Unit 8. Disturbances and threats

Forests are facing a range of threats. They can be damaged by fires, airborne

pollution, storms, invasive species, pests, diseases, and insects.

About 1 % of forests is consumed by fire each year, causing casualties, economic

damage, loss of biodiversity and release of carbon to the atmosphere. Every

fire is a tragedy for the wildlife killed in the blaze that destroys its habitat and a major

commercial disaster for Man.

Globally, 3 % of forest area is reported to be affected by insects and diseases.

Other forest disturbances include climatic factors such as wind, snow, ice, floods,

tropical storms and drought, or impacts of animals such as deer and rodents.

Before reading Text 1 study the topical vocabulary and then do some exercises.

Topical Vocabulary

disturbance [di'stε:bəns] — нарушение; вторжение в естественный ход вещей,

нарушение порядка;

disrupt — разрушать; разрывать; нарушать;

insect outbreak — вспышка; внезапное появление насекомых;

anthropogenic [an,θrǩpǩu'dȢenik] disturbance — нарушение, причиняемое

человеком;

forest clearing — участок леса, расчищенный под пашню, росчисть;

introduction — интродукция, введение в состав животного или растительного

мира;

upset the balance — нарушить равновесие;

restore balance — восстановить равновесие;

quarantine ['kworəntain / 'kworənti:n] law — закон о карантине;

safeguard — гарантия; защита; охрана || гарантировать; защищать; охранять;

virulent ['virulənt] strain — вирулентный (опасный) штамм;

remedy — средство; лекарство, лечебное средство;

oxidation — окисление;

alteration — изменение;

strength — прочность; интенсивность, мощность;

suffer fatigue [fə'ti:g]— страдать от усталости; испытывать усталость;

repeated stressing — многократное, частое напряжение (нагрузка);

derive (from) — получать; происходить;

decompose — гнить, портиться, разлагаться;

clutter up — загромождать;

decay — гниение, разложение, разрушение;

dead remains — мертвые останки;

saprophyte ['sæprəfait] — сапрофиты (микроорганизмы, питающиеся

отмершими тканями);

heart-rot — ядровая гниль;

butt-rot — напенная гниль; комлевая гниль;

gale — шторм; буря; ветер от 7 до 10 баллов (с 51 до 100 километров в час);

preservative [pri'zε:vətiv] — предохраняющее средство; профилактическое

средство; консервант.

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TEXT 1. A SYSTEM IN BALANCE AND THREATS

No communities of plants and animals are stable. Many factors are

constantly disrupting these ecosystems — weather, predation, food supply,

and, above all, humans. Conditions are favorable to different species at different

times. Ecosystems are constantly changing, and after every change,

it is impossible to re-create the ecosystem that existed before.

In ecology, a disturbance is a temporary change in average environmental

conditions that causes a pronounced change in an ecosystem. Outside

disturbance forces often act quickly and with great effect, sometimes

resulting in the removal of large amounts of biomass. Ecological disturbances

include fires, flooding, windstorm, insect outbreaks, as well as anthropogenic

disturbances such as forest clearing and the introduction of

exotic species. Disturbances can have profound immediate effects on ecosystems

and can greatly alter the natural community.

Every old-established forest provides a home for vast numbers of animals,

birds and insects which live in a delicate state of balance with each

other and with their environment. Seed-eaters might, in theory, destroy the

forest by devouring all the nuts destined to produce seedling trees, but in

practice this rarely happens. Predatory owls, hawks, foxes and pine martens

limit the numbers of seed-eating birds, mice and squirrels and allow

sufficient seeds to survive to ensure the replacement of old and diseased

trees. If the predators become too successful and destroy their prey, they in

turn will decline in numbers through shortage of food.

The wildlife population is markedly different in deciduous and coniferous

woodlands. Broad-leaf forests support a great variety of life. More

than 200 insect species have been found on oak trees alone, including leafroller

moths, gall-makers, predators and vegetarians. Insect-eating birds

like thrushes, blackbirds and warblers abound, sharing their habitat with

seed-eating wood-pigeons, pheasant, dormice and squirrels. Coniferous

forests have a more restricted fauna comprising species better equipped to

deal with their resinous bark and foliage and their tough leaves and seeds.

