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HO CHI MINH UNIVERSITY OF INDUSTRY INSTITUTE FOR ENVIRONMENTAL ENGINEERING & MANAGEMENT Compiled by VO DINH LONG ENVIRONMENTAL SCIENCES (Specialized English course for Environmental Students) HO CHI MINH CITY - 2006 CONTENTS CHAPTER 1: BASIC UNITS OF ECOLOGY After studying this chapter, you should be able to: Define environment Define an ecosystem Identify the components of the biosphere Describe the living and nonliving components of the environment Explain that bacteria and fungi are agents of decay Discuss the process of photosynthesis Enumerate the important factors that affect the growth of plants and the survival of animals 1.1 THE ECOSYSTEM When God created the world, He said, “Let the earth produces all kinds of plants, those that bear grain and those that bear fruit”, and it was done Then He also created animals, including human beings and provided light God, therefore, saw to it that everything needed for them to live is found in the world which He created He provided space, ways and means by with different organisms can interact with one another and with their environment Part of the world where life operates is known as the biosphere The biosphere consists of the air (atmosphere), water (hydrosphere), and earth (lithosphere) where living things interact with their environment Figure 1.1: The biosphere When you study the interaction or relationship between organisms and their environment, you are studying an ecosystem The term ecosystem refers to all the living things and the nonliving things in a given area It includes all the plants and animals together with their surroundings The ecosystem of an aquarium, for example, consists of the hydrilla and others plants, fish, snails, and other aquatic animals, some of which can only be seen under a microscope It also includes sand and pebbles at the bottom We can also include the owner who takes care of the aquarium A grassland, too, is an ecosystem This ecosystem consists of the grass, earthworms, insects, bacteria, soil, water, sunlight, and other plants and animals that live on it The pond is another example of an ecosystem The forest is a more complex ecosystem Can you identify some of the components of this ecosystem? The entire earth can be thought of as an ecosystem It has an abundance of different kinds of species of living things which, although separate by great distances, still react with one another and with the nonliving world In a forest ecosystem, interrelationships among its living and nonliving components occur The branches and leaves of trees help break the force of the rain Layers of dead leaves and twins and branches on the forest floor soak up water and prevent rain from washing soil away Little water runs off the land The roots of trees hold the soil and water on which they depend Moreover, when the leaves and branches decay, they become part of the rich topsoil The soil is made up of minerals like silica and clay They come from the breakdown of rocks There are spaces between the mineral particles which are filled with air and water Roots of plants penetrate deeper into the soil causing physical change They loosen the tightly packed particle Chemical change also occurs The roots absorb the minerals present Figure 1.2: Plant-soil relationship There are thousands of organisms that live in the soil, like earthworms, that decompose the dead plants and animals Some are too small to be seen, but they all help maintain the ecological balance in the soil Figure 1.3: Organisms in the soil Guide questions What is an ecosystem? How the living components of an ecosystem affect the nonliving components? Give example Can a fallen log be considered as an ecosystem? Explain your answer 1.2 COMPONENTS OF AN ECOSYSTEM In the preceding section you learned what an ecosystem is The living component is known as the biotic and the nonliving component is known as abiotic The biotic component consists of plants, animals, and bacteria The abiotic component includes all the factors of the nonliving environment such as the substratum, light, rainfall, nutrients, soil, and others Both the biotic and abiotic components are equally important in the ecosystem because without one of them the ecosystem would not function Insightfulness The ecosystem consists of the biotic and abiotic components The biotic components are the plants, animals, and decomposers The abiotic components are the non living factors, such as temperature, water, and