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

Вариант

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

ECOSYSTEM ECOLOGY

Ecosystem ecology, sometimes referred to as system ecology, is concerned with the flow of energy and circulation of matter in a whole ecosystem, that is how the whole system functions. The intimate couplings between the environment and the species: living there will influence the balance of the ecosystem and the living conditions for its members. It is only by knowing how the whole system works that we are able to understand how changes in abiotic factors that is environmental impacts, will affect a community of organisms.

Organisms can use energy in several forms. Depending on the form of "food" they use, the systems contain several categories of plants and animals.

The majority of plants obtain their energy directly from sunlight using green chlorophyll and sometimes additional pigments (like the brown and red algae). Plants are the primary producers of the ecosystem. In their photosynthesis, they convert the energy from sunlight into energy stored in carbohydrates (sugar, starch, cellulose etc.) and other organic compounds. They build biomass in the form of roots, stems and leaves. In addition to sunlight they need water, carbon dioxide from the air and nutrients such as nitrogen, potassium and phosphorus from the ground.

Animals living on plant biomass are called grazers or herbivores. They fill the role of consumers, or primary consumers, in the ecosystem.

Those animals that live by catching other living animals are predators, or carnivores, also called secondary consumers.

Finally, bacteria, and other organisms living on dead organic matter, detritus, are called decomposers. Soil animals, such as earthworms make up the first stage in the ecomposition of detritus, while fungi and bacteria take care of the final decomposition. By decomposing the organic matter they return the nutrients to mineral form and the organically bound carbon to carbon dioxide. The roots of plants can then again capture the mineral nutrients, and the circulation of chemical matters is closed. The decomposers are in many ways the most important organisms in the ecosystem. Plant growth in most terrestrial ecosystems is limited by the lack of nitrogen and in aquatic ecosystem often by lack of phosphorus. If the decomposers did not effectively re-circulate these nutrients, primary production would soon cease. Re-circulation of nutrients and other substances is thus essential to all ecosystems.

TASK1. GRAMMAR

A. TURN THE FOLLOWING VERBS INTO NOUNS AND TRANSLATE THEM INTO RUSSIAN:

1. to affect;

2. to describe;

3. to protect;

4. to observe;

5. to violate;

B. TURN THE FOLLOWING NOUNS INTO VERBS AND TRANSLATE THEM INTO RUSSIAN:

6. population;

7. eutrophication;

8. addition;

9. gradation;

10. exploitation.

TASK2.

REFER THE MODAL VERBS TO THE PAST AND FUTURE WHERE POSSIBLE:

1. Organisms can use energy in several forms.

2. Animals are able to receive their nitrogen through the food.

3. We may also discuss the whole system involved in material flows.

4. The plants may be unable to take up all nutrients.

5. It should be possible to improve control.

6. A first step must follow and “harvest” the wild herd.

7. The use of natural resources must be balanced.

8. We have to make both continental and global comparisons whenever this is relevant.

9. Our use of ecosystems should not jeopardize central ecosystem functions in the short or long run.

10. The varieties should be protected by patent rights.

TASK3. PREPOSITIONS

FILL IN THE MISSING PREPOSITION:

1. In autumn omnivores feed … seeds and are herbivores, but … summer they feed their offsprings … insects and are then predators.

2. Human use … ecosystem resources, … instance … agriculture, forestry or fishing has had dramatic effects … energy flow, nutrient circulation and biological diversity.

3. Ecosystem ecology, sometimes referred … as system ecology, is concerned … the flow … energy and circulation … matter … a whole ecosystem.

4. Soils animals, such as earthworms make … the first stage … the decomposition … detritus, while fungi and bacteria take care … the final decomposition.

5. The study … ecology gives us an understanding … which basic principles man has to observe … order to create a society that is … the long term … harmony … the environment.

6. We may sum … four ecological principles … sustainability to be used as guidelines.

7. The violation … basic principles will bring us … pollution.

8. Nutrients circulate … plants … consumers and decomposers and back … plants.

9. The role … ecologists is to try to establish levels … resource use, … instance fishing quotas that lead … sustainable use … the ecosystems.

10. The intimate couplings … the environment and the species living there will influence the balance … the ecosystem and the living conditions … its members.

TASK4.

TRANSLATE FROM ENGLISH INTO RUSSIAN:

1. Plants are the primary producers of the ecosystem.

2. Plant growth in most terrestrial ecosystem is limited by the lack of nitrogen and inn aquatic ecosystem often by lack of phosphorus.

3. Many bird species, such as finches and sparrows are examples of omnivores.

4. Energy enters the ecosystem through photosynthesis and is gradually lost as heat through the trophic levels.

5. Nutrients circulate from plants to consumers and decomposers and back to plants.

2 Вариант

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

Food Chains and Food Webs

A feeding relationship in an ecosystem is called a food chain, while the totality of the chains constitutes a food web. Often the food webs are quite complex with many different feeding relationships. In addition to primary producers, herbivores and carnivores, omnivores are common in some ecosystems. Many bird species, such as finches and sparrows are examples of omnivores. In autumn they feed on seeds and are herbivores, but in summer they feed their offsprings on insects and are then predators. However, it is often possible to differentiate between the levels described. They are called trophic levels. In an ecosystem there are normally four trophic levels but there might be more or fewer.

The biomass in an ecosystem is very unevenly distributed between the trophic levels. This is because not all of the biomass consumed is converted to the body mass on the next level; rather it is used as energy source for running, flying, swimming, for keeping the body temperature, etc. Thus, no more than 1- 10% of the mass of a lower level becomes biomass on the next level. This explains why an ecosystem normally does not support more than three or four trophic levels. So in the transfer between trophic levels, most energy is lost as heat (much like the engine in an automobile - much petrol is wasted as the

From this description we can see the distinct difference between the transfer of energy and nutrients in the ecosystem. Energy enters the ecosystem through photosynthesis and is gradually lost as heat through the trophic levels.

Nutrients circulate from plants to consumers and decomposers and back to plants. An important environmental issue is how closed this circulation is. With excessive addition of fertilizers to arable land

and by nitrogen added as an air-borne pollutant, the plants may be unable to take up all nutrients, and excess nutrients is then leaking to soil water. This water ends up in rivers and lakes and leads to eutrophication of these and, finally, of the Baltic Sea.

Human use of ecosystem resources, for instance by agriculture, forestry or fishing has had dramatic effects on energy flow, nutrient circulation and biological diversity, locally as well as globally. Sustainability has been suggested as an overall aim for environmental protection work. This implies that our use of ecosystems should not jeopardise central ecosystem functions in the short or long run. The role of the ecologists is to try to establish levels of resource use, for instance fishing quotas that lead to sustainable use of the ecosystems.

To really know if human use of ecosystems is sustainable we need environmental monitoring.

This means that we carefully measure long-term
changes in species diversity, nutrient levels and vital
ecosystem functions.

TASK1

A. TRANSLATE THE FOLLOWING COLLOCATIONS FROM ENGLISH INTO RUSSIAN:

1. artificial fertilizer;

2. to convert the energy;

3. organic compounds;

4. to fill the role;

5. living conditions;

B. TRANSLATE THE FOLLOWING COLLOCATIONS FROM RUSSIAN INTO ENGLISH:

6. поглощать питательные вещества;

7. получать энергию;

8. пищевая цепь;

9. воздействие на окружающую среду;

10. органическое вещество.

TASK2