SITUACIÓN DE NAVARRA RESPECTO A LOS OBJETIVOS DE LA

affect how the species are managed in the forest. For example, most oak, hickory, and walnut trees have deep and extensive taproot systems which provide extremely solid anchorage. Thus, these and other trees with similar root systems are not as prone to uprooting by severe winds. In harvesting a forest, wind damage is a minor concern with these trees. Spruces and balsam, on the other hand, have shallow root systems and can be uprooted even by moderate winds. In planning the harvest, such trees must be removed or allowed to remain in a pattern that will ensure adequate wind protection. Most forest trees fall somewhere between these extremes. Generally, the root system provides sound anchorage except in relatively extreme conditions. Of course, even deep-rooted species can be uprooted under severe conditions, such as prolonged heavy rains before or during high winds. Hurricane conditions can level extensive areas of forest. In addition, trees that normally produce taproots may develop shallow root systems because of poor soil conditions, e.g. only a thin layer of soil above the bedrock. In such cases trees may be not only stunted but also easily blown over.

This text is taken from BARDEN et al., Plant Science, McGraw-Hill

II. Comprehension questions

Now read the text carefully, looking up any new items in a dictionary or reference book. Then answer the following questions:

1. Why are forest usually managed ?

2. What is the difference between an angiosperm and gymnosperm ? 3. How are hardwoods and softwoods differentiated ?

4. What kind of tree is the aspen ?

5. How long does it take for a forest to manure ?

6. How do you assess the amount of wood you will get from a tree ? 7. What is a crown ?

8. Why is the storage function of a tree‟s roots less important than those of a field crop? 9. Why is an oak less likely to be uprooted than a balsam ?

10. When is the root system inadequate to anchor a tree ?

III. Vocabulary

1. look at par.1, what words have the same meaning as: Well-informed

2. Look at par.2, what words have the opposite meaning to: Straightforward, easy to understand

As an exception

3. Look at par. 2 again, can you explain the words: Hard hardwood

Hard softwood

4. Look at par.3, what words have the same meaning as: Go on living

Deciding

Hundred of years Part

All the time Seldom

5. Look at par.4 & 5, which words correspond to these definitions: Holding something down so that it is not blown over Liable or inclined to

Going on for a long time Poorly developed

Qualities which are as wide apart as possible.

B. GRAMMAR

EXERRCISE A: Asking questions

Find out about the oil palm by asking questions following these points (Note down the answers from your teacher)

1. Botanical name: What ...? 2. Family: Which ...? 3. Varieties: How many ...? 4. Seed rate: What ...? 5. Planning out: Where ...? 6. Spacing: What ... per hectare ? 7. Maturation: When ...? 8. Harvest: When ... ? 9. Yield: What ...?

10. Composition percentage: What ... ? 11. Diseases: What kind of ... ? 12. Processing: How ... ?

EXERCISE B: Expressing purpose: to-infinitive

E.g. We cut ditches at certain intervals between the crops. Our purpose in doing this is to remove surface water.

= Ditches are cut at certain intervals between the crops to remove surface water

Rewrite the following sentences using the passive forms of the main verbs as in the example above.

1. A plant 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. The roots of plants such as sugar beet, carrots and parsnips store food. The object of doing this is to enable them to live more than one season.

4. We should add fertilizers or manure to the soil. Our aim in doing this is to encourage plant growth.

5. If a soil is very acid we can spread lime on it. Our purpose in doing this is to correct the acidity.

6. A plant transforms water and carbon dioxide into sugar and starch in the presence of light. Its purpose in doing this is to provide the plant with food and energy for growth and reproduction.

7. 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, phosphorous, and potash.

8. Tile drains may be laid in or on the land. The reason for this is to remove surplus water from the fields.

9. We should keep ditches as straight as possible and on an even gradient. The reason for this is to prevent them from silting up.

10. We add bulky materials to the soil like animal or green manure. Our aim in doing this is to improve the physical condition of the soil and to keep up its humus content.

EXERCISE C: Expressing purpose: in order to + infinitive / so as to + infinitive

For example:

We need irrigation. The reason for this is to make up for lack of natural rainfall. = Irrigation is needed in order to/so as to make up for lack up natural rainfall.

Rewrite the sentences in Exercise B using the new structure in order to/so as to +infinitive and the passive form as in the above example.

C. LANGUAGE IN USE

EXERCISE B: 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.

A B 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 things like the soil, the slope and exposure (winds, 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)

EXERCISE C

Use the information in the table below to explain the terms

E.g. - In forestry we use the word/term „seedling‟ to describe a tree grown from seed that is not yet one metre high.

- A standard tree is one which is between thirty and sixty centimetres dbh.

Term Height Diameter

1. Seedling 2. Shoot 3. Small sapling 4. Large sapling 5. Small pole 6. Large pole 7. Standard 8. Veteran Up to 1m Up to 1m 1 - 3m over 3m Up to 10 dbh 10 - 20 cm dbh 20 - 30 cm dbh 30 - 60 cm dbh over 60 cm dbh

EXERCISE D

Classification according to defining characteristics

Classifications are made according to some principle of classification, and statements are made in the active or passive form.

E.g. We may/can classify plants according to how long they live.

Or Plants may/can be classified according to how long they live. For example annuals

plants complete their life cycle in a single season, but biennial plants require two years to complete their life cycle.

Make statements about how the following objects may be classified as in the example above. You will need to add the necessary words in the statements.

Object Principle of

classification

Examples Characteristics

1. Plants How long they live

Annuals plants Complete life cycle in single season Biennial plants Require two years to complete life cycle 2.Plant

nutrients

Source Oxygen and carbon Derived from air Minerals such as

phosphorus,

potassium, calcium, iron, and zinc

Extracted from mineral substances

3. Soils Proportions of sand, silt and clay each contain

Light sandy soil Contain low proportion of clay and higher proportion of sand and silt

Heavy clay soil Contains almost equal proportions of sand, silt and clay

4. Crops Use made of them

Cereal or grain crops, such as wheat and barley

Grown primarily for seed which is used for food

Forage and pasture crops, such as legumes

Grown primarily for leafy parts which are used for livestock feed

5.

Weathering agents

Natural force involved

Physical agents such as water, ice and wind

Change size, form and shape of rock and mineral debris

Chemical agents such as oxygen and natural acids

Alter chemical composition of rocks and minerals

New words and expressions: