone of mixed or deciduous forests. Let's compare the conditions in some of its paragraphs. In Moscow (55.8°N, 37.6°E) the average temperature in July is +18°С, in January –10°С; the annual amount of precipitation is 600 mm. In Kazan (55.8°N, 49°E) in July +20°С, in January -13°С; precipitation for the year 459 mm. In Novosibirsk (55.0°N, 82.9°E) +19°C in July and -19°C in January; precipitation for the year 425 mm. The maximum precipitation everywhere occurs in the summer.

Further north is the taiga zone, which stretches from Scandinavia to the Pacific Ocean, with the same patterns in climate change from west to east, but with more severe winters. The southern border of the taiga zone in the eastward direction will shift towards lower latitudes.
In Transbaikalia, the taiga climate already directly borders on the steppe climate; the zone of deciduous forests between the taiga and the steppe disappears here. To the north, the taiga and its climate go farthest in Taimyr. Summer in the taiga zone is as hot as in more low latitudes but the winter is even colder. It is due to the severity of winter that the climate in the eastern part of the taiga zone reaches the greatest continentality. Precipitation falls in general as much as in the zone of deciduous forests; moistening is generally sufficient, in Western Siberia even leading to swamping.
In Kargopol (61.5° N, 38.9° E) the average temperature in July is +17°С, in January -12°; precipitation for the year 540 mm. In Yeniseisk (58.4°N, 92°E) in July +18°C, in January -223C; precipitation for the year 460 mm. In Yakutsk (62.0°N, 129.6°E) in July +19°C. in January -44°С; rainfall for the year 190 mm. It is in Yakutia that the continentality of the climate reaches its greatest value.

On the mainland of North America, the same types of continental climate of temperate latitudes are found. They are distributed very difficult, partly under the influence of orography. In the west of the inner part of the mainland, protected by the Rocky Mountains from air masses from the Pacific Ocean, deserts and steppes predominate, in the east - deciduous forests. North most of Canada is occupied by taiga, which extends especially far to the north in Alaska. Accordingly, they are distributed climatic conditions. Let's take a look at some stations.

AT steppe zone, in Salt Lake City (40.8° N, 112° W), at a significant altitude above sea level (1300 m), the average temperature in July is +25°С, in January -2°С; precipitation for the year 395 mm. In the zone of deciduous forests, in Chicago (41.9 ° N, 87.6 o W), in July the average temperature is + 23 ° C, in January -4 ° C; precipitation for the year 815 mm.

In more northern latitudes in the taiga zone, at Prince Albert station (53.2°N, 105.6°W), the average temperature in July is +17°C. January –20°С; precipitation for the year 406 mm.

A special type of continental climate is the climate of mountainous regions in temperate latitudes. In the mountainous regions of the Tien Shan, precipitation is more abundant than in the Turan lowland and the Pamirs. In favorable terrain conditions, they can exceed 2000 mm; precipitation decreases from west to east. The temperatures here are, of course, lower than in the lowlands. For example, in Przhevalsk (42.4°N, 78.4°E, 1744 m) +17°C in July and -7.1°C in January.

AT highland area Sayan and Altai temperature regime very diverse and depends on the height and topography. Precipitation is significant on the windward slopes (up to 1500 mm or more in Western Altai) and small on the southern slopes and in closed basins (less than 200 mm in Altai).
In the Sayans, on the western and northwestern slopes, the annual precipitation exceeds 1000 mm. Therefore, a large snow cover accumulates on the windward slopes and the snow line decreases.

In North America, very large quantities precipitation falls on the windward slopes of the Cascade Mountains, more than 2000 mm per year. The maximum precipitation due to increased cyclonic activity occurs in winter, and the snow cover in some places exceeds 5 m. In the Rocky Mountains located to the east, precipitation is less: on the western slopes up to 1000 mm, in the valleys in some places only 150–200 mm. The average January temperatures in the inner valleys and on the plateau are about -5 - 10°C and below. Very sharp temperature fluctuations in winter are often associated with a foehn on the western slopes of the Rocky Mountains. There were such cases as an increase in temperature in January with a hair dryer from -31 to + 19 ° C, however, for a considerable time (several tens of hours). Summers are dry and not hot, but, of course, temperatures depend on both latitude and altitude.

Special climate conditions of high steppes and semi-deserts are observed in Mongolia. At altitudes of 700–1200 m and above warm summer and a very cold and little snowy winter; precipitation is generally very small and falls mainly in summer, since in winter it is the region of the central part of the Asian winter anticyclone. In Ulaanbaatar (47.9° N, 106.8° E, 1309 m) the average temperature in July is +17°С, in January -28°С; very large diurnal temperature ranges. Precipitation (243 mm per year) falls mainly from May to September. In Jargalant (Kobdo) (47.9°N 91.6"E 1370 m) precipitation is even less, about 122 mm, and precipitation is typically summer, winter is almost snowless.

