6th Grade. Slide 1 / 115. Slide 2 / 115. Slide 3 / 115. Ecosystem Dynamics. Table of Contents: Ecosystem Dynamics

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1 Slide 1 / 115 Slide 2 / 115 6th Grade Ecosystem Dynamics Table of Contents: Ecosystem Dynamics Slide 3 / 115 Intro to Ecology Click on the topic to go to that section Ecological Interactions Population Dynamics Energy in Food Webs

2 Breaking It Down Lab Slide 4 / 115 What environmental factors affect the rate of decomposition? Make careful observations for the next 10 days. Slide 5 / 115 Introduction to Ecology Return to Table of Contents Ecology Slide 6 / 115 Ecology is the study of the interactions between organisms and their environment. This picture includes one squirrelfish (red), two cleaner wrasse (little blue-striped fish) and some coral. What interactions can you observe in this picture?

3 Ecology Slide 7 / 115 The squirrelfish is being cleaned by the cleaner wrasse. The cleaner wrasse are being protected by the squirrelfish. All of the fish are being protected by the coral. Organisms are able to interact with living and nonliving aspects of their environment. Levels of Organization Slide 8 / 115 Scientists often classify living things into different kinds of groups. In an ecosystem, classifications are known as levels of organization. Species Population Community Ecosystem Biome (smallest) Biosphere (largest) Species Slide 9 / 115 Species is a group of organisms that share common characteristics. Individuals within a species are only able to breed with others from the same species. Examples of different species include the following: Panda Bald Eagle Blue Spruce Pandas cannot breed with eagles because they are different species.

4 Population Slide 10 / 115 A population is a group of the same species living in the same place, at the same time. Blue and gold snappers are found in the Pacific, from Mexico down to Ecuador. Although they are all the same species, a group of snappers that live off the coast of Ecuador is a different population than a group that live off the coast of Mexico. Community Slide 11 / 115 A community is composed of all the different populations of species that live together in a given area. This deciduous forest community is composed of lots of different populations: trees deer fungus insects birds bears What are some ways that the organisms in this community interact with each other? Ecosystem Slide 12 / 115 An ecosystem includes all of the living and nonliving factors that exist in a community. What living factors do you see in this ecosystem? What nonliving factors do you see in this ecosystem?

5 Factors Slide 13 / 115 Abiotic factors are physical, nonliving factors that shape an ecosystem. Temperature Wind Sunlight Precipitation Temperature Wind Soil type Nutrient availability Nutrients Soil Slide 14 / 115 Factors Biotic factors are the living things that make up an ecosystem. Plants Animals Fungi Bacteria Biome Slide 15 / 115 A biome is a set of ecosystems that share similar characteristics. Biomes are often defined by abiotic factors such as climate, geology, moisture, and soil type. This is the tundra, the world's coldest and driest biome. The average annual temperature is -28 C. It is very windy and receives about the same amount of precipitation as the desert.

6 Biome Slide 16 / 115 Look at the map. How is a biome related to the climate of its area? Biome Slide 16 () / 115 The climate of an area describes temperature, rainfall, wind conditions and sunlight in an area. This determines what plants and animals can survive in each area. Look at the map. How is a biome related to the climate of its area? Biome There are also marine biomes. What type of marine biomes are located near you? Slide 17 / 115 Source: US Dept. of Agriculture Click here to watch a video of beautiful imagery of different biomes.

