Forestry

TABLE OF CONTENT INTRODUCTION Unit 1: THE ROLE OF TREES............................................................................ Page 1-3 Unit 2: THE DEVELOPMENT OF CONSERVATION........................................ Page 4-6 Unit 3: IDENTIFICATION OF TREES (I)............................................................ Page 7-9 Unit 4: IDENTIFICATION OF TREES (II)...................................................... Page 10-12 Unit 5: TREE SIZE AND TYPE CLASSIFICATION....................................... Page 13-16 Further Reading: TREES AND FORESTS........................................................ Page 17-20 Unit 6: FOREST AND FLOODING.................................................................. Page 21-24 Further Reading: WINDBREAKS..................................................................... Page 25-26 Unit 7: CREATING A NEW STAND............................................................... Page 27-31 Unit 8: DIFFERENT TYPE OF CUTTING....................................................... Page 32-36 Unit 9: FOREST MEASUREMENTS DEFINED............................................. Page 37-39 Unit 10: FOREST HARVESTING.................................................................... Page 40-42 Unit 11: FOREST TREE INSECTS AND HOW TO CONTROL THEM ........ Page 43-47 Further Reading: TREES DISEASES................................................................ Page 48-53 Unit 12: PREVENTION AND CONTROL OF WILDFIRES........................... Page 54-57 REFERENCES........................................................................................................ Page 58

Unit 1:

THE ROLE OF TREES

For hundreds of years people have planted trees to serve the needs of future generations for timber and tree products. In Europe and Asia forests were planted by rulers, church leaders and farmers – for the people. By planting trees they particularly and symbolically showed faith and hope for the future. Trees are fundamental to life and the processes that maintain healthy soil, and clean air and water. There is evidence which shows that in regions where the trees are cleared to less than 30% of their original surface area, other sustainable life processes begin to collapse. Rivers silt up, soils wash away, and air quality declines. James Lovelock, a renowned ecologist, claimed these breakdowns in natural systems will in turn affect other word bio-areas continent or cyclones may occur more frequently. It will be sad if these things happen before we change from consumers to producers.

I/ Comprehension 1. What do people plant trees for? 2. What do European and Asian people want to show by planting trees? 3. What are fundamental roles of trees? 4. What will happen to the area when the trees are cut down?

II/ Grammar ADJECTIVE + PREPOSITION Exercise 1: Complete these sentences with the correct preposition 1. It’ very nice ................... you to let me use your car. Thank you very much. 2. Why are you always so impolite ………….. your parents? Can’t you be nice ……...….. them? 3. It wasn’t very polite ………….….him to leave without saying thank you. 4. I can’t understand people who are cruel to …………. animals. 5. Why do you always get so annoyed …………….. little thing? 6. We enjoyed our vacation, but we were disappointed ………….…. the hotel. 7. I was surprised ………….….. the way he behaved. It was out of character. 8. These days everybody is aware ……………….. the danger of smoking. 9. Mr. Davis spends a lot of time gardening. His garden is very well-kept, and he’s very proud … ……..…. it. 10.Bill has been doing the same job for too long. He’s bored ……..……… it. Exercise 2: Fill in the gaps with words in the box boundary ; slopes ; verges ; sanctuary ; shelter ; indigenous pressures ; surrounding ; reptiles ; uncontaminated ; backbones

1.……….. forests involved over millions of years with all the …………. of natural selection operating, so that finally what we see is a highly refined complex which is beautifully honed to survive in the ………….. environment. 2. If the forest is large enough it will offer ………… to indigenous mammals, birds and ……… ………. . 3. Forest may be established in the areas such as: creeks, gullies, farm ………….., ridges and places with …………. greater than 15, and roadside …………………. . 4. Your garden is the natural forest that are the …………. and security for the whole landscape. 5. Like your food forest and structural forest, this assembly of trees and their organisms provides …………… and protection, and maintains air, water and soil in ……………. states. Exercise 3: Expressing purposes: To-Infinitive 1. A tree uses sunlight. The purpose in using it is to combine carbon dioxide with water to form carbohydrates. 2. In countries with inadequate rainfall we irrigate the land. Our object in doing this is to supply enough moisture for satisfactory plant growth. 3. We should add fertilizers or manure to the soil. Our aim in doing this is to encourage plant growth. 4. Tile drains may be laid in or on the land. The reason for this is to remove surplus water from the fields. 5. We apply inorganic materials to the soil. Our object in doing this is to increase the supply of one or more of the essential nutrients such as nitrogen, phosphorus, and potash. Expressing conditions 1. Take one clause from each of the two columns below to make one sentence. Make sure your sentences make sense: If you don’t understand the trees, If a soil is badly drained, Crops are often lost If you don’t take notes, If agriculture fails, You get better crops Most trees die People get sick

it can become waterlogged you will never be a good forester the world will starve if the farmer does not look after them if they don’t get enough water if they don’t eat proper food you won’t remember the lectures if the soil is fertile

2. Now say what you think would be the result if the circumstances below actually happened. Complete the sentences, giving your opinion: Example: My car/not/start If my car didn’t start ……………………. a. drought/hit/my country b. My land/flood c. Lose/my note d. My country’s population/double e. There/be/no rice/my country f. we/not/test/new plant varieties

Unit 2:

THE DEVELOPMENT OF CONSERVATION

In very early pioneer days, trees were cut down with no thought of replacing them. However, the significance of trees was indicated as early as the 1620s by the Plymouth Colony, when an ordinance was passed prohibiting the felling of timber on any colony land without official consent. A little later in Pennsylvania, William Penn, the governor, ordered that, for every 5 acres of forest land cleared, 1 acre was to be left uncut. After the United States was established, laws with penalties were passed by several states to prevent thoughtless waste of the forests. In the early 1800s Congress authorized the president to protect live oak and red cedar timber in the state of Florida and to use the Army and Navy for enforcement. During this same period the first step in forestry was taken by the government by providing for the growing of live oaks in the southern states for ship timbers. A federal act also provided for preservation of nearly 250.000 acres of forest land in Florida, Mississippi, and Louisiana. According to another act passed in that decade, any person cutting down or destroying living red cedar, live oak, or other trees on federal land could be punished by the government. These laws and regulations, through which the government tried to control the forest land, helped call attention to the importance of forests and led to the development of conservation at the state level. In January 1867, the first state committee on forest protection was appointed in Michigan, and Wisconsin followed in March of that year. Two years later the State Board of Agriculture of Maine appointed a committee to develop a state policy for the preservation and production of trees. Minnesota created a law in 1871 that granted bounties to encourage the planting of forest trees. The first Arbor Day, a day in late April or early May observed by the planting of trees was celebrated the following year in Nebraska. The federal government adopted the Timber Culture Act in the early 1870s. It provided that the government would donate 160 acres of land to any person who planted 40 acres of that trees with trees not more than 12 feet apart and kept the trees growing and healthy for one decade. This act, however, was repealed after 10 years because of serious abuses; too many recipients of these grants were not honoring their commitments by failing to follow the rules and regulations pertaining to the grants. In many instances, while employing fire to prepare their land for cultivation, the settlers disregarded caution relating to neighboring land. Gross carelessness often resulted in destruction of property well.

I/ Vocabulary 1. Look at paragraph 1 again. Which word has the same meaning as: A. harvested C. importance B. without thinking of D. banning

2. Look at paragraph 3 again. Find the synonym of the words: A. agreement C. give hope and courage B. conservation 3. Look at paragraph 4 again. Which word has the same meaning as: A. 10 years B. parliament

II/ Put the appropriate word in the blank conserve cut significance fell prevented

protection growing timber laws destruction

1. The…………………….…of Eucalyptus on waste land is becoming popular. 2. In Sweden, machines have been used to……………….….trees. 3. It is very important to……………….….all the valuable wood species. 4. Shifting cultivation causes a lot of forest……………….… . 5. Nowadays, most of people are aware the…………………of forests. 6. Forests……………..…….is a very important subject for us. 7. Long, long ago, trees were………………………with no thought of replacing them. 8. …………………..consumption of Japan has been increasing since the Second World War. 9. Everybody should respect the……………….………. . 10. New forest laws have……………..……people from destroying forests.

III/ Comprehension A/ True or False? 1. Trees were cut with thought of replacing them in very early pioneer days. 2. The importance of trees was known in the 17th century. 3. Before USA was founded laws with penalties were passed by several states to prevent thoughtless waste of the forests. 4. In the early 10th century, live oak and red cedar timber in the state of Florida were protected. 5. Red cedars were grown by the government in southern states for ship timbers in the early 19th century. 6. In some states of America, about 250.000 acres of forest land were preserved by a federal act. 7. Any persons cutting down one acre of living red cedar, live oak or other trees on federal land could be punished by the government.

8. In the early 19th century police were used to enforce forest laws and regulations. 9. In 1896 the state Board of Agriculture of Maine appointed a committee to develop a state policy for the preservation and production of trees. 10. These early laws and regulations played an important role in the establishment of forestry in USA. B/ Answer the questions: 1. In very early pioneer days, why were trees cut with no thought of replacing them? 2. What was the content of the ordinance passed in 1620? 3. What did William Penn order? 4. In the early 1800s, what did the congress authorize the president to do? 5. When was the planting of trees started? When was the timber culture Act adopted and what was its content?

IV/ Grammar + Some verbs in English must be followed by the - ing form: For example: He admitted taking my book. + Others are followed by the infinitive, “to”: For example: He agreed to lend me his book. + Verbs followed by a particles like ‘in’, ‘from’, etc. are followed by the -ing form: For example: He insisted on going to a film last night. Exercise : Make sentences from the following notes. Think whether you should use the infinitive or the – ing form after the verbs. 1. He/suggest/read/chapter 5/before/we/go/lecture 2. The rain/not stop/fall/until yesterday evening 3. He/wants/spend/more time/study. 4. A good farmer/try/set/objectives. 5. Peter/prevent/harvest/his crop/bad weather. 6. I enjoy/listen/music. 7. He/not mind/work/weekends. 8. He/forget/hand in/essay/ last night. 9. There/nothing/that shop/worth/buy. 10. It/no use/leave/your work/last minute. 11. I/miss/watch/college football match/last week.