The climate of the western parts of the continents in temperate latitudes. In the western parts of Eurasia and North America, in temperate latitudes, the transfer of marine air masses to the mainland both in winter and in summer sharply prevails. Therefore, here the climate bears a strong imprint of oceanic influences and is a maritime climate. It is characterized by not very hot summers and mild winters without sustained snow cover, adequate rainfall and a more or less uniform seasonal distribution. This defines the landscape of deciduous forests and meadows. Precipitation sharply increases on the western slopes of the mountains.

In North America, due to the presence of the Cascade and Rocky Mountains, this type of climate is limited to a relatively narrow coastal area. AT Western Europe it spreads inland with a gradual increase in continentality. For example, in Paris (48.8°N, 2.5°E) the average temperature in July is +18°C, and in January +3°C; precipitation for the year 613 mm.
In higher latitudes, in Bergen (60.4°N, 5.3°E), in July, precipitation is 1730 mm - the influence of orography affects (Bergen lies to the west of the Scandinavian Mountains, on the coast). Beyond the ridge, inside and in the east of the peninsula, the climate becomes continental. In Stockholm, for example, in July +16°C, in February -3°C, and precipitation for the year is 540 mm with a summer maximum; in terms of landscape, this is already the south of the taiga zone.

In Europe, east of Berlin, the climate becomes continental. Within Russia, this type of climate turns into continental climate temperate latitudes described above. Largest Quantities precipitation falls in this type of climate in Europe on the windward slopes of mountains. Above is a large amount of precipitation for Bergen, but at some stations in the Alps, more than 2500 mm falls per year.

The maritime climate for the west of North America is characterized by data from Sitka station in Alaska (57, G N, 135.3° W), where +13°C in August and 0°C in January; the annual amount of precipitation is 2343 mm. But on the slopes of the Cascade Mountains, even greater amounts of precipitation fall out - from 3000 to 6000 mm. Such a huge amount of precipitation is also associated with a pronounced influence of topography.

The climate of the eastern parts of the continents in temperate latitudes. In eastern Asia, the climate is typically monsoonal. Monsoons of temperate latitudes are a continuation of tropical and subtropical monsoons, they are very distinct and are observed approximately to the latitude of northern Sakhalin. The south of Kamchatka is free from them, and over the Sea of ​​Okhotsk and over the north of Kamchatka only a monsoonal tendency is found. Thus, a moderate monsoonal climate is observed in Primorsky Krai, in northeastern China, in northern Japan and on Sakhalin.

In winter, the outskirts of the mainland are shown on the periphery of the Asian anticyclone and the transfer of cold air from Eastern Siberia prevails here, so the winter is cloudy and dry with significant cold and a sharp minimum of precipitation. In summer, cyclonic activity dominates over the east of Asia with fairly heavy precipitation. An example is the data for Khabarovsk (48.5°N, 135.0°E), where the average temperature in July is +21°C, in January -22°C and precipitation is 569 mm per year, from which in the winter half-year (October-March) accounts for only 99 mm.

The situation is more complicated in Japan, where even in winter cyclones with frontal precipitation are quite frequent, which are further enhanced by orography. In summer, on the contrary, there is a relative minimum of precipitation in the middle of the season due to the retreat of cyclonic activity to the north.
As a result, winter can be no less rich in precipitation than summer. In Sapporo (43.1°N, 141.4°E) the average temperature in August is +21°C, in January -6°C; precipitation is 1078 mm per year, and for the winter half of the year 560 mm and for the summer 518 mm.

AT northern regions Russian Primorye, where the monsoon wind regime is weak or absent, winter is milder due to strong cyclonic activity and the distribution of precipitation throughout the year is uniform. Thus, at Klyuchi station in Kamchatka (56°N, 160°E), the average temperature in July is +15°С, in January –17°С; precipitation is 562 mm per year, of which 314 mm falls in the winter half of the year.

On the Atlantic coast of Canada and Newfoundland, the monsoon circulation is weak or absent. Winters are not as cold as in eastern Asia, and summers are quite warm. For example, in Halifax (44.6°N, 63.6°W) in July and August the average temperature is +18°C, and in January -4°C; precipitation for the year is 1386 mm, and their distribution over the seasons is quite uniform.

