How to Use This Presentation To View the presentation as a slideshow with effects select “View” on the menu bar and click on “Slide Show”, or simply press F5 on the top row of your keyboard. To advance to the next slide click the left mouse button once. From the Chapter screen you can click on any section to go directly to that section’s presentation. Blank or “missing” areas of a slide will remain hidden until the left mouse button is clicked. You may exit the slide show at any time by pressing the Esc key Copyright © by Holt, Rinehart and Winston. All rights reserved.

The Earth’s Ecosystems Chapter 20 Section 1: Land Biomes Section 2: Marine Ecosystems Section 3: Freshwater Ecosystems Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

Land Biomes Section 1 Bellringer What is a biome? List seven land biomes and an animal that can be found in each. Write your answers in your science journal. Copyright © by Holt, Rinehart and Winston. All rights reserved.

Land Biomes Section 1 Objectives Distinguish between abiotic factors and biotic factors in biomes. Identify seven land biomes on Earth. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

Land Biomes Section 1 The Earth’s Land Biomes What Is a Biome? A biome is a large area characterized by its climate and the plants and animals that live in the area. A biome contains related ecosystems. The next slide shows major land biomes around the planet. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

Land Biomes Section 1 Copyright © by Holt, Rinehart and Winston. All rights reserved.

Land Biomes Section 1 Copyright © by Holt, Rinehart and Winston. All rights reserved. Temperate Deciduous Forest Deciduous trees shed their leaves to save water during the winter. A variety of animals, such as bears, snakes, and woodpeckers, live in temperate deciduous forests. Coniferous Forest Most of the trees in a coniferous forest are called conifers.Conifers produce seeds in cones. A coniferous forest is shown on the next slide. Forests End of Slide

A Coniferous Forest Section 1 Copyright © by Holt, Rinehart and Winston. All rights reserved.

Land Biomes Section 1 Copyright © by Holt, Rinehart and Winston. All rights reserved. Tropical Rain Forest Tropical rain forests have more biological diversity than other places on Earth have. A tropical rain forest is shown on the slide after next. Forests, continued End of Slide

A Tropical Rain Forest Section 1 Copyright © by Holt, Rinehart and Winston. All rights reserved.

Land Biomes Section 1 Copyright © by Holt, Rinehart and Winston. All rights reserved. Temperate Grasslands Temperate grassland plants include grasses and other flowering plants. Temperate grasslands have few trees. Fires, drought, and grazing prevent the growth of trees and shrubs. Savannas A grassland that has scattered clumps of trees and seasonal rains is called a savanna. Savannas are found in parts of Africa, India, and South America. Grasslands End of Slide

Land Biomes Section 1 Copyright © by Holt, Rinehart and Winston. All rights reserved. Dry Climate Biomes that are very dry and often very hot are called deserts. Many kinds of plants and animals are found only in deserts. These organisms have special adaptations to live in a hot, dry climate. Deserts End of Slide

Land Biomes Section 1 Copyright © by Holt, Rinehart and Winston. All rights reserved. Polar Tundra Polar tundra is found near the North and South Poles. In polar tundra, the layer of soil beneath the surface soil stays frozen all the time. This layer is called permafrost. Alpine Tundra Alpine tundra is similar to arctic tundra. Alpine tundra also has permafrost. But alpine tundra is found at the top of tall mountains. Tundra End of Slide

Marine Ecosystems Section 2 Bellringer What are some abiotic factors in marine ecosystems? Are these abiotic factors different from the abiotic factors in land biomes or freshwater ecosystems? Record your responses in your science journal. Copyright © by Holt, Rinehart and Winston. All rights reserved.