others The abiotic affect the biotic components and vice versa 1.2.1 Green plants Green plants are known as the producers They capture the energy from the sun and together with carbon dioxide (CO2) in the air and water (H2O) convert together those into food energy Since plants are able to manufacture their own food, they are also known as autotrophs (or self-nourishing) These plants are able to manufacture food though the process of photosynthesis, which will be explained in the next section Green plants also take substances, such as nitrogen and sulfur from the environment and convert those into plant materials that can be used by other organisms as food These green plants further provide oxygen which is taken in by humans and animals in the process of respiration For these reasons, all life, whether in the pond, forest, or grassland, depend on green plants You might think that green plants consist only of the trees or big plants that you see around The other producers are invisible to your eyes These are the microscopic drifting plants which are greater sources of food than the big plants that you can see We call these microscopic plants phytoplankton When they become too abundant, they can give a pond or a body of water a green color Have you ever seen a pond or a lake with green surface? Guide questions What are producers? What producers perform in an ecosystem? What are phytoplanktons? 1.2.2 Animals Animals, or the consumers, obtain their food from plants or other animals Because of this, they are also known as heterotrophs, which means that they feed on others and cannot manufacture their own food, unlike the green plants There are three different types of consumers, namely, the herbivores, the carnivores, and the omnivores Figure 1.4: There are three different types of consumers The herbivores are those that eat plants only For example, the caterpillar that feeds on leaves is an herbivore while the snake that eats the caterpillar is a carnivore Omnivores eat both plants and animals A human being is a good example of an omnivore Through the process of respiration, animals combine the food they eat with oxygen to produce CO and H2O which are used by plants in the photosynthesis process Animals also convert the materials of the plant bodies into the materials that make-up their own bodies All the energy produced and used by animals comes from the plants Guide questions What are consumers? What are the three types of consumers? and give one example for each type 1.2.3 Bacteria and fungi as agents of decay Have you ever observed what happen to leaves that fall on the ground? After some time, the leaves wither, break down into smaller pieces, decay, and finally become part of the soil What you think is responsible for this change? Have you heard of the word decomposer? What you think does a decomposer do? Decomposers make-up the third biotic component of the ecosystem They use the bodies of dead animals and plants for their food The materials contained in these dead bodies are broken down by the decomposers, thus they get the energy they need and release the minerals and other nutrients back into the environment for use again by other organisms Bacteria are among the most abundant decomposers while fungi are known to be the fast-acting decomposers Decomposers are found everywhere In the pond, they are abundant at the bottom where the remains of the dead organisms (plants and animals) settle On land, they abound on the surface of the soil where the dead bodies of plants and animals are found Each of the three groups of the biotic component of the ecosystem - producers (plants), consumers (animals), and decomposers (bacteria and fungi) - has its own specific function or task to perform Figure 1.5: Relationship among biotic component of the ecosystem The work performed by an organism is known as its ecological niche, while the place where the organism lives in the ecosystem is known as its ecological habitat Guide questions What are producers? Give examples of producers? What decomposers perform in the ecosystem? 1.2.4 Nonliving factors The nonliving factors of the environment make-up abiotic component of the ecosystem These include the chemical and physical factors in the environment, such as light, temperature, water, pH (acidity), wind, chemical nutrients, salinity (saltiness), soil, and others Organisms are affected by the biotic factors simultaneously but, of course, different species of organisms are affected differently For example, lichens may not survive when temperature gets very high but cactus may Different organisms thrive in different conditions There are animals, like the earthworms, which favor wet condition, while others, like ants, prefer drier conditions Some plants, such as cactus, grow best in sandy soil while tomatoes grow best in loamy soil As a whole, these environmental factors not only provide essential energy and materials but also determine the kind of organisms that will inhabit the area Hence, they provide the conditions necessary for the survival of the organisms Guide questions What are the components of an ecosystem? Give examples for each component of the ecosystem In general, what are the functions of these components? Can an ecosystem exists without one of its components? Justify your answer Vocabulary Autotroph: Organism that is self-nourishing; one that can produce its own food Hetertrop: Organisms that feeds on others and cannot manufacture its own food Biological magnification: Accumulation or increase of chemical substances on organisms in succeeding higher trophic levels Biomass: Amount of organic materials in plants or animals from which energy can be derived Energy: Capacity to work Energy content: The amount of energy available for doing work For example, the amount of energy in fuel available for powering a motor vehicle Food chain: Energy pathway which proceeds from the producers to the consumers Food web: Series of interrelated food chains in an ecosystem Pyramid of energy: Representation of the organic content in each trophic level Biosphere: Portion of the earth and its environment within which life in any of its form is manifested Photosynthesis: Process of manufacturing food by green plants in the presence of sunlight Atmosphere: Layer of air surrounding the earth Hydrosphere: The part of the Earth composed of water including clouds, oceans, seas, ice caps, glaciers, lakes, rivers, underground water supplies, and atmospheric water vapor Lithosphere: The outer, rigid shell of the Earth, situated above the atmosphere and containing the crust, continents and plates or the solid part of the earth’s surface Grassland biome: Community where grass is abundant while trees are scarce and where mostly herbivores and rodents dwell Carnivore: Animals that get food from killing and eating other animals Herbivore: Organisms that eat plants only Omnivore: Organisms that consume both plants and animals Biotic factor: Living component of the ecosystem which includes plants, animals, and bacteria Biotic potential: Reproductive capacity of the living components of the ecosystem Producer (autotroph): Green plant or organism that, performs photosynthesis Consumer: Organism that feeds on other organisms Decomposer (also known as microconsumer): Organism which breaks down nonliving organic material; example are bacteria and fungi Environment: Sum of all external forces and conditions acting on an organism or a community of organisms 10 Eutrophication: Accumulation of nutrients in a lake or pond due to human intervention or nature causes Exclusion principle: Idea that no two species can occupy exactly the same niche Fecundity: Ability of the population to bear children Fission: splitting of heavy nuclei when struck by neutrons or other subatomic particles Fluorocarbon: Organic molecule consisting of chlorine and fluorine covalently bonded to carbon Food chain: Energy pathway which proceeds from the producer to the consumer Food web: Series of interrelated food chains in an ecosystem Fossil fuel: that which is composed of coal, gas, and soil which are derived from the decomposition of dead organisms after along time Frontier mentality: Kind of attitude among people to effects that the environment can be abused and misused Fusion: See nuclear fusion Geothermal energy: Energy derived from magma 59 Grassland biome: Community where grass is abundant while trees are scarce and where mostly herbivores and rodents dwell Greenhouse effect: Rising of the average global temperature caused by the accumulation of the carbon dioxide and other gases in the atmosphere These gases trap radiant heat and prevent its escape into space Groundwater: Water below the earth’s surface Habitat: Place where the organism lives Halophyte: Plant that grows in saline or salty environment, like seaweeds and algae Hazardous substance: Substance that poses a threat to human heath and the environment Herbivore: Organisms that feeds directly on plants Hetertrop: Organisms that