Переведите текст, обращая внимание на прецизионную информацию ( рекомендуется для последовательного перевода ):

Chapter I What is Forest?

Lesson 1  What is Forest?

Terms and expressions

wooded area	- лесная территория
animal habitats	- место обитания животных
Earth’s biosphere	- земная биосфера
angiosperms	- покрытосеменные виды растений
gymnosperms	- голосеменные растения
tree species	- виды деревьев
plant detritus	- отмершие растения
lignin	- лигнин
cellulose	- целлюлоза
carbohydrates	- углеводы
woodland	- лес, насаждения
canopy	- полог (насаждения)
foliage	- листва
biome	- биом, биоценоз
rain forest	- тропический лес
hardwood forest	- лиственные породы
broadleaf	- широколиственный
conifer	- хвойный
needleleaf	- хвойный
laurel forest	- лавровый лес
ponderosa pine	- сосна желтая
Douglas–fir forest	- лес, состоящий из лжетсуги тиссолистной
forestry	- лесное хозяйство
forester	- лесник, обитатель леса
wood extraction	- лесозаготовка
silviculture	- лесоводство
logging	- лесозаготовка, вырубка леса
acid rain	- кислотный дождь
herbivores	- травоядные животные
impact	- воздействие
biodiversity	- разнообразие видов
serial pattern	- сукцеосионный (серийный) образец
anthropogenic forest	- антропогенный, вызванный деятельностью человека
exotic species	- экзотические виды

 

Introductory exercises

1. Переведите следующие предложения на русский язык:

1. Forest is a complex ecosystem in which trees are the dominant life form.

2. Tree–dominated forests can occur wherever the temperatures rise above 50^oF (10^oC) in the warmest months and the annual precipitation is more than 8inс (200mm).

3. They can develop under various conditions within these limits and the kind of soil, plant and animal life differs according to the extremes of environmental influences.

4. In cool, high – latitude subpolar regions, TAIGA (boreal) forests are dominated by hardy CONIFERS.

5. In more temperate high–latitude climates mixed forests of both conifers and broad–leaved deciduous trees predominate.

6. Broad–leaved deciduous forests develop in mid–latitude climates.

7. In humid equatorial climates, tropical rain forests develop.

8. There heavy rainfall supports evergreens that have broad leaves instead of the needle leaves of cooler evergreen forests.

9. Forests are among the most  complex ecosystems in the world with

extensive vertical layering.

10. Conifer forests have the simplest structure: a tree layer, a shrub layer that is spotty or even absent, and a ground layer covered with lichens, mosses, and liverworts.

11. Deciduous forests are more complex (the tree canopy is divided into an upper and lower story), and rain–forest canopies are divided into at least three layers.

12. The forest is nature’s most efficient ecosystem with a high rate of photosynthesis effecting both plant and animal systems in complex organic relationships.

2. Найдите в тексте и переведите словосочетания:

A high density of trees; set aside for hunting; plant communities; hydrologic flow modulators; soil conservers; sustain tree growth; to impair the environment; human activities; species – rich forest; birch stands in northern latitudes; vegetation communities; canopy coverage; leaf longevity; dominant species; boreal forests; forest ecology; management of forests; to cause damage to trees; urban sprawl; to impact by humans; to change established serial patterns.

Переведите письменно:

Forest

A forest is an area with a high density of trees (or, historically, a wooded area set aside for hunting). Actually, many definitions of a forest exist. These plant communities cover large areas of the globe and function as animal habitats, hydrologic flow modulators, and soil conservers, constituting one of the most important aspects of the Earth’s biosphere.

Forests can be found in all regions capable of sustaining tree growth, at altitudes up to the tree-line, except where natural fire frequency is too high, or where the environment has been impaired by natural processes or by human activities. As a general rule, forests dominated by angiosperms (broadleaf forests) are more species-rich than those dominated by gymnosperms (conifer or needleleaf forests), although exceptions exist (for example, species-poor aspen and birch stands in northern latitudes). Forests sometimes contain many tree species within a small area (as in tropical rain and temperate deciduous forests), or relatively few species over large areas (e.g., taiga and arid montane coniferous forests). Forests are often home to many animal and plant species, and biomass per unit area is high compared to other vegetation communities. Much of this biomass occurs below-ground in the root systems and as partially decomposed plant detritus. The woody component of a forest contains lignin, which is relatively slow to decompose compared with other organic materials such as cellulose or carbohydrate.

Forests are differentiated from woodlands by the extent of canopy coverage: in a forest the branches and foliage of separate trees often meet or interlock, although there can be gaps of varying sizes within an area referred to as forest. A woodland has a more continuously open canopy, with trees spaced further apart, which allows more sunlight to penetrate to the ground between them (see also savanna).

Among the major forested biomes are:

* rain forests (tropical and temperate);

* taiga;

* temperate hardwood forest;

* tropical dry forest.

Classification

Forests can be classified in different ways and to different degrees of specificity. One such way is in terms of the biome in which they exist combined with leaf longevity of the dominant species (whether they are evergreen or deciduous). Another distinction is whether the forests composed predominantly of broadleaf trees, coniferous (needle-leaved) trees, or mixed. Boreal forests occupy the sub arctic zone and are generally evergreen and coniferous.

Temperate zones support both broadleaf deciduous forests (e.g., temperate deciduous forest) and evergreen coniferous forests (e.g., Temperate coniferous forests and Temperate rainforests). Warm temperate zones support broadleaf evergreen forests, including laurel forests.

Tropical and subtropical forests include tropical and subtropical moist forests, tropical and subtropical dry forests, and tropical and subtropical coniferous forests.