AT South America the climate of the eastern part of the mainland in temperate latitudes can be attributed to the whole of Patagonia, from about 38 to 52 ° S.l. and from the foothills of the Andes to the Atlantic Ocean. The peculiar geographical situation of the area also creates a peculiar semi-desert climate in close proximity to the ocean. The reason is that from the influence of sea air masses from the Pacific Ocean, Patagonia is closed by the Andes. At the same time, cold air masses of Antarctic origin freely penetrate here from the south. Atlantic air, occasionally intruding into Patagonia, first passes over the cold waters of the Falkland Current, where it becomes steadily stratified, and therefore also does not give much precipitation.

In most of Patagonia, the annual precipitation is 120–200 mm, and in summer months there are very few of them, no more than 20–30 mm in three months. The average temperature in January is from +20°С in the north to +10°С in the south, i.e. summers are colder compared to the deserts of the Northern Hemisphere under the same latitudes. The average temperature in July is close to +5°С, but on high plateaus it drops to –5°С; consequently, winters are considerably milder than in the extratropical deserts of the Northern Hemisphere. On the low coast of the Atlantic Ocean in the south of Patagonia, in Santa Cruz (50.0 ° S, 68.5 ° W), precipitation falls only 171 mm per year, the average January temperature is + 15 ° C, and June and July +2°С.

Oceanic climate in temperate latitudes. The Atlantic and Pacific oceans occupy large areas in the temperate latitudes of both hemispheres, and Indian Ocean in the temperate latitudes of the Southern Hemisphere. The prevailing westerly transport is better expressed over the oceans than over the continents, especially in the Southern Hemisphere. The wind speed is greater than over the continents. In the 40th and 50th latitudes of the Southern Hemisphere, between the zone of subtropical anticyclones and subantarctic latitudes, where the centers of deep cyclones most often pass, the average wind speeds are 10–15 m/s. Storms here are frequent and prolonged; It was not for nothing that sailors called the 40th latitude of the Southern Hemisphere roaring. The temperature distribution over the oceans is more zonal than over the continents at the same latitudes, and the differences between winter and summer are less pronounced.
In connection with the cold summer, the tundra landscape is located on oceanic islands in such low latitudes, in which there is still no tundra on the continents. Thus, the Aleutian and Commander Islands are covered with tundra, at 55–52 ° N: in the Southern Hemisphere, the Falkland Islands at 52 ° S, South Georgia Island, the South Orkney Islands, etc. are covered with tundra.

In the Northern Hemisphere, the western parts of the oceans are noticeably colder than the eastern ones in winter due to frequent intrusions of cold air masses from the continents. In summer, the difference is less. Cloudiness over the oceans of temperate latitudes is large and precipitation is significant, especially in subpolar latitudes, where the deepest cyclones are observed.

In the zone between 40 and 60°N. in both oceans of the Northern Hemisphere, the average August temperatures are between +22 and +8°C. In February at Atlantic Ocean– from +15 to –10°С, but in pacific ocean much lower - from +10 to -10°С. In general, the temperature difference between the 40th and 60th latitudes decreases from winter to summer. The annual amplitudes here are on the order of 10–15°C. In the Southern Hemisphere, the average temperatures of these oceans are between 40 and 60°S. in February from +15 to 0°С, in August from +10 to –10°С. Dominant westerly winds here are very strong and stable, storms are frequent.

NOU VPO "Tver Institute of Ecology of Ecology and Law"

Faculty of Ecology

Department of General Ecology and Nature Management

Correspondence form of education

Course work

In the discipline "General Ecology"

Flora and fauna of deciduous forests

Completed by: 1st year student

Faculty of Ecology

Simonenkova L.I.

Supervisor:

PhD, Medvedev A.G.

Introduction 3

1. Deciduous Forest 3

1.1 General characteristics 4

1.2 Climate characteristic 4

1.3 Flora 4

1.4 Wildlife 14

References 29

Introduction

The ecosystem of the deciduous forest is represented by several thousand species of animals, more than a hundred species of plants. Where there is a dependence of living organisms that make up the food chain and enjoy the right to survive in the various ways that nature has endowed them with.

My task was to show this dependence, to describe the inhabitants of this type of biome and how they depend on each other.

General characteristics of deciduous forest

Deciduous forest is a summer-green forest dominated by broad-leaved (beech, oak, hornbeam, elm, maple), small-leaved (birch, aspen) or hard-leaved species. The deciduous forest is distributed mainly in the temperate climate zone, in the Nearctic and Palearctic regions.

In the Nearctic region, broad-leaved forests with a dense crown predominate: oak, beech, maple; lots of flowers. Main animals: mole, gopher, black squirrel, raccoon, opossum, chipmunk, red fox, black bear, songbirds. And hardwood forests. Thickets of juniper and shrubs with leathery leaves. Representatives of the fauna come from neighboring biomes. In the Palearctic - mainly beech, maple, oak, hornbeam, linden, but of different species than in the Nearctic. The fauna of the deciduous forests is also very similar to the Nearctic.