Unit 3:

IDENTIFICATION OF TREES (I)

Trees are woody plants, but not all woody plants are trees. A tree usually grows upright to at least 20 feet (15.5 metres) at maturity and has a single stem, often called bole or trunk. The stem supports limbs and leaves, forming the top or crown. Other woody plants are vines and shrubs. Vines may have woody stems but do not have a distinct crown of upright branches. Shrubs may have several woody stems growing from a clump, and they usually are smaller than trees. Trees generally develop a typical shape when they grow in an open area. Trees that grow in crowded forests usually have trunks of greater clear length. Essentially, we have no timberline resulting from high elevation in the East, but at timberline and at higher mountain elevations in the West many trees are knurled, twisted, and sometimes prostrate. Such tortuous form is the result of many factors, including thin soils, limited growth periods, deep snows, and continuous exposure to strong winds. However, under favorable conditions, most species develop characteristic shapes. Several field trips with a good identification manual showing local species should enable an inexperienced person to become rather proficient in identifying trees. Identification features are also found in bud, flower, fruit, leaf, twig, and bark structure. The precise botanical characteristics by which trees are classified (primarily flower parts) are too small or fleeting to be useful in field identification for those with little experience. The gross features (shape, leaf, and bark structure, buds and twigs) are more useful for quick field identification.

I/ Comprehension A/ Multiple-choice 1. A tree usually grows…………… . A. vertically B. horizontally C. downward 2. A tree usually has…………… . A. two stems B. one stem C. some stems 3. Vines has got……………… . A. great crown B. small crown C. complex crown D. indefinite crown 4. The branches of a vine are…………… . A. big B. long and thin C. not upright D. hard 5. When growing in an open area, trees often have a………… . A. nice form B. popular form C. great form 6. The tree that has to compete for light often has …………. .

D. dense form

A. a long stem B. many branches C. thick bank D. a beautiful crown 7. The tree that grows on very adverse place generally has…………. . A. a long stem B. a usual shape C. an unusual shape D. a dense brown B/ Answer the questions 1. All woody plants are trees or not? 2. At maturity, how high is a tree? 3. How many stem does a tree have? 4. What does the stem support? 5. Do vines have distinct crowns? 6. How do trees develop when they grow in an open area? 7. What kind of trunk does a tree often have when it has to compete for light? 8. Why are some trees knurled or twisted? 9. In what conditions do most species develop characteristic shape? 10. In order to have quick field identification what should be used?

II/ Vocabulary Put the appropriate word into the blank: stem crown shape branches light

knurled factors identification bark characteristics

1. …………………..is very important for the growth of trees. 2. Trees…………………...is a subject that we are going to study next week. 3. The……………………………..of this tree is very thick. 4. Many………………………affect the growth of a tree. 5. After the flood, the………………………..of the river banks changed so much. 6. This kind of Pine has got a lot of………………….….. . 7. We used to play under the…………………………….of this old, big tree. 8. The…………………………....of this bamboo is 10 metres long. 9. Yesterday, a car run into that tree, but only the……………………….is damaged.

III/ Paragraph writing Match the following clauses together, using and, but, when, after, so and because.

a. b. c. d.

the next evening he needed them Robert could not attend he arrived at the canteen Robert finally arrived they did not please Andrew very much he went to the canteen to look for Last night Andrew lend Robert his lecture Robert note Robert has not returned them e. Andrew needed his notes immediately Robert was not there f. He had waited for an hour he decided to wait

Unit 4:

IDENTIFICATION OF TREES (II)

Trees and other plants often have several common names, which vary with locality or local use. To make specific identities world-wide, botanists employ Latinized names, which remain constant since Latin is a language that no longer changes. The scientific name consists of two parts: the genus (a collection closely related species) and the specific epithet or species (a collection of individuals so similar that they suggest common percentage and produce like offspring). The generic name always appears first and is capitalized, while the specific name follows and begins with a lowercase letter. Because general and regional guides to field identification of trees and government publication that describe local or native trees are readily available, only a few of the important commercially significant trees of the major forest regions will be studied in this chapter. Most of these are valued for their wood products. Prior to studying individual tree species, it is necessary to know that trees are divided into two main groups. These are the conifers (gymnosperms) or softwood trees and the broadleaf (angiosperms) or hardwood trees. Conifers have mostly needle-like or scale-like leaves and bear their seeds in cones or cone-like structures. The conifers or evergreens do not shed all their leaves annually, with the exception of larch and bald cypress. Deciduous trees, those that shed all their leaves in the fall, generally are broadleaved hardwoods. The term hardwood and softwood can be misleading because the wood of some hardwood trees is softer than that of some softwood trees. For example, the wood of yellow poplar and basswood is much softer than that of the longleaf pine. We will first study the conifers, which are very widely distributed in the various regions and are very significant in the production of lumber and paper.

I/ Vocabulary Find word or combination of words that means: 1. some (paragraph 1) 6. types (paragraph 2) 2. definite (paragraph ) 7. accurate (paragraph 1) 3. the same (paragraph 1) 8. sawn wood (paragraph 4) 4. before (paragraph 2) 9. easily to be seen, bought (paragraph 1) 5. classified (paragraph 2) 10. different (paragraph 4)

II/ Comprehension A/ Find an appropriate word to fill the blank 1. He is a very famous……………. . (paragraph 1) 2. These trees do not………….leaves in the autumn. (paragraph 2) 3. In old time, people used to………to construct bridges. (paragraph 4) 4. ……………….….is often used to produce paper. (paragraph 4) 5. It is difficult to store the…………...of this tree, because their germination capacity is decreased by the time. (paragraph 2) 6. To conserve valuable………..….resources is a task of great importance. (paragraph 1) 7. This kind of trees are often…………………on high mountains. (paragraph 4) 8. Names of trees………………with different regions. (paragraph 1) 9. The generic name always……………………first. (paragraph 1) 10. ………………..….do not shed all their leaves annually. (paragraph 2) B/ Choose A, B, C or D. 1. Trees and plants have………… . A. very few names B. many names C. two names D. one name 2. The scientific name of a tree has……….. . A. only one part B. two parts C. four parts D. many parts 3. The specific name stands………….. . A. first B. in the middle C. last D. anywhere 4. ……….is written or printed in capital letters. A. the generic name B. the specific name 5. Trees are classified into………. . A. three types B. four types C. two types D. several types 6. Conifers are often……………… . A. hardwood trees B. softwood trees 7. Most of softwood trees do not change their leaves……… . A. in autumn B. in spring C. in summer D. in winter 8. The wood of………..hardwood trees is hard. A. all B. most of C. some D. many C/ Questions 1. How many names do trees and other plants have? 2. Why do they have many names? 3. Why do botanists have to use Latin to name trees? 4. How many parts does the scientific name consist of? What are they? 5. How are trees classified?

D/ Reading test Complete the following text by filling in the blank spaces with the expressions given below. A dotted line………requires a phrase to be added and a straight line ________ requires a word. the leaf very carefully plant groups identifiable some other plant

of how for example grass doing

the surrounding environment unfamiliar plant functions smell

If you want to identify an…………………, use your natural senses. Feel the texture of the leaves. Then____________ the plant- crush the leaves and see if the scent reminds you ________other plants you know. All the mints are ____________by smell, and so are the lavenders, eucalypts and citrus. Taste……………. and spit it out, and again see what it reminds you of; ____________the oxalis family all have the same acidic taste, so do the sorrels. (Notes: it is very hard to poison yourself by ___________simply a test taste and then spitting the leaf out.) Look at the plant……………… - all the thyme family have small hairy leaves; other……………. can be similarly recognised by sight. Now you can probable see that this plant is like……………………. you know. Think about it and then check its growing place. Examine ……………………- soil, aspect, slope- and the plant’s habit- tree, shrub, herb or____________. Identify its yields and ________________- mulch, groundcover, shelter food, and so on. Now tell yourself where and _____________you would use it in a permaculture design.

Unit 5:

TREE SIZE AND TYPE CLASSIFICATION Tree age and size can be described in a general and approximate way by use of such words as seedling, sapling, pole-size, mature, and veteran. A stand of trees can be even-aged or all-aged. A forest made up principally of one species is a pure stand, while one composed of several species is a mixed stand. Trees are also classified by the positions of their crowns relative to the general level of the forest canopy, the covering created by the crowns interweaving each other. Dominant: A tree having a well-developed crown that extends above the general level of the other crowns and is exposed to full light from above and partial light from the sides. Co-dominant: A tree with smaller crown than the dominants that helps form the general level of the canopy and receives full light from above but limited amount from the sides. Intermediate: A small-crowned tree crowded into the general level of the forest canopy, receiving some light from above and virtually none from the sides. Suppressed: A tree with poorly developed crown, beneath the level of the canopy (overtopped), receiving very little light from above or the sides. Foresters refer to a measure of the number and size of trees in a given area as stand density. It indicates whether the forest is under stocked, medium stocked, or well stocked. For example, if the canopy of a tract of timber is closed over as much as 40 to 70 percent, it is medium- stocked.

I/ Vocabulary 1. Look at paragraph 1 again. Which words have the same meaning as: A. newly born tree B. trunk 2. Look at paragraph 2 again. Which words correspond to the definitions? A. unique C. mixing with each other B. a forest of different species 3. Look at paragraph 3, 4 and 5. Can you find the synonym of the following words? A. face to the sun B. layer of forest

C. actually D. not any 4. Find out an appropriate word in the text to fill the blank: a. How many…………does your nursery produce per year? (paragraph 1 ) b. I think these pines are…………….enough to be cut. (paragraph 1) c. This stand is……….…….because it is made up principally one species. (paragraph 2) d. This……………of pine grows very fast. (paragraph 2) e. He has been a…………..….for twenty years. (paragraph 7) f. The roots of this tree have………………….over a lot of land. (paragraph 3) g. Dominant trees receive full……..…….from the sun. (paragraph 3) h. Biomass production is affected by stand…………………. . (paragraph 7) i. The economic…………………of Japan is admirable. (paragraph 7) j. A given area of trees, which is consisted of species is called a……..……… . (paragraph 7)

II/ Comprehension: True or false? a. A pure stand is made up of different species. b. Trees can not be classified by the positions of their crowns. c. In a forest, each crown of each tree stays away from each other. d. A dominant tree receives some light from the sides. e. A co-dominant tree gets no sunlight from the sides. f. A suppressed tree receives no light at all. g. An intermediate tree does not have any light from the sides. h. Stand density is the number and sizes of trees in a given area. i. Basing on the crowns of trees that are relative to the general level of the forest canopy, trees can be classified into four types. j. If the canopy of a tract of timber is closed as much as 55%, it is medium-stocked.