Physiognomy classifies forests based on their overall physical structure or developmental stage (e.g. old growth vs. second growth).

Forests can also bу classified more specifically based on the dominant tree species present, resulting in numerous different forest types (e.g., ponderosa pine/Douglas-fir forest).

Forest management

The scientific study of forests is referred to as forest ecology, while the management of forests is often referred to as forestry, often with the goal of sustainable resource extraction. Forest ecologists concentrate on forest patterns and processes, usually with the aim of elucidating cause and effect relationships. Foresters often focus on wood extraction and silviculture, including tree regeneration and growth processes.

Forests can be altered when logging, forest fires, acid rain, herbivores, or diseases, among other things, cause damage to trees. In the United States, most forests have historically been affected by humans to some degree, though in recent years improved forestry practices has helped regulate or moderate 1arge scale or severe impacts. However the United States Forest Service estimates that every year about 1-5 million acres (6,000 km²) of the nation's 750 million acres (3,000,000 km²) of forestland is lost to urban sprawl and development. It is expected that the South alone will lose 20 to 25 million acres (80,000 to 100,000 km²) to development.

Globally two types of forests can be identified:  Natural and  Anthropogenic.

Natural forests  contain only the original patterns of biodiversity,  the  native

species occurring in established serial patterns.

These formations and processes have not been impacted by humans with а frequency or intensity to change established serial patterns. Anthropogenic forests have been impacted by humans with а frequency or intensity to change established serial patterns. Often, they contain elements of exotic species.

4. Переведите вопросы и ответьте на них:

1. What functions does a forest perform?

2. What are broadleaf and needleleaf forests?

3. What does the woody component of a forest contain?

4. What are the main forested biomes?

5. Could you name the distinctions according to which the forests are classified?

6. Give the definitions to the terms of “forest ecology” and “forestry”, please!

7. What are the factors which cause damage to trees?

8. How many acres of forestland are lost to urban sprawl every year?

9. What are the two types of forests? Give the definitions.

5. Переведите на слух:

Cover large areas; пожары в лесах, разнообразие видов; вызванные природными факторами; natural processes, dominated by angiosperms; needle leaf forests; на северных широтах; temperate deciduous forests; виды растений; biomass per unit area; корневая система; to decompose plant detritus; содержать лигнин; to differentiate from woodlands; листва деревьев; to interlock; редко стоящие (растущие деревья); to penetrate to the ground; доминирующие виды; mixed forests; вечнозеленые хвойные леса; broadleaf deciduous forests; тропические леса; forest ecology; лесоводство; silviculture; лесозаготовка; acid rain; вызывать повреждения; improved forestry practices;  в результате роста городов;  anthropogenic forests;  the native

species;  под  воздействием  человека;  to change seral patterns;  желтая

сосна; different forest types.

6. Переведите текст (рекомендуется для зрительно-письменного, зрительно-устного, устного перевода на слух и письменного перевода на слух):

Members of the human species are children of the forest. The evolution of civilization is intertwined with forests; at the center of our history lies the story of their use. Our ancestors believed that gods inhabit the forests, living in the trees. Remnants of these beliefs underlie the strong feelings many people still have about forests and provoke intensely passionate debates over the way they are used.

Forests of one sort or another have existed for something like 300 million years, humans for perhaps one million. In our short span we have been both destroyers and creators of forests. Today, after several thousand years of forest use, eighty percent of the five-billion-hectare, pre-agricultural-era forest remains, covering about one-third of the earth's surface. Because of the explosive growth of population during the past century, this gives each individual slightly less than three-quarters of а hectare of forestland.

There is enormous diversity in the world's forests. No two hectares are identical. There are broad types of forests, however, each type determined by the varied influences of geography and climate. Tropical forests occupy а broad area along the Equator, in Central and South America, Africa and Southeast Asia. Variations in these forests are caused by the amount of rainfall, which declines as the distance from the Equator increases. Tropical rain forests run along the Equator. Their most notable characteristic is the wide diversity of species they contain. The Amazon forest, for instance, hosts about 6,000 tree species. Relatively few of them are commercially valuable, and harvesting timber in these forests is both economically and ecologically challenging.

As the distance from the Equator increases, and rainfall  declines, the

tropical  seasonal forests merge into dry savanna forests. Most forests of this type are found in Africa. As rain levels drop even  further, the savanna forests

give way to dry, scrub woodlands consisting mostly of hardy bushes and shrubs.

In the Northern Hemisphere, at the greatest distance from the Equator, lie the boreal coniferous forests. They occupy two areas: а broad band across North America, from Alaska to Newfoundland; and across northern Europe and Asia, from Scandinavia to the Siberian Pacific. In this region there is а short, intense growing season, offset by long cold winters during which tree growth ceases. There are relatively few tree species, almost all coniferous, and large areas of land are covered with а single species, in part due to the frequency of intense fires which sweep through these forests. Various types of pines and spruces dominate in the boreal forest; birch and aspen are the major deciduous species.

The broad, mid-latitudinal area lying between the tropical and boreal zones contains а variety of different forest types. Perhaps the most important are the northern temperate deciduous forests found in the northeastern United States, Western Europe, Korea and China. Compared to the tropics there are few species, the most prominent including the various oaks, maples, ash, beech, birch and elm. Through human history many of these species have been widely used, and their cu1tivation has, in many cases, become highly developed. Conifers also grow in these forests, but to а lesser degree.

Because of mild temperatures in the Temperate Zone, decomposition of forest litter is almost continuous, and а large portion of the nutrients is stored in the soil. Consequently, these soils are well suited to agriculture and extensive areas have been cleared for growing food crops. This factor has contributed to the concentrated growth of industrialized societies in temperate deciduous forest zones.