The Mediterranean area is very similar to the corresponding Nearctic biome, which is home to animals from various neighboring communities. Also in the neotropical region, deciduous forests can be found, in arid zones, which shed their foliage during a drought.

Mixed - broad-leaved, deciduous forests occupy almost the entire forest part of Western Europe, and in Eastern Europe their border with the taiga runs along the line St. Petersburg - Nizhny Novgorod, further to the east a narrow strip of deciduous forests between the taiga and the steppe stretches to the Urals. In North America, deciduous forests are located primarily around the Great Lakes. A characteristic feature of the vegetation is the presence of broad-leaved trees (oak, linden, maple, etc.), the number of which gradually increases towards the south.

Climatic characteristic

The climate is temperate continental, the humidity is moderate. In the zone of deciduous forests, the climate is seasonal: warm winter, warm summer, winter t<0, хотя не ниже -16 С, летом средняя температура июля 16 С-24 С.

Precipitation - 750 -2000 mm / year. Such high rainfall, neither hot nor cold climates, and correspondingly moist soils, contribute to the flourishing of deciduous plants, which shed their leaves depending on the time of year. But although at the moment there are about 18-20% of the total forest area of ​​deciduous forests, American scientists predict a climate shift around the 2030s, as a result of which the area of ​​deciduous forests will increase by 3 times and cover all the shores of the Pacific Ocean, and coniferous forests will die out as mammoths.

Vegetable world

Daily fluctuations in temperature in the forest are smoothed out by the presence of vegetation and high humidity. More precipitation falls over the forest than over the field, but a significant part of it does not reach the soil surface during light rains and evaporates from the leaves of trees and plants. The ecosystem of the deciduous forest is represented by several thousand species of animals, more than a hundred species of plants.

The roots of trees of the same species often grow together. As a result, nutrients are redistributed in a complex manner. In dense spruce forests, up to 30% of trees grow together with roots, in oak forests - up to 100%. The fusion of roots of different species and genera is extremely rare. Depending on the action of various environmental factors, trees of the same age may have the form of powerful fruit-bearing individuals or thin shoots, or they may even grow old before reaching a mature state.

Forest vegetation competes intensively for light. Only a small part of the sun's rays reaches the soil, so the plants in the forest live in several tiers. The lower the tier, the more shade-tolerant species occupy it. In the upper tier there are crowns of light-loving trees: oak, birch, ash, linden, aspen. Below are less light-loving forms: maple, apple, pear. Undergrowth bushes grow even lower: viburnum, lingonberry, hazel. Mosses and herbaceous plants form the lowest tier - the ground cover.

Upper tier:

ASH (Fraxinus excelsior). Some of its flowers are female (2 anthers fall off early), some are male, some are bisexual, while there is a very different combination of these flowers on one tree and even in one inflorescence: male and bisexual, female and bisexual on one plant; female on one, bisexual on the other; female, bisexual and male are all on different trees, and so on. In Central Europe, up to 10 forms of ash were counted in relation to the distribution of sexes, and it was noted that it can change in different years, apparently being partly determined by external conditions. Ash trees with a developed corolla, such as the manna ash (Fraxinus ornus), are among the purely entomophilous plants, they have sticky pollen with a pronounced sculpture and are readily visited by beetles.

MANN ASH (Fraxinus ornus) Growing in Europe from the Mediterranean regions to the south of Czechoslovakia and the northeastern Carpathians, it is valuable as a source of manna, a sweetish juice that hardens in the air, flowing out when the branches are tapped. Manna is used as a mild laxative and for coughs.

WHITE POPLAR (Populus alba), distributed in the middle and southern strip of all of Europe, in the Caucasus and Asia Minor, in South Siberia (to Altai and the Tomsk region). In addition, it is very widely cultivated in parks and on the streets almost all over the world. In particular, white poplar is very common in cultivation throughout Central Asia, where its wild and root-renewed groves are sometimes mistaken for primordial wild ones.

ASPEN (Populus tremula), or Euro-Siberian aspen, has the largest area of ​​distribution among all poplars (and one of the largest among all tree species in general). Aspen grows almost throughout Europe (except for the tundra and desert zones and the strip of Mediterranean vegetation), as well as in the Caucasus, in Asia Minor, in the Tien Shan, throughout non-Arctic Siberia, in our Far East, in Japan and in the mountains of China up to the southernmost province - Yunnan.