7 Biosphere Slide 18 / 115 All of the terrestrial and marine biomes blend into each other on Earth. The biosphere is the sum of all the ecosystems established on Earth. 1 Which is not a level of organization in an ecosystem? Slide 19 / 115 A Population B Neighborhood C Community D All are levels of organization in an ecosystem 1 Which is not a level of organization in an ecosystem? Slide 19 () / 115 A Population B Neighborhood C Community B D All are levels of organization in an ecosystem

8 2 A chipmunk and a ground squirrel are two different species. This means that they cannot Slide 20 / 115 A live in the same area. B interact in any way. C breed. D eat the same food. 2 A chipmunk and a ground squirrel are two different species. This means that they cannot Slide 20 () / 115 A live in the same area. B interact in any way. C breed. D eat the same food. C 3 There are many types of populations within a given community. Slide 21 / 115 True False

9 3 There are many types of populations within a given community. Slide 21 () / 115 True False True 4 Which is not true of ecosystems? Slide 22 / 115 A Ecosystems only contain living things. B Ecosystems contain both living and non-living things. C Ecosystems are found on both land and in water. D Ecosystems only contain several communities. 4 Which is not true of ecosystems? Slide 22 () / 115 A Ecosystems only contain living things. B Ecosystems contain both living and non-living things. A C Ecosystems are found on both land and in water. D Ecosystems only contain several communities.

10 5 Which of the following is not an abiotic factor? Slide 23 / 115 A rocks B water C soil D All are abiotic factors 5 Which of the following is not an abiotic factor? Slide 23 () / 115 A rocks B water C soil D D All are abiotic factors 6 Which is not a biotic factor? Slide 24 / 115 A people B plants C sunlight D All are biotic factors

11 6 Which is not a biotic factor? Slide 24 () / 115 A people B plants C sunlight C D All are biotic factors 7 All biomes have similar climates. Slide 25 / 115 True False 7 All biomes have similar climates. Slide 25 () / 115 True False False Different climates create different biomes.

12 Stranded! Activity Slide 26 / 115 You are stranded in your biome! Conduct research and think carefully in order to determine what items you need in order to survive? Slide 27 / 115 Ecological Interactions Return to Table of Contents Ecological Interactions Organisms in an ecosystem interact with their surroundings in numerous ways. They can interact with both biotic and abiotic components. Slide 28 / 115 Remember this squirrelfish? List a biotic and abiotic interaction of the squirrelfish with its environment.

13 Ecological Interactions Organisms in an ecosystem interact with their surroundings in numerous ways. They can interact with both biotic and abiotic components. Biotic: The cleaner wrasse clean parasites off the squirrelfish. Remember this squirrelfish? Abiotic: Hiding under the coral protects the squirrelfish. List a biotic and abiotic interaction of the squirrelfish with its environment. Slide 28 () / 115 Habitat Slide 29 / 115 The term habitat describes the specific area where an organism lives within an ecosystem. A habitat is like an organism's home within an ecosystem. An organism's habitat answers the question "Where do you live?". Habitat Slide 30 / 115 This penguin's habitat is the ice shelves of Antarctica. The saguaro cactus's habitat is the desert of the southwestern US.

14 Niche Slide 31 / 115 An organism's niche is a description of the role it plays in its habitat. A niche includes all aspects of where and how an organism lives including: * the type of food it eats * how it obtains food * where it lives in its environment (tree, nest, hive, etc.) * when and how it reproduces Niche Slide 32 / 115 An organism's niche answers the question "How do you make a living?". Komodo Dragon Niche Komodo dragons live in the Indonesian Islands. They hunt and ambush invertebrates, birds and mammals. They lay up to 20 eggs at a time in self-dug holes. The eggs incubate for eight months. Komodo dragons take nine years to mature and can live up to 30 years. 8 The Venus flytrap lives in subtropical wetlands where the soil is low in nitrogen and phosphorus. This is a description of the Venus flytrap's Slide 33 / 115 A habitat. B niche.

15 8 The Venus flytrap lives in subtropical wetlands where the soil is low in nitrogen and phosphorus. This is a description of the Venus flytrap's Slide 33 () / 115 A habitat. B niche. A 9 The Venus flytrap is a carnivorous plant that catures insects and arachnids that crawl on its leaves. Although they produce food via photosynthesis, their prey gives them nutrients that are lacking in their environment. They are perennial plants, meaning that they flower every year. This is a description of the Venus flytrap's A habitat. Slide 34 / 115 B niche. 9 The Venus flytrap is a carnivorous plant that catures insects and arachnids that crawl on its leaves. Although they produce food via photosynthesis, their prey gives them nutrients that are lacking in their environment. They are perennial plants, meaning that they flower every year. This is a description of the Venus flytrap's B A habitat. Slide 34 () / 115 B niche.