This delicate balance may, however, be upset by the introduction of a

species into a new country where it has no natural enemy. Today, quarantine

laws attempt to safeguard each country's woodlands, but without complete

success. The bark beetles that carried a virulent strain of Dutch elm

disease to Britain in 1970 made the crossing from Canada in consignments

of unsawn rock elm used in the boat-building industry. Maps plotting the

spread of the disease focused on ports at which the timber was landed.

Poisons are the simplest large-scale means of attack, but these need

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repeated application and may also harm innocent species. Biological control

offers a better remedy. American Monterey pines, planted in Australia,

suffered great damage from Sirex wood wasps accidentally imported from

Europe. The balance was restored by the introduction of the European ichneumon

fly — a natural, and destructive, parasite of the wood wasp.

Timber, naturally durable material, provided by the forest, does not

change or lose its nature, as result of age. So long as timber is protected

from moisture and insect attack it can remain unchanged for centuries.

Many materials become brittle and crumble after a certain number of years

due to oxidation and other slow chemica1 alterations in their composition,

but wood retains its strength indefinitely. Nor does it suffer fatigue, as do

metals, after repeated stressing.

Under damp conditions, however, and when in contact with the soil all

natural materials derived from plants and animals decompose, more or less

slowly. It is in fact fortunate that they do so as otherwise forests would become

cluttered up with fallen trees, branches and leaves. Decay does not

happen as a result of wet conditions alone but is brought about by the fungi

and, though to a lesser extent, by bacteria.

Fungi are forms of plant life that do not possess the chlorophyll which

enables greens plants to make organic materials from the carbon dioxide in

the air. Consequently they must obtain their nutrients from living on other

plants, on animals, or on their dead remains. The fungi that attack living

plants are called “parasites” and those that grow only on dead remains are

known as “saprophytes”. Some fungi grow in the sapwood and block the

vessels that carry the sap to the leaves thus causing the tree to die of desiccation.

Others grow deeper in the trunk causing the disease known as

“heart-rot”, while “butt-rot” is caused by a fungus entering the tree at its

base and may eventually result in the tree-falling in a gale. It is however

the saprophytes with which the timber user is most concerned. These fungi

live on fallen logs and branches and attack timber in storage and also

wooden structures in service if these are not protected by preservative or

paint.

EXERCISES

Exercise 1. Write the following word groups as one word, hyphenated

word or two separate words. Check spelling of the following separate and

compound words in the text under study. Comment on the examples with

two possible choices.

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black bird; boat building; butt rot; carbon dioxide; chloro phyll; eco system;

food supply; gall maker; heart rot; large scale; leaf roller; old established; pine marten;

safe guard; sap wood; seed eaters; seedling trees; tree falling; wind storm; wood

land; wood pigeon; wood wasp.

Exercise 2. Translate the word combinations with attributive Past or

Present Participles, taken from the text.

Find those word groups in the suggested sentences in the text under

study and check your translation in a wider context.

boat-building industry; diseased trees; fallen logs; fallen trees, branches and

leaves; insect-eating birds; living plants; old-established forest; pronounced change;

repeated application; repeated stressing; seed-eating birds, seed-eating wood-pigeons;

unsawn rock elm; wooden structures.

Exercise 3. Choose the right word to be used in the following sentences:

1. Ecosystems are constantly changing, and after every change, it is

possible / impossible to re-create the ecosystem that existed before. 2. In

ecology, a disturbance is a temporary / permanent change in average environmental

conditions that causes a pronounced change in an ecosystem. 3.

Every newly established / old-established forest provides a home for vast

numbers of animals, birds and insects. 4. Seed-eaters might, in theory, destroy

the forest by devouring all the nuts, but in practice this often / rarely

happens. 5. Coniferous / deciduous forests have a more restricted fauna

comprising species better equipped to deal with their resinous bark. 6. The

delicate / stable balance may be upset by the introduction of a species into

a new country where it has no natural enemy. 7. American Monterey

pines, planted in Australia, suffered great damage from Sirex wood wasps

intentionally / accidentally imported from Europe. 8. Timber, naturally durable

/ fragile material, provided by the forest, does not change or lose its

nature, as result of age. 9. Under damp conditions and when in contact

with the soil all artificial / natural materials decompose more or less

slowly. 10. It is however the parasites / saprophytes with which the timber

user is most concerned. These fungi live on fallen logs and branches and

attack timber in storage and also wooden structures in service if these are

not protected by preservative or paint.

Exercise 4. Match the word (numbers 1—12) with its definition or explanation

(letters A—L).

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1. disturbance A. a bird or other animal that feeds on tree or other plant seeds

2. quarantine law B. the fungi that grow only on dead remains

3. remedy C. substance added to food or material to keep it from spoiling

4. preservative D. the disease when the fungi grow deep in the heartwood of

the tree trunk

5. parasites E. the disease of the wood with a fungus entering the tree at its

base

6. saprophyte F. rotting, decomposition, deterioration of matter

7. heart-rot G. an insect whose eggs cause a gall (tumour) on plant tissue

or tree stem

8. butt-rot H. a temporary change in average environmental conditions

that causes a pronounced change in an ecosystem

9. seed-eater I. forms of plant life that do not possess the chlorophyll and

live on other plants, on animals, or on their dead remains

10. gall-maker J. rules for isolation or restriction on travel or transportation

imposed to keep diseases, insect pests, etc. from spreading

11. decay K. the fungi that attack living plants

12. fungi L. something that corrects or counteracts the evil or wrong

TEXT 2. FOREST FIRES

Read text 2 and 1) give definitions to the words in italics and 2) find the answers

to the following questions:

- Are forest fires only destructive?

- What causes forest fires?

- How do uncontrolled forest fires differ?

- How do forest fires affect wildlife? Give positive and negative examples.

- What is the key factor in fire fighting? How is the monitoring done?

Fire is one of natural disturbances. Periodic fires caused by lightning

have shaped and altered forests for millions of years. A wildfire, also

known as a wildland fire, forest fire, brush fire, vegetation fire, grass fire,

peat fire, or hill fire, is an uncontrolled fire often occurring in wildland areas,

but which can also consume houses or agricultural resources. Common

causes include lightning, human carelessness, arson, volcano eruption,

and pyroclastic cloud from active volcano.

Wildfires are common in many places around the world. Fires are particularly

prevalent in summer when fallen branches, leaves, and other material

can dry out and become highly flammable. It is also suggested that

global warming has been increasing the intensity and frequency of

droughts in many areas, creating more intense and frequent wildfires.

Wildfires tend to be most common and severe during years of drought and

occur on days of strong winds.

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Forest fires move in varying and often unpredictable ways. Ground

fires creep through the duff, and fires may smolder below the surface for

long periods of time. Surface fires are another form of forest fire, and

move along at up to 1.3 meters in height. Crown fires occur higher in the

trees (in the upper branches known as the "crown" of a tree), and can be of

several different varieties. These include " dependent crown fires ", which

use convection to pre-heat the crown, and most dangerous of all, independent

crown fires which leap from tree to tree. Often the battle is won

only when heavy rain falls or the fire reaches a natural obstacle such as a

river or mountain range.

Recently there have been made serious efforts at fire suppression. The

relationships between forests, fire, insects, disease, and climate are just beginning

to be understood. The huge fires in Yellowstone National Park in

1988 caused many people to wonder whether a more natural approach to

fire might be better than complete suppression. There is no doubt that fire

destroys trees, which humans consider a waste. But the hidden benefits of

natural fires might be greater than were previously thought. Most forest

ecologists agree that controlled fires are essential to restoring forest health

and biodiversity.

Fires affect forests in various ways. Most animals can successfully

evade fires, and many thrive afterwards on abundant new growth on the

forest floor. New conditions support a wider variety of plants, often rich in

nutrients compared to pre-disturbance vegetation. The plants in turn support

a variety of wildlife, temporarily increasing biological diversity in the

forest.

In general a disturbance changes forests significantly. Afterwards, the

forest floor is often littered with dead material. This decaying matter and

abundant sunlight promote an abundance of new growth. In the case of

forest fires a portion of the nutrients previously held in plant biomass is returned

quickly to the soil as biomass burns. Many plants and animals benefit

from the conditions created by disturbances. Habitats are most often destroyed,

as well as the food source which means that even if the animals

escape the flames, they have to find new territory. Other animals which

live in the surrounding forest come to feed on the new seedlings and young

plants growing in a recently burned area.

