Find in Text 14 English equivalents for the following words and expressions and memorize them.

1) грибы (как царство)

2) мицелий

3) плесень

4) актиномицеты

5) внешнее сходство

6) плотоядные

7) земляные черви

8) заслуживать внимание

9) декоративные растения

10) членистоногие

11) клещи

12) личинки

13) извлекать пользу, выгоду из чего-либо

14) искоренять, уничтожать

15) грызуны

16) суслики

17) сурки

18) луговые собачки

Translate the text from English into Russian.

TEXT 14

The soil is the home of innumerable forms of plant, animal, and microbial life.

Bacteria

Bacteria are single celled, among the smallest living organisms, and exceed all other soil organisms in kinds and numbers.

Fungi

Fungi are heterotrophs that vary greatly in size and structure. Fungi typically grow or germinate from spores and form a threadlike structure, called the mycelium. Whereas the activity of bacteria is limited to surface erosion in place, fungi readily extend their tissue and penetrate into the surrounding environment. The mycelium is the working structure that absorbs nutrients, continues to grow, and eventually produces reproductive structures that contain spores. The most common fungi are molds and mushrooms. Mold mycelia are commonly seen growing on bread, clothing, or leather goods.

Actinomycetes

Actinomycetes refers to a group of bacteria with a superficial resemblance to fungi. The actinomycetes resemble bacteria in that they have a very simple cell structure and are about the same size in cross section. They resemble filamentous fungi in that they produce a branched filamentous network. The network compared to fungi, however, is usually less extensive. Many of these organisms reproduce by spores, which appear to be very much like bacterial cells.

SOIL ANIMALS

Soil animals are numerous in soils. Soil animals can be considered both consumers and decomposers because they feed on or consume organic matter and some decomposition occurs in the digestive tract. Animals, however, play a minor consumer-decomposer role in organic matter decomposition. Some animals are parasitic vegetarians that feed on roots, whereas others are carnivores that prey on each other.

Worms

There are two important kinds of worms in soils. Microscopic roundworms, nematodes, are very abundant soil animals. They are of economic importance because they are parasites that invade living roots. The other important worm is the ordinary earthworm.

EarthwormsEarthworms are perhaps the best known of the larger soil animals.

Nematodes(roundworms) are microscopic worms and are the most abundant animals in soils. Parasitic nematodes deserve attention owing to their economic importance in agriculture. Many plants are attacked, including tomatoes, peas, carrots, alfalfa, turf grass, ornamentals, corn, soybeans, and fruit trees. Some parasitic nematodes have a needlelike anterior end (stylet) used to pierce plant cells and suck out the contents. Host plants respond in numerous ways: plants, for example, develop galls or deformed roots. In the case of a root vegetable such as carrots, the market quality is seriously affected.

Arthropods

A high proportion of soil animals is arthropods; they have an exoskeleton and jointed legs. Most have a kind of heart and blood system, and usually a developed nervous system. The most abundant arthropods are mites and springtails. Other important soil arthropods include spiders, insects (including larvae), millipedes, centipedes, wood lice, snails, and slugs.

Nitrogen Fixation

We live in a "sea" of nitrogen, because the atmosphere is 79 percent nitrogen. In spite of this, nitrogen is generally considered the most limiting nutrient for plant growth. Nitrogen exists in the air as N 2 and, as such, is unavailable to higher plants and most soil microbes. There are some species of bacteria (nitrogen fixers) that absorb N 2 gas from the air and convert the nitrogen into ammonia that they and the host plant can use. This process of nitrogen fixation is symbiotic. The bacteria obtain food from the host plant and the host plant benefits from the nitrogen fixed.

Pesticide Degradation

Pesticides include those substances used to control or eradicate insects, disease organisms, and weeds. One of the first successful synthetic pesticides, DDT, was used to kill mosquitoes for malaria control. After decades of use it was found in the cells of many animals throughout the world. This dramatized the resistance of DDT to biodegradation and its persistence in the environment. The structure of DDT appears to be different from naturally occurring compounds and, therefore, few if any organisms have enzymes that can degrade DDT. The difference in structure and degradability of 2,4-D and 2,4,5-T is illustrated in Figure 8.13.

Rodents

Many rodents, including mice, ground squirrels, marmots, gophers, and prairie dogs inhabit the soil.

(H.D. Foth, Fundamentals of Soil Science)