16 Needs of Organisms Slide 35 / 115 All organisms need certain things to survive. How many can you think of? Write your ideas below. Organisms need... Slide 36 / 115 Food Water Shelter Air Importance of the Environment Slide 37 / 115 Organisms are constantly interacting with biotic and abiotic factors in their ecosystems in order to obtain food, water, shelter and air. This beaver gets food by eating plant life. He gets water from the local river or stream by which he lives. He gets air from the surrounding atmosphere. He makes their own shelter by building a den out of wood. In what ways does this beaver interact with biotic factors in the environment? How about abiotic factors?

17 Importance of the Environment Slide 37 () / 115 Organisms are constantly interacting with biotic and abiotic factors in their ecosystems in order to obtain food, water, shelter and air. This beaver gets food by eating plant Biotic: eating life. He plant gets life, water using from wood the local river for shelter or stream by which he lives. He gets air Abiotic: from drinking the surrounding water, breathing atmosphere. He makes their air own shelter by building a den out of wood. In what ways does this beaver interact with biotic factors in the environment? How about abiotic factors? Ecological Interactions Every organism in an ecosystem survives by obtaining their needs from the environment. Slide 38 / 115 The act of obtaining these needs leads to different types of interactions within an ecosystem. Competition Predator/prey Mutually beneficial Clownfish receive shelter from the anemone and the anemone receives nutrition from the presence of the clownfish. This is a mutually beneficial interaction. Obtaining Needs Slide 39 / 115 As organisms try to survive in an ecosystem, their needs sometimes overlap with other organisms. Consider the beaver again. The beaver eats plant life. Many other rodents, however, also eat plant life. If there are more beavers and rodents than there are available plant life, what will happen? Write your thoughts below:

18 Competition Slide 40 / 115 Organisms in ecosystems often have needs that overlap with one another. Perhaps they eat the same food or they use the same type of shelter. When there are more organisms than there are resources, this leads to competition. Organisms must compete, or fight, for resources in order to survive. In this picture, three different types of animals are competing to eat the dead zebra. Can you find all three? Competition in Plants Slide 41 / 115 Although we often think of animals when we talk about competition, plants also compete for resources Plants compete for water, access to light, the minerals in the soil and attention of certain animals for pollination and seed dispersion. Interspecific Competition Slide 42 / 115 Competition can occur between different species or between members of the same species. Interspecific competition occurs between members of different species. (Hint: "inter" means between) Different plants on the forest floor must compete for sunlight in order to survive.

19 Intraspecific Competition Slide 43 / 115 Intraspecific competition occurs between members of the same species. (Hint:"intra" means among) For what resource(s) might these polar bears be fighting? Case Study: Competition Competition occurs in a variety of ways over a variety of resources. Click below to watch a video about lion and hyena competition. Then, answer the questions. Click here to watch the competition video. Slide 44 / For what resource do hyenas and lions compete? 2. What is an example of interspecific competition in the video? 3. What is an example of intraspecific competition in the video? Case Study: Competition Competition occurs in a variety of ways over a variety of resources. Click below to watch a video about lion and hyena competition. Then, answer the questions. 1. Food 2. Interspecific competition Click here to watch the competition video. occurs between the lion and the hyenas. 1. For what resource do 3. Intraspecific competition hyenas and lions occurs among the hyenas as they fight for the compete? food at the end of the 2. video. What is an example of interspecific competition in the video? 3. What is an example of intraspecific competition in the video? Slide 44 () / 115

