FOCUS ON EARTH SCIENCE (15)

Ecology and Resources Field of Flowers California poppies cover this meadow in Antelope Valley, at the poppy reserve This is the most consistent poppy bearing land in California 40,000–12,000 Years Ago 1861 1874–1892 Scientists have described ancient organisms from fossils found in La Brea Tar Pits (California) and organized them according to what they ate and how they related to each other First oil well in California is drilled by hand in Humboldt County John Muir writes about the natural beauty of northern California, leading to the establishment of Yosemite National Park A.D 1770 347 1770s Chinese drill oil wells as deep as 240 m using bits attached to bamboo poles Jan Ingenhousz discovers how plants react to sunlight; this leads to understanding of photosynthesis 510 (bkgd)Nik Wheeler/CORBIS, (t)Ethel Davies/ImageState, (b)Stewart Cohen/Index Stock Imagery 1840 1860 August 1859 Edwin L Drake drills first oil well in the United States in Titusville, Pennsylvania 1880 1900 To learn more about ecologists and their work, visit ca6.msscience.com Interactive Time Line To learn more about these events and others, visit ca6.msscience.com 1932 1980–1990 1996–2005 Third-largest producing oil field in the United States is discovered in Wilmington, California Wind farms are built in three California mountain passes, including near Palm Springs here shown Scientists climbing redwoods to measure their height discovered hemlock trees, huckleberry bushes, and small sea animals living in the tops of the redwoods 1920 1940 1960 1980 1931 1957 Construction begins outside Las Vegas to dam the Colorado River Hoover Dam was the largest dam at the time First full-scale nuclear power plant in the world goes into service at Shippingport, Pennsylvania 2000 2020 March 2005 Solar power station in Morocco projected to meet energy demands by 2008 511 (t)Mark Gibson, (b)Lennox McLendon/AP/Wide World Photo Ecological Roles /iÊ Êì> Living things interact with each other and with nonliving factors in ecosystems 4.a, 5.e, 7.c } > and Biotic Abiotic *VÌÕÀi ì> Factors LESSON >Êì> Living things ,i>`} and nonliving factors, iV such as air, water, sunlight, and soil, interact in Earth’s ecosystems LESSON } > 5.c, 5.d, 5.e, 7.a, 7.b, 7.d *VÌÕÀi ì> Organisms and ,i>`} iV Ecosystems >Êì> Climates and the types of life they support define biomes on Earth Ecological roles are the same in different biomes but may be filled by different species } > ì> *VÌÕÀi ,i>`} iV What’s so special about this place? This environment is located in the Sierra Nevada mountain range in California It is characterized by plants that are specially adapted to survive a drought season It also supports native animals, like these gray foxes that were once common throughout California, but are now isolated to these areas -ViViÊÊ+PVSOBM Write three questions you have about this photo that you might like to explore further 512 Kevin Schafer/CORBIS Start-Up Activities How tangled is the life web? How many things affect an animal? The sunshine and the air affect it It may eat plants and animals Think of an animal Where does it live? What is that area like? Abiotic Factors Make the following Foldable to identify the abiotic factors in an ecosystem STEP Collect two sheets of paper and layer them about cm apart vertically Keep the left edges even Procedure Write the name of an animal in a circle in the center of a blank sheet of paper Write things in the environment that affect the animal every day in circles Connect them to your animal Include interactions of the living and nonliving factors that affect your organism STEP Fold up the bottom edges of the papter to form equal tabs Crease the fold to hold the tabs in place Think About This • Determine if the animal lives in water, soil, or trees • Imagine that a factor has suddenly disappeared from the animal’s life How would your animal survive without it? STEP Staple along the fold Label as shown 5.c, 7.h LÌV >VÌÀÃ ELA6: R 2.4 Visit ca6.msscience.com to: ▶ ▶ ▶ ▶ view explore Virtual Labs access content-related Web links take the Standards Check Drawing Conclusions As you read about the abiotic factors, write their names on the tabs Include information about how each factor affects the number and types of organisms the environment can support 513 Matt Meadows Get Ready to Read Make Inferences Learn It! When you make inferences, you draw conclusions that are not directly stated in the text This means you “read between the lines.” You interpret clues and draw upon prior knowledge Authors rely on a reader’s ability to infer because all the details are not always given Practice It! Read the excerpt below and pay attention to highlighted words as you make inferences Use this Think-Through chart to help you make inferences Human activities can impact population size and therefore affect entire biomes For example, if Text Question Inferences Human activities What human activities? Resource use? people did not allow fires to burn in chaparrals, there would be no young pine trees As older trees die, they would not be replaced The animals that depend on the trees for food, shelter, and space would either die or move elsewhere Population size How can human activities affect population size? Death rates are high? Birth rates are low? Populations move? affect entire biomes How can it affect biomes? Causes changes to abiotic factors? Biotic factors? —from page 537 Apply It! As you read this chapter, practice your skill at making inferences by making connections and asking questions 514 Target Your Reading Use this to focus on the main ideas as you read the chapter ke infera m u o y es ng Sometim ing other readi s u ing ences by question s a h c u sk i l l s , s icting and pred Before you read the chapter, respond to the statements below on your worksheet or on a numbered sheet of paper • Write an A if you agree with the statement • Write a D if you disagree with the statement After you read the chapter, look back to this page to see if you’ve changed your mind about any of the statements • If any of your answers changed, explain why • Change any false statements into true statements • Use your revised statements as a study guide Before You Read A or D Statement After You Read A or D A park in the city can be an ecosystem Animals, such as cats and dogs, use energy from the Sun to make food Earth is colder near the poles because it usually is cloudy Water moves through cycles Every organism in an ecosystem depends on other organisms Populations of organisms can grow without limits Print a worksheet of this page at ca6.msscience.com More species of organisms live in tropical rain forests because of the wet, warm climate There are six major zones on Earth that support different ecological communities There are many trees in the polar tundra 10 Each species can fill many different roles in an ecosystem 515 LESSON Science Content Standards 4.a Students know the sun is the major source of energy for phenomena on Earth’s surface; it powers winds, ocean currents, and the water cycle 5.e Students know the number and types of organisms an ecosystem can support depends on the resources available and on abiotic factors, such as quantities of light and water, a range of temperatures, and soil composition 7.c Construct appropriate graphs from data and develop qualitative statements about the relationships between variables Reading Guide What You’ll Learn ▼ Explain how abiotic factors including light, temperature, air, water, and soil influence living things >Êì> Living things and nonliving factors, such as air, water, sunlight, and soil, interact in Earth’s ecosystems Real-World Reading Connection What you think of when you hear the word ecosystem? Perhaps you imagine a tropical rain forest with monkeys swinging from vine to vine, or California’s Mojave Desert, with coyotes searching for food These } are examples of ecosystems, but ecosystems > *VÌÕÀi can ì>be much smaller and closer to home ,i>`} iVis an ecosystem? What An ecosystem consists of living things, called organisms, and the physical place they live There are many types of ecosystems on Earth—coral reefs, woodlands, and ponds The patch of weeds shown in Figure may not seem like an ecosystem But if you look closely, you may find insects eating the plants or using them for shelter Robins and other birds may be searching for earthworms and other food Organisms in an ecosystem interact with each other as well as with nonliving parts of their environment ▼ Describe how systems depend on biotic and abiotic factors Abiotic and Biotic Factors Figure A patch of weeds is an ecosystem Identify the interactions that may exist in this ecosystem Why It’s