Today, there is а new type of forest found in several parts of the world. Plantation forests are man-made forests which are beginning to play а significant role in global forest economy. At present, а little more than 100 million hectares of plantations exist worldwide. About forty percent of them produce fuelwood, with most of the remainder grown for pulp, wood and, to а lesser extent, lumber. With few exceptions, plantations are grown for commercial use and supply an increasing share of global timber production.

1. Переведите предложения на слух в быстром темпе:

1. Лес – один из основных типов растительности, господствующий ярус которого образован деревьями одного или нескольких видов, с сомкнутыми кронами.

2. Из других жизненных форм для леса характерны травы, кустарники, мхи, лишайники.

3. Различают хвойные, лиственные (как чистые, так и смешанные), листопадные и вечнозеленые леса.

4. Лес – это жизненная среда для многих птиц и зверей, источник древесины, ягод, грибов и технического сырья.

5. Биомасса, накаливаемая лесом, составляет от 60 – 90 ц/га (в еловых лесах русской равнины) до 300 ц/га и более (во влажно-тропических лесах).

6. Имея важное климат–регулирующие, почво- и водозащитнoе значение, лесной покров Земли является одним из факторов устойчивости биосферы и требует постоянной заботы о его сохранности и возобновления.

7. Лесные ресурсы представляют собой запасы древесины, а также пушнины, дичи, грибов, ягод, лекарств, растений и т.п. в лесах.

8. Лесами занято 3700 млн га или 30% суши земного шара.

9. Мировые запасы древесины составляют 357 млрд. м³, в т.ч. в России – 79, Бразилии – 66, Канаде – 24, США – 20.

Champion trees

The world's champion trees can be considered on several factors; height, trunk diameter or girth, total size, and age. It is significant  that in each case,  the

top position is always held by а conifer,  thoughа different  species in each case;

in most measures, the second to fourthplaces are also held by conifers.

Tallest trees

The heights of the tallest trees in the world have been the subject of considerable dispute and much (often wild) exaggeration. Modern verified measurement with laser rangefinders combined with tape drop measurements made by tree climbers, carried out by the U.S. Eastern Native Tree Society has shown that most older measuring methods and measurements are unreliable, often producing exaggerations of 5% to 15% above the real height. Historical claims of trees of 114m, 117m, 130m, and even 150m, are now largely disregarded as unreliable, fantasy or outright fraud. The following are now accepted as the top five tallest reliably measured species:

1. Coast Redwood Sequoia sempervirens: 115.55 m (378.1 ft.), Redwood National Park, California (Gymnosperm Database).

2. Coast Douglas-fir Pseudotsuga menziesii: 100.3m (329.1ft.), Brummit Creek, Coos County, Oregon (Gymnosperm Database).

3. Sitka Spruce Picea synthesis: 96.7m (317.3ft.), Prairie Creek Redwoods State Park, California (Gymnosperm Database).

4. Giant Sequoia Sequoiadeпdroп gigaпteum: 94.9m (307.1ft.), Redwood Mountain Grove, Кings СаnyonNational Park, California (Gymnosperm Database).

5. Australian Mountain-ash Eucalyptus regпaпs: 92.0m (301.8ft.), Styx Valley, Tasmania (Forestry Tasmania [pdf fi1e]; also reported, less verifiably, as 97.0m Tasmanian Giant Trees).

Stoutest trees

The girth (circumference) of а tree is - or at least should be - much easier to measure than the height, as it is а simple matter of stretching а tape round the trunk, and pulling it taut to find the circumference. Despite this, U K tree author Аlаn Mitchell made the following comment about measurements of yew

trees in the British Is1es: "The aberrations of past measurements of yews are

beyond belief. For example, the tree at Tisbury has а well-defined, clean, if irregular bole at least 1.5m long. It has been found to have а girth which has dilated and shrunk in the following way: 11.28m (1834 Loudon), 9.3m (1892 Lowe), 10.67m (1903 Elwes and Henry), 9.0m (1924 Е. Swanton), 9.45m (1959 Mitchell)… Earlier measurements have therefore bееn omitted".

     As а general standard, tree girth is taken at 'breast height'; this is defined differently in different situations, with most foresters measuring girth at 1.3m above ground,while ornamental tree measurers usuallymeasure at 1.5m above ground;in most cases this makes little difference to the measured girth. On sloping ground, the "above ground" reference point is usually taken as the highest point on the ground touching the trunk, but some use the average between the highest and lowest points of ground. Some of the inflated old measurements may have been taken at ground level. Some past exaggerated measurements also result from measuring the complete next-to-bark measurement, pushing the tape in and out over every crevice and buttress.

     Modern trends are to cite the tree's diameter rather than the circumference; this is obtained by dividing the measured circumference by π; it assumes the trunk is circular in cross-section (an oval or irregular cross-section would result in a mean diameter slightly greater than the assumed circle). This is cited as dbh (diameter at breast height) in tree literature. A further problem with measuring baobabs Adaпsoпia is that these trees store large amounts of water in the very soft wood in their trunk. This leads to marked variation in their girth over the year, swelling to а maximum at the end of the rainy season, minimum at the end of the dry season. Although baobabs have some of the highest girth measurements of any trees, no accurate measurements are currently available, but probably do not exceed 10-11m diameter.

The stoutest species in diameter, excluding baobabs, are:

1. Montezuma  Cypress   Taxodiuт  тucroпatuт:   11.42 m, Arbol  del Tule,

Santa Maria del Tulе, Oaxaca, Mexico (А.F. Mitchell, International Dendrology Society Year Book 1983: 93, 1984).