III/ Grammar The form of Definition Definitions often take one of the following forms: 1. [ A] is / are, may be defined as [ B ] which [ C ] E.g. A soil profile [ A ] is defined as a succession of soil horizons [ B ] which extends from the surface of the soil to the parent rock. 2. [ B ] which [ C ] is / are called, is / are known as [ A ] E.g. A succession of soil horizons [ B ] which extends from the surface of the soil to the parent rock [ C ] is called a soil profile.

A 1. Photosynthesis

B

C

The process

Transforms light energy from

the

sun

into

chemical energy 2. A soil profile

A

succession

of

horizons

soil Extends from the surface of the soil to the parent rock

3. Aerobic bacteria

Organisms

Can live in the presence of air

4. Osmosis

Biophysical process

Take place through the tissues of living plants

5. A leaf

Complex structure

Utilizes energy from the sun in the manufacture of food

6. Chloroplasts

Bodies

Absorb

sunlight

and

manufacture food 7. Stomata of plants

8. Chlorophyll

Minute openings on the Lead to the interior of the surface of a leaf

leaf and the chloroplasts

The chemical

Enable sunlight to convert carbon dioxide into food and other substances

Definition of Terms: Combine the items in Column A with the ones in column B to make the correct definition of each term. You will need to add some necessary words (articles, pronouns and adjectives, forms of the verb “be”) where appropriate. Forest

Ecologically complex unit-community of trees and undergrowth spreading, sometimes, over really enormous areas.

Stand

Collection of trees which are more or less uniform (i.e. more or less the same) in species, age distribution etc.

Type

Rather like a stand but more extensive- group of similar stands defined by the species composition

Site class

Physical factors which affect the productivity of the trees, concerning the thing like the soil, the slope and exposure (wind, rain)

Size of tree

Height of tree and diameter.

Diameter of tree

Measured at one point three five metres from the surface of the soil.

Cm dbh

Measurements used for the diameter of trees (dbh: diameter at breast height)

Further Reading: TREES

AND FORESTS

A mature forest cannot be precisely measured nor cost. However, it is clear that forests have special functions. In addition to providing habitats for animals and contributing to environmental stability, forests influence wind patterns, rainfall and nutrients turnover.

The Function Of A Forest The waru The trees are the fixed elements of a forest and the associates of trees- fungi, bacteria, squirrels, possums, insects, birds, and other animals- can be seen as the mobile elements. The whole- the tree and its associates- can be imagined as a guild or waru (the Australian Aboriginal word waru expresses the sense of all organisms belonging together and working co-operatively.) the tree provides habitat for the animals (shelter, food, nesting materials); in return animals carry out the tree’s needs for pollination, seed dispersal, pruning, cultivation and fertilising. In permaculture, you are aiming to create landscapes and ecosystems that function with the wonder, diversity and efficiency of a waru. Trees and wind Trees are “pruned” or deformed by prevailing winds and from this you can predict local wind direction and intensity, and assess the need for windbreaks. Heavy trees with large canopies, such as oak trees, rely mainly on their weight to withstand severe winds. Trees with lighter canopies insert roots deeply into the ground to anchor themselves. It is important to use anchoring trees in cyclone areas. Wind carries a “load”. It carries ice particles, sand, dust, bacteria, viruses and seed. Trees with small fine leaves can “trap” the load and deposit the nutrients for their own growth. Because fine-leaved trees are often found on the edges of forests, you will sometimes find that the edge facing the prevailing wind has richer soils than the edge on the leeward side. Typically, in a forest about 60% of the windstream is deflected up and over the trees. The remaining 40% that enters the “edge” or forest closure is absorbed and warms the forest with its energy. Within 100m the wind dies. At this point in the forest the air is clean, warm, still and slightly humid. This is a perfect growing place.

The deflected wind is compressed in a region up to 20 times the height of the tree canopy. If the air is humid, it will be compressed and cooled, and it will rain. The forest edge is essential to the lift of the wind. The species growing on the edge are dense, small-leaved and thick-stemmed, and can withstand the force of the wind. The edge must be kept intact because if it is destroyed the plants in the forest may suffer from windburn and abrasion, and diseases and weeds can enter the forest and destroy its integrity. Trees and temperature Forests can be seen as nature’s air conditioners because they clean the air and modify extremes of humidity and temperature. Trees absorb the sun’s light energy and turn it into chemical energy. If leaves are dark green or reddish in colour, as often found in the tropics, more light as absorbed and local temperatures are reduced. Trees transpire water into the atmosphere as humidity. (one medium-sized elm will transpire 7000 litres of water on a clear day.) this evaporation is accompanied by cooling so that by day it is cooler in and near a forest than it is in unvegetated areas. At night, in humid conditions, water condenses on the leaves and warms the surrounding air. In very dry areas, the evapotranspiration from trees will humidify air which is uncomfortably dry; in very damp areas, water captured by trees dehumidifies the air by absorbing water. Trees and precipitation Where the air stream is very humid (i.e. coasts and islands), air flows rapidly and condenses on leaf surfaces. In these conditions dense rainforests will grow and the condensation from leaf surface can be 80-86% of the total precipitation. Trees pump moisture into the air as they transpire- up to 75% of precipitation is returned to the atmosphere in this way. The Tasmanian Blue Gum, Eucalyptus globulus, which averages about 60 trees to a hectare in a natural mixed forest, pumps 4000 litres/ day. This is a huge return of moisture to the airstreams. The environmental effects of forest removal are dramatic, both in the local area and further field. It has been calculated that as much as 60% of inland water comes from forest transpiration. Hence, forest removal in one area may relate directly to drought in another area.

Forests protect the soil from erosion. In one heavy deluge up to 80 tones/ hectare of soil can be lost from bare earth. In addition, the topsoil and subsoil start to dry out if water runs across the surface and off the land into waterways. Dams and rivers silt up and eventually flood, carrying the valuable topsoil downstream. When it rains……… When it rains over a forest the impact of each rain drop on the soil is reduced and the rain is spread as a film of water, bound by surface tension, over all the leaves of the trees. It is caught in stems and bark, in webs, flowers and insect nests. The amount caught is influenced by the crown thickness and density. For 100% of rain falling, 1015% is caught by the tree canopy, branches and trunks of deciduous trees; more is caught in evergreen trees. This is called interception. The rest of the rain- the throughfall- drifts through the canopy as mist and droplets. It contains organic salts, dust, plant exudates, insect droppings and sheddings. It is nutrient-rich and is directed towards the outer plant canopy (also known as the drip line) and the underlying feeding roots. Before the water reaches the roots however, the organic humus layer of the soil acts like a great water blotter and soaks up 1cm of rain for every 3cm of depth. This moisture is held for later use, when the soil begins to dry out again. In the underlying 40-60cm of soil, the throughfall is filtered into water and air channels, nests and burrows, and is absorbed by soil fungi and bacteria, and of course, the tree roots. This water is first bound by particles of clay and humus and then the excess percolates slowly through the soil. At any time some of this water is valuable to soil organisms and plant roots. Once all this has been accomplished, water starts to flow very slowly to rivers and the sea. And when it does, it is clean.

I/ Vocabulary 1. In paragraph 3, line 1, the word “that” refers to: A. permaculture B. landscapes C. ecosystems 2. In paragraph 6, line 2 , the word “their” refers to: A. trees’ B. leaves’ C. loads’ 3. In paragraph 7, line 3, the word “its” refers to: A. 40% B. forest closure’s C. windstream’s 4. In paragraph 8, line 2, the word “it” refers to: A. tree B. region C. height 5. In paragraph 9, line 4, the word “its” refers to:

D. B & C D. nutrients’ D. forest’s D. air

A. edge’s B. plant’s C. forest’s 6. In paragraph 11, line 1, the word “it” refers to: A. tree B. sun C. light 7. In paragraph 14, line 1, the word “which” refers to: A. areas B. evatranspiration C. air 8. In paragraph 16, line 1, the word “they” refers to: A. trees B. moistures C. air 9. In paragraph 23, line 2, the word “it” refers to: A. rain B. throughfall C. canopy

II/ Comprehension: 1. Can a mature forest be precisely measured or cost? 2. What is the definition of the term “waru”? 3. How can you predict local wind direction and intensity? 4. How can trees withstand severe wind? 5. Are fine-leaved trees benefit? Where can we find them in a forest? 6. What is the perfect growing place? 7. What tree species usually grow on the edge of a forest? 8. Why can forests be seen as nature’s air conditioners? 9. When does air flow rapidly and condense on leaf surface? 10. Can trees pump moisture into the air? When? 11. How can trees help the soil? 12. Which acts like a great water blotter?

D. weed’s D. energy D. trees D. precipitation D. mist

Unit 6:

FOREST AND FLOODING

Under normal conditions, streams establish channels sufficient to carry the water discharged into them. However, prolonged torrential rains and rapidly melting snow can fill streams beyond their capacity. The resulting overflow causes damage to property and in some instance loss of human life. Flood damage usually is correlated with population density along main rivers. Rapid rise of water in headwater streams (tributaries) results in flooding of the main rivers, the destruction of bridges, buildings, and roads, and the deposition of debris on land and in buildings. During our country’s development, large areas of forest were cleared from the water-sheds of rivers such as the Ohio, Mississippi, Missouri, and Columbia river basins, to make way of farming, industry, and urban areas, thus making them more prone to flooding than before, and local and downstream flood control much more difficult. It became necessary to build levees, usually walls of dirt or of sandbag construction, to prevent excess water from spilling ever the banks. Good forest management regulates runoff, which moderates extremes in stream flow in headwater regions and, in turn, helps prevent downstream floods. In this chapter, the science called ecology was defined and various aspects of ecology were touched upon, such as the ecology of forest wildlife, the impacts of human activity upon the environment, possible interaction between climate and the forests supply and forests, and so on. Rainfall removes dust from the atmosphere, provides the water necessary for tree growth, replenishes the underground water table, dissolves nutrient materials in the soil, sometimes creates erosion, fills the river headwater streams, and may result in disastrous floods. Lack of rainfall, wind and barren soil caused the famous Dust Bowl. Forests are affected by climate and in turn produce some effects upon climate. Air and ground temperatures within forests differ somewhat from those outside. Forests affect the speed of air movement. Shelterbelts protect agricultural fields from winds and snowdrifts, while windbreaks protect farmsteads by changing wind direction and reducing wind speed. Ground litter retards flow of rainwater and also serves as a thermal insulator, reducing the rapidity of changes in forest temperature. Excessive conversion of forest land into agricultural fields has contributed to soil erosion, silted streams, and contributed to the need for levees.

I/ Vocabulary A/ Find out the word in the text which means 1. set up (paragraph 1) 2. enough (paragraph 1)

3. lengthened (paragraph 1) 4. over (paragraph 5) 5. a certain area that supplies water for a river or a stream (paragraph 2) 6. causes (paragraph 1) 7. the start of a river or a stream (paragraph 2) 8. control (paragraph 2) 9. fills up again (paragraph 4) 10. too much/ too great (paragraph 5) B/ Put the right word in the blank (use the words in the text) 1. One million dollars is………………………to plant one thousand hectares of forest. (paragraph 1) 2. The………………….…..of this water pump is 500 cubic meters of water per an hour. (paragraph 1) 3. People living in the down region of Mekong river are often threatened with……..... …… . (paragraph 1) 4. Last year, he took part in a………………….management workshop which was organized by FAO in Bangkok. (paragraph 2) 5. Forest……………………..is one of the main causes that lead to floods. (paragraph 1) 6. The presence of forest………………....the flow of streams. (paragraph 2) 7. Rainfalls………………....the underground water table. (paragraph 4) 8. Excessive……………….…..of forest land into agricultural fields is happening in most of developing countries. (paragraph 5) 9. People in the poor countries are killing themselves by……………....their forests. (paragraph 5) 10. The population………………..of America is 365 persons on a square kilometer. (paragraph 1)

II/ Comprehension A/ Fill in the blank with one word from the text 1. Streams…….establish channels sufficient to carry the water discharged into them. A. always C. sometimes B. often D. never 2. Flood damage is usually correlated with the…….. . A. forests along the main rivers B. shelter belts along the main rivers C. population density along the main rivers D. construction along the main rivers 3. ………results in flooding of the main rivers.

A. Storms B. Forest destruction C. Population density in headwater streams area D. Quick increase water in headwater streams 4. Levees can be built with……… . A. cement C. wood B. dirt and sandbags D. bricks 5. Proper rain fall has got……… . A. one advantage C. three advantages B. two advantages D. four advantages 6. Over-raining causes only…….. . A. one disadvantage B. some disadvantages 7. Air and ground temperatures within forests are……… . A. the same as somewhat from those outside B. different from somewhat from those outside C. higher than somewhat from those outside D. lower than somewhat from those outside 8. Shelter belts fights against……… . A. floods C. drought B. storms D. desertification B/ Answer the questions 1. In what condition do streams establish sufficient to carry the water discharged into them? 2. In what condition do rivers and streams cause flood? 3. What can a flood damage? 4. What are the relationships between floods and forest destruction? 5. Can you illustrate the above mentioned relationship? 6. To lessen the impact of flood, what must be done? 7. What are the advantages of proper rain fall? 8. What are the disadvantages of over raining? 9. What can forest do to the climate and vice versa? 10. What are the functions of shelter belts and windbreaks?

III/ Grammar:

Active or Passive Voice

Change the following sentences into passive or active voice a. During our country’s development, people cleared large areas of forests from the water-shed of rivers. b. Rainfall removes dust from the atmosphere.

c. Shelterbelts protect agricultural fields from winds and snowdrifts, speed of air movement. d. After the United States were established, laws with penalties were passed by several states to prevent thoughtless waste of the forest. e. In very early pioneer days, trees were cut down with no thought of replacing them.

FURTHER READING: WINDBREAKS When you design windbreaks you call on your knowledge of how forests function. Well-designed windbreaks modify climate, reduce erosion, and hold water on land. Wind is a fluid, and like water it can be deflected sideways or upwards. It naturally forms into layers with hot air rising and cooler air flowing underneath. You can use the natural characteristics of winds to achieve specific planting effects including: • Suntraps • Firebreaks/ fire-retardants • Increased wind velocity (for energy) • Erosion control • Shelterbelts for stock • Dust filtration • Nutrient traps (wind and water) Every site has a predictable wind pattern. Sometimes you can find this out from weather records; otherwise you will use your observations of how tree shapes are deformed (wind pruned) and the amount of wear on buildings. Every windbreak should be designed to work many ways, and to yield a variety of products such as mulch, bee folder, animal browse, firewood and building timber. It should be noted that a line of pine trees is not an efficient windbreak. Once the lower branches fall off, the wind velocity under the trees is increased. Also, the long black shadows cast by the trees reduce the land’s productivity. How windbreaks work There must be some movement of air through a windbreak or the wind forms into eddies, which can be quite destructive, on the other side of the barrier. The principle is to create the equivalent of the forest “edge” which will lift the wind up and over the area you wish to protect. The wind can then be “shaped” so it tapers off at the ends and wind velocity is reduced. The most effective shape for a windbreak planting is a boomerang or parabola shape. This allows the wind to be diverted around the site. In addition these windbreaks work as suntraps.

How to design your windbreak The design is based on the concept of succession. You start off your windbreak with smaller-growing plants and nurse species which prepare the environment for the final (climax) species.

• • • • •

Plants with the following characteristics should be included in the windbreaks: Hardy species with deep anchoring root systems. Plants with fibrous stems and fleshy leaves- these are more likely to be wind and fire resistant. Plants with fast early growth, i.e pioneer species. Nitrogen-fixing plants. Self-mulching plants, i.e plants which have good leaf fall.

Windbreaks for orchards: Several parabola-shaped windbreaks can be planted in the orchard to protect individual trees or small groups of fruit trees. Windbreaks for small areas: These are very important an need not be permanent. For example, Jerusalem artichokes make an excellent summer windbreak or suntrap in cool climate- they may be just what is required to collect and focus sun on ripening tomatoes. Even knee-high windbreaks, such as small hedges or herbs, can provide protection for plants growing nearby.

Unit 7:

CREATING A NEW STAND

To establish a forest of a desirable kind where it does not at present exist may require three steps: (1) clear-cutting of an existing stand, (2) conditioning of the soil to provide the proper root environment and space in the sun for the desired species, and (3) reproduction by direct seeding of planting. Clear-cutting allows for establishment of new trees without their being influenced by previously existing trees, and the resulting stand will be even-aged. Having a clear-cut site may be unintentional because complete destruction of all or a large portion of a stand may occur naturally from insects, disease, fire, flood, wind, and so on. In the event that brush, weeds, or grass are present on the land to be planted, site preparation of some kind may be desirable to reduce the future competition for sunlight and moisture. Preparing the site for new growth is important. Three steps in site preparation are the following: 1. Control of non-tree plant species that may compete with the future crop or modify its environment. 2. Removal, reduction, or pilling of debris (slash) left after a previous stand of trees has been felled. 3. Preparation of the soil. All these operation may be accomplished through the use of herbicides and heavy machines that both break down dead or living organic material and turn over the soil. The debris left after a logging operation may be physically detrimental to tree reproduction or to the operations required to make and tend a new stand of trees. It may also be a fire hazard, because the small pieces of wood, limbs, and leaves dry quickly and may burn readily. Fires have been used for site preparation, since natural fires have been observed to create good conditions for regeneration and growth of new forests. Forest managers must be careful in using fire. It is not safe in some locations because of fuel conditions or because the terrain is too steep or irregular for proper control of a fire. Mechanical site preparation may be practiced in these cases. Logging operations can also aid in site preparation, because through the use of skidding equipment the log movement can eliminate vegetation and break down the debris left from the felling of the trees.

I/ Find out the word that means: 1. happen (paragraph 1) 2. help (paragraph 4) 3. get rid of 4. make up (paragraph 4) 5. fall (paragraph )

6. harmful (paragraph 3) 7. makes changes in (paragraph 2) 8. part (paragraph 1) 9. scattered broken pieces of wood (paragraph 2) 10. things needed for a purpose (paragraph )

II/ Find out an appropriate word to fill the blank 1. The working…………………of the workers has been much improved. (paragraph 4) 2. The………………..….of the city is very effective. (paragraph ) 3. The logs have been……………………..up. (paragraph ) 4. Thanks to the project funded by UNDP, the tissue culture laboratory has been equipped with some modern…………….…. . (paragraph 4) 5. In Thailand, elephants are used to………….…..the logs. (paragraph ) 6. The erosion has been worse because the hills there are very……………..… . (paragraph ) 7. Forest destruction is very……………..….to the ecological balance. (paragraph 3) 8. A large……………….…of timber of Malaysia is exported to Japan. (paragraph 1) 9. It is very difficult to………………..…the shifting cultivation. (paragraph 2) 10. The reforestation programme of Vietnam has been assisted………………....by FAO. (paragraph )

III/ Comprehension 1. In the establishment of a new forest stand, ……….steps are required. A. two B. three C. four D. five 2. Clear-cutting helps the establishment of new trees………… . A. free from damage caused by insects B. free from destruction by storms C. free from influence of previous existing trees D. easier 3. If the land to be planted has got brush, weeds or grass, site preparation is needed, because this……… . A. makes the land more fertile B. increases the moisture of the land C. decreases the future competition for sunlight and moisture 4. Site preparation goes through……… . A. two steps C. four steps

B. three steps D. five steps 5. The debris left after a logging operation should be put away because they…….. . A. increase the erosion C. give way to forest fire B. give way to insect epidemic D. reduce the moisture of the land 6. On the other stand, fires……..the regeneration and growth of new forests. A. promote B. influence C. limit D. reduce 7. ……..attention should be paid to the use of fire for site preparation. A. Little B. No C. Much D. Some 8. Generally speaking, it may be said that there are……….types of site preparation. A. two B. four C. three D. five

IV/ Comprehension questions 1. How many steps are required in the establishment of a new forest stand? 2. What are the advantages of clear cutting? 3. When is site preparation needed? And why? 4. What are the three steps of site preparation? 5. How are all the operations of site preparation accomplished? 6. Where can fires be used for site preparation? 7. Where should not fires be used for site preparation? 8. Can logging operations promote site preparation? Why? 9. Where should a bedding plow be used?

