The Earth’s Ecosystems

1. Chapter 20 The Earth’s Ecosystems Preview Section 1Land Biomes Section 2Marine Ecosystems Section 3Freshwater Ecosystems Concept Mapping

2. Chapter 20 Section 1Land Biomes Bellringer • Write the answers to the following questions in your science journal: • What is a biome? • List seven land biomes.

3. Chapter 20 Section 1Land Biomes Objectives • Distinguish between abiotic factors and biotic factors in biomes. • Identify seven land biomes on Earth.

4. Chapter 20 Section 1Land Biomes The Earth’s Land Biomes • Abiotic Factors Abiotic factors are the nonliving parts of an environment. • Biotic Factors Biotic factors are the living parts of an environment. • Biomes A biome is a large area characterized by its climate and the plants and animals that live in the area.

5. Chapter 20 Section 1Land Biomes

6. Chapter 20 Section 1Land Biomes Forests • Temperate Deciduous Forests In a temperate deciduous forest, mammals, birds, and reptiles thrive on the many leaves, seeds, nuts, and insects.

7. Chapter 20 Section 1Land Biomes

8. Chapter 20 Section 1Land Biomes Forests, continued • Coniferous Forests Coniferous forest has evergreen trees and many animals must hibernate through the cold winters.

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10. Chapter 20 Section 1Land Biomes Forests, continued • Tropical Rain Forests Tropical rain forests have a greater variety of organisms than any other biome.

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12. Chapter 20 Section 1Land Biomes Grasslands • Temperate Grasslands Temperate grasslands have few trees, and many different kinds of seed and grass-eating animals.

13. Chapter 20 Section 1Land Biomes Grasslands, continued • Savannas A grassland that has scattered clumps of trees and seasonal rains is called a savanna.

14. Chapter 20 Section 1Land Biomes Deserts • Dry and Hot Biomes that are very dry and often very hot are called deserts.

15. Chapter 20 Section 1Land Biomes

16. Chapter 20 Section 1Land Biomes Tundra • Polar Tundra In polar tundra, the layer of soil beneath the surface soil stays frozen all of the time. This layer is called permafrost. • Alpine Tundra Alpine tundra also has permafrost. But alpine tundra is found at the top of tall mountains.

17. Chapter 20 Section 1Land Biomes

18. Chapter 20 Section 2Marine Ecosystems Bellringer Write the answer to the following question in your science journal: What are abiotic factors in marine ecosystems?

19. Chapter 20 Section 2Marine Ecosystems Objectives • List three abiotic factors that shape marine ecosystems. • Describe four major ocean zones. • Describe five marine ecosystems.

20. Chapter 20 Section 2Marine Ecosystems Life in the Ocean • Abiotic Factors Marine ecosystems are shaped by abiotic factors including water temperature, water depth, and the amount of sunlight that passes into the water. • Plankton Trillions of plankton live in the ocean. Plankton are tiny organisms that float near the surface of the water.

21. Chapter 20 Section 2Marine Ecosystems Temperature • Depth and Temperature The temperature of ocean water decreases as the depth of the water increases.

22. Chapter 20 Section 2Marine Ecosystems Depth and Sunlight • The Intertidal Zone The intertidal zone is the place where the ocean meets the land. • The Neritic Zone As you move farther away from shore, into the neritic zone, the water becomes deeper. • The Oceanic Zone In the oceanic zone, the sea floor drops sharply • The Benthic Zone The benthic zone is the ocean floor. The deepest part does not get any sunlight.

23. Chapter 20 Section 2Marine Ecosystems

24. Chapter 20 Section 2Marine Ecosystems

25. Chapter 20 Section 2Marine Ecosystems A Closer Look • Intertidal Areas Intertidal areas are found near the shore. These areas include mudflats, sandy beaches, and rocky shores. • Coral Reefs Coral reefs are found in warm, shallow areas of the neritic zone. Reefs provide homes for many marine animals and plants. • Estuaries An area where fresh water from rivers spills into the ocean is called an estuary. Plants and animals living in estuaries must be able to survive in a changing concentration of salt.

26. Chapter 20 Section 2Marine Ecosystems A Closer Look, continued • The Sargasso Sea An ecosystem called the Sargasso Sea is found in the middle of the Atlantic Ocean. The ecosystem contains floating rafts of algae. • Polar Ice The Arctic Ocean and the ocean around Antarctica have icy waters, which are rich in nutrients. Many fishes, birds, and mammals live in this ecosystem.

27. Chapter 20 Section 3Freshwater Ecosystems Bellringer Write the answer to the following question in your science journal: What are four freshwater ecosystems?

28. Chapter 20 Section 3Freshwater Ecosystems Objectives • Describe one abiotic factor that affects freshwater ecosystems. • Describe the three zones of a lake. • Describe two wetland ecosystems. • Explain how a lake becomes a forest.

29. Chapter 20 Section 3Freshwater Ecosystems Stream and River Ecosystems • Water in Streams and Rivers The water in brooks, streams, and rivers may flow from melting ice or snow. Or the water may come from a spring. • Tributaries Each stream of water that joins a larger stream is called a tributary.

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31. Chapter 20 Section 3Freshwater Ecosystems Tributary, River System, and Drainage Basin Click below to watch the Visual Concept. Visual Concept

32. Chapter 20 Section 3Freshwater Ecosystems Pond and Lake Ecosystems • Life near Shore The are of water closest to the edge of a lake or pond is called the littoral zone. The plants in the littoral zone are homes to small animals. • Life Away from Shore The area of a lake or pond that extends from the littoral zone across the top of the water called the open-water zone. Beneath the open-water zone is the deep-water zone, where no sunlight reaches.

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34. Chapter 20 Section 3Freshwater Ecosystems Wetland Ecosystems • Marshes A treeless wetland ecosystem where plants, such as grasses, grow is called a marsh. Muskrats, turtles, frogs, and birds live in marshes. • Swamps A wetland ecosystem in which trees and vines grow is called a swamp. Water lilies and other plants grow in standing water. Many fishes, snakes, and birds also live in swamps.

35. Chapter 20 Section 3Freshwater Ecosystems From a Lake to a Forest • Build Up of Sediments Water entering a standing body of water usually carries nutrients and sediments. These materials build up on the bottom of the lake or pond. • Formation of a Wetland Over time, the pond or lake is filled with sediments. Plants grow in the new soil and the pond or lake starts becoming a wetland. The wetland then may develop into a forest.

36. Chapter 20 The Earth’s Ecosystems Concept Mapping Use the terms below to complete the Concept Mapping on the next slide.

37. Chapter 20 The Earth’s Ecosystems

38. Chapter 20 The Earth’s Ecosystems