20 10 Competition occurs when organisms fight over resources in order to survive. Slide 45 / 115 True False 10 Competition occurs when organisms fight over resources in order to survive. Slide 45 () / 115 True False True 11 Deer and squirrels both eat acorns. This behavior can lead to competition. Slide 46 / 115 A interspecific B intraspecific

21 11 Deer and squirrels both eat acorns. This behavior can lead to competition. Slide 46 () / 115 A interspecific B intraspecific A 12 Male deer often lock antlers when they compete over territory. This is an example of competition. Slide 47 / 115 A interspecific B intraspecific 12 Male deer often lock antlers when they compete over territory. This is an example of competition. Slide 47 () / 115 A interspecific B intraspecific B

22 Predator/Prey Interactions Slide 48 / 115 Predator/prey interactions occur as a result of organisms obtaining food to survive. The animal that is doing the hunting is called the predator, while the animal being hunted is the prey. Identify the predator and prey in each picture. Predators and Prey Slide 49 / 115 Not all predators are big animals, and they're not always bigger than their prey. In any one ecosystem, there are many different predator prey interactions. Click here to watch a video about the Okavango delta in Botswana, Africa. Mutually Beneficial Interactions Slide 50 / 115 In both competition and predator/prey interactions, one organisms benefits while the other organism suffers. In mutually beneficial interactions, all organisms benefit from the interaction. The oxpeckers on the back of this hippo are looking for food to eat. They eat parasites, like ticks, from the backs of animals. How is this a mutually beneficial relationship?

23 Mutually Beneficial Interactions Slide 50 () / 115 In both competition and predator/prey interactions, one organisms benefits while the other organism suffers. In mutually beneficial interactions, In order to all be organisms mutually beneficial, benefit from the interaction. both organisms must benefit. In this relationship, the oxpeckers get food. The hippo benefits by having parasites removed from its body The (increased oxpeckers health). on the back of this hippo are looking for food to eat. They [This eat object parasites, is a pull like ticks, from the backs of animals. How is this a mutually beneficial relationship? Mutually Beneficial Interactions Slide 51 / 115 Click on the image below to watch a video about a relationship between ants and the acacia tree. Then, answer the questions. 1. Describe two ways that the ants benefit the tree. 2. Describe how the tree benefits the ant. Mutually Beneficial Interactions Slide 51 () / 115 Click on the image below 1. to watch The ants a video remove about any a relationship between ants and the acacia growing tree. Then, vines. answer They the fight questions. off any insects. 2. The tree provides the ants with nectar. 1. Describe two ways that the ants benefit the tree. 2. Describe how the tree benefits the ant.

24 Pollination 75% of all living flowering plants are pollinated by animals. Pollination is essential for these plants' survival and represent an important type of mutually beneficial relationship. Animals receive nutrition (nectar, pollen) while the plant is pollinated. Slide 52 / 115 Obligate Mutualism Some mutually beneficial relationships are so special that they have become necessary for the organisms to survive. This is called obligate mutualism. The yucca tree, for example, is only pollinated by the yucca moth. The yucca moth also lays eggs inside of the flower and the larvae are able to eat some of the seeds as they develop. Without the yucca moth, the yucca tree would die because it would not be pollinated. Without the yucca tree, the yucca moth would have no method for the development of the larvae. Slide 53 / 115 Case Study: Coral Reef Interactions Slide 54 / 115 Click here to watch a video about coral reef ecology. Then, answer the questions on the Coral Reef Interactions Worksheet.

