Научная электронная библиотека

Монографии, изданные в издательстве Российской Академии Естествознания

БИОГЕОЦЕНОЛОГИЯ НА АНГЛИЙСКОМ ЯЗЫКЕ

Жумабекова Б. К., Рамазанова А. С.,

Chapter 5. SOIL AS A PART OF BIOGEOCENOSIS

Read the given text. Make the questions for the text / Мәтінді оқып шығыңдар. Мәтінге қатысты сұрақтар құрастырыңдар / Прочитайте текст. Составьте вопросы к тексту.

Soil is the upper layer of ground (also known as ‘The skin of the Earth’), which is the habitat for many organisms and medium for plant growth. Fertility of soil is defined by its physical and chemical properties, which in their turn are named edaphic factors. Thus, edaphic quality refers to soil characteristics such as drainage, texture, chemical properties, etc.

Soil is the mixture of minerals, organic matter, gases, liquids, and the countless organisms that together support life on earth. Soil is the end product of climate, relief (elevation, orientation, and slope of terrain), organisms, and parent materials (underlying geological material, usually bedrock or various deposits) interacting over time. It is formed by interrelations of rock, climate, plants, animals and microorganisms. Soil changes in time, it develops, transforms, thus there are different kinds of soils. Soil upper layer contains humus. The thicker the layer of humus, the more fertile the soil is.

Chemical content of soil depends on its mineral composition. Soil contains different kinds of microbes, which mineralize organic matter. They are called decomposers. Among others nitrification, bacteria inhabiting soil fix atmospheric nitrogen and transport it into soil.

Soil is a major component of the Earth’s ecosystem. The world’s ecosystems are impacted in far-reaching ways by the processes carried out in the soil, from ozone depletion and global warming, to rainforest destruction and water pollution. Following the atmosphere, the soil is the next largest carbon reservoir on Earth, and it is potentially one of the most reactive to human disturbance and climate change. As the planet warms, soils will add carbon dioxide to the atmosphere due to its increased biological activity at higher temperatures. Thus, soil carbon losses likely have a large positive feedback response to global warming [1].

Soil acts as an engineering medium, a habitat for soil organisms, a recycling system for nutrients and organic wastes, a regulator of water quality, a modifier of atmospheric composition, and a medium for plant growth. Since soil has a tremendous range of available niches and habitats, it contains most of the Earth’s genetic diversity. A gram of soil can contain billions of organisms [2] [3], belonging to thousands of species. Soil has a mean prokaryotic density of roughly 1013 organisms per cubic meter, whereas the ocean has a mean prokaryotic density of roughly 108 organisms per cubic meter. The carbon content of the soil is eventually returned to the atmosphere through the process of respiration carried out by heterotrophic organisms that feed upon the carbonaceous material in the soil. Since plant roots need oxygen, ventilation is an important characteristic of soil. This ventilation can be accomplished via networks of soil pores, which also absorb and hold rainwater making it readily available for plant uptake. Since plants require a nearly continuous supply of water, but most regions receive sporadic rainfall, the water-holding capacity of soils is vital for plant survival.

Soils can effectively remove impurities, kill disease agents, and degrade contaminants. Typically, soils maintain a net absorption of oxygen and methane, and undergo a net release of carbon dioxide and nitrous oxide. Soils offer plants physical support, air, water, temperature moderation, nutrients, and protection from toxins. Soils provide readily available nutrients to plants and animals by converting dead organic matter into various nutrient forms.

Of all the factors influencing the evolution of soil, water is the most powerful due to its involvement in the solution, erosion, transportation, and deposition of the materials of which a soil is composed. The mixture of water and the dissolved or suspended materials that occupy the soil pore space is called the soil solution. Since soil water is never pure water, but contains hundreds of dissolved organic and mineral substances, it may be more accurately called the soil solution. Water is central to the solution, precipitation and leaching of minerals from the soil profile. Finally, water affects the type of vegetation that grows in a soil, which in turn affects the development of the soil.

The most influential factor in stabilizing soil fertility are the soil colloids, clay and humus. Soil colloids behave as repositories of nutrients and moisture and so act to buffer the variations of soil solution ions and moisture. The contribution of soil colloids to soil nutrition are out of proportion to their part of the soil. Colloids act to store nutrients that might otherwise be leached from the soil or to release those ions in response to changes of soil pH, and so, make them available to plants.

The greatest influence on plant nutrient availability is soil pH, which is a measure of the hydrogen ion (acid-forming) soil reactivity, and is in turn a function of the soil materials, precipitation level, and plant root behavior. Soil pH strongly affects the availability of nutrients.