Important Changes in living and nonliving factors can affect ecosystems Vocabulary ecosystem abiotic factor humus biotic factor species population community limiting factor Review Vocabulary climate: the long-term average of the weather patterns of an area (p 483) 516 Chapter 12 • Ecological Roles Cdgi]EdaZ CZVgi]ZedaZh!i]ZHjc¼hZcZg\n hig^`Zh:Vgi]ViVcVc\aZ!hegZVY^c\ djii]ZZcZg\ngZXZ^kZYdkZgVaVg\Zg VgZVi]VccZVg i]ZZfjVidg# HjcGVnh HjcGVnh :fjVidg HjcGVnh Hdji]EdaZ :VX]hfjVgZbZiZgd[VgZVVii]ZZfjVidg gZXZ^kZhbdgZZcZg\n[gdbi]ZHjci]Vc ZVX]hfjVgZbZiZgVi i]ZedaZhYdZh# Figure The climate is colder at the poles than the equator At the poles, the Sun’s energy is less intense because it reaches Earth at an angle Abiotic Factors Abiotic factors are the nonliving parts of an ecosystem Suppose you want to grow a plant in your classroom You could plant a seed in a pot of damp soil and place the pot on a sunny windowsill What are the factors affecting this plant? Soil, water, and energy from the Sun are some of the abiotic factors that help control the growth of green plants The Sun Most life on Earth depends on energy from the Sun, an important abiotic factor Green plants use energy from the Sun to make food Other animals eat those green plants Still other animals eat those animals Most organisms depend on green plants The Sun’s energy also controls many other abiotic factors in the environment Recall from Chapter that areas of Earth receive different amounts of radiation from the Sun because Earth’s surface is curved Figure shows how rays of sunlight hit Earth at a low angle at the equator This causes the land areas along the equator to be among the warmest places on Earth, and life is abundant The poles are colder because the Sun’s rays hit Earth at an angle, spreading the heat There are fewer organisms at the poles due to the harsher climate Why are the poles colder than areas near the equator? Lesson • Abiotic and Biotic Factors 517 (t)Dan Guravich/Photo Researchers, (b)Folio/Omni-Photo Communications "' Figure The temperature of the water at the surface of Earth’s oceans ranges from 30°C near the equator to 0°C at the poles * &% &* '% '* (% (* 8 Temperature Without the Sun, Earth would be a frozen wasteland The Sun’s energy warms Earth and makes it possible for humans and other organisms to survive The uneven warming of Earth’s surface from the Sun’s rays causes great temperature differences The Sun influences temperature, an abiotic factor in ecosystems Figure shows the temperatures of Earth’s oceans Temperature is one of the abiotic factors that affects plant growth Plants grow best in regions that are moderate—not too cold and not too hot Plants also grow well when the temperature does not change greatly This means that daily and seasonal temperatures are consistent Because there are more plants, regions with constant warm temperatures support the greatest numbers of living things Why you think this is the case? Animal life is dependent on green plants More types of plants and animals can live in areas where the temperatures are consistent This explains why many more species live in tropical rain forests than in deserts or polar regions Why are there more plants and animals in the tropics than the desert? 518 Chapter 12 • Ecological Roles Climate The Sun influences climate, another abiotic factor When you need to decide what to wear each morning, perhaps you start by checking the weather forecast In any area, the weather can change from day to day Climate is the pattern of weather that occurs in an area over many years You learned in Chapter xx that climate does not change from day to day, so you would not check a climate forecast to decide whether to take your raincoat along when you head out for the day Earth’s climate patterns are controlled by the temperature differences between the equator and the poles This difference creates winds and ocean currents that affect climate Scientists average temperature, precipitation, humidity, and the number of days of sunshine to determine an area’s climate For example, Figure shows zones of average temperature in the United States during the coldest time of the year Farmers and gardeners use these zones to decide what kinds of plants to grow in their part of the country Figure Climate zones are based on long-term weather patterns This map shows the average