Giant Sequoia Sequoiadeпdroп gigaпteuт: 8.85m, General Grant tree, Grant Grove, California (Gymnosperm Database).

Coast Redwood Sequoia seтpervireпs: 7.44m, Prairie Creek Redwoods State Park, California (Gymnosperm Database).

Largest trees

The largest trees in total volume are those which are both tall and of large diameter, and in particular, which hold а large diameter high up the trunk. Measurement is very complex, particularly if branch volume is to be included as well as the trunk volume, so measurements have only been made for а small number of trees, and generally only for the trunk. No attempt has ever been made to include root volume. The top fourspecies measured so far are (Gymnosperm Database):

1. Giant Sequoia Sequoiadeпdroп gigaпteuт: 1489 m³, General Sherman.

2, Coast Redwood Sequoia seтpervireпs: 1045 m³, Del Norte Titan tree.

3. Western Redcedar Thuja plicata: 500 m³, Quinault Lake Redcedar.

4. Kauri Ag athis australis: 400m³, Таnе Mahuta tree (total volume, including branches, 516.7m³).

However, the Alerce Fitzroya cupressoides, as yet un-measured, may well slot in at third or fourth рlасе, and Montezuma Cypress Taxodium тucroпatuт is also likely to be high in the list. The largest angiosperm tree is an Australian Mountain-ash, the 'Еl Grande' tree of 439m³ in Tasmania (Tasmanian Giant Trees).

Oldest trees

The oldest trees are determined by growth rings, which can be seen if the tree is cut down or in cores taken from the edge to the centre of the tree. Accurate determination is only possible for trees which produce growth rings, generally those which occur in seasonal climates; trees in uniform non-seasonal tropical climates grow  continuously and do not have  distinct  growth

rings. It is also only possible for trees which are solid to the centre of the tree; many very old trees become hollow as the dead heartwood decays away. For some of these species, age estimates have been made on the basis of extrapolating current growth rates, but the results are usually little better than guesswork or wild speculation.

The verified oldest measured ages are (Gymnosperm Database):

1. Great Basin Bristlecone Pine Piпus loпgaeva: 4844 years.

2. Alerce Fitzroya cupressoides: 3622 years.

3, Giant Sequoia Sequoiadeпdroп gigaпteuт: 3266 years.

4. Huon-pine Lagarostrobos fraпkliпii: 2500 years.

5. Rockv Mountains Bristlecone Pine Piпus aristata: 2435 years.

Other species suspected of reaching exceptional age include EuropeanYew Taxus baccata (probably over 3000 years) and Western Redcedar Thuja plicata.

9. Приготовьте сообщения:

“What is Forest?”, “Diversity in the world’s forests”, “Champion trees”.

Сделайте сообщения с переводом (один обучаемый делает сообщение, а другой переводит это сообщение).

 

Lesson 2 Types of forests

Terms and expressions

seeds and pollen	– семена и пыльца
cone-shaped	– в форме шишки
shrubs	– кустарники
pine	– сосна, желтая сосна
juniper	– можжевельник
spruce	– ель
hemlock	– 1) болиголов 2) тсуга
larch	– лиственница
yew	– тис ягодный, тис европейский
cypresses	– кипарис
bold cypresses	– кипарис болотный
Douglas fir	– лжетсуга тиссолистная
arborvitae	– туя
softwood timber	– хвойные лесоматериалы
crates	– ящики
pulpwood	– балансовая древесина
plywood	– фанера
veneers	– шпон; фанера
resins	–смола; живица
volatile oil	– эфирное масло
turpentine	– скипидар
tar	– смола, деготь
water loss	– потеря воды, испарение
needles	– хвоя, иглы
cedar	– кедр
scale like leaves	– чешуйчатые листья
club mosses	– мхи
fern	– папоротник
seasonality	– сезонность
precipitation	– осадки
nutrient – poor soil	– почва, бедная питательными веществами
heavy leaching	– сильнoе выщелачиваниe
buttressed trunks	– извилистые стволы
shallow roots	– поверхностные корни
distribution of rainfall	– распределение осадков
decaying litter	– разлагающаяся подстилка
boreal forest	– северный лес
terrestrial biome	– наземный биом

 

Introductory exercises

ТНЕ FOREST BIOME

About 420 million years ago, during the Silurian  Period, ancient plants and

arthropods began to occupy the land. Over the millions of years that followed,

these land colonizers developed and adapted to their new habitat. The first forests were dominated by giant horsetails, club mosses, and ferns that stood up to 40 feet tall.

Life on Earth continued to evolve, and in the late Paleozoic, gymnosperms appeared. By the Triassic Period (245-208 mуа), gymnosperms dominated the Earth's forests. In the Cretaceous Period (144-65m mуа), the first f1owering plants (angiosperms) appeared. They evolved together with insects, birds, and mammals and radiated rapidly, dominating the landscape by the end of the Period. The landscape changed again during the Pleistocene Ice Ages-the surface of the planet that had bееn dominated by tropical forests for millions of years changed, and temperate forests spread in the Northern Hemisphere.

Today, forests occupy approximately one-third of Earth's land area, account for over two-thirds of the leaf area of land plants, and contain about 70% of carbon present in living things. They have been held in reverence in folklore and worshipped in ancient religions. However, forests are becoming major casualties of civilization as human populations have increased over the past several thousand years, bringing deforestation, pollution, and industrial usage problems to this important biome.

Present-day forest biomes, biological communities that are dominated by trees and other woody vegetation (Spurr and Barnes), can be classified according to numerous characteristics, with seasonality being the most widely used. Distinct forest types also occur within each of these broad groups.