BIRCH (Betula), a genus of trees and shrubs of the birch family (Betulaceae), which also includes alder, hornbeam and hazel. About 40 species growing throughout the Northern Hemisphere from the Arctic to Texas, Southern Europe, the Himalayas and Japan. Birches are found on the northern border of the distribution of woody plants. Because of their beautiful light green foliage, colored bark and graceful crown shape, they are often bred for ornamental purposes. Gardeners have bred many of their cut-leaved and weeping varieties planted in parks and squares. The wood of some birches is a valuable material for the production of furniture, plywood veneer and other products.

Dwarf forms of birches are known, and a number of alpine and arctic species are not immediately distinguishable among the surrounding grass. However, in most cases, birches are slender trees up to 12–27 m high and even higher. The color of the bark, depending on the species, is white, yellow, orange, reddish brown or black. The bark often peels off in thin, papery layers. The branches are usually short, thin and drooping with simple alternate leaves. Male and female flowers are produced in different catkins on the same tree. Birch trees usually bloom in early spring before the leaves open. The fruit is a small conical nut with wings, easily dispersed by the wind.

In the Old World, common birch is warty, or drooping (B. pendula), growing from Europe to Japan. Its height is up to 18 m. At home and in North America, this species is often used as an ornamental. The range of the downy birch (B. pubescens) extends from Northern and Central Europe to Eastern Siberia. Usually it is a little smaller. The bark (birch) of both of these species is white, easily peeling off. Erman's birch (B.ermanii), growing in Eastern Siberia and the Far East, is also called stone because of its durable wood. It reaches a height of 25 m.

In North America ca. 15 local species of birch, 10 of which are tall trees. Together with beeches, oaks and maples, these are the main species of deciduous forests of the northeastern United States and neighboring areas of Canada.

PAPER BIRCH (B. papyrifera) is very similar to downy birch. This is one of the most beautiful trees in North America and the most widespread representative of this genus here.

It grows from New Jersey to Iowa, in the north reaches almost the coast of Hudson's Bay, in the east - to Labrador and Newfoundland, in places it is found in South Dakota, Wyoming, Colorado and in northern Nebraska. It reaches a height of 21 m with a diameter of 0.9 m, but usually the trees are smaller.

The bark of this species is snow white to creamy white, peeling off in papery layers. The Indians made canoes, household utensils out of it, covered wigwams with it. The wood, like that of other birches, is thin-layered, uniform in texture, but lighter and softer than that of yellow and cherry birches. White sapwood, when turned on a lathe, gives a very smooth surface. It is widely used in the production of spools, toys, clothespins, jewelry.

OAK (Quercus), a genus of deciduous trees of the beech family (Fagaceae).

The genus includes about 600 species growing in the temperate and tropical zones of the Northern Hemisphere. There are about 20 species of oak in our country.

Large beautiful deciduous or evergreen trees with a powerful tent-shaped crown, leathery leaves, deep root system with a powerful tap root, rarely shrubs. Most species are forest-forming species that provide valuable wood. Light-loving, demanding on the richness of the soil, wind-resistant, drought-resistant, distinguished by exceptional longevity.

OAK PEDIOUS (ordinary) - Quercus robur. It occurs naturally in the European part of Russia, Central and Western Europe. A very powerful tree up to 50 m tall, in close stands with a slender trunk, highly debranched, in single plantings in open places - with a short trunk and a wide, spreading, low-set crown. Lives 500-900 years.

The bark on trunks up to 40 years old is smooth, olive-brown, later grayish-brown, almost black. The leaves are alternate, at the top of the shoots close together in bunches, leathery, oblong, obovate, up to 15 cm long, with an elongated apex and 3-7 pairs of obtuse, lateral lobes of unequal length. Lobes entire, or with 1-3 teeth, often with auricles at the base of the leaf blade. The leaves are shiny, bare, dark green above, lighter below, sometimes with sparse hairs. In spring, the oak blossoms late, one of the last among our trees. Oak blossoms in April-May, when it still has very small leaves. The flowers are unisexual, monoecious, very small and inconspicuous. Male or staminate flowers are collected in peculiar inflorescences - long and thin yellowish-greenish drooping catkins, reminiscent of hazel catkins. Acorns up to 3.5 cm, 1/5 covered with a cupule, ripen in early autumn.

Grows slowly, the greatest energy of growth in 5-20 years. Moderately photophilous, wind-resistant due to powerful root system. Excessive waterlogging of the soil does not tolerate, but withstands temporary flooding for up to 20 days. It prefers deep, fertile, fresh soils, but is able to develop on any, including dry and saline ones, which makes it indispensable in green building in many regions of Russia. It has high drought and heat resistance. One of the most durable breeds, lives up to 500-1500 years.

Has powerful energy. Oak in Russia became a sacred tree. In the springs located in the oak forests, the water has an excellent taste and is particularly clean.