25 Case Study: Coral Reef Interactions Slide 54 () / 115 Click here to watch a video about coral reef ecology. Then, answer the questions on the 1. Coral Reefs Reef provide Interactions food and Worksheet. shelter to other animals. 2. Interspecific competition 3. Algae, called zooxanthellae, live inside of coral polyps. The zooxanthellae receive shelter. In exchange, they carry out photosynthesis and provide food to the corals. 4. Crown of thorns sea stars and parrot fish eat corals. Corals eat plankton. 5. s will vary. 13 Which animal is the prey? Slide 55 / 115 A Cow B Grass 13 Which animal is the prey? Slide 55 () / 115 A Cow B Grass B

26 14 Predator/prey interactions result from animals trying to meet their needs for shelter. Slide 56 / 115 True False 14 Predator/prey interactions result from animals trying to meet their needs for shelter. Slide 56 () / 115 True False False 15 In a mutually beneficial interaction, Slide 57 / 115 A both organisms are harmed. B one organism is harmed while the other benefits. C both organisms benefit. D one organism benefits while the other experiences no impact.

27 15 In a mutually beneficial interaction, Slide 57 () / 115 A both organisms are harmed. B one organism is harmed while the other C benefits. C both organisms benefit. D one organism benefits while the other experiences no impact. 16 Some flowers are shaped so that only the beak of a specific hummingbird can reach to the bottom to pollinate the flower. For this flower, the mutually beneficial interaction can be described as. Slide 58 / 115 A obligate B harmful C abiotic D unnecessary 16 Some flowers are shaped so that only the beak of a specific hummingbird can reach to the bottom to pollinate the flower. For this flower, the mutually beneficial interaction can be described as. Slide 58 () / 115 A obligate B harmful C abiotic D unnecessary A

28 Slide 59 / 115 Population Dynamics Return to Table of Contents Population Size Slide 60 / 115 Remember that a population is a group of the same species living together in one area. The size of a population is always changing based on biotic factors, abiotic factors and all interactions affecting that population. Think back to corals. What is an example of a biotic factor, an abiotic factor and an interaction that would affect coral population size? Source: NOAA Photo Library Population Size Slide 60 () / 115 Remember that a population is a group of the same species living together in one area. s will vary. Examples: The size of a population Biotic is always factors: changing presence based of on biotic factors, abiotic factors and all plankton, interactions health affecting of zooxanthellae that population. Abiotic factors: sunlight, water temperature Interactions: predator/prey with parrotfish, intraspecific Think back competition to corals. for What is an sunlight example of a biotic factor, an abiotic factor and an interaction that would affect coral population size? Source: NOAA Photo Library

29 Population Size Slide 61 / 115 Suppose that we think about your family as a distinct population. How would the following events affect your population? Would they increase it or decrease it? Click in the box to check your answers. Your mom has a baby. A grandparent dies. Your older brother gets married and brings home his new wife. Increase Decrease Increase Population Growth Slide 62 / 115 Populations in ecosystems work much the same way. Populations increase when: new organisms are born organisms immigrate, or join, the population Population Growth Slide 63 / 115 Populations decrease when: organisms die organisms emigrate, or leave, a population Illegal poaching of elephants for their ivory tusks severely decreased many elephant populations.

30 Resources As populations try to obtain the resources necessary for survival, their population size changes accordingly. Slide 64 / 115 Consider a population of deer in a forest. For most of the year, they eat plants, fruit, seeds and nuts. During the winter, however, it is more difficult for them to find food. They will eat whatever they can find, including twigs, leaves and bark. If they are unable to find food, how will this affect their population size? Population will decrease. Resources Slide 65 / 115 Think about how resources impact population size. Complete the blanks in the following statements. Click on the boxes to check your answers. When resources are readily available, population size will increase. When resources are not available, population size will decrease. 17 When plenty of resources are available, a population will decrease. Slide 66 / 115 True False

31 17 When plenty of resources are available, a population will decrease. Slide 66 () / 115 True False False 18 What conditions will cause a population to decrease? Select all that apply. Slide 67 / 115 A New organisms are born. B Organisms die. C Emigration of organisms. D Immigration of organisms. 18 What conditions will cause a population to decrease? Select all that apply. Slide 67 () / 115 A New organisms are born. B Organisms die. C Emigration of organisms. B, C D Immigration of organisms.

32 Interspecific Competition Slide 68 / 115 In the grasslands of Africa, lions, leopards and hyenas all compete for the same food source. How do you think this affects their population sizes? Interspecific Competition Slide 69 / 115 In interspecific competition, the strongest competitor will gain access to additional resources and experience a population increase. The weakest competitor will not have access to necessary resources and will experience a population decrease. If lions continually fight off hyenas, then lions will eat more food and have a stable or increasing population. Hyenas will eat less food and will have a decreasing population. Intraspecific Competition Slide 70 / 115 Suppose that the oak tree in your front yard is discovered by a population of squirrels. The oak tree is tall and wide, offering abundant food and shelter. In light of these abundant resources, what do you predict will happen to the squirrel population? The squirrel population will increase.

33 Intraspecific Competition Slide 71 / 115 Over the next several years, the squirrel population increases dramatically due to the availability of shelter and food. During this time, the tree continues to be healthy and produces the same amount of food and offers the same amount of shelter. The amount of shelter and food necessary to allow the squirrel population to survive, however, has increased. What do you predict will happen to this squirrel population now? Since there is a large population but limited resources, the squirrel population will decrease due to intraspecific competition. Source: wildlifehotline.com Population Growth Slide 72 / 115 For any population, in the presence of plentiful resources, the population will increase. However, as the population grows, the amount of resources necessary for survival also grows. Population Growth Slide 73 / 115 If the population becomes bigger than the resources available, individuals will have to compete in order to survive (intraspecific competition).

34 Carrying Capacity Slide 74 / 115 Eventually, the population will level out at a certain size that is a balance between individuals and resources available. The population size that allows the largest population that can survive given the available resources is called the carrying capacity. 19 Interspecific competition can cause: Slide 75 / 115 A one population to decrease while another population increases. B both populations to increase. C both populations to decrease. 19 Interspecific competition can cause: Slide 75 () / 115 A one population to decrease while another population increases. B both populations to increase. C both populations to decrease. A

35 20 When a population is introduced to unlimited resources, what will happen? Slide 76 / 115 A Population size will remain the same. B Population size will dramatically decrease. C Population size will dramatically increase. 20 When a population is introduced to unlimited resources, what will happen? Slide 76 () / 115 A Population size will remain the same. B Population size will dramatically decrease. C C Population size will dramatically increase. 21 When does intraspecific competition affect population size? Slide 77 / 115 A When resources are plentiful. B When resources are limited. C When interspecific competition is also present. D When a new environment is introduced.

36 21 When does intraspecific competition affect population size? Slide 77 () / 115 A When resources are plentiful. B When resources are limited. C When interspecific competition is also present. D When a new environment is introduced. B 22 When a population reaches its carrying capacity, what does this mean? Slide 78 / 115 A There are enough resources for the population to increase. B Interspecific competition forces the population to decrease. C Predation controls the size of the population. D The population has reached a size that can be maintained by available resources. 22 When a population reaches its carrying capacity, what does this mean? Slide 78 () / 115 A There are enough resources for the population to increase. D B Interspecific competition forces the population to decrease. C Predation controls the size of the population. D The population has reached a size that can be maintained by available resources.

37 Predator Prey Interactions Slide 79 / 115 Predator prey interactions also affect population size. The lynx is the predator of the snowshoe hare. The population of each is dependent on the other. Predator Prey Interactions Slide 80 / 115 Think about predators and prey. How do you think the prey population is dependent on the predator? How do you think the predator population is dependent on the prey? Case Study: Predator Prey Slide 81 / 115 Suppose you are studying a population of snowshoe hare (red) and lynx (green). When you begin the study, both populations are equal. List below the number of each in the population. Lynx: Hare:

38 Case Study: Predator Prey Slide 82 / 115 A disease enters the ecosystem and kills half of the lynx population. Cross off half of the lynx population below and then write the new population count. Lynx: Hare: What do you think will happen to the hare population? Case Study: Predator Prey Slide 83 / 115 Because the predator's population has been cut in half, the hare population is not being eaten as much. The hare population increases. Write the new population count. Lynx: Hare: How do you think the populations will change next? Case Study: Predator Prey Slide 84 / 115 Although the lynx population is small, it has an abundant food source due to the rise in hare population. Draw in 4 more lynx circles. Take away 4 hare circles due to increased predation. Write the new population count. Lynx: Hare:

39 Predator Prey Interactions Slide 85 / 115 Predators and prey are dependent on each other. If one population changes, it will create a change in the other population. Think about how predators and prey interact. Decide if each of the occurrences below would result in an increase or decrease. Prey population decreases. Predator population decreases. Predator population decreases. Prey population increases. Prey population increases. Predator population increases. Predator population increases. Prey population decreases. 23 Prey populations are dependent on predators but predator populations are not dependent on prey. Slide 86 / 115 True False 23 Prey populations are dependent on predators but predator populations are not dependent on prey. Slide 86 () / 115 True False False

40 24 Crown of thorn sea stars are predators of coral. If coral bleaching destroys the coral in an ecosystem, what will happen to the crown of thorns sea star population? A increase Slide 87 / 115 B decrease 24 Crown of thorn sea stars are predators of coral. If coral bleaching destroys the coral in an ecosystem, what will happen to the crown of thorns sea star population? A increase B decrease B Slide 87 () / Ospreys are birds of prey that feed on fish. Suppose that one population of osprey is moved from their ecosystem because of human development. This population joins another population. The new population is now doubled in size. How will this affect the fish population? A increase Slide 88 / 115 B decrease

41 25 Ospreys are birds of prey that feed on fish. Suppose that one population of osprey is moved from their ecosystem because of human development. This population joins another population. The new population is now doubled in size. How will this affect the fish population? B A increase Slide 88 () / 115 B decrease Coral Reef Fish Survey Activity Slide 89 / 115 How do scientists gather information about the sizes of populations? Learn how to conduct a belt transect on coral reef fish in this simulation. Slide 90 / 115 Energy in Food Webs Return to Table of Contents

42 Healthy Ecosystem Slide 91 / 115 A healthy ecosystem is composed of: Producers Consumers Decomposers What do you already know about these categories? Can you think of examples of organisms that fit into each category? Producers Slide 92 / 115 Plants are called producers because they make their own food. They do this by using light energy from the sun, carbon dioxide from the air, and water from the soil to produce food. Consumers Slide 93 / 115 Organisms that cannot make their own food are called consumers. They survive by consuming plants and animals. There are three groups of consumers : Herbivores, Omnivores, and Carnivores.

43 Herbivores Slide 94 / 115 Herbivores are animals that get their energy from eating only plants. Omnivores Slide 95 / 115 Omnivores eat both plants and animals. Carnivores A carnivore is an animal that eats only other animals. Slide 96 / 115

44 Decomposers Slide 97 / 115 Bacteria and fungi are decomposers. They eat decaying matter (dead plants and animals). By doing this, they break them down and help them decompose. During decomposition, nutrients and minerals are released back into the soil. The nutrient-rich soil helps plants grow. Why are decomposers important? Slide 98 / 115 Decomposers are an essential part of the ecosystem. Consider a forest. When you walk in a forest, there are usually leaves and dead plants littering the ground. There are also dead animals that end up on the forest floor. What happens to these dead organisms? Why are there not piles and piles of dead organisms all over the forest? Why are decomposers important? Slide 99 / 115 Decomposers eat dead plants and animals. By doing this, they eliminate a buildup of dead organisms. This process also recycles nutrients. The nutrients settle back into the soil, creating healthier soil. Healthy soil supports healthy plants that can create their own food and support the entire ecosystem. In this way, energy is constantly moving through an ecosystem, from one group to another. Producers Consumers Decomposers

45 26 Some animals can be called producers since they are food for other animals. Slide 100 / 115 True False 26 Some animals can be called producers since they are food for other animals. Slide 100 () / 115 True False False Some organisms are producers because they make their own food. 27 Herbivores, omnivores, and carnivores are all. Slide 101 / 115 A Producers B Consumers C Decomposers D None of the above

46 27 Herbivores, omnivores, and carnivores are all. Slide 101 () / 115 A Producers B Consumers C Decomposers B D None of the above 28 Decomposers are important because they make soil nutritious for other organisms. Slide 102 / 115 True False 28 Decomposers are important because they make soil nutritious for other organisms. Slide 102 () / 115 True False True

47 Ecosystem Interactions Slide 103 / 115 One way to illustrate the transfer of energy in an ecosystem is through food chains and food webs. Think about the difference between a chain and a web. How do you think this relates to food chains and food webs? Food Chain A food chain shows one pathway of energy flow in an ecosystem. Slide 104 / 115 Each arrow shows where the energy is going. The energy in grass goes to the grasshopper when the grasshopper eats the grass. Food Web Slide 105 / 115 In most communities, relationships are more complex than can be shown in a single food chain and energy flows in more than one direction. A food web is a diagram that shows the complex interactions and feeding relationships between all organisms in an ecosystem.

48 Atoms Slide 106 / 115 As energy moves throughout the food webs it does so as atoms. Atoms are the small building blocks that make up all matter. They are the smallest particle of an element. Cycle of Atoms Slide 107 / 115 Atoms of both the living and nonliving things in an ecosystem are repeatedly transferred. As the atoms move along, they transfer energy and nutrients. Matter Cycles Through the Food Web Slide 108 / 115 If it was possible to label a single Carbon atom, for example,we could track it cycling through the entire food chain.

49 Aquatic Food Web Slide 109 / 115 The same can be said about an atom cycling through an aquatic food web. Aquatic Food Web Slide 109 () / 115 Teacher Notes It is important to emphasize that all organisms are part of a food web, even though most examples to this point have been terrestrial. The same can be said about an atom cycling through an aquatic food web. [This object is a teacher notes pull Ecosystem Interactions Slide 110 / 115 By looking at food chains and food webs, we can hypothesize (guess) what will happen to organisms if certain changes occur. If a disease destroys the grasshopper population, the snake population will have nothing to eat and that population will decrease as well. If the grasshopper population is destroyed, what would happen to the grass population?

50 Ecosystem Interactions Slide 110 () / 115 By looking at food chains and food webs, we can hypothesize (guess) what will happen to organisms if certain changes occur. Since the grass no If a longer disease has destroys a the predator, its population will grasshopper population, increase. the snake population will have nothing to eat and that population will decrease as well. If the grasshopper population is destroyed, what would happen to the grass population? 29 Food chains follow a single path of energy flow. Slide 111 / 115 True False 29 Food chains follow a single path of energy flow. Slide 111 () / 115 True False True

51 30 Food are connected by many different paths. Slide 112 / 115 A webs B chains 30 Food are connected by many different paths. Slide 112 () / 115 A webs B chains A 31 If a disease destroys the dragonfly population, what animal population will not decrease? Slide 113 / 115 A Salamander B Trout C Frog D Phytoplankton Source: EPA

52 31 If a disease destroys the dragonfly population, what animal population will not decrease? Slide 113 () / 115 A Salamander B Trout C Frog D D Phytoplankton Source: EPA 32 Scientists discover that the trout population has become toxic due to pollution in the water. What other population should they monitor for toxicity? Slide 114 / 115 A Mayfly B Bald eagle C Dragonfly D Salamander Source: EPA 32 Scientists discover that the trout population has become toxic due to pollution in the water. What other population should they monitor for toxicity? Slide 114 () / 115 A Mayfly B Bald eagle C Dragonfly B D Salamander Source: EPA

53 Desert Food Web Activity Slide 115 / 115 Food webs show the flow of energy through an ecosystem. Use the given information to create a food web for a desert ecosystem.