There are three major types of forests, classed according to latitude:

* tropical;

* temperate;

*boreal forests (taiga).

Tropical forests

Tropical forests are characterized by the greatest diversity of species. They occur near the equator, within the area bounded by latitudes 23.5 degrees N and 23.5 degrees S. One of the major characteristics of tropical forests is their distinct seasonality: winter is absent, and only two seasons are present (rainy and dry).

The length of daylight is 12 hours and varies little.

Temperature is on average 20-25^o С and varies little throughout the year: the average temperatures of the three warmest and three coldest months do not differ by more than 5 degrees.

Precipitation is evenly distributed throughout the year, with annual rainfall exceeding 2000 mm.

Soil is nutrient-poor and acidic. Decomposition is rapid and soils are subject to heavy leaching.

Canорy in tropical forests is multilayered and continuous, allowing little light penetration.

Flora is highly diverse: one square kilometer may contain as many as 100 different tree species. Trees are 25-35 m tall, with buttressed trunks and shallow roots, mostly evergreen, with large dark green leaves. Plants such as orchids, bromeliads, vines (lianas), ferns, mosses, and palms are present in tropical forests.

     Fauna include numerous birds, bats, small mammals, and insects.

Further subdivisions group are determined by seasonal distribution ofrainfall:

evergreen rainforest: no dry season;

seasonal rainforest:   short dry period in а very wet tropical region  (the

forest exhibits definite seasonal changes as trees undergo developmental changes simultaneously, but the general character ofvegetation remains the same as in evergreen rainforests);

semievergreeп forest: longer dry season (the upper tree story consists ofdeciduous trees, while the lower story is still evergreen);

moist/dry  deciduous forest (monsoon):   the  length of the  dry  season

increases  further as rainfall decreases (all trees are deciduous). More than  ½  of

tropical forests have already been destroyed.

Temperate forests

Temperate forests occur in eastern North America, northeaster Asia, and western and central Europe. Well-defined seasons with а distinct winter characterize this forest biome. Moderate climate and а growing season of 140-200 days during 4-6 frost-free months distinguish temperate forests.

Temperature varies from –30^o С to 30^o C.

Precipitation (75-150 сm) is distributed evenly throughout the year.

Soil is fertile, enriched with decaying litter.

Саnору is moderately dense and allows light to penetrate, resulting in well developed and richly diversified under story vegetation and stratification of animals.

Flora is characterized by 3-4 tree species per square kilometer. Trees are distinguished by broad leaves that are lost annually and include such species as oak, hickory, beech, hemlock, maple, basswood, cottonwood, elm, willow, and spring-flowering herbs.

Fauna is represented by squirrels, rabbits, skunks, birds, deer, mountain lion, bobcat, timber wolf, fox, and black bear.

Further subdivisions of this group are determined by seasonal distribution of rainfall:

- moist conifer and evergreen broad-leaved forests wet winters and dry summers

(rainfall is concentrated in the winter months and winters are relatively mild);

- dry conifer forests: dominate higher elevation zones; low precipitation;

- тediterraпeaп forests: precipitation is concentrated in winter, less than 1000 mm per year;

- temperate coniferous: mild winters, high annual precipitation (greater than 2000 mm);

- temperate broad-leaved rainforests: mild, frost-free winters, high precipitation (more than 1500 mm) evenly distributed throughout the year.

       Only scattered remnants of original temperate forests remain.

Boreal forests

Boreal forests, or taiga, represent the largest terrestrial biome. Occurring between 50 and 60 degrees north latitudes, boreal forests can be found in the broad belt of Eurasia and North America: two-thirds in Siberia with the rest in Scandinavia, Alaska, and Canada. Seasons are divided into short, moist, and moderately warm summers and long, cold, and dry winters. The length of the growing season in boreal forests is 130 days.

Temperatures are very low.

Precipitation is primarily in the form of snow, 40-100 сm annually.

Soil is thin, nutrient-poor, and acidic.

Саnору   permits low light penetration, and as а result, under story is limited.

Flora consist mostly of cold-tolerant evergreen conifers with needle-like leaves, such as pine, fir, and spruce.

Fauna include woodpeckers, hawks, moose, bear, weasel, lynx, fox, wolf, deer, hares, chipmunks, shrews, and bats. Current extensive logging in boreal forests may soon cause their disappearance.

4. Переведите вопросы и ответьте на них:

How many years ago did ancient plants begin to occupy the land?

What were the first forests dominated by?

When did gymnosperms appear?

In what period did angiosperms appear?

What are tree major types of forests, classed according to latitude?

Could you give the characteristic features of tropical  forests (temperature,

precipitation, soil, canopy, flora, fauna)?

What are the subdivisions of tropical forests determined by seasonal distribution of rainfall?

Could you give the characteristic features of temperate forests?

What are the subdivisions of temperate forests?

Could you characterize the largest terrestrial biome – boreal forests?

5. Переведите на слух:

To adapt a new habitat; возвышаться до 40 футов; radiated rapidly; распространяться в Северном полушарии; occupy one – third of Earth’s land area; содержать 70% углерода; worshiped in ancient religions; основные очаги цивилизации; bring deforestation and industrial usage problems; классифицировать согласно географической широте; the greatest diversity of species; выраженная сезонность; evenly distributed precipitation; годовые осадки; nutrient–poor soil; подвергаться выщелучиванию; multilayered canopy; пропускать мало света; diverse flora; извилистые стволы деревьев; сезонные распределения осадков; undergo developmental changes; лиственные леса; temperate forests; плодородная почва; enriched with decaying litter; сомкнутый (густой) полог; richly diversified under story vegetation; мягкие зимы; high annual precipitation; северные леса; the largest terrestrial biome; вечнозеленые леса из хвойных пород, устойчивые к морозам; extensive logging.