Fast and effective detection is a key factor in wildfire fighting. Recently,

there have been significant efforts to create automatic solutions for

early wildfire detection. An integrated approach is best, based on a practical

combination of different detection systems depending on wildfire risk

and the size of the area.

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A careful GIS data analysis will suggest how to divide the area in subcategories

based on different risk level and human presence (which imply

a higher wildfire risk and a need for earlier intervention). A small high risk

area (thick vegetation, strong human presence or close to critical urban

area) could be monitored using a local sensor network. Although it is a

relatively new approach, it seems to be the only solution able to penetrate

thick vegetation and guarantee early detection without false alarms, as well

as detecting crawling wildfires. The main limitation of this technology is

its high cost which at this time limit its application to small areas.

A larger medium risk area could be monitored by infrared scanning

towers. Satellite and aero monitoring can provide a wider view and may be

sufficient to monitor very large and low risk areas.

Topical Vocabulary

lightning ['laitniŋ] — молния;

wildfire ['waildfaiə] — лесной пожар;

peat fire — подземный (торфяной) пожар;

(un)controlled fire — (не)управляемый пожар;

human carelessness — небрежность, халатность человека;

arson — поджог;

volcano [vǤl'keinəu] eruption — извержение вулкана;

flammable ['flæməbl] (= inflammable) — легко воспламеняющийся,

огнеопасный; горючий;

ground fires — низовой пожар;

creep — ползти; стлаться;

duff — грубый (сырой) гумус лесной подстилки;

smolder ['sməuldə] (= smoulder) — тлеть;

surface fire — наземный пожар;

crown fire — верховой пожар;

fire suppression —подавление пожара;

evade fire — избегать; уклоняться от пожара;

detection — обнаружение, выявление;

wildfire fighting — битва, борьба;

GIS data analysis — анализ данных ГИС;

crawl — ползать, ползти;

disrupt — разрушать; разрывать (узы); нарушать;

infrared scanning tower — вышка инфракрасного сканирования;

satellite ['sætəlait] monitoring — спутниковый мониторинг;

aero monitoring — аэромониторинг.

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EXERCISES

Exercise 5. Provide verbal and nominal word-groups. Translate the

resulting word combinations into Russian

A) Give all possible verbs which combine with noun fire

Model: to cause fire; to extinguish fire …

B) Give all possible attributes to describe fires.

Model: forest fire; crawling fire …

Exercise 6. Make sure you know the meaning of prefixes sub-, over-,

pre-, inter-, under-, super- and some others. Translate the suggested sentences

into Russian.

1. The genus is sub divided by its morphology into a number of sections

and sub sections. 2. A careful GIS data analysis will suggest how to

divide the area in sub- categories based on different risk level and human

presence. 3. Everything from the direct and obvious effects of over -cutting

to the more subtle effects of climate change are threatening to destroy the

last of the remaining natural forests. 4. Much of the human-caused forest

destruction stems from over population. 5. Dependent crown fires use convection

to pre -heat the crown. 6. The futures of people and forests are still

interc onnected. 7. New conditions support a wider variety of plants, often

rich in nutrients compared to pre- disturbance vegetation. 8. The controlled

burn clears much of the under growth through forest and woodland areas.

9. A new material called "gel" (made from super- absorbent polymer) is

used in California, USA for fighting forest fire. 10. All wild land firefighters

carry a fire shelter, but it provides limited protection from radiant and

convective heat, as well as super heated air. 11. Succession often leads to

conditions that will once again pre dispose an ecosystem to disturbance. 12.

Forest fires move in varying and often unpredictable ways. Ground fires

creep through the duff, and fires may smolder below the surface for long

periods of time. 13. Constant vigilance by fire wardens using watch-towers

and patrolling aircraft is essential if out breaks are to be dis covered

promptly and tackled while still small. 14. Ecosystems are constantly

changing, and after every change, it is im possible to re-create the ecosystem

that existed before.

Exercise 7. Translate the sentences with pairs of suffixes which either

form an adjective or a noun ( import ant — import ance)

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1. It is suggested that global warming has been increasing the intensity

and frequency of droughts in many areas, creating more intense and frequent

wildfires. 2. Douglas-firs, having dense crowns, severely limit the

amount of sunlight reaching the forest floor. 3. In rocky, mountainous terrain

areas of high and low tree density alternate depending on the soil and

climatic variables. 4. Spruce and fir forests have a greater biodiversity than

most other forests because of their multiple layers of canopy and dense

understories. 5. The heterogeneous, diverse stand structure leads to an assortment

of fire types which usually leave patches of unburned trees. 6.

