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1. Interactions of Living Things Chapter 16 Preview Section 1 Everything is Connected Section 2Living Things Need Energy Section 3Types of Interactions Concept Map < Back Next > Preview Main

2. Section 1 Everything is Connected Chapter 16 Bellringer Brainstorm a list of things that you might find in a pond ecosystem. Select an organism from your list. Then, identify two living things and two nonliving things in the ecosystem that help that organism survive. Write your answers in your Science Journal.

3. Section 1 Everything is Connected Chapter 16 What You Will Learn • Biotic factors are the effects of living organisms on each other and on the environment. • Abiotic factors are the nonliving parts of the environment. • Ecosystems are made up of organisms and the abiotic factors of the environment.

4. Section 1 Everything is Connected Chapter 16 Studying the Web of Life • In the web of life, energy and other resources flow between organisms and their environment. • Ecology is the study of the interactions of organisms with each other and with their environment. • An organism’s environment is made up of all of the factors that affect the organism.

5. Section 1 Everything is Connected Chapter 16 Studying the Web of Life, continued • The nonliving factors, such as water, soil, light, and temperature, make up the abiotic factors of the environment. • The interactions between organisms in an area, such as competition, make up the biotic factors of the environment.

6. Section 1 Everything is Connected Chapter 16 Studying the Web of Life, continued • The environment can be arranged into six levels. • Biosphere • Biome • Ecosystem • Community • Population • Individual

7. Section 1 Everything is Connected Chapter 16 Studying the Web of Life, continued

8. Section 1 Everything is Connected Chapter 16 Studying the Web of Life, continued Populations • Each plant and animal is part of a population. • A population is a group of individuals of the same species that live together. • Individuals in a population often compete with each other for food, shelter, and mates.

9. Section 1 Everything is Connected Chapter 16 Studying the Web of Life, continued Communities • A community is made up of all of the populations of organisms that live and interact in an area. • The populations in a community depend on each other for many things, such as shelter and food. • For example, an animal obtains energy, nutrients, and some water by eating other organisms.

10. Section 1 Everything is Connected Chapter 16 Studying the Web of Life, continued Ecosystems • An ecosystem is made up of a community of organisms and their abiotic environment. • In an ecosystem, energy and other resources flow between organisms and their physical environment.

11. Section 1 Everything is Connected Chapter 16 Studying the Web of Life, continued • For example, the river that empties into a salt marsh ecosystem, carries nutrients such as nitrogen. • The cordgrass will grow more quickly because of the extra source of nutrients.

12. Section 1 Everything is Connected Chapter 16 Studying the Web of Life, continued

13. Section 1 Everything is Connected Chapter 16 Studying the Web of Life, continued Biomes • A biomeis made up of many ecosystems. • A biome is an area where the climate typically determines the plant community. • For example, a typical desert biome receives little rainfall, is hot during the day, and cold at night.

14. Section 1 Everything is Connected Chapter 16 Studying the Web of Life, continued • Desert plants and animals are suited to these climate conditions. • Some of these desert organisms would not survive in a biome that received snow, or one that received ample rain. • Similar biomes are found in different parts of the world where the climate is similar.

15. Section 1 Everything is Connected Chapter 16 Studying the Web of Life, continued The Biosphere • The biosphere is the part of Earth where life exists. • It extends from the deepest parts of the oceans and Earth’s crust, to high in the air where spores drift. • Scientists study the biosphere to learn how organisms interact with the abiotic environment.

16. Section 2 Living Things Need Energy Chapter 16 Bellringer Do you think the flowering plant Indian pipe is a producer or a consumer? Where does it get the energy it needs to survive? Write your answers in your Science Journal.

17. Section 2 Living Things Need Energy Chapter 16 What You Will Learn • Producers, consumers, and decomposers have specific functions in an ecosystem. • Energy flows from one organism to another in food chains. Many food chains make up a food web. • The availability of living and nonliving resources affects all organisms.

18. Section 2 Living Things Need Energy Chapter 16 The Energy Connection • Organisms in every community can be divided into three groups: producers, consumers, and decomposers. • Organisms that change the energy in sunlight into chemical energy or food are called producers. • Producers convert sunlight into food through the process of photosynthesis.

19. Section 2 Living Things Need Energy Chapter 16 The Energy Connection, continued • Most producers are green plants, but algae and some bacteria are also producers. • Grasses are the main producers in a prairie ecosystem. • Cordgrass and algae in a salt marsh are also producers.

20. Section 2 Living Things Need Energy Chapter 16 The Energy Connection, continued • Consumers must eat other organisms to obtain energy and nutrients. • A consumer that eats only plants is called an herbivore. • A consumer that eats other animals is called a carnivore.

21. Section 2 Living Things Need Energy Chapter 16 The Energy Connection, continued • A consumer that eats both plants and animals is called an omnivore. • Scavengers are omnivores that eat dead animals and plants.

22. Interactions of Living Things Chapter 16 Comparing Consumers and Producers

23. Section 2 Living Things Need Energy Chapter 16 The Energy Connection, continued • Organisms that get energy and nutrients by breaking down dead organisms are called decomposers. • Bacteria and fungi are decomposers. • Decomposers produce simple materials, such as carbon dioxide and water, that can be used by other organisms.

24. Section 2 Living Things Need Energy Chapter 16 The Energy Connection, continued Food Chains • A food chain is a diagram that shows how energy and nutrients are transferred from one organism to another. • Producers, such as plants, form the base of the food chain.

25. Section 2 Living Things Need Energy Chapter 16 The Energy Connection, continued • Herbivores, such as prairie dogs, are also called primary consumers because they are the first consumers in the food chain. • Organisms, such as coyotes, that eat primary consumers are called secondary consumers. • Organisms that eat secondary consumers are called tertiary consumers.