6. Переведите текст устно и письменно (может быть использован для абзацно-фразового перевода):

TAIGA

Taiga (IPA pronunciation: [ 'taigə] or [tai 'ga ],from Mongolian) is а

biome characterized by coniferous forests. Covering most of inland Alaska, Canada, Sweden, Finland, northern Kazakhstan and Russia (especially Siberia), as well as parts of the extreme northern continental United States, the taiga is the world's largest terrestrial biome and а major source of oxygen. In Canada, boreal forest is the term used to refer to the southern part of this biome, while "taiga" is used to describe the more barren northern areas south of the Arctic tree-line.

Since North America and Eurasia were recently connected by the Bering land bridge, а number of animal and plant species (more animals than plants) were able to colonise both continents and are distributed throughout the taiga biome. Others differ regionally, typically with each genus having several distinct species, each occupying different regions of the taiga.

Climate and geography

White Spruce taiga, Denali Highway, Alaska Range, Alaska

The taiga biome has а harsh continental climate with а very large temperature range between summer and winter, classified as "Dfc" or "Dfb" in the Кöрреn climate classification scheme. Aside from the tundra and permanent ice caps, it is the coldest biome on Earth. High latitudes mean that, for much of the year the sun does not rise far above the horizon; winters last at least 6 months, with average temperatures below freezing. Temperatures vary from –50^oC to 30^o C throughout the whole year, with 8 or more months of temperatures averaging below 10^oС. The summers, while short, are generally warm and humid. In general, taiga grows north to the 10^oС July isotherm, occasionally to the 9^o C July isotherm (Аrnо & Hammerly 1984, Аrnо et аl. 1995). The southern limit is more variable, depending on rainfall; taiga may be replaced by open steppe woodland south of the 15^oC Julyisotherm where rainfall is very low, but more typically extends south to the 18^oC Julyisotherm, and loсаllу where rainfall is higher (notably in eastern Siberia and adjacent northern Manchuria) south to the 20^oC Julyisotherm. In these warmer areas, the taiga has higher species diversity with more warmth-loving species such as Korean Pine, Jezo Spruce and МаnсhuгiаnFir, and merges gradually into mixed temperate forest, or more loсаllу (on the Pacific Ocean coasts of North America and Asia) into coniferous temperate rainforests.

The taiga experiences relatively low precipitation throughoutthe year (200-750 mm аnnuаllу), primarily as rain during the summermonths, butalso as fog and snow; as evaporation is also low for most of the year, precipitation exceeds evaporation and is sufficient for dense vegetation growth. Snow may remain on the ground for as long as nine months in the northernmost extensions of the taiga (Sayre, 16).

Much of the area currently classified as taiga was recently glaciated. As the glaciers receded, they left depressions in the topography that have since filled with water, creating lakes and bogs (especially muskeg soil), found throughout the taiga.

Soils

Taiga soil tends to be young and nutrient-poor; it lacks the deep, organically-enriched рrоfilе present in temperate deciduous forests. The thinness of the soil is due largely to the cold; it hinders the development of soil, as well as the ease with which plants can use its nutrients (Sayre, 19). Fallen leaves and moss can remain on the forest floor for а long time in the cool, moist climate, which limits their organic contribution to the soil; acids from evergreen needles further leach the soil, creating spodosol (Sayre, 19-20). Since the soil is acidic, the forest floor has only lichens and some mosses growing on it.

Flora

Black Spruce taiga, Copper River, Alaska

There are two major types of taiga, closed forest, consisting of many closely-spaced trees with mossy ground cover, and lichen woodland, with trees that are farther-spaced and lichen ground cover; the latter is more common in the northernmost taiga.

The forests of the taiga are largely coniferous, dominated by larch, spruce,

fir, and pine. Evergrееn species in the taiga (spruce, fir, and pine) have а number of adaptations specifically for survival in harsh taiga winters, though larch, the most cold-tolerant of аll trees, is deciduous. Taiga trees tend to have shallow roots to take advantage of the thin soils, while many of them seasonally alter their biochemistry to make them more resistant to freezing, called "hardening" (Sayre, 23). The narrow conical shape of northern conifers, and their downward-drooping limbs, also help them shed snow (Sayre, 23).

Because the sun is low in the horizon for most of the year, it is difficult for plants to generate energy from photosynthesis. Pine and spruce do not lose their leaves seasonally and are able to photosynthesize with their older leaves in late winter and spring when light is good but temperatures are still too low for new growth to commence. The adaptation of evergreen needles limits the water lost due to transpiration and their dark green color increases their absorption of sunlight. Although precipitation is not а limiting factor, the ground freezes during the winter months and plant roots are unable to absorb water, so desiccation can be а severe problem in late winter forevergreens.

Although the taiga is dominated by coniferous forests, some broadleaf trees also occur, notably birch, aspen, willow,and rowan. Many smaller herbaceous plants grow closer to the ground. Periodic stand-replacing wildfires (with return times of between 20-200 years) clear out the tree canopies, allowing sunlight to invigorate newgrowth on the forest floor. For some species, wildfires are а necessary part of the life cycle in the taiga; some, e.g. Jack Pine have cones which only open to release their seed after а fire, dispersing their seeds onto the newlycleared ground. Grasses grow  wherever they can  find а patch of sun, and

mosses and lichens thrive on the damp ground and on the sides of tree trunks. In

comparison with other biomes, however, the taiga has а low biological diversity.