Evaporation is low in taiga forests for most of the year, precipitation exceeds

evaporation and is sufficient for the dense vegetation growth. 7. This

decaying matter and abundant sunlight promote an abundance of new

growth. 8. Biological diversity is dependent on natural disturbance. 9.

Many shade- intolerant plant species rely on disturbances for successful establishment

and to limit competition. 10. Fire, in this case, is important not

only to the species directly affected but also to many other organisms

whose survival depends on those key plants. 11. Russia's vast forests are a

natural resource of global importance, both ecologically and economically.

12. The late wood of all species is denser than that formed early in the season,

hence the greater the proportion of late wood the greater the density

and strength.

Exercise 8. Translate the pairs of sentences with the words in italics

in different functions, as a noun or verb (conversion).

1. Forests can be damaged by fire, agricultural and urban expansion,

and other disturbances. // American Monterey pines, planted in Australia,

suffered great damage from Sirex wood wasps accidentally imported from

Europe.

2. So long as timber is protected from moisture and insect attack it can

remain unchanged for centuries. // The fungi live on fallen logs and

branches and attack timber in storage and also wooden structures in service

if these are not protected by preservative or paint.

3. Periodic fires caused by lightning have shaped and altered forests

for millions of years. // Common causes include lightning, human carelessness,

arson, volcano eruption, and pyroclastic cloud from active volcano.

4. The hidden benefits of natural fires might be greater than were previously

thought. // Many plants and animals benefit from the conditions

created by disturbances.

5. Spruce and fir forests are greatly impacted by slight fluctuations in

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climate. // Other forest disturbances include climatic factors such as wind,

snow, ice, floods, tropical storms and drought, or impacts of animals such

as deer and rodents.

6. The forest floor is often littered with dead material. // Fuel is readily

available in the form of standing timber, bark, branch-wood, fallen

branches and leaf- litter on the forest floor.

7. Disturbance forces often act quickly and with great effect, sometimes

resulting in the removal of large amounts of biomass. // The transition

to a market economy has forced forest producers to be much more efficient

economically.

8. Mounds (холмы) are caused by decaying fallen trees, and pits

(ямы) by the roots pulled out of the ground when trees fall due to natural

causes.

Exercise 9. Translate the sentences with the for + infinitive construction

in italics in different functions. Start with stating the function of the

for-phrase and translate the sentence accordingly, using subordinate

clauses in most cases.

1. The conventional practice has been for forests to be measured in

terms of economic or physical parameters, e. g. area and increment rate. 2.

Aircraft "bomb" fiercely burning hot-spots with retardant chemicals, which

cling to the foliage and branches — slowing the rate of burning long

enough for teams of fire-fighters to arrive and tackle the blaze on the

ground. 3. Trees are cleared not only for wood and other products, but so

that the land they once grew on can be turned into pastures for cattle and

agricultural fields to feed growing numbers of people. 4. Small, frequent

fires in certain areas make it easier for pines to survive where oaks would

otherwise grow. 5. It is typical for large and valuable specimens from the

overstory to be removed thus creating a gap in the canopy simulating the

death of an old-growth tree. 6. In a situation where a vast majority of trees

are valuable to harvest, it is easier for loggers and economically sound to

remove trees in an open clearcut, as opposed to moving equipment around

standing trees. 7. It is quite common for firefighters to simply observe a

fire burn towards control lines through forest rather than attempt to put it

out more quickly. 8. Virtually every part of Earth's surface has at some

time been either too dry or too cold for plants to survive. 9. The time it

takes for fir and spruce to regenerate varies greatly, but it takes a number

of years if no roots or snags remain. 10. It may be much more difficult for

fir and spruce to be established on a slope, because erosion is greatly increased

by fire, making it harder for the seeds to take root. 11. Individual

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plant species vary their resistance to fire injury in predictable ways, and

these resistances make it possible for the biodiversity to greatly increase

during recolonization after a fire.

Exercise 10. Translate the sentences with the Subjective-with-the-

Infinitive construction. Start the translation with the predicate.