26. Section 2 Living Things Need Energy Chapter 16 The Energy Connection, continued

27. Section 2 Living Things Need Energy Chapter 16 The Energy Connection, continued Food Webs • A food web is a diagram that shows the feeding relationships between organisms in an ecosystem. • The energy and nutrient connections in nature are more accurately shown by a food web than by a food chain.

28. Section 2 Living Things Need Energy Chapter 16 The Energy Connection, continued

29. Section 2 Living Things Need Energy Chapter 16 The Energy Connection, continued • Energy moves from one organism to another in one direction in a food web. • Each organism uses energy for its life processes. • During these processes, some energy is lost to the environment as heat.

30. Section 2 Living Things Need Energy Chapter 16 The Energy Connection, continued • Any energy not immediately used by an organism is stored in its cells. • Only the energy stored in an organism’s cells can be used by the next consumer.

31. Section 2 Living Things Need Energy Chapter 16 The Energy Connection, continued Energy Pyramids • Only a small part of the energy an organism obtains is transferred to the next consumer in a food chain. • Thus, more organisms have to be at the base of a food chain than at the top of a food chain.

32. Section 2 Living Things Need Energy Chapter 16 The Energy Connection, continued • The amount of energy at each level of a food chain can be seen in an energy pyramid. • An energy pyramid is a diagram that shows an ecosystem’s loss of energy. • Only about 10% of the energy in each level of the energy pyramid is transferred to the next level of the pyramid.

33. Section 2 Living Things Need Energy Chapter 16 The Energy Connection, continued

34. Section 2 Living Things Need Energy Chapter 16 Wolves and the Energy Pyramid • Even a single species can be very important to the flow of energy in an environment. • Gray wolves are consumers that control the populations of many other animals. • Wolves are predators that belong at the top of the energy pyramid.

35. Section 2 Living Things Need Energy Chapter 16 Wolves and the Energy Pyramid, continued • As the wilderness of the United States was settled, gray wolves were nearly wiped out. • Without wolves, elk populations were no longer controlled, so these populations grew. • The overpopulation of elk in some areas led to overgrazing.

36. Section 2 Living Things Need Energy Chapter 16 Wolves and the Energy Pyramid, continued • Overgrazing left too little grass to support elk and other herbivores. • The decline in grass led to a decline in herbivores, which led to a decline in predators in the area. • Soon, almost all of the species in the area were affected by the loss of the gray wolf.

37. Section 2 Living Things Need Energy Chapter 16 Wolves and the Energy Pyramid, continued • Gray wolves were reintroduced into Yellowstone National Park in 1995. • As the wolves become established, they kill old, injured, and diseased elk. • The smaller elk population is allowing more plants to grow.

38. Section 2 Living Things Need Energy Chapter 16 Wolves and the Energy Pyramid, continued • The numbers of herbivores, such as snowshoe hares, and the carnivores that eat them, such as fox, are increasing. • The reintroduction of wolves appears to be balancing the Yellowstone ecosystem. • However, area ranchers worry about wolves eating their livestock.

39. Section 3 Types of Interactions Chapter 16 Bellringer Create a list of predators that are also prey. Write your answers in your Science Journal.

40. Section 3 Types of Interactions Chapter 16 What You Will Learn • Limiting factors determine the carrying capacity of an environment. • Competition occurs when two or more organisms try to use the same resource.

41. Section 3 Types of Interactions Chapter 16 What You Will Learn, continued • Prey have unique characteristics to avoid predation. • Mutualism, commensalism, and parasitism are three kinds of symbiotic relationships that exist between organisms.

42. Section 3 Types of Interactions Chapter 16 Interactions with the Environment Limiting Factors • Populations cannot grow without limits, because the environment contains a limited amount of food, water, living space, and other resources. • A resource that is so scarce that it limits the size of a population is called a limiting factor.

43. Section 3 Types of Interactions Chapter 16 Interactions with the Environment, continued Carrying Capacity • The largest population that an environment can support is known as the carrying capacity. • When a population grows larger than the carrying capacity, limiting factors in the environment cause individuals to die or leave.

44. Section 3 Types of Interactions Chapter 16 Interactions with the Environment, continued • As individuals die or leave, the population size decreases. • During a rainy season, plants may produce a large crop of seeds and leaves. • This abundance of food may cause an herbivore population to grow.

45. Section 3 Types of Interactions Chapter 16 Interactions with the Environment, continued • If rainfall decreases the following year, there won’t be enough food for the herbivore population. • The population has become larger than the carrying capacity. • Lack of food or other limiting factors will cause the population to decrease.

46. Section 3 Types of Interactions Chapter 16 Interactions Among Organisms • The three main relationships through which species affect each other are: • competitive relationships • predator and prey relationships • symbiotic relationships.

47. Section 3 Types of Interactions Chapter 16 Competition • Competition happens when two or more individuals or populations try to use the same resource. • Resources such as food, water, shelter, or sunlight may be in limited supply in the environment. • When one individual or population uses more of a resource, less is available to other organisms.

48. Section 3 Types of Interactions Chapter 16 Competition, continued • Competition can happen between individuals within a population. • Elk in Yellowstone National Park compete for the same food plants in the park. • Competition is especially high in the cold winter, when fewer plants are available.

49. Section 3 Types of Interactions Chapter 16 Competition, continued • Competition can reduce the size of a population. • Competition can also happen between populations. • Different plant species compete with each other for sunlight and space in a forest.

50. Section 3 Types of Interactions Chapter 16 Predators and Prey • Many interactions between species consist of one organism eating another to obtain energy and nutrients. • The organism that is eaten is called prey. • The organism that eats the prey is called the predator.