Chapter 1 Lesson 4Changes in Ecosystems

P A G E 6 4 W O R K B O O K P A G E S 1 6 - 1 7

Look and Wonder:This stone building was once a magnificent temple built by kings. Today trees and plants grow out of the stone. What has changed in this ecosystem?

Chapter 1 Lesson 4 Vocabulary pg 66

1. pollution2. extinct species3. endangered species4. threatened species5. primary succession6. pioneer species7. climax community8. secondary succession

Create the Foldable on page 77.

Ecosystem Changes

Extinct Primary andSecondary Succession

How can ecosystems change? pgs 66-67

� Main Idea- Ecosystems can change through human activities or through natural events.

� There are two types of natural changes that can affect an ecosystem.

� The first type includes earthquakes, floods, storm, hurricanes, volcanoes, droughts, and other natural disasters.

� The second type is caused by organisms. How do organisms alter the ecosystem?

� Beavers build dams using mud, stones, and trees. Their dams can cause flooding, but they can also be helpful by creating new habitats for other organisms.

� Also think about elephants and coral reefs.

How can ecosystems change?

� Humans can also change ecosystems by introducing new species or removing species.

� Introduced plant and animal species can threaten native species in an area.

� Without natural predators, the introduced species can threaten