feeds on others and cannot manufacture its own food Humus: Material which consist of decaying matter and inorganic substances that result from the decomposition of dead plants and animal Hydroelectric power: Power produced in turbines powered by running water 60 Hydrophytes: Plant that grows in water and permanently water logged soil Insecticide: From of pesticide used to control insect population Life expectancy: Average age at which a person is calculated to live Limnetic zone: Open water zone of lakes through which sunlight penetrates Littoral zone: Shallow waters along a lakeshore where rooted vegetation grows Magma: Molten rock beneath the earth’s crust Maximum temperature: Highest limit of temperature by which an organism can still function Mesophyte: plant of grows in moderate conditions between the environmental extremes Microconsumer: decomposition Bacterium of fungus that carries out Minimum temperature: Lower limit of temperature by which an organism can still function or survive Mutation: Any damage done to the DNA or chromosomes Natural gas: Fuel containing about 50 to 90 percent methane 61 Niche: Place where organisms live Nitrate: Inorganic anion containing three oxygen atoms and one nitrogen atom Nitrite: Inorganic anion containing two oxygen atoms and one nitrogen atom Nitrogen cycle: Cycling of nitrogen between the organisms and the environment Noise pollution: Unwanted sound that have harmful effects on the body Nuclear fission: Splitting of an atomic nucleus when struck by neutrons Nuclear fusion: Joining of two small atomic nuclei to from a new and large nucleus Nuclear power: Energy derived from nuclear fission or fusion Oil: See petroleum Oil shale: Sedimentary rock which is finely grained and contains an inorganic substance called kerogen Omnivore: Organism that consumes both plants animals Optimum temperature: Temperature at which the organism can function best 62 Ozone: Molecule that contains three molecules of oxygen found in the atmosphere and which screens ultraviolet rays Ozone layer (or the ozonosphere): Thin layer of ozone in the upper atmosphere which absorbs ultraviolet light and converts it to infrared radiation Paralytic shellfish poisoning: Effect to red tide poisoning Particulate radiation: That which consists of parts of atoms that are radiated either by natural radioactive disintegration or by artificial means like the explosion of atomic bombs Passive solar: Capture and retention of the sun’s energy within a building though windows and some from of heat storage in the building pH: Measure of the acidity on a scale of to 14 Photosynthesis: Process of manufacturing food by green plants in the presence of sunlight Physiological drought: The result when the roots of plants become les permeable at low temperatures Pioneer community: First group of organisms that becomes established in an environment that was not previously occupied by any life form Pollution: That which occurs when there is a change in the physical, chemical, or biological conditions in the environment 63 which harmfully effects the quality of life, including effects on other animals and plants Population: Group of organisms that belong to the same species and can interbreed freely Population growth rate: Natural increase in population represented by the different between birth and death rates Predator: Organism that kills and eats another organism Prey: Organism that is killed and eaten by a predator Primary consumer: First organisms that eats the plants in the tropic level Primary succession: Development of communities where no organisms previously existed Principle of least effort: phenomenon when the population of the herbivores increases Producer (autotroph): Green plant or organism that, performs photosynthesis Profundal zone: Deeper part of the lake water into which sunlight does not penetrate Pyramid of energy: Representation of the organic content in each trophic level 64 Radiation dose absorbed in the human or animal tissue equivalent to 100 grs/gram of tissue Reactor core: That which consists of fuel rods in a reactor vessel Recycling: Processing of material into new products that may or may not resemble the original material Red tide: Phenomenon that occurs when the population of the dinoflagellates increases tremendously Relative humidity: Amount of moisture in a give quantity of air divided by the amount the air could hold at that temperature Rem (or roentgen equivalent man): dose from any radiation that produces biological