Most nutrients, with the exception of nitrogen, originate from minerals. Some nitrogen originates from rain (as dilute nitric acid), but most of the nitrogen is available in soils as a result of nitrogen fixation by bacteria. The action of microbes on organic matter and minerals may be to free nutrients for use, sequester them, or cause their loss from the soil by their volatilisation to gases or their leaching from the soil. The nutrients may be stored on soil colloids, or within live or dead organic matter, but they may not be accessible to plants due to extremes of pH.

The organic material of the soil has a powerful effect on its development, fertility, and available moisture. Following water and soil colloids, organic material is next in importance to a soil’s formation and fertility [4].

Glossary of essential terms / Негізгі терминдер глоссарийі / Глоссарий основных терминов

I. Read the text and fill in the table / Мәтінді оқып шығыңдар және кестені толтырыңдар / Прочитайте текст и заполните таблицу.

The physical properties of soils, in order of decreasing importance, are texture, structure, density, porosity, consistency, temperature, colour and resistivity. Soil texture is determined by the relative proportion of the three kinds of soil mineral particles, called soil separates: sand, silt, and clay. At the next larger scale, soil structures called peds are created from the soil separates when iron oxides, carbonates, clay, silica and humus, coat particles and cause them to adhere into larger, relatively stable secondary structures. Soil density, particularly bulk density, is a measure of soil compaction. Soil porosity consists of the void part of the soil volume and is occupied by gases or water. Soil consistency is the ability of soil to stick together. Soil temperature and colour are self-defining. Resistivity refers to the resistance to conduction of electric currents and affects the rate of corrosion of metal and concrete structures. These properties may vary through the depth of a soil profile. Most of these properties determine the aeration of the soil and the ability of water to infiltrate and to be held within the soil.

Physical properties of soils

II. Work in groups. Divide the class into three groups. Use the information from the table and describe one of the types of soil. How do Soil separates influence on the Soil properties? / Топпен жұмыс. Сыныпты үш топқа бөліңдер. Кестедегі ақпаратты пайдалана отырып, топырақтың бір түрін сипаттаңдар. Топырақ компоненттері оның қасиетіне қалай әсер етеді? / Работа в группах. Разделите класс на три группы. Используя информацию из таблицы, опишите один из типов почвы. Как компоненты почвы влияют на ее свойства?

Influence of Soil Separates on Some Properties of Soils [5]

III. Look at the picture and give comments on the topic “Soil types” / Суретті қарап шығыңдар және «Топырақ түрлері» тақырыбына түсініктеме беріңдер / Рассмотрите рисунок и дайте комментарии на тему «Типы почв».

Figure 4. Soil types by clay, silt and sand composition as used by the USDA [6]

IV. Write out the list of literature on the properties of the soils using the systematic and alphabetic catalogues of your University library. Prepare the abstract on the topic “Soil as component of a biogeocenosis” / Университет кітапханасының жүйелі және алфавитті каталогын пайдалана отырып, топырақ қасиеті бойынша әдебиеттер тізімін жасаңдар. «Топырақ биогеоценоз компоненті ретінде» тақырыбына реферат дайындаңдар / Пользуясь систематическим и алфавитным каталогами Университетской библиотеки, составьте список литературы по свойствам почвы. Подготовьте реферат на тему “Почва – как компонент биогеоценоза”.

V. Prepare a PPT presentation on the topic “The interaction of soils with other components of biogeocenosis” / «Топырақтың биогеоценоздың басқа компоненттерімен өзара әрекеттесуі» тақырыбына РРТ презентациясын дайындаңдар / Подготовьте презентацию PPT на тему “Взаимодействие почвы с другими компонентами биогеоценоза”.

Topics for essay:

1. History of the study of soil.

2. Physical properties of soils.

3. Soil structural classes.

4. Color of soil.

5. Composition of soil particles.

6. Classification of soils.

7. The properties of the soil.

8. The acidity of the soil.

9. Soil erosion as a natural process.

10. The types of soils on the territory of Kazakhstan.

References:

1. Powlson, David (20 January 2005). “Climatology: Will soil amplify climate change?”.Nature 433 (433): 204–205. doi:10.1038/433204a. (subscription required (help)).

2. Donahue, Roy Luther; Miller, Raymond W.; Shickluna, John C. (1977). Soils: An Introduction to Soils and Plant Growth. Prentice-Hall. ISBN 0-13-821918-4.

3. Clark. “Living Organisms in the Soil”. In Stefferud (1957).

4. “Sources. Negative Charge”. Jan.ucc.nau.edu. Retrieved 7 November 2012.

5. The Soil Hugger’s Journey // https://thesoilhuggersjourney.wordpress.com/2014/09/10/soil-series-high-level-components-of-soil-episode-2-3-resultant-soil-properties/

6. https://en.wikipedia.org/wiki/Earth_structure