Propagated by sowing acorns, decorative forms - by grafting and green cuttings. It is well renewed by shoots from a stump. Acorns do not tolerate desiccation, as soon as they lose even a small part of the water, they die. In heat, they easily rot, they are very sensitive to cold and frost. This circumstance presents a certain difficulty for preserving acorns for seeds. In nature, there is no such problem: acorns that have fallen in late autumn in the forest overwinter in a wet bed of leaves under a thick layer of snow that protects them from both drying and frost. The germination of an acorn resembles the germination of a pea: its cotyledons do not rise above the soil surface, as in many plants, but remain in the ground. A thin green stem rises up. At first it is leafless, and only after some time small leaves appear on its top.

RED OAK - Quercus rubra. In nature, it occurs along the banks of rivers, where there is no stagnation of water in the soil, north of the 35th parallel of the North American continent, up to Canada. Tree up to 25 m in height. A slender tree with a dense hipped crown.

The trunk is covered with thin, smooth, gray bark, cracking in old trees. Young shoots are reddish-felt, annual shoots are red-brown, smooth. The leaves are deeply notched, thin, shiny, up to 15-25 cm, with 4-5 pointed lobes on each side of the leaf, reddish when blooming, dark green in summer, lighter below, in autumn, before falling off, scarlet-red in young trees, the old ones are brownish-brown. Blooms at the same time as the leaves open. Acorns are spherical in shape, up to 2 cm, red-brown, as if chopped off from below, unlike English oak, they ripen in the fall of the second year. It bears fruit steadily and abundantly from 15-20 years. When young, it grows faster than European oaks.

Frost-resistant. Medium light-loving, easily tolerates lateral shading, but prefers full coverage of the top of the crown. Not drought tolerant. Wind-resistant, not very demanding on soil fertility, withstands even acid reaction, but does not tolerate calcareous and wet soils. Resistant to pests and diseases, including powdery mildew - the scourge of our oaks. It has high phytoncidal properties. Due to its high decorativeness, resistance to adverse environmental factors, magnificent autumn decoration, it deserves the widest use in green building, for creating single and group plantings, alleys, arrays, lining roads and streets.

FLUFFY OAK - Quercus pubescens. In nature, it is found in the southern Crimea, the northern part of the Transcaucasus, southern Europe and Asia Minor. Tree up to 10 m tall. Durable.

Significantly inferior in size to the previous species, with a low, winding trunk and a wide crown, sometimes even a shrub. Young shoots are strongly pubescent. Leaves 5-10 cm long, very variable in shape and size, with 4-8 pairs of obtuse or pointed lobes, dark green above, glabrous, gray-green below, pubescent. The scales of the plush surrounding the acorn are also fluffy.

Grows slowly, light and thermophilic, lives on dry rocky slopes and soils containing lime. Handles haircut well. Valuable species for green building in arid areas, grows on stony soils where other species do not develop. An excellent material for high hedges and figured, sheared forms.

Middle tier:

RED MAPLE (Acer rubrum), it turns out, lives up to its name not only in autumn, when it is decorated with red leaves (they can also be purple and yellow), but also in spring. At this time, dark red bunches appear on leafless trees - inflorescences. In some specimens of the red maple, many parts of the flowers are colored, and the scales of the flower buds are reddish. A particularly spectacular sight opens under a magnifying glass: not only long pedicels and perianth, but also forked stigmas and anthers turn out to be red. And the filaments and the connective are bright green.

SUGAR MAPLE (Acer saccharum), can dominate the upper forest layer. The sugar maple, found in eastern North America, is one of the tallest maples (reaching over 40 m in height). The sugar maple leaf is the national symbol of Canadians. His stylized image flaunts on the jackets of Canadian hockey players and on the flag of Canada. The sugar maple owes its popularity, however, not at all to decorative qualities. Once, before the expansion of sugar cane into America (shortly after the voyages of Columbus), sugar maple was the most important source of sugar for the natives, and then for the first white settlers. The production of maple sugar, syrup, molasses, and maple beer developed in the 19th century. into a particular industry, especially in Canada. Nowadays, the extraction of sugar from maple sap has become a typical tourist industry. The release of maple sap occurs in the spring, before flowering and leafing out. This is the so-called weeping of plants. It is quite analogous to a similar phenomenon in birch and is also characteristic of other types of maples, such as sycamore and Norway maple.

WHITE WILLOW (Salix alba) or willow, - a medium-sized or even large tree with whitish-silvery leaves, usually along the river valleys of the middle and southern strip of the European part of Russia, Central Asia, Kazakhstan and the south of Western Siberia; very often bred, especially in rural areas (and in Central Asia along ditches). There are also decorative weeping forms.