Fauna

The taiga is home to а number of large herbivorous  mammals and smaller

rodents. These animals have also adapted to survive the harsh climate. Some of the larger mammals, such as bears, eat during the summer in order to gain weight and then go into hibernation during the winter. Other animals have adapted layers of furor feathers to insulate them from the cold.

Due to the climate, carnivorous diets are an inefficient means of obtaining energy; energy is limited, and most energy is lost between trоphiс levels. However, predatory birds (owls and eagles) and other smaller carnivores, including foxes and weasels, feed on the rodents. Larger carnivores, such as lynхеs and wolves, prey on the larger animals. Omnivores, such as bears and raccoons are fairly common, sometimes picking through human garbage.

А considerable number of birds such as Siberian Thrush, White's Thrush and Dark-throated Thrush, migrate to this habitat to take advantage of the long summer days and abundance of insects found around the numerous bogs and lakes. Of the perhaps 300 species of birds that summer in the taiga, only 30 stay forthe winter (Sayre, 28). These are either carrion - feeding or large raptors that can take live mammal prey, including Golden Eagle, Rough-lagged Buzzard, and Raven, or else seed-eating birds, including several species of grouse and crossbills.

Fire

Fire is the dominant natural disturbance in the taiga, as well as being an important disturbance mechanism in many other forest types, such as temperate, sub-alpine and chaparral forests. Large, stand-replacing fires, particularly in the taiga, determine the age distribution and spatial age mosaic of the forested landscape.

Timber Extraction

In the boreal region, the major cause of old growth forest destruction and secondary forest degradation, is the increasing  industrial  extraction of

timber for human consumption.

The northern boreal forests provide 60% of the worlds supply of industrial round wood. Some northern forests are among the most threatened habitats in the world, in terms of loss of old growth or primary woodland. In Scandinavia, the large scale commercial exploitation of the forests began more than 100 years ago. Today, vitally all forest land has been transformed into intensively managed secondary forests (less than five percent of the old growth forests remain). In the interior and remote parts of Alaska, Canada and Siberia most of the primary forests still remain intact, but on the other hand we find all the characteristics of the first phase of industrial forest exploitation; the resource is still considered unlimited, reforestation is close to non-existent and nature consideration is minimal. The "timber frontier" is continuous1y moving into new areas of primary forests, and the speed of forest destruction is enormous.

Climate

Taiga in Exile

А conservative temperature increase of +20^o С over the next century

would force trees to migrate around 1.5 - 5.5km а year further north or higher in altitude. Forests are generally only able to migrate at а much slower rate of between 0.02 and 2km а year. The predicted continuing rise in global temperatures

will have а severe impact on the global climate and  а devastating  effect on the

boreal forest eco-system.

7. Переведите письменно:

Хвойные – это подкласс голосеменных растений.

Это–главным образом вечнозеленые деревья и кустарники, как правило, с игловидными (хвоя) или чешуйчатыми листьями и однополыми стробилами (шишками).

Существует около 50 родов и 600 видов хвойных.

Многие хвойные (сосна, ель, лиственница и др.) – ценные лесообразующие породы.

Хвойные породы используют для получения древесины, живицы и др.

Плоды некоторых хвойных пород съедобны (например: кедровые орешки).

Тайга – это тип растительности с преобладанием хвойных лесов.

Тайга распространена в умеренном поясе Евразии и Северной Америки.

В древостое тайги – главным образом ель, сосна, пихта.

Подлесок тайги беден.

Травянисто-кустарничковый ярус тайги – однообразный (черника, брусника, зеленые мхи).

12.В Евразии преобладают ель, пихта, в Восточной Сибири – лиственница, сосна.

13.Для тайги Северной Америки характерны ель черная, ель белая, туя.

14.Тайга – основной источник древесины и сырья для лесохимической промышленности.

 

2. Переведите устно (рекомендуется для зрительно-устного перевода с подготовкой):

Taiga or Boreal Forest

Introduction. The taiga or boreal forest exists as а nearly continuous belt of coniferous tree across North America and Eurasia. Overlying formerly glaciated areas and areas of patchy permafrost on both continents, the forest is mosaic of successional and subclimax plant communities sensitive to varying environmental conditions. Taiga is the Russian name for this forest, which covers so much of that country. However, the term is used in North America as well.

Climate. The taiga corresponds with regions of subarctic and cold continental climate (Köeppen’s Dfc, Dfd, and Dwd climate types). Long, severe winters (uр to six months with mean temperatures below freezing) and short summers (50 to 100 frost-free days) are characteristic, as is а wide range of temperatures between the lows of winter and highs of summer. For example, Verkhoyansk, Russia, has recorded extremes of minus 90^o  Fand plus 90^o F. Mean annual precipitation is 15 to 20 inches, but low evaporation rates make this а humid climate.

Vegetation. Needleleaf, coniferous (gymnosperm) trees are the dominant plants of the taiga biome. А very few species in four main genera are found: the evergreen spruce (Picea), fir (Abies), and pine (Pinus), and the deciduous larch or tamarack (Larix). In North America, one or two species of fir and one or two species of spruce are dominant. Across Scandinavia and western Russia the Scots pine is а common component of the taiga.

Broadleaf deciduous trees and shrubs are members of early successional stages of both  primary and secondary  succession. Most  common are alder

(Alnus), birch (Betula), and aspen (Populus).

