TABLE OF CONTENT
INTRODUCTIONUnit 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
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.
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 D. dense form 6. The tree that has to compete for light often has …………. .
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.
III/ Paragraph writing
Match the following clauses together, using and, but, when, after, so and because.
a. the next evening he needed them b. he arrived at the canteen
c. they did not please Andrew very much d. Last night Andrew lend Robert his lecture
note
e. Andrew needed his notes immediately f. He had waited for an hour
Robert could not attend Robert finally arrived
he went to the canteen to look for Robert
Robert has not returned them Robert was not there
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 broad-leaved 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 of the surrounding environment very carefully how unfamiliar plant
plant groups for example functions identifiable grass smell some other plant doing
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
B. a forest of different species
C. mixing with each other
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
B C
1. Photosynthesis 2. A soil profile 3. Aerobic bacteria 4. Osmosis 5. A leaf 6. Chloroplasts 7. Stomata of plants 8. Chlorophyll The process A succession of soil horizons Organisms Biophysical process Complex structure BodiesMinute openings on the surface of a leaf
The chemical
Transforms light energy from the sun into chemical energy
Extends from the surface of the soil to the parent rock
Can live in the presence of air
Take place through the tissues of living plants Utilizes energy from the sun in the manufacture of food
Absorb sunlight and manufacture food
Lead to the interior of the leaf and the chloroplasts 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 Stand Type Site class Size of tree Diameter of tree Cm dbh
Ecologically complex unit-community of trees and undergrowth spreading, sometimes, over really enormous areas.
Collection of trees which are more or less uniform (i.e. more or less the same) in species, age distribution etc. Rather like a stand but more extensive- group of similar stands defined by the species composition
Physical factors which affect the productivity of the trees, concerning the thing like the soil, the slope and exposure (wind, rain)
Height of tree and diameter.
Measured at one point three five metres from the surface of the soil.
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, 10- 15% 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 D. B & C 2. In paragraph 6, line 2 , the word “their” refers to:
A. trees’ B. leaves’ C. loads’ D. nutrients’ 3. In paragraph 7, line 3, the word “its” refers to:
A. 40% B. forest closure’s C. windstream’s D. forest’s 4. In paragraph 8, line 2, the word “it” refers to:
A. tree B. region C. height D. air
A. edge’s B. plant’s C. forest’s D. weed’s 6. In paragraph 11, line 1, the word “it” refers to:
A. tree B. sun C. light D. energy
7. In paragraph 14, line 1, the word “which” refers to:
A. areas B. evatranspiration C. air D. trees 8. In paragraph 16, line 1, the word “they” refers to:
A. trees B. moistures C. air D. precipitation 9. In paragraph 23, line 2, the word “it” refers to:
A. rain B. throughfall C. canopy D. mist 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?
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.
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.
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……… .
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………… .
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?
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?