BIRD BIRD (in Nenets - pya) - a large shrub or tree up to 15 m high, with matte dark gray bark, on which there are large rusty-brown or whitish-yellow lenticels. The leaves are bare, dark green, sometimes wrinkled, lighter below. The leaf blades are thin, oblong-elliptical, narrowed at both ends, pointed at the apex, finely serrate at the edges. The flowers are white, with a strong smell. Collected in drooping multi-flowered brushes. The fruit is a black, shiny, round, juicy drupe 7-8 mm in diameter. Blossoms in May - June, bears fruit in July - September.

It is distributed almost throughout Europe and in Western Siberia, penetrates north to the south of Scandinavia, east to the Yenisei. It grows along the banks of rivers, in riverine forests, shrubs, on forest edges.

Similar species: Asian bird cherry, Ainu and others - are found in the south of Siberia, the Far East, Sakhalin and the Kuril Islands.

Bird cherry fruits contain tannins, malic and citric acids, amygdalin glycoside. The leaves contain up to 200 mg% of ascorbic acid. Fruits, flowers and leaves contain benzoic aldehyde and have volatile properties.

Medicinal raw materials are fruits, leaves, bark and flowers. A decoction of the fruit is used as an astringent for diseases of the stomach and intestines, as well as for eye lotions. Bird cherry fruits for medicinal purposes can be harvested for future use in dried form. Bird cherry is used to treat headaches, purulent infected wounds, gangrene of the extremities, and pulmonary tuberculosis. This plant is also used to treat sexually transmitted diseases, relieve toothache, joint and muscle rheumatism.

Kissels and compotes are prepared from dried and fresh fruits.

Pounded dried berries are used to prepare the filling for pies, cakes and cheesecakes. Jelly and soft drinks are prepared from them. Bird cherry is food for reindeer, elk, muskrats. Dry leaves of bird cherry have a detrimental effect on the Colorado potato beetle, its larva and eggs.

A genus of trees in the Rosaceae family. It is distributed almost throughout Russia both in cultivated and wild form. Exceptionally polymorphic. Currently, more than ten thousand varieties are known.

Apple tree wild (forest) - the ancestor of most cultivated varieties - a tree (large shrub) up to 10 m high with a spreading crown. Light-loving - grows on the edges and in well-lit undergrowth. Frost-resistant - used as a frost-resistant rootstock for cultivars. It has a strong root system.

In the Kursk and Voronezh regions, there are its monocultural forests that have arisen,

presumably, in part by artificial means: lumberjacks spared apple trees (possibly due to an echo of pre-Christian beliefs) and, harvesting the surrounding trees for firewood, thus created favorable conditions for the development of apple trees.

Leaves are elliptical or round. The upper surface of the leaf is dark, shiny; the bottom is light, matte. The leaves are used in tea collections.

Blooms in May-June. Flowers are white, pale pink. Collected in small shields.

Good honey plant. Fruiting begins, as a rule, in the fifth year. Fruits (apples) ripening in August-September are small, sour; yellow-green, yellow-pink. The harvest is not annual, but every other year.

Lower tier:

JUNIPER (Juniperus drupacea). This species was isolated in 1857 by the Austrian botanist F. Antoine as a separate genus Arceuthos. Until now, among botanists there is no consensus on whether this plant is an independent genus or not. This dioecious tree up to 10-12, sometimes up to 18 m, with an irregular pyramidal crown formed by outstretched branches, grows in southern Greece, in the mountains of Asia Minor, Syria and Palestine. Female specimens of stone fruit juniper with large dark blue cones developing on them against the background of dense green needles are especially beautiful. The juicy fleshy pulp of the cones is very sweet and suitable for making marmalade.

Class BASIDIAL LICHES (Basidiolichenes). The group of basidial lichens is small, it contains only about 20 species. The thallus in these lichens is formed from basidiomycetes belonging to two orders - aphyllophoric (Aphyllophorales) and agaric (Agaricales) - and from some green and blue-green algae. For a long time, basidial lichens were known only in the tropics, but not so long ago they were found in the temperate zone and even in the Subarctic. Basidial lichens differ from marsupials in a number of ways. Firstly, their fruiting bodies are short-term, often one-year, while in marsupials they exist for a long time - tens and hundreds of years. Secondly, symbiosis in basidiomycetes and algae did not lead to the formation of special life forms, to morphogenetic isolation. Therefore, members of this class are

Animal world

Burrowing rodents (mice, voles), shrews and other small creatures live in the soil. Predatory animals - foxes, bears, badgers - also live in the lower tier of the forest. Some mammals occupy the upper tier. Squirrels, chipmunks and lynxes spend most of their time on trees. Birds nest in different tiers of the forest: on branches and in hollows of trees, in bushes and grass.