Growthforms.  The conical or spire - shaped needle leaf trees common to

the taiga are adapted to the cold and the physiological drought of winter and to the short-growing season: conical shape - promotes shedding of snow and prevents loss of branches; needleleaf - narrowness reduces surface area through which water may be lost (transpired), especially during winter when the frozen ground prevents plants from replenishing their water supply. The needles of boreal conifers also have thick waxy coatings - a waterproof cuticle - in which stomata are sunken and protected from drying winds; evergreen habit - retention of foliage allows plants to photosynthesize as soon as temperatures permit in spring, rather than having to waste time in the short growing season merely growing leaves. [Note: Deciduous larch are dominant in areas underlain by nearly continuous permafrost and having а climate even too dry and cold for the waxy needles of spruce and fir]; dark color - the dark green of spruce and fir needles helps the foliage absorb maximum heat from the sun and begin photosynthesis as early as possible.

Soil. Podzolization occurs as а result of the acid soil solution produced under needleleaf trees. The main soil order associated with the taiga is spodosol.

Subclimaxes. Edaphic conditions result in sometimes extensive, present patches of vegetation other then spruce and fir: bogs (muskeg) occur in poorly drained, glacial dерressions. Sрhаgnum moss forms а spongy mat over роndеd water. Grоwing оn this mat are species of the tundra such as соttоngrаss and shrubs of the heath family. Black spruce and larch ring the edge.

Рinе forests, in North America dominated by the jack pine (Pinus bаnksiаnа), occur on sandy outwash plains and former dune areas. These are low nutrient, droughty substrates not tolerated by spruce and fir.

Larch forests claim the thin, waterlogged substrate in level areas underlain with permafrost. These forests are open with understories of shrubs, mosses and lichens. In Alaska stands of Larix larichina are localized phenomena, but in Siberia east of the Yenesei River the extreme continentality

and nearly continuous permafrost give rise to vast areas dominated by Larix dihurica.

Fauna. Fur-bearing predators like the lynx (Felis lynx) and various members of the weasel family (e.g., wolverine, fisher, pine martin, mink, ermine, and sable) are perhaps most characteristic of the boreal forest proper. The mammalian herbivores on which they feed include the snowshoe or varying hare, red squirrel, lemmings, and voles.

Large herbivores are more closely associated with successional stages where there is more nutritious browse available and include elk or wapiti (Cervus elaphus, known as red deer in Europe) and moose (Alces alces, known as elk in Europe). The beaver (Castor саnаdеnsis), on which the early North American fur trade was based, is also а creature of early successional communities, indееd its dams along streams create such habitats.

Among birds, insесt-еаtеrs like the wood warbles are migratory and leave after the breeding season. Seed-eaters (e.g., finches and sparrows) and omnivores (e.g., ravens) tend to be year-round residents. During poor cane years, normal residents like the evening grosbeak, pine siskil1, and red crossbill leave the taiga in winter and may be seen at bird feeders here in Virginia.

Distribution patterns within the boreal forest. The boreal forest is restricted to the northern hemisphere. It is сiгсumро1ar in distribution, as are many of the species which comprise it and even more of the genera. In general, plants have different species represented in North America and Eurasia; the mammals of both continents tend to be conspecific.

There are latitudinal zones within the forest. Running north to south, one finds the tundra/taiga ecotone: an open coniferous forest (the section most properly called taiga); the characteristic closed-canopy needleleaf evergreen boreal forest, and а mixed needleleaf evergreen-broadleaf deciduous forest, the ecotone with the Temperate Broadleaf Deciduous Forest. In the US, this southern есоtоnе is dominated by white pine (Pinus strobes), sugar mарlе (Асег saccharum), and American beech (Fagus americanus).

Alpine expressions of the biome. In Merriam's Life Zones, the Hudsonian and the Canadian zones corrеsроnd with the Boreal Forest.

In North America, several variants of the boreal forest occur in the mountains of the West. In the Pacific Northwest, what amounts to а temperate rainforest is dominated by needleleaf species such as Douglas fir, western hеmlосk, and other giants. This forest type is the center of а major controversy regarding timber operations in old growth forests.

On the windward (western) slopes of the Sierra Nevada at elevations between 4,000 and 8,000 feet, the tall western conifers are joined by the magnificent giant sequoia (Sequoia gigantea). The specimen named General Sherman is some 3,800 years old, 272 feet tall, and has а diameter of 37 feet. The congener of this sequoia, the redwood (S. sempervirens) grows along the northern California coast. Their closest relative is the Dawn Redwood, a deciduous conifer of the genus  Metasequoia

from Сhinа. In the Rocky Mountains, where fire is аn important part of the environment lodgepole pines (Pinus contorta) form nearly pure, single-aged stands. The great fire of Yellowstone National Park demonstrated оnсе again the association of this species and its ecosystem with repeated burns.

Chapter I What is Forest?

Lesson 1  What is Forest?

Terms and expressions

wooded area	- лесная территория
animal habitats	- место обитания животных
Earth’s biosphere	- земная биосфера
angiosperms	- покрытосеменные виды растений
gymnosperms	- голосеменные растения
tree species	- виды деревьев
plant detritus	- отмершие растения
lignin	- лигнин
cellulose	- целлюлоза
carbohydrates	- углеводы
woodland	- лес, насаждения
canopy	- полог (насаждения)
foliage	- листва
biome	- биом, биоценоз
rain forest	- тропический лес
hardwood forest	- лиственные породы
broadleaf	- широколиственный
conifer	- хвойный
needleleaf	- хвойный
laurel forest	- лавровый лес
ponderosa pine	- сосна желтая
Douglas–fir forest	- лес, состоящий из лжетсуги тиссолистной
forestry	- лесное хозяйство
forester	- лесник, обитатель леса
wood extraction	- лесозаготовка <