Title: The Earth
1Chapter 20
The Earths Ecosystems
Preview
Section 1 Land Biomes Section 2 Marine
Ecosystems Section 3 Freshwater Ecosystems
Concept Mapping
2Section 1 Land Biomes
Chapter 20
Bellringer
- Write the answers to the following questions in
your science journal - What is a biome?
- List seven land biomes.
3Section 1 Land Biomes
Chapter 20
Objectives
- Distinguish between abiotic factors and biotic
factors in biomes. - Identify seven land biomes on Earth.
4Section 1 Land Biomes
Chapter 20
The Earths 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.
5Section 1 Land Biomes
Chapter 20
6Section 1 Land Biomes
Chapter 20
Forests
- Temperate Deciduous Forests In a temperate
deciduous forest, mammals, birds, and reptiles
thrive on the many leaves, seeds, nuts, and
insects.
7Section 1 Land Biomes
Chapter 20
8Section 1 Land Biomes
Chapter 20
Forests, continued
- Coniferous Forests Coniferous forest has
evergreen trees and many animals must hibernate
through the cold winters.
9Section 1 Land Biomes
Chapter 20
10Section 1 Land Biomes
Chapter 20
Forests, continued
- Tropical Rain Forests Tropical rain forests have
a greater variety of organisms than any other
biome.
11Section 1 Land Biomes
Chapter 20
12Section 1 Land Biomes
Chapter 20
Grasslands
- Temperate Grasslands Temperate grasslands have
few trees, and many different kinds of seed and
grass-eating animals.
13Section 1 Land Biomes
Chapter 20
Grasslands, continued
- Savannas A grassland that has scattered clumps of
trees and seasonal rains is called a savanna.
14Section 1 Land Biomes
Chapter 20
Deserts
- Dry and Hot Biomes that are very dry and often
very hot are called deserts.
15Section 1 Land Biomes
Chapter 20
16Section 1 Land Biomes
Chapter 20
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.
17Section 1 Land Biomes
Chapter 20
18Section 2 Marine Ecosystems
Chapter 20
Bellringer
Write the answer to the following question in
your science journal What are abiotic factors in
marine ecosystems?
19Section 2 Marine Ecosystems
Chapter 20
Objectives
- List three abiotic factors that shape marine
ecosystems. - Describe four major ocean zones.
- Describe five marine ecosystems.
20Section 2 Marine Ecosystems
Chapter 20
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.
21Section 2 Marine Ecosystems
Chapter 20
Temperature
- Depth and Temperature The temperature of ocean
water decreases as the depth of the water
increases.
22Section 2 Marine Ecosystems
Chapter 20
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.
23Section 2 Marine Ecosystems
Chapter 20
24Section 2 Marine Ecosystems
Chapter 20
25Section 2 Marine Ecosystems
Chapter 20
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.
26Section 2 Marine Ecosystems
Chapter 20
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.
27Section 3 Freshwater Ecosystems
Chapter 20
Bellringer
Write the answer to the following question in
your science journal What are four freshwater
ecosystems?
28Section 3 Freshwater Ecosystems
Chapter 20
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.
29Section 3 Freshwater Ecosystems
Chapter 20
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.
30Section 3 Freshwater Ecosystems
Chapter 20
31Section 3 Freshwater Ecosystems
Chapter 20
Tributary, River System, and Drainage Basin
Click below to watch the Visual Concept.
Visual Concept
32Section 3 Freshwater Ecosystems
Chapter 20
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.
33Section 3 Freshwater Ecosystems
Chapter 20
34Section 3 Freshwater Ecosystems
Chapter 20
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.
35Section 3 Freshwater Ecosystems
Chapter 20
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.
36The Earths Ecosystems
Chapter 20
Concept Mapping
Use the terms below to complete the Concept
Mapping on the next slide.
land biomes biotic factors tundra biomes marine freshwater abiotic factors grasslands
37The Earths Ecosystems
Chapter 20
38The Earths Ecosystems
Chapter 20