1. Globally, 3 % of forest area is reported to be affected by insects

and diseases. 2. Although sensor monitoring is a relatively new approach,

it seems to be the only solution able to penetrate thick vegetation and

guarantee early detection without false alarms, as well as detecting crawling

wildfires. 3. Cedar wood and cedar oil is known to be a natural repellent

to moths, hence chests were made of cedar when available. 4. Recent

systematic studies appear to confirm the high tendency of Quercus species

(oak) to hybridize as a result of a combination of factors. 5. Firs, very

popular Christmas trees, are generally consi dered to be the best trees for

this purpose, with aromatic foliage that does not shed many needles on

drying out. 6. Birch sap is consumed as a refreshing beverage, and is believed

to have tonic qualities. 7. The cross that Christ was crucified on is

sometimes said to have been aspen wood. 8. Overall, the world’s forest

ecosystems are estimated to store more carbon than the entire atmosphere.

9. The most common tree species appear to have remained the same in

most countries over the last 15 years. 10. Trees have also been found to

play an important role in producing oxygen and reducing carbon dioxide in

the atmosphere, as well as moderating ground temperatures.

Exercise 11. Translate the text about fires into English, sentence by

sentence. Then speak about the damage forest fires make and their benefits

and comment on the suggested approach.

Огонь играет значительную роль в жизни леса как экологический

фактор. Огонь — разрушитель и созидатель леса. Лесные пожары из-

меняют окружающую среду. Они происходят преимущественно по

вине человека.

Во многих частях нашей планеты формирование природных ле-

сов связано с влиянием пожаров. Уничтожая моховой и травяной по-

кровы, толстую подстилку и гумус, огонь создает благоприятные ус-

ловия для возобновления леса — прорастания семян, появления и

формирования самосева; особенно сосны, лиственницы. В то же вре-

мя уничтожая молодняк, пожар нередко способствует появлению ма-

лоценных пород и приводит к ухудшению условий среды для возоб-

новления хозяйственных пород.

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Лесные пожары обусловливают процессы смены состава лесов,

влияют на состав древостоев, на их возрастную структуру, видоизме-

няют типы леса. Пожары существенно изменяют численность и со-

став фауны — зверей, птиц, насекомых.

Они обусловливают жизнедеятельность почвенных микроорга-

низмов, стимулируя или подавляя ее. Огонь влияет на санитарное со-

стояние леса. Нанося травмы деревьям, ослабляя их, он способствует

образованию ветровала и бурелома, нападению и размножению вред-

ных насекомых и некоторым заболеваниям деревьев. С другой сторо-

ны огонь уничтожает источники инфекции, носителей ряда грибных

и других заболеваний, а также и вредных насекомых. Вызывая отми-

рание в первую очередь отставших в росте деревьев и ускоряя этим

процесс изреживания в лесу, огонь может способствовать более ин-

тенсивному приросту сохранившихся крупномерных деревьев. Воз-

действуя на все компоненты леса, пожары вносят коренные измене-

ния в лесные экосистемы.

Лесоводы используют положительную роль огня в практике лес-

ного хозяйства (при очистке лесосек, при подготовке почвы для во-

зобновления леса и др.). Огонь — величайшее благо, когда он нахо-

дится в умелых руках, но он становится страшнейшим врагом, вы-

рвавшись из повиновения. Лесные пожары — грозное глобальное яв-

ление. На земном шаре они ежегодно охватывают площадь до 10—

15 млн га и выше, а в отдельные годы эта цифра более чем удваивает-

ся. Проблема борьбы с лесными пожарами — одна из важнейших в

лесном хозяйстве.

Questions and tasks

1. Why aren’t communities of plants stable?

2. What is disturbance? What kind of disturbances do you know? How are they

caused?

3. What living organisms create the stability and balance?

4. Which forests are characterized by a greater variety of species? Explain why.

5. How can the introduction of a new species affect the forest environment?

What is the best remedy? Is poison always a good solution?

6. What is timber affected by? What makes timber different from other materials?

7. What is fungus? What types of fungi are there? In what do they differ?

8. Is there a remedy against fungi?

9. What is fire caused by? Which cause is the most common?

10.How are different types of fires distinguished?

11.What are the different attitudes to fire suppression?

12.How does fire affect animals? How can animals and plants benefit from fire?

13.What methods of fire detection do you know? Which would you prefer?

Why?

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