effects in man equivalent to one rad or X ray Resilience: Ability of an organism to return to its normal state after a disturbance Roentgen unit(R): Quantity of radiation(gamma or X ray) that will produce electrostatic unit of positive or negative electricity in 1cm3 of air at normal temperature and pressure Secondary consumer: Organism that belongs to the third trophic level in a food chain Secondary succession: Sequential development of biotic communities occurring after the complete or partial destruction of an existing community 65 Sediment: Soil particles, sand, and other mineral mater eroded from land and carried to surface waters Shale oil Thick heavy oil formed when shale is heated Slash-and-burn agriculture: Practice in farming in which the forests are cleared by cutting and burning Sludge: Solid organic material produced during sewage treatment Solar aqua cell Waste water treatment, using solar heat Solar collector Derived from the sun and natural phenomena driven by the sun Species: Kind of organism Species diversity: Different kinds of plants and animals in a community Succession: Natural replacement of one community by another community Sustainable ethics: Set of views in which man and nature are one and that the earth’s resources are limited Taiga: Biome found south of North America, Asia, and Europe and characterized by coniferous forests Temperate deciduous forest: Biome characterized by deciduous tress and abundant rainfall 66 Teratogen: Agent or chemical that causes birth defects Top-down approach: Approach in solving environmental problems which involves the creation of laws and regulations that will regulate behavior Toxic substance: substance poisonous to human beings and animals Transpiration: Evaporation of water from the leaves Trophic level: Position occupied by lack of trees and low temperature Weathering: Process of breaking down rocks into small particles Wetland: Land area along freshwater and salt water Xerophytes: Plant that grows in dry or arid conditions 67 METRIC UNIT CONVERSION TABLES THE METRIC SYSTEM Standard metric Units Standard unit of mass Standard unit of length Standard unit of volume Common Prefix Kilo Centi Milli Micro (µ) Unit 1,000 0.01 0.001 One-millionth Nano (n) One-billionth Pico (p) One-trillionth Units Gram Meter Liter Abbreviations g m l Examples A kilogam is 1,000 grams A centimeter is 0.01 meter A milliter is 0.001 liter A micrometer is0.000001 (onemillionth) of a meter A nanogram is10-9 (onebillionth) of a gram A pictogram is10-12 (onebillionth) of a gram UNITS OF LENGTH Unit Meter Centimeter Millimeter Micrometer Nanometer Abbreviations m cm mm µm nm 68 Equivalent Approximately 39 in 10-2m 10-3m 10-6m 10-9m Angstrom 10-10m Ǻ Length conversions in = 2.5 cm ft = 30 cm yd = 0.9 cm mi = 1.6 km To convert Inches Feet Centimeters Millimeter mm = 0.039 in cm = 0.39 in m = 39 in m = 1.094 yd km = 0.6 mi Multiply by 2.54 30 0.39 0.039 To obtain Centimeters Centimeters Inches Inches UNITS OF VOLUME Unit Liter Milliliter Miccroliter Abbreviations l ml µl Volume conversions tsp = 5ml tbsp = 15ml fl oz = 30ml Equivalent Approximately 1.06 qt 10-3 (1ml = 1cm3 = 1cc) 10-6l Equivalent 1ml = 0.3fl oz 1l = 2.1 pt 1l = 1.06 qt 69 cup = 0.24l pt = 0.47l pt = 0.95 l gal = 3.8 l 1l = 0.26 gal To convert Fluid ounces Quarts Milliliters Liters Multiply by 30 0.95 0.03 1.06 To obtain Milliliters Liters Fluid ounces Quarts UNITS OF WEIGHT Unit Kilogram Gram Milligram Microgram Nanogram Pico gram Abbreviations kg g mg µg ng pg Equivalent 103g (approximately 2.2 lb) Approximately 0.035 oz 10-3 g 10-6 g 10-9 g 10-12 g Weight conversions 1oz = 28.3g 1lb = 453.6g 1lb = 0.45kg 1g = 0.035 oz 1kg = 2.2 lb 70 To convert Ounces Pounds Pounces Grams Kilograms Multiply by 28.3 453.6 0.45 0.035 2.2 Temperature conversions o C= F= Some equivalents 0C = 32 0F ( F − 32) * 0 To obtain grams grams kilograms ounces pounces 370C = 98.6 0F C *9 +32 100 0C = 212 0F 71 REFERENCE Barrington, Ernest, and James William Environmental Biology New York, U.S.A.: Wiley Inc., 1980 Chiras, DanielD Environmental Science: A Framework fo Decision Making California, U.S.A.: Benjamin/Cummings Publication, Co., 1988 Committee For Global Biosphere Program Global Change and Our Common Factor Washington, D.C., U.S.A.: National Academy Press, 1986 Erickson, Jon Greenhouse Earth Tomorrow’s Disaster Today Blue Ridge Summit, P.A., U.S.A.: Tab Books, 1990 Nebel, Bernard Environmental Science Englewood Cliffs, N J., U.S.A.: Prentice Hall, 1990 72