The Earth

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The Earths Ecosystems
Preview
Section 1 Land Biomes Section 2 Marine
Ecosystems Section 3 Freshwater Ecosystems
Concept Mapping
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Section 1 Land Biomes
Bellringer
What is a biome? List seven land
biomes. Write your answers in your science
journal.
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Section 1 Land Biomes
Objectives

• Distinguish between abiotic factors and biotic
  factors in biomes.
• Identify seven land biomes on Earth.

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Section 1 Land Biomes
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.

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Section 1 Land Biomes
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Section 1 Land Biomes
mammals, birds, and reptiles thrive on the many
leaves, seeds, nuts, and insects.
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Section 1 Land Biomes
evergreen trees and many animals must hibernate
through the cold winters.
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Section 1 Land Biomes
greater variety of organisms than any other biome
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Section 1 Land Biomes
Grasslands

• Temperate Grasslands Temperate grasslands have
  few trees, and many different kinds of seed and
  grass-eating animals.

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Section 1 Land Biomes
Grasslands, continued

• Savannas A grassland that has scattered clumps of
  trees and seasonal rains is called a savanna.

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Section 1 Land Biomes
are very dry and often very hot
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Section 1 Land 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.

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Section 1 Land Biomes
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Section 2 Marine Ecosystems
Bellringer 9/29
What are some abiotic factors in marine
ecosystems? Are these abiotic factors different
from the abiotic factors in land biomes? Record
your responses in your science journal.
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Section 2 Marine Ecosystems
Objectives

• List three abiotic factors that shape marine
  ecosystems.
• Describe four major ocean zones.
• Describe five marine ecosystems.

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Section 2 Marine 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.

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Section 2 Marine Ecosystems
Temperature

• Depth and Temperature The temperature of ocean
  water decreases as the depth of the water
  increases.

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Section 2 Marine 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.
• drops sharply
• The Oceanic Zone In the oceanic zone, the sea
  floor
• The Benthic Zone The benthic zone is the ocean
  floor. The deepest part does not get any sunlight.

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Section 2 Marine Ecosystems
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Section 2 Marine Ecosystems
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Section 2 Marine 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.

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Section 2 Marine 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.

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Section 3 Freshwater Ecosystems
Bellringer 9/30
Can you think of four different freshwater
ecosystems? Which of these ecosystems are similar
to a marine ecosystem or a land biome? Record
your answers in your science journal.
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Section 3 Freshwater 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.

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

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Section 3 Freshwater 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.

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The Earths Ecosystems
Concept Mapping
Use the terms below to complete the concept map
on the next slide. land biomes marine biotic
factors freshwater Tundra abiotic
factors biomes grasslands

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The Earths Ecosystems