Variant 5

1. Read the text and translate the italised extract in written form

Acidification of the Soil

The critical load, the ability of the soil to resist is sooner or later used up and it becomes acidified. The following may be said to be the worst effects:

Plant nutrients are leached out. The ability of plants to take up nutrientsdiminishes when the availability of base cations in the soil, such as magnesium, calcium, and potassium, is reduced. Forest growth can be affected, and some sensitive plant species possibly eliminated. It is estimated that the content of easily available base cations in the soil of southern Sweden os declining at a rate of 1-2 % per annum.

Poisonous metals are freed. Aluminium ions, which are poisonous to plant’s root systems, are freed through the weathering of the soil at lower pH-values. As the soil becomes more acid, the mobility of many heavy metals also increases. In acidified soil, it is likely that uptake by the plantsof cadmium, zink, manganese, and nickel, to mention a few, is increased.

Phosphates become bound. Plants also suffer indirectly when the concentrations of dissolved aluminium increased. Alumimiun ions have the ability to bind phosphate, which is an important nutrient and make it less easily available. The effect of an insufficiency of phicphate i moreover heightened when the process of decomposition becomes slowed down in the soil as a result of acidification. Some other important nutrients besides phosphate, such as molybdenum, boron, and selenium, also become less easily available to plants when the soil is acidified.

Up to the early 1980’s, most soil scientists believed belived it to be unlikely that the soil would be affected by acidification. There are parts of Europe where the soil has a large content of easily weathred minerals, enabling it to accept great amounts of acid without becoming acidified. But where the soil minerals weather less easily, as in Scandinavia, the resistance to acidification is low. The amount of acidific deposition that the various types of soil can accepr without becoming acidified, vries in Europe. Continuous sampling in Sweden has shown that the pH value of the soil has decreased by 0.3 to 1.0 units in only a few decades. The drop has not only taken place in the upper layers, but also far down into the mineral soil. The store of base cations available to plants has on the average been halved in forty years.

While sulphur is responsible for most of the soil acidification caused by air pollutants, nitrogen compounds also contribute, but in a more complicated manner. To put it simply, there will be a net acidifying effect only to the extent that the nitrogen is not taken up by the plants but leached out. An obvious conclusion is that the acidifying affect of nitrogen increases if the vegetation fails to take up as much as is deposited. The resulting state known as nitrogen saturation, relatively large leakages of nitrogen have been noted from forest land.

The nitrogen that is leached out of the soil ends up in streams and lakes where it eventually leads to biological changes. Some finds its way to the sea where the eutrophication effect is still greater causing algal blooms, oxygen depletion, and lifeless depths.

2. PUT THE WORDS IN THE CORRECT ORDER TO MAKE A QUESTION:

1. most evident/on freshwater life/ where/have/of acidification/the effects/been?

2. the number/why/rapidly/does/diminish/of phytoplankton?

3. forest decline/seriously/was/when/air pollutants/the connection/taken/between/and?

4. and/how/toxic substances/ affect/land, water, air living beings/do?

5. fish/stock/the/for/reason/declining/what/main/is?

3. MAKE UP NEW WORDS USING PREFIXES de-, dis- AND EXPLAIN THEIR MEANING:

1. ability – disability;

2. acceleration –

3. acidification –

4. appearance –

5. aquation –

6. composition –

7. connection –

8. intoxication –

9. population –

10. position -

4. A. MATCH SYNONYMS:

1. to eliminate; 2. conclusion; 3. capacity; 4. to compound; 5. available;

a. to combine; b. aptitude; c. inference; d. to remove; e. obtainable.

B. MATCH THE WORDS WITH THEIR DEFINITIONS:

1. leakage; 2. nutrient; 3. concentration; 4. to deplete; 5. to leach out;

a. a substance that provides nourishment essential for growth and the maintenance of life; b. the amount of a component in a given area or volume; c. the accidental admission or escape of a fluid or gas through a hole or crack; d. to dissolve out by the action of a percolating liquid. e. to empty of a principal substance;

5. A. CHOOSE THE BEST VARIANT TO COMPLETE THE SENTENCES:

1. The ability of the soil (to withstand, to resist, to oppose) is sooner or later used up.

2. Alumnium ions are (vindictive, toxic, poisonous) to plants’ root system.

3. Plants (suffer, endure, undergo) when the concentration of dissolved aluminium increase.

4. There are parts of Europe where the (loam, soil, area) has a large content of easily weathered minerals.

5. Aluminium ions are (freed, liberated, exempted) through the weathering of the soil at lower pH-values.

B. MARK THE STATEMENTS AS TRUE (T) OR FALSE (F). CORRECT THE FALSE STATESMENTS:

6. The ability of plants to take up nutrients is reduced when the availability of base cations in the soil diminishes.

7. Aluminium ions are very useful to plants’ root systems.

8. Molybdenum, boron, selenium become more available to plants when the soil is acidified.

9. As the soil becomes more acid, the mobility of many heavy metals also increases.

10. Where the soil minerals weather less easily, the resistance to acidification is high.

6. A. TRANSLATE FROM ENGLISH INTO RUSSIAN:

1. Large leakages of nitrogen have been noted from forest land in the Netherlands, Denmark, northern Germany.

2. Aluminuim ions have the ability to bind phosphate, which is an important nutrient, and make it less easily available.

3. Most scientists believed it to be hardly likely that the soil would be affected by acidification.

4. To put it simply, there will be a net acidifying effect only to the extent that the nitrogen is not taken up by the plants but leached out.

5. The resulting state, known as nitrogen saturation, can be reached at quite a low load.

B. ANSWER THE FOLLOWING QUESTIONS:

6. What is acidification?

7. What is acidification caused by?

8. Does the ability of the soil in Europe to resist acidification increase? Explain your answer.

9. What is toxicology?

10. What are the causes of forest decline?