V/ Grammar 1. Defining or Non-Defining Relative Clauses Look at these: +The water which can be taken up by the plant roots is called the available water. +The amount of water which is then retained by the soil is called the field capacity. The clauses in italics define the kind of water: they are defining relative clauses. +The pore space, which may be filled with air or water or bot, is a network of spaces or channels. +Nitrogenous fertilizers, which have nitrogen as the main food element, strengthen plant tissues.

The clauses in italics gives us additional information about the pore space and fertilizer. They are non-defining relative clauses. They are separated from the rest of the sentences by commas. Use the relative clauses to combine each pair of sentences into a single sentence. In each case say whether the relative clause is defining or non-defining: 1. The amount of water depends on a number of factors. The amount of water is required for irrigation. 2. Soil texture is the characteristic of soil. Soil texture determined by the amount of silt, sand and organic matter. 3. The top soil or the surface soil is a layer about 4-45cm deep. Most of the plant roots are found in the topsoil. 4. A compost is a mixture of partly broken down material. This material is usually made up leaves or grass cutting. 5. Organic matter is broken down most rapidly in warm, moist soils. The soils are well limed and well aerated. 6. The amount of humus formed is greatest from plants. Plants have a lot of strengthening (lignified) tissues (e.g. straw) 7. Fungi attack the aerial parts of the crop, the leaves, stems etc. Fungi can be controlled by means of chemical substances. These chemical substances are known as fungicides. 8. Fertilizers or manure is required for rice cultivation. The quantity of fertilizer or manure depends on the fertility of the soil and the nutrients. The nutrients are released from the rooted weeds and stubble. The weeds and stubble are ploughed in during cultivation. 2. Short-Form Relative Clauses Relative clauses often appear in a shortened form. The relative pronoun and the form of verb to be can be omitted and with, the -ing form of the verb, past participle, adjective or noun may be used instead. Example: Viruses are very small organisms transmitted by means of insects. Rewrite the following sentences using the short form of relative clauses: 1. Fungi are microscopic organisms. These organisms produce tread-like growths. These growths are known as hyphae. 2. Nematodes are small worms in the soil that enter tree roots. They cause serious losses in some crops, particularly in the tropics. 3. The types of disease organisms are fungi and bacteria. They are found in the soil. They attack the roots of trees and they cause root wilt and rot. 4. A soil will contain quite a high proportion of calcium. Such a soil has a pH value of 6.5 or more. 5. A compost is a mixture of partly broken down material. This material is usually made up leaves or grass cutting.

6. Organic matter is broken down most rapidly in warm, moist soil. The soils are well limed and well aerated. 7. The amount of humus formed is greatest from plants. Plants have a lot of strengthening (lignified) tissues (e.g. straw) 8. Fungi attack the aerial parts of the crop, the leaves, stems etc. Fungi can be controlled by means of chemical substances. These chemical substances are known as fungicides.

Unit 8:

DIFFERENT TYPES OF CUTTING

Sometimes trees are cut simply for stand improvement. More often cutting takes place as a harvesting operation, with close attention paid at the same time to stand renewal and improvement. The cutting methods employed in forest management are regarded as a part of silviculture. If proper cutting methodology is employed in the management of a forest stand, reproduction of desirable tree species may be obtained, as well as control of tree density, quality, size, growth rate, and maximization of yield. The number of years between the establishment of a crop or stand of trees and its final cutting at a specified stage of maturity is known as the rotation period of tree growth. This number of years will vary widely for various species and locations, and will depend upon many factors. Clear-cutting: As a method of harvesting, clear-cutting has some advantages. Today, wood chips and pulpwood are often so valuable that everything cut can be sold, removal from site simplified, and an excellent stage is set for stand removal. Adequate reproduction may be obtained by beginning the harvest at about the time seed fall begins in a good seed year. However, the most certain way to obtain reproduction is to plant a desired species after cutting. Site preparation often is necessary for the establishment of desirable reproduction. Seed- tree cutting: Scattered groups or individual trees are left standing in the cut-over area to provide seed. Even-aged stands result from this style of harvesting. The seed trees should be carefully selected to be the best of the stand and be well distributed over the cut area. Site preparation is often necessary before and after cutting to ensure adequate reproduction. Shelter-wood cutting: The mature stand is cut in a series of two or three partial cuttings, which provide spaces for reproduction. Fairly even-aged stands result from this procedure. In southern pine, prescribed burning as site preparation often is necessary prior to cutting to ensure establishment of reproduction. Selective cutting: Selective cutting is the annual or periodic removal of trees, particularly the mature individuals or small groups from an uneven-aged stand, in order to get a better yield. The oldest and largest trees are removed periodically, with reproduction becoming established in the openings made by these cuttings. A modification of this method is group selection, where groups of trees are cut, providing large openings and more light. The forest as a whole is divided into nearly equal parts, and an individual part is selectively cut each year in a cutting cycle. Site preparation is not often practical when the selection method is employed.

Coppice cutting with standards: Some high-quality trees (standards) whose origins were from seeds are standing while the remainder of the stand is cut, and reproduction is obtained through sprouts from the stumps. The standards protect the site and produce high-value products. The standards are preserved for at least two coppice rotations. This system, of course, only works with species and ages capable of producing vigorous coppice sprouts. Seedlings and saplings have problems in growing because of trees that grow above them. This may require a cleaning operation, removal of undesired species or poorly formed individuals of a desired species. Such cuttings are made in the sapling stage or younger. Stand improvement is the phrase employed if the stand of trees is older. Liberation cutting is the removal of undesirable older, larger trees that have been left from the preceding stand and may be overtopping the desirable trees. Liberation cutting normally results in financial cost, but if the large trees are salable, these cuts may yield a return. Pruning is another intermediate operation, not often practiced in forests. It is the altering of the form of specific trees, rather than their complete removal. These cuttings are made in an immature stand to increase the quality of production. For example, improvement of stem wood is attained by cutting all the lower branches of trees so that more clear or knot-free lumber is produced. Christmas-trees shaping is achieved by cutting off branch ends. Salvage cutting is performed when trees have been killed or damaged by insects, fires, disease, or other natural disaster. Such trees are removed to recover some of the loss and to possibly forestall outbreak of an epidemic. Thinning or forest density control is the most used of intermediate silviculture operations. Thinning is the adjustment of numbers of trees in a particular stand in order to concentrate the growth capability of the land on the remaining trees so that they may grow strong and tall and will be more valuable. The removed trees usually are not in a dominant position in the stand. Thus, thinning may result in the harvest of some trees that would be lost because of inadequate soil, water, and sun. Low thinning is removal of the smaller individual trees, which leaves the larger ones more room. Crown thinning is freeing the crowns of the best and biggest trees. Pre-commercial thinning is the cutting of trees too small to be marketable. After thinning operations are completed, the remaining trees are in optimum condition to make use of additional nutrients and crown space. Aerial fertilization is employed by forestry firms to supply the nutrients needed for faster growth. The kind of nutrient to use, whether it be nitrogen, phosphorus, or some other chemical elements, is indicated by soil tests on the areas concerned.

I/ Vocabulary A/ Find out words or combination of words that means 1. considered (paragraph 1) 2. conserve (paragraph 7) 3. choose (paragraph 4) 4. rather (paragraph 5) 5. point out (paragraph 13) 6. complete ( 7. appropriate (paragraph 1) 8. make something simpler, easier… (paragraph 3) 9. making the space between trees wider (paragraph 12) 10. get back to the former position properly (paragraph 11) B/ Find an appropriate word to fill in the blank 1. The inflation has been…………….……as the root cause of the economic crisis. 2. This new kind of eucalyptus has got the…………….…..……period of 7 years. (paragraph 2) 3. I shall have to………….………..this new shirt, because it is too long for me. (paragraph 3) 4. Producing a seedling require different…………………..…. . (paragraph 8) 5. His speech at the meeting…………………clearly his point of view. (paragraph 11) 6. Thanks to the new kind of medicine, he soon……………..…..from his illness. 7. That new forest stand should be………….…….as soon as possible. 8. It is vital task for us to……………..….the natural forests. (paragraph 7) 9. In some countries, …………….….fertilization has been introduced. (paragraph 13) 10. These…………..…are to be transported to the paper mill. (paragraph 3)

II/ Comprehension A/ Choose A, B, C or D 1. According to the text, there are………types of cutting. A. three B. four C. six D. five 2. The length of rotation-period is determined by……… . A. four factors C. species and locations B. two factors D. many factors 3. Clear-cutting has………… . A. many advantages C. some advantages

B. some disadvantages D. four advantages 4. Clear-cutting often leads to………. . A. soil erosion C. ecological imbalance B. air pollution D. establishment of new desirable species 5. Seed-tree cutting does not touch…………. . A. matured trees C. parents-trees B. shrubs D. vines 6. Within a mature stand, shelter cutting is done……….. . A. once C. four times B. twice or three times D. many times 7. Shelter wood cutting is done to……………….. . A. soft wood stands C. even-aged stands B. hard wood stands D. all-aged stands 8. Selective cutting is employed with…………. . A. shrubs B. mature individuals or small groups from an even aged stand C. vines D. mature trees in an uneven-aged stands 9. Selective cutting is done……………. . A. four times a year C. annually or periodically B. once a month D. twice a year 10. Coppice cutting results in…………….. . A. the establishment of a new stand by planting seedlings B. survival of immature trees C. reproduction through sprouts from the stumps D. survival of some high-quality trees 11. Improvement cutting involves…………..of cutting. A. two types B. four types C. many types D. some types 12. Thinning is carried out in…………….. . A. four forms B. three forms C. two forms D. five forms B/ Comprehension questions: 1. What are the cutting forms regarded as? 2. What may be achieved if proper cutting methodology is employed? 3. What is the rotation period of tree growth? 4. What are the advantages of clear-cutting? 5. What is the purpose of seed tree cutting? 6. What should be done to seed trees? 7. What is the aim of shelter wood cutting? 8. What is the purpose of selective cutting? 9. When is selective cutting done to groups of trees? What must be done? 10. What is the objective of coppice-cutting?

11. How long are the standard trees preserved? 12. Why is cleaning operation necessary for the development of seedlings and saplings? 13. What is stand improvement? 14. What is liberation cutting? 15. What is pruning? 16. What is salvage cutting? 17. What is thinning? 18. What is the result of the completion of thinning?

Unit 9:

FOREST MEASUREMENTS DEFINED

Forest measurement or mensuration is concerned with making evaluations and estimates that are required in the management of forest land and in connection with all the products and services derived from such land. Forest measurements are mathematical in nature, being concerned with numerical values obtained from use of instruments or by estimation. Forest measurement has to do with the ages, diameters, heights, volumes, rates of growth and land areas of standing timber. It has to do with the volumes and growth of logs, pulpwood, fuel wood, chips and single species, such as posts, poles, pilling, mine props and railroad crossties. The most recent aspect is the measurement for possible use of all the plant material on the site (biomass). It also encompasses surveying or measurement of land on which forests grow. Forest mensuration as a science perceives the forest as a dynamic community that can lose by damage, is reduced by harvest, and gains by growth. Thus it is an element in maximizing multiple use of forest land. Measurement plays a significant role in the management of a forested area, with the intent to achieve such objectives as the production of more wood, forage, game animals, water or recreational benefits. Periodic inventories of forested land are required for determining amounts and quality of wood available for yearly use, for tax records, and for justifying management expenditures. The saw-timber, pulp, and plywood industries have become more adapt at using various qualities for different products, hence log weighing has become a common practice. In brief, measurement is a strategic part of forest management and consists of the following specific works: 1. Measurement of tree diameter 2. Measurement of tree height 3. Measurement of tree age growth rate 4. Measurement of timber stand volume

I/ Vocabulary A/ Find out the word that means: 1. exact (paragraph 3) 2. assessment (paragraph 1) 3. spending (paragraph 3) 4. the link between (paragraph 1) 5. rise (paragraph 2) 6. take a general view of (paragraph 2) 7. find the size, extent, volume of something… (paragraph 8. show that somebody or something is right (paragraph 3)

9. the width of the stem of a tree (paragraph 2) B/ Find the word from the text to fill in the blank: 1. It is not an easy work to give out accurate……………….…..of timber stand volume. (paragraph 1) 2. He can play four musical…………….. . (paragraph 1) 3. Before the start of the project, there should be a careful field…………..….. . (paragraph ) 4. The project…………….4 steps. (paragraph 3) 5. They are being given instructions on how to use……………….to measure tree diameters. (paragraph ) 6. His speech has…………….…clearly his work. (paragraph ) 7. To reduce the cost of the product, management must be considered………..….. . (paragraph ) 8. The problem of forest protection should be put in…………..……with other problems. (paragraph 1) 9. Eucalyptus has a very high…………….…….of growth. (paragraph 2) 10. According to his proposal, the social……………..….of the problem should be solved first. (paragraph 2)

II/ Comprehension A/ Multiple-choice 1. Forest measurements involves………………of measurements. A. two types C. four types B. three types D. five types 2. Forest measurements have to do with……………. . A. two objects C. four objects B. three objects D. six objects 3. Forest is a………………community. A. stable C. complex and changeable B. simple D. tree 4. Measurements are……….the management of a forested area. A. useless C. determined by B. very important to D. free from 5. Periodic inventories of forested land are very necessary for determining………. . A. four problems C. three problems B. five problems D. two problems 6. Tree diameters are measured by one of the…….dendrometers.

A. two C. three B. four D. five 7. Age and diameter growth rate of standing timber are estimated by…………… . A. tree caliper D. optical devices B. Biltmore stick. E. trigonometry C. increment borer 8. It is………………to give out an accurate forest measurement. A. easy C. rather difficult B. very difficult D. terribly difficult B/ Comprehension questions 1. What is forest measurement concerned with? 2. What are forest measurements like? 3. What does forest measurement have to do with? 4. What is the latest aspect of forest measurements? 5. What does forest mensuration perceive the forests as? 6. Why is the forest a dynamic community? 7. What are the objectives of new forest management? 8. Why log weighting has become a common practice? 9. How is biomass production measured? 10. By what devices are tree diameters measured? 11. By what ways are tree heights measured? 12. How is the age of a felled tree determined? 13. How are age, diameter and growth rate of standing timber found?

Unit 10:

FOREST HARVESTING

A correctly managed forest has its crop harvested when it is economically and biologically ripe, through a series of planned operations. Logging is the term commonly employed in referring to the harvesting of timber. This activity may include felling, limbing, bucking and transportation to saw mills or other processing plants. When a timber harvest is going to take place, a logging plan usually is prepared. These plants may include a description of the location of the place to be logged, design of a road system for removal, and methods of harvesting considered best economically and ecologically. The logging plan is also involved with factors that include soil conditions, slopes, overall wildlife requirements and visual effects. Buffer strips in which no cutting is to take place often are left along streams and generally along roads. These provide escape cover, den trees and food for wildlife. Undisturbed strip along flooding streams prevent siltation by serving as silt screens or filters or supply shade that keeps the water cool for fish. Buffer strips also maintain visual quality along streams and highways. The logging plan should identify the intended market, the approximate number of hours required for felling, bucking, loading and transportation and the personnel assignment for various jobs involved. The plan is also concerned with the requirement needed maintenance of the equipment, what alternate plan to use of the equipment fails and a very important factor, the safety precautions to be taken for the people on the job. The logging plan should also describe the follow-up work (contract agreements) needed on the harvest site to reduce erosion after harvesting; the logging foreman should have a thorough understanding of the costs of these operations. His responsibility includes supervision and direction of all phases of work so that it will move smoothly and the costs be minimized. Co-ordination of these numerous and varied operations requires specialized skill. Nowadays different methods of felling of trees are being employed. They are: manual felling of trees mechanical felling of trees The chance of each method is dependent on specific conditions of the harvesting sites. The felling is followed by the following works such as: skidding from stump to landing loading and transportation of logs measuring the raw product Last but not least, living conditions for loggers must be considered carefully.

I/ Vocabulary A/ Find out the word that means: 1. matured and ready to be harvested (paragraph 1) 2. an angle less than 900 to the earth’s surface (paragraph 3) 3. processes (paragraph ) 4. profound (paragraph 4) 5. targeted (paragraph 4) 6. by hands (paragraph 5) 7. by machines (paragraph 5) 8. the concentration camp of logs (paragraph ) 9. useless (paragraph ) 10. things needed for a purpose (paragraph ) B/ Find out an appropriate word to fill the blank: 1. It is reported that Mrs. Andersen has been…………………..to work as prime minister. (paragraph 4) 2. Look! That orange is……………….. . (paragraph 1) 3. …………..……….aids should be used in teaching. (paragraph 3) 4. In factory……………….of machines is carried out once a month. 5. The deforestation has caused……………….in the down streams indirectly. 6. Thanks to the assistance of FAO, modern……………..….for training and research have been purchased. (paragraph 4) 7. In harvesting of tree crops, much attention must be paid to………..….. . 8. Harvesting of tree crops consists of different……………..….of work. 9. Trees can be felled manually or……………….. . 10. The distance between the harvesting site to the logs ………….…..site is 6km long.

II/ Comprehension A/ Multiple-choice 1. Logging may include………….. . A. two B. three C. four D. many 2. The logging plan is prepared…………. . A. at the same time with harvesting operations B. after the harvesting C. before the harvesting D. a month before the harvesting 3. The logging plan is concerned with……….problems.

A. six B. four C. many D. seven 4. Because of………..reasons, forest areas along the streams and roads are left uncut. A. two B. three C. four D. many 5. On the other hand, logging plan should keep close touch with……….problems. A. seven B. many C. ten D. six 6. Coordination of the different phrases of harvesting work is……….. . A. important B. easy C. difficult D. time-consuming 7. The……..must be sure of the costs of these operations. (harvesting) A. loggers B. foreman C. foresters D. drivers 8. A tree can be felled by………..ways. A. two B. three C. four D. five 9. The felling is followed by…………… . A. planting seedlings C. four works B. three more works D. two works 10. To harvest a mature forest, there should be……………. . A. only one plan C. five plans B. ten plans D. more than one plan B/ Reading comprehension 1. When is a forest harvested? 2. What is the term “logging”? 3. How many works does “logging” include? 4. What does a logging plan comprise of? 5. What factors is the logging plan involved in? 6. Where are buffer strips situated? 7. Why are buffer strips left uncut? 8. What should a logging plan identify? 9. What should a foreman have? 10. What are his responsibilities and skills? 11. How can a tree be felled? 12. Why must the living conditions for loggers be considered carefully?

Unit 11:

FOREST TREE INSECTS AND HOW TO CONTROL THEM

Insects that can injure or if not kept under control destroy stands of trees exist in eight classes, as follow: 1. The defoliators 2. Wood borers 3. Sucking insects 4. Gall makers 5. Bark beetles 6. Terminal feeders 7. Root feeders 8. Seed insects Bark beetles are the most destructive of all forest insects, even though they are quite small. However, insects can be controlled in different ways. Natural control of injurious insects takes place through climatic conditions, parasites, predators, disease, rodents and birds. Rearing parasites and predators and releasing them in a region of insects’ outbreak is called biological control. Nature produces insect mortality by means of high and low temperatures and through extreme drought and moisture. Through special methods of log piling and brush disposal, people can also help nature control insects. Special forest practices and in rare case the use of insecticides are two forms of insect control. Insect damage can be prevented to some extent by proper management and silviculture practices. It is difficult to use and apply insecticides under normal forest conditions, but spraying from low-flying planes seems to be an effective practice in the few situations where controls are possible and the benefits justify the cost. Most of the damages from insects take place during the insects’ growth (developing) period and some species produce several generations a year. Most insects have a life cycle that includes metaphoric or complete transformation in form between the juvenile and adult stages. For example, a caterpillar becomes a butterfly. For one group of insects, the eggs hatch into larvae, developing into caterpillars that feed on trees. The caterpillars when fully developed go through a resting age during which they

form cocoons and change into pupae. After a period of being pupae, they undergo metamorphic and become adult. Where defoliator insects are epidemic, the forest appears to look brownish and unnatural at a distance. Large quantities of insect droppings on the ground are a good indication that insects are at work. Boring insects can be found where a fine wood powder called frass is seen at the base of the tree. Where there is tip-moth damage, new growing leaders bend and shrivel up or turn reddish brown and die. The natural elements play a big part in helping trees fight off insect attacks. A good freeze, for example, can help. On the other hand, a tree’s resistance to bark-beetle attack is lowered by drought. Then, too, a flood or excess rain can weaken trees just as insect attack does.