temperature for each zone at the coldest time of year Identify which states contain the zone covering –6°C to –1°C? KI L6 BI C9 BC DG CN L> H9 >9 B> LN E6 >6 C: CK >A JI 8D 86 LK BD @H D= >C D@ CB 8I C? 9: B9 C= B6 G> C8 H8 6G BH IM K6 @N IC 6O B: 6A *VÌÕÀi ì> • > Air is an abiotic } factor that affects and is affected by living things • • • • • • • *VÌÕÀiand respiration determine the concentrations of oxygen and ì> Photosynthesis carbon dioxide in the air ,i>`} • • ,i>`} iV iV A population of organisms represents a single species Populations of organisms in the same ecosystem interact as members of ecological communities • Population growth is limited by factors such as food, water, shelter, and space • Changes in populations can affect ecosystems Lesson Organisms and Ecosystems 5.c, 5.d, 5.e, 7.a, 7.b, 7.d biome (p 532) habitat (p 536) • niche (p 536) • >Êì> Climates and the types of life they support define biomes on Earth Ecological roles are the same in different biomes but may be filled by different species • abiotic factor (p 517) biotic factor (p 523) community (p 524) ecosystem (p 516) humus (p 521) limiting factor (p 524) population (p 523) species (p 523) • Ecosystems on Earth are categorized into biomes such as tundra, tropical rain forest, or grassland Each biome has a different climate and supports different types of ecological communities } > *VÌÕÀi • ì> Biomes with mild climates support a greater variety of organisms than • biomes with harsh climates ,i>`} • iV In every ecosystem, each species fills its own niche • A niche describes how a species interacts with other species and with abiotic factors in its environment • Different species may fill similar ecological roles in similar biomes 542 Chapter 12 • Standards Study Guide Download quizzes, key terms, and flash cards from ca6.msscience.com Interactive Tutor ca6.msscience.com Standards Review CHAPTER Linking Vocabulary and Main Ideas Use vocabulary terms from page 542 to complete this concept map Ecosystems include energy from the Sun temperature water include can be soil influences include air decaying organisms form climate that make up such as Each has its own that make up food water shelter space live in Visit ca6.msscience.com for: ▶ ▶ ▶ Vocabulary PuzzleMaker Vocabulary eFlashcards Multilingual Glossary Using Vocabulary Match a vocabulary term to each definition below Fill in each blank with the correct vocabulary term 10 the place an organism lives 16 The nonliving parts of the environment are called factors 11 the living parts of an ecosystem 12 Earth’s major ecological communities 17 A(n) _ is all the organisms in an area and the place they live 13 a factor that limits growth of a population 18 A single species living in an area is a(n) 14 all the interacting species in an ecosystem 15 an organism’s role in the environment—how it obtains food and shelter, cares for its young and avoids danger Chapter 12 • Standards Review 543 CHAPTER Standards Review Understanding Main Ideas Choose the word or phrase that best answers the question Which would you use to describe a collection of sea anemones, sea stars, barnacles, and other organisms that live in a tide pool? A a community 5.c B a limiting factor C an abiotic factor D a population Which measurement would you include in an assignment to measure biotic factors in a grassy area near your school? A number of hours of sunlight 5.e B number of species of insects C average air temperature D amount of rainfall Because green plants need moisture, light, and soil, what they depend on? A biotic factors 5.e B abiotic factors C ecological communities D shelter The figure below shows how the Sun’s rays hit Earth :fjVidg Why are the poles colder than the equator? A The Sun’s rays hit Earth more dispersed at the poles B The Sun’s rays hit Earth more dispersed at the equator C There are more green plants near the equator 5.e D Polar regions are usually cloudy 544 Chapter 12 • Standards Review Which group is a population? A plants and animals in a meadow 5.c B species of birds living in a rain forest C Mojave rattlesnakes in the Mojave Desert D fish and whales in the Pacific Ocean In which type of biome would you find the greatest number of species of plants and animals? A tundra 5.d B desert C chaparral D rain forest Use the figure below of a biome map to answer question IjcYgV IV^\V