Marine Ecosystems Section 2 Objectives List three abiotic factors that shape marine ecosystems. Describe four major ocean zones. Describe five marine ecosystems. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

Marine Ecosystems Section 2 Life in the Ocean Producers Marine ecosystems are shaped by abiotic factors. These factors include water temperature, water depth, and the amount of sunlight that passes into the water. The animals and plants that live in the ocean come in all shapes and sizes. Copyright © by Holt, Rinehart and Winston. All rights reserved. Three Zones The temperature of ocean water decreases as the depth of the water increases. However, the temperature change is not gradual. There are three temperature zones of ocean water. Temperature End of Slide

Marine Ecosystems Section 2 Depth and Sunlight The Intertidal Zone The intertidal zone is the place where the ocean meets the land. This area is exposed to the air for part of the day. The Neritic Zone As you move into the neritic zone, the ocean floor starts to slope downward. The water is warm and receives a lot of sunlight. The Oceanic Zone In the oceanic zone, the sea floor drops sharply. This zone contains the deep ocean water. The Benthic Zone The benthic zone is the ocean floor. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

The Ocean Zone: A Section 2 Copyright © by Holt, Rinehart and Winston. All rights reserved.

The Ocean Zone: B Section 2 Copyright © by Holt, Rinehart and Winston. All rights reserved.

Marine Ecosystems Section 2 A Closer Look Intertidal Areas Intertidal areas are found near the shore. These areas include mudflats, sandy beaches, and rocky shores. Coral Reefs Most coral reefs are found in warm, shallow areas of the neritic zone. The reefs are made up of small animals called corals. Estuaries An area where fresh water from streams and rivers spills into the ocean is called an estuary. In estuaries, the fresh water from rivers and the salt water from the ocean are always mixing. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

Marine Ecosystems Section 2 A Closer Look continued The Sargasso Sea An ecosystem called the Sargasso Sea is found in the middle of the Atlantic Ocean. This ecosystem contains floating rafts of algae called sargassum. Polar Ice The Arctic Ocean and the ocean around Antarctica make up another marine ecosystem. These icy waters are rich in nutrients, which support large numbers of plankton. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

Freshwater Ecosystems Section 3 Bellringer Can you think of four different freshwater ecosystems? Which of these ecosystems are similar to a marine ecosystem or a land biome? Record your answer in your science journal. Copyright © by Holt, Rinehart and Winston. All rights reserved.

Freshwater Ecosystems Section 3 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. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

Freshwater Ecosystems Section 3 Stream and River Ecosystems Copyright © by Holt, Rinehart and Winston. All rights reserved. Limiting Factors The water in brooks, streams, and rivers may flow from melting ice or snow. Or the water may come from a spring. Each stream of water that joins a larger stream is called a tributary. As more tributaries join a stream, the stream contains more water. The stream becomes stronger and wider. A very strong, wide stream is called a river. The next slide shows how a river develops. End of Slide

How a River Develops Section 3 Copyright © by Holt, Rinehart and Winston. All rights reserved.

Freshwater Ecosystems Section 3 Pond and Lake Ecosystems Copyright © by Holt, Rinehart and Winston. All rights reserved. Life Near Shore The area of water closest to the edge of a lake or pond is called the littoral zone. Life Away from Shore The area of a lake or pond that extends from the littoral zone across the top of the water is called the open-water zone. Beneath the open-water zone is the deep-water zone, where no sunlight reaches. The zones of a lake are shown on the next slide. End of Slide

Lake Zones Section 3 Copyright © by Holt, Rinehart and Winston. All rights reserved.

Freshwater Ecosystems Section 3 Wetland Ecosystems Copyright © by Holt, Rinehart and Winston. All rights reserved. Marshes A treeless wetland ecosystem where plants, such as grasses, grow is called a marsh. Swamps A wetland ecosystem in which trees and vines grow is called a swamp. End of Slide

Freshwater Ecosystems Section 3 From a Lake to a Forest Copyright © by Holt, Rinehart and Winston. All rights reserved. Filling In with Sediment Over time, the pond or lake is filled with sediment. Plants grow in the new soil. Shallow areas fill in first. So, plants slowly grow closer and closer to the center of the pond or lake. What is left of the lake or pond becomes a wetland, such as a marsh or swamp. Eventually, the wetland can become a forest. End of Slide

The Earth’s Ecosystems Chapter 20 Concept Map Copyright © by Holt, Rinehart and Winston. All rights reserved. Use the following terms to complete the concept map on the next slide: biomes, land biomes, biotic factors, marine, freshwater, tundra, abiotic factors, grasslands.

Concept Map Chapter 20 Copyright © by Holt, Rinehart and Winston. All rights reserved.

Concept Map Chapter 20 Copyright © by Holt, Rinehart and Winston. All rights reserved.