RACCOON (Procyon lotor) is one of the typical representatives of the family. He is about the size of a medium sized dog. The body of a raccoon is stocky, on short paws with long movable fingers. The head is wide, with a short thin muzzle, large ears. The coat is thick, long, its color is brownish-gray. The muzzle is characterized by a black mask with a white trim. There are 5-7 wide black or brown rings on the tail. In appearance, especially in the color of the head, the gargle looks like a raccoon dog. The raccoon is widely distributed in Central and North America, where it reaches the St. Lawrence River. Its acclimatization was carried out on the islands of the West Indies, in Germany, Russia. From release points, the raccoon enters France and the Netherlands and other European countries. For the raccoon, mixed forests with old hollow trees located near water bodies and swamps are most favorable. It does not interfere with the proximity of settlements. He arranges his dwellings in hollows, crevices of rocks, sometimes in his own or other people's holes, and even in heaps of brushwood. Within a radius of about 1.5 km from its shelter, the raccoon wanders at dusk and at night in search of food. It is a good tree climber but usually forages on the ground, in marshes and shallow waters. It feeds on frogs, crayfish, fish, rodents (even young muskrats), as well as all kinds of berries, acorns, nuts, and fruits. Before eating prey, the raccoon rinses it in the water, which gave reason to call it a gargle. The raccoon is the only member of the family that goes into a long sleep for the winter. In Canada, it lasts 4 months, and in more southern regions it is observed only while the snow is lying and the weather is frosty. Depending on the habitat, mating in raccoons occurs in winter or early spring, and in some cases in summer. Pregnancy lasts 63 days. In Transcaucasia, young (from 3 to 8, usually 4) appear in April - early May. They begin to see on the 20th day; at the age of 4-5 months they independently obtain food; Sexual maturity is reached in a year. The raccoon-poloskun belongs to valuable fur-bearing animals. In some countries, it is even bred on farms.

Deciduous forests are located along the southern edge of the forest zone.

Among deciduous species, broad-leaved species with large leaves (oak, maple, ash, beech, elm, elm, etc.) and small-leaved species (birch, aspen) are distinguished. The former are relatively shade-tolerant, so their plantations are shady. The latter need a significant amount of light, and the forests of them are light. Obviously, in connection with such an attitude towards light, broad-leaved species gain the upper hand in the struggle against small-leaved species and form the most stable phytocenoses.

Of the broad-leaved forests, oak forests, or oak forests, are the most widespread in the USSR. They are floristically richer than coniferous forests, almost always contain impurities of ash, linden, maple, elm, elm, and in the west - beech and hornbeam; in the second tier there are wild apple trees and maples, the undergrowth usually consists of hazel or forest hazel. Since oak forests belong to ancient phytocenoses that developed back in the Tertiary, develop in a mild climate and on rich soils, they have a complex structure: they usually have two tree tiers, two shrubs, and the grass cover also breaks up into three or four tiers. The grass cover includes grasses with wide leaf blades, the same sedges, various dicotyledons, etc. When they die, all these plants form a thick dead layer that interferes with the development of a moss carpet, which, as a rule, is absent in oak forests.

In the spring, while the oak leaves have not yet unfolded, numerous oak ephemera develop, forming a colorful carpet of yellow anemone, lilac corydalis, azure snowdrops, pink toothbrush, etc. Snowdrops appear right from under the snow.

In the first half of summer, linden blossoms, and the herbaceous vegetation becomes poorer; this impoverishment progressively increases until autumn, when the grass dries up, although some spring species bloom a second time. Plants that bloom in the spring before the forest is shaded have mostly yellow or pink-purple corollas, while those that bloom already in the shade of oak crowns have white corollas.

Oak forests of Eurasia are characteristic of the continental climate. In more favorable conditions, they are replaced by beech forests, and in a mild Mediterranean-Atlantic climate by chestnut forests. In Western Europe and the Caucasus, beech forests play the main role, in Middle-earth they are joined by walnut forests.

Deciduous forests in North America are very diverse. In the area of ​​the Appalachian Mountains (34-40 ° N), the lowest vertical zone is represented by a belt of chestnut forests, which are distinguished by a wide variety of species. The oak distribution area, gravitating towards the Great Lakes region, is characterized by plantations of red oak (Quercus rubra), black oak (Q. velutina), white oak (Q. alba), hickory (Hicoria ovata), etc. forests of Nyssa aquatica and swamp cypress Taxodium distichum grow in water areas; in places less flooded, in addition to these species, ash and poplar also grow, and in even drier places - Caribbean pine, oak, ash, hickory, red maple, etc.

Between the areas occupied by deciduous forests and the taiga zone, mixed forests are often located, where coniferous and deciduous species are found.