I/ Vocabulary A/ Find out the word that means: 1. destroy 2. chemicals that are used to kill insects 3. fighting against 4. insects that feed on leaves of trees 5. insects that eat the outside layer of the stem 6. the beginning 7. the larva of a butterfly 8. the young insect 9. the thing where the eggs change into caterpillars 10. the illus at butterfly B/ Find out an appropriate word to fill the blank 1. The……………..…are the insects that feed on the leaves of coniferous and deciduous trees. 2. The heart-wood of this log has been badly damaged by the ……………….. . 3. Look! The buds and shoots of this tree are being destroyed by……………….…. . 4. He has found out an effective…………………...control of pine caterpillar. 5. Nature causes………….….to insects by means of high and low temperatures and through extreme drought or moisture. 6. Under normal forest conditions it is not easy to use and apply……………..….. . 7. The developing period of the insects causes most of the………………………to the tree.

8. After a period of being pupae, caterpillars undergo………………and become adults. 9. The defoliator insects make the forest…………………………and unnatural at a distance. 10. ……………….…..can be used to determine the appearance of boring insects.

II/ Comprehension A/ Multiple-choice 1. Insects can be classified into……….groups. A. four B. six C. eight D. seven 2. ……..destroy the tips of the twigs, buds and shoots. A. The defoliators C. Sucking insects B. Gall makers D. Terminal feeders 3. There are……..ways of controlling of insects. A. three B. two C. four D. five 4. Insects are……….used to control insects. A. rarely B. often C. usually D. always 5. Spraying from low-lying planes are……….effective. A. always B. often C. sometimes D. usually 6. Some insects regenerate…………. . A. twice a year C. several times a year B. once a year D. four times a year 7. Proper management and silvicultural practices can…………………..….forests from insect damage. 8. Under normal condition, it is …………………….……to use and apply insecticides. 9. Most of the destruction from insects happens during………………………………. . 10. The forest looks…………………………where defoliator insects are epidemic. 11. Frass seen as the base of the tree can be used to determine the existence of………… ……… . 12. The complete transformation in form between the juvenile and adult stages is called………………..……. . B/ Reading comprehension 1. What can insects do to the trees? 2. What are the names of different types of insects? 3. Which insects are the most destructive? 4. What are the different ways of insect control? 5. How does the natural control take place?

6. How is the biological control carried out? 7. How does the nature kill insects? 8. Where and when should spraying insecticides from low-flying planes be used? 9. When does most of the damage from insects take place? 10. What do most species of insects have? 11. What does a life cycle include? 12. When fully developed, what do caterpillars do? 13. After a period of being pupae, what do caterpillars do? 14. When a forest is being attacked by defoliators’ insects, what can be seen on the ground? 15. What appear where there is tip-moth damage? 16. What do the natural elements help the trees? Give example.

III/ Grammar Comparative Sentences E.g. a) Particles of fine sand are coarser than particles of clay. = Particles of clay are not as coarse as particles of fine sand. b) Transported soils are more common than sedentary soil in humid regions. = Sedentary soils are less common than transported soils in humid regions. Exercise 1 : Complete these sentences. Use the comparative of the words in parentheses (……) + than 1. Sorry I’m late. It took me …………………………. to get here ……….………… I expected. (long) 2. My toothache is …………………. it was yesterday. (painful) 3. She looks about 20, but in fact she’s much …………………………….. she looks. (old) 4. The problem is not so complicated. It’s ……………………………. you think. (simple) 5. Your English has improved. You speak a lot ……………………… you did when we were last met. (fluently) 6. Health and happiness are ………………….………. money. (important) 7. We always go camping when we go on vacation. It’s much ………………..… ….. staying in a hotel. (cheap) 8. I like the country. It’s ……………..……and ……………….…living in the city. (healthy/ peaceful)

Exercise 2: Write sentences with the ….. the. Choose a half sentence from box A to go with a half from box B the earlier we leave the longer he waited the more I got to know him the more you practice your English the longer the telephone call the more goods you sell

the faster you’ll learn the more you have to pay the sooner we’ll arrive the more profit you’ll make the more impatient he became the more I like him

Exercise 3: Use the following verbs in the correct form to complete the paragraph below: Carry, be help, perforate, carry, be , not lignify, usually find, form, thicken, make , know The movement of materials through the plant ..................... as translocation. The xylem or wood vessels which ........................ the water or mineral salts from the root to the leaves ...................... tube. These tubes ........................ from dead cells. The cross walls of the cell have disappeared and the longitudinal walls ........................... with lignum. These ....................... wood. The tubes ................... to strengthen the stem. The phloem tubes ....................... organic material through the plant. These vessels ….............. chains of living cells which ....................... . They have cross walls which ............................. - hence the alternative name, sieve tubes. In the stem the xylem and phloem tubes ...................... in a ring near the outside of the stem.

FURTHER READING: TREE

DISEASES

A. READING & COMPREHENSION I. Reading text Trees, like people, are vulnerable to many diseases. Like people, trees are attacked in various places by different kinds of diseases. Forest pathology is the study of diseases of trees. Some foes work on the main body trunk, some on the roots, and some on the leaves. Vigorous trees are attacked less by diseases. The older, weak trees or young seedlings that are struggling to become established trees are the most susceptible. If a forest is managed correctly, seldom will disease be serious enough to require overt control. Well-managed forests are healthy and comparatively devoid of disease. Tree diseases are of two main types: nonparasitic and parasitic, often called environmental and organic. The nonparasitic diseases are caused by drought, sunscald, winter injury as from heavy ice storm and snow, improper nutrition of the trees, air pollution by smoke and gases, flooding, and soil pollution. The salt laid on the highways during winter months pollutes the nearby soil and in some instances kills trees. Ocean spray, which feels so good on one’s face, is a prime cause of disease in the coastal area. This sea spray can be blown inland by hurricanes and result in tree damage far from the coast. The parasitic diseases are caused by organisms that live within various parts of nutrients from it while contributing nothing to the well-being of the tree. There are five groups of such organisms: viruses, bacteria, nematodes, mistletoes, and fungi. Viruses cause minor gall, a condition known as witches-broom, and the serious phloem necrosis in elms and locusts. A number of bacteria that are involved in many serious diseases of agricultural plants are of little importance in forest trees. Nematodes, a group of parasitic worms, can be a problem for tree seedlings. Mistletoes, parasitic seed-bearing plants, are widespread and cause serious damage, the dwarf mistletoes of the West in particular. The most important cause of tree disease are the parasitic fungi. Saprophytic fungi decay dead tree and are important in the recycling of nutrients within the forest ecosystem. The parasitic fungi attack living trees and are serious problems in all forest regions. Considerably more timber is lost annually to fungal disease than is lost to fire. The life cycle of a typical fungus consists of two basic stages, the vegetative and the reproductive. The vegetative stage begins with the germination of a spore, the fugal equivalent of a seed. Out of the spore grown a microscopically fine hollow filament called a hypha, which penetrates into wood or foliage and grows very rapidly,

branching and rebranching to produce a gossamer, interwoven network known as a mycelium. These mycelia dissolve the tree’s cell walls and convert them and the contents of the cell into food. The second stage is the reproductive stage in which hyphae grow to the surface and produce fruiting bodies, which split and release spores to be carried away by the wind. The form, texture, colour, and location of these fruiting bodies are how most fungi are recognized. Familiar examples are mushrooms and conks. For convenience the fungal diseases can be sorted into three large groups: the foliage diseases, the stem diseases, and the rotting diseases. Although widespread and of great importance in horticulture, foliage diseases are problems in forest trees only in that they can reduce the rate of growth of the infected trees. Stem diseases can in turn be broken into three groups, the cankers, the rusts, and the wilts. Among these are the epidemic diseases, which can result in rapid and widespread loss of forest trees. The chestnut blight is an example of a stem canker diseases. The American chestnut once was one of the most important and useful eastern trees. Very widespread, it often accounted for as much as one half of the trees in many forest stands. The fungus was introduced into New York probably prior to 1900 on imported Chinese chestnuts, and the native species had no resistance. The windblown spores from an infected tree could travel great distances to enter tiny cracks or breaks in the bark of other chestnuts. The stem is killed by girdling as the cambium is destroyed. By 1950 a living noninfected chestnut tree was a rarity. Today the American chestnut is no longer a viable species. The potential threat of similar epidemics of exotic disease to other native species is source of anxiety for many foresters. The Dutch elm disease is an example of the wilt disease. This fungus, probably native to the Orient, was introduced into this country from Europe around 1930. The disease is spread by the elm bark beetle, which upon emerging from an effected tree is covered with spores. When the insect burrows under the bark of an uninfected tree, it is effectively inoculated. The fungus grows rapidly within the vascular tissue of the elm, and death is caused by physical blocking of the movement of moisture and nutrients to the foliage and perhaps by the production of a poison that kills living cells. The spread of this disease has been rapid. Many feel that the future of elms, particularly in the northern sates, is in jeopardy. There are a number of serious ruts of fruit trees. White pine blister rust and the fusiform rusts of the southern pines are the most important. These rusts have an unusual and complex life cycle involving the infection of two widely different species of plants known as alternate hosts and the production of more than one type of spore. The fungus moves from one host, species A, to a second host, species B, and then back to species A again.

White pine blister rust, another disease introduced from Europe, is and extremely destructive disease of eastern and western white pines and of sugar pine of California and Oregan. Simply put, the disease is spread by the movement of spores from infected currant or gooseberry bushes to the needles of the pines. The fungus moves from the needles into the phloem and cambium of limbs and stem. The name is from the orangeyellow spore- filled blisters formed on the bark. Whenever infection reaches the main stem the tree is doomed, for destruction of phloem continues until the stem, no matter how large, is girdled. Infection can be severe and often entire stands are killed. The southern fusiform rust, which infects a number of the southern pines, has as its alternate host any of the numerous red oak species of the region. While not as destructive as the white pine blister rust, this disease is of increasing concern to forest managers. It is most virulent on loblolly pine, which is being intensively managed with costly site preparation and fertilization. The rotting fungi, while they rarely cause death directly, are responsible for rendering great volumes of wood worthless. There are two major types, the rootdecaying fungi and the heart-rotting fungi. The Fomes root rots typify the first category. Though they attack a variety of species, they are most troublesome in eastern white pine and in plantations of the southern pines. Working in the roots and butt of the tree, they weaken the tree, making it susceptible to windthrow, and reduce its growth. The heart-rotting fungi destroy the nonliving heart wood of the tree and, aside from leaving it mechanically weaker, do not otherwise influence its health and vigor. The rotten wood of course valueless. Spores of the heart-rotting must enter through breaks in the bark. Once they have germinated, the disease develops very slowly, and rot is rarely a problem in young stands. In the oldgrowth conifer forests of the West, a 50 to 60 percent loss of volume to rot is not common. II. Comprehension questions 1.What are trees vulnerable to? 2. What does “ Forest pathology “ study? 3. What parts of a tree can be attacked by different diseases? 4. Which trees are the most susceptible to diseases? 5. What are the two main types of tree diseases? 6. What are the non-parasitic diseases caused by? 7. By how many agent are the parasitic diseases caused by? 8. How do organisms destroy the trees? 9. How are the organisms classified? 10. What does each type of organisms damage? 11. Which fungi are the most important cause of tree diseases? 12. What do parasitic fungi attack? 13. What are the two basis stages in the life cycle of typical fungus? 14. What are the characteristics of each stage? 15. What are the 3 large groups of the fungal diseases?

16. What are the 3 groups of stem diseases? 17. What is the life cycle of the rusts like? 18. How do these rusts regenerate and develop? 19. Which fungi make great volumes of wood worthless? 20. What are the two types of rooting fungi? 21. What do root-decaying fungi attack and cause? 22. What do heart- rotting fungi destroy? 23. How do spores of the heart-rotting fungi enter the heart wood? III. Vocabulary 1. Find out the word that means a. the science that studies forest tree diseases b. can be attacked c. strong d. easily affected by …… e. enters f. without g. taking place h. single cell by which a fungus reproduces itself i. all j. main 2. Find out an appropriate word to fill the blank a. These houses are ……. ………. to storm b. Next term, we will study forest ………………..…… . c. The ……………..…. diseases are caused by organisms. d. ………………….. often destruct seedlings. e. …………………. fungi help the recycling of nutrients within the forest ecosystem. f. The vegetative stage of the life cycle of a typical fungus starts with the ………… ……of a spore. g. The rotting fungi …………..…… great volumes of wood worthless. h. The pain in his leg has been ………………………. . i. Due to over forest exploitation for export, several valuable tree species are in danger of ………………….. j. His speech ……………………… the thinking of the young generation.

B. EXERCISE I. Checking your understanding 1. As a matter of fact, there are ………..…….. tree diseases. A. four B. some C. a lot of D. six 2. ………….... can be attacked by different kinds of diseases. A. Only the trunk B. Only the leaves C. Only the roots D. All the parts of a tree 3. Trees diseases fall in …………..…….. classes. A. three B. two C. four D. five 4. Organisms that cause the parasitic diseases are of ………..……. Types. A. four B. two C. three D. five 5. The life of a fungus undergoes …………………. periods. A. four B. two C. three D. five 6. …………. rendered great volumes of wood worthless. A. The foliage fungi B. The stem fungi C. The rotting fungi D. None are correct 7. Rooting fungi can be sorted in ………………….……. . A. three major groups B. two major groups C. four major groups D. five major groups 8. Heart-rotting fungi usually attack ………………..…. . A. young stands B. primitive forests C. old stands D. pine stands 9. The most important cause of tree diseases are: A. fungi & viruses B. bacteria & nematodes C. mistletoes D. All of these are correct 2. Reading text Read the text carefully and answer the following questions: For hundreds of years people have planted trees to serve the needs of future generations for timber and tree products. In Europe and Asia forests were planted by rulers, church leaders and farmers – for the people. By planting trees they particularly and symbolically showed faith and hope for the future. Trees are fundamental to life and the processes that maintain healthy soil, and clean air and water. There is evidence which shows that in regions where the trees are cleared to less than 30% of their original surface area, other sustainable life processes begin to collapse. Rivers silt up, soils wash away, and air quality declines. James Lovelock, a renowned ecologist, claimed these breakdowns in natural systems will in

turn affect other word bio-areas continent or cyclones may occur more frequently. It will be sad if these things happen before we change from consumers to producers. 1. What do people plant trees for? 2. What do European and Asian people want to show by planting trees? 3. What are fundamental roles of trees? 4. What will happen to the area when the trees are cut down?

Unit 12:

PREVENTION AND CONTROL OF WILDFIRES Prevention of wildfires and suppression of those that do get started are the objectives of fire-control planning. Since nine out of ten wildfires are caused by the activities or carelessness of people, attempts at prevention are worth making. Fires caused by people have been reduced greatly by closing forests to hunters and campers during extremely dry seasons, stopping logging operations during hazardous periods, requiring permits for any types of burning operation, stringent enforcement of state laws against arson, and constantly using public safety advertisements with specific emphasis on caution about the use of fire in forests. In prevention activities, the causes of fires are analyzed and a major plan is designed to provide prompt fire detection and prompt suppression. Detection of a fire a forest in its early stages, before major destruction can take place, is a very significant part of fire management. Use of the fire tower for spotting fires in their early stages has been of great value in this country. Large maps are employed in reporting exact locations of fires to those who fight them. The maps are marked with circles centered upon the locations of fire towers or their points of observation. When a lookout spots smoke, he or she sights an alidade at it and determines the azimuth bearing (the angular direction with respect to north), estimates the distance of the source of smoke from the station, and notes any landmarks. This information is telephoned to the district ranger or central dispatcher, who obtains similar data from other lookouts. He or she then plots the azimuth bearings on a map. The location of the fire is indicated where the lines on sight from the various points of observation intersect. This process is called triangulation. The dispatcher is then able to send off suppression crews with information on the location and size of the fire, type of fuel, and how quickly the fire is spreading. Many states in the Pacific Northwest and Canada have replaced many of their lookout towers by fire watch patrol planes. These planes, flying a precise and routine pattern, can cover vast areas and can give more specific details about fires that are located. However, coverage cannot be as continuous as it is form a tower, and in uniform terrain the ability of the pilot to be precise is less than that of the system of triangulation. Hence, where speed of reaction is most critical, in the Southeast and in California, planes are employed to supplement but not replace the towers. While smoke is the first sign of a fire, observed smoke does not necessarily indicate a wildfire; it may be just a campfire of the burning of rubbish. Where lightning-caused fires are the principal problem, air patrols are most effective. When an

existing fire has produced haze and smoke blankets through which ground patrols cannot see, air patrols are especially useful. A new method for spotting a wildfire employs infrared detection. This has the ability to recognize the presence of a fire by the heat emitted by fire, rather than from seeing its flames or smoke. This works well when the fire cannot be seen because of smoke. The infrared method also can measure the size of a fire and help determine its speed of spreading. It may also show the position of rivers, roads, and other landscape points through temperature differences and thus help show the best way to get to the fire area. Another type or remote sensing is radar, which is especially useful in tracking lightning storms. The U. S weather bureau employs radar to track cumulo-nimbus cloud formations, which are associated with thunderstorms. Pulses of micro-wave energy in narrow beams are reflected by a target such as a cloud formation. From the time that a fire is first discovered to the time control actions can be applied, four events must happen: discovery of the fire; report of its presence and location; getaway of fire-fighting personnel; and travel to get to the fire. The time required for each of these steps needs to be made as brief as possible.

I/ Vocabulary A/ Find out the word or combinations of words that means: 1. aims 6. to find out 2. implementation 7. short 3. damage 8. situated 4. detecting 9. without stops 5. exact 10. visible part of a fire B/ Find out an appropriate word to fill the blank 1. ………………….….is better than cure. 2. ……………….…..forests to hunters and campers may reduce fires in dry seasons. 3. All the data have been carefully…………….……….. . 4. To spot forest fires in time, a fire……………………has just been put up on that kili. 5. The…………….…..crew consists of 15 firemen. 6. Canada has used………………..……to detect forest fires. 7. Our paper is being…………….…………. . 8. The stolen car was…………….……in the forest 100 kilometers west of the city. 9. Due to the fires in the petrol pump, the sky has been covered with a……………… of smoke.

10. He is a specialist in remote……………..……. .

II/ Comprehension A/ Multiple-choice 1. ……………………wildfires are caused by the activities or carelessness of people. A. Seven ninths B. Eight ninths C. Nine tenths D. One third 2. Reduction of fire may be achieved through taking……………………measures. A. three B. four C. five D. six 3. To report exact locations of fires, …………………..are used. A. telephones B. radios C. cameras D. large maps 4. Some countries have used…………………………to detect forest fires. A. spaceships B. jetfighters C. patrol planes D. balloons 5. The patrol planes fly……………….……. . A. one after another C. in a cross-line B. one above another D. at the same speed 6. Air patrols are most effective……………………….. . A. in uniform terrains B. in dry season C. in the night time D. where lightning-caused fires are the principal problem 7. Infrared detection is a……………….……method for spotting a wildfire. A. effective B. new C. time-consuming D. old 8. The size and speed is spreading of a fire can be measured by……………………… . A. fire towers B. foresters C. patrol planes D. infrared method 9. To spot lightning storms, ……………..…….should be employed. A. fire towers B. patrol planes C. radar D. spaceships 10. From the time that a fire is discovered to the time control actions can be applied… …………….. . A. two works must be carried out B. three events must be done C. five works must be implemented D. four events must happen

B/ Comprehension questions 1. How many wildfires are caused by people? 2. How are fires caused by people reduced? 3. How are wildfires spotted? 4. When detecting smoke, what does the responsible person do? 5. How is the location of the fire indicated? 6. When does the dispatcher send off suppression crews? 7. To improve the fire prevention and control wildfires, what have some countries done? 8. What are the advantages and disadvantages of the employment of planes in detecting fires? 9. What are the advantages of infrared methods? 10. When is radar used?

REFERENCES 1. Lê Thị Thanh Chi. 2004. A course of English for students of agricultural extension and rural development. 2. Võ Thị Kỳ. 2001. English in agriculture for students of animal husbandry. 3. Nguyễn Văn Tú.1992. English for forestry students. NXB Đại Học Quốc Gia Hà Nội, Hà Nội. 4. Stephen Denny, Lewis Kerr, Martin Phillips, Clarence Shettlesworth. 1985. Science and technology: Agriculture. Longman, Hongkong. 5. Rosemary Morrow. 1993. Earth user’s Guide to Permaculture. Kangaroo Press, Australia. 6. C. St. J. Yates. 1990. English for academic purposes series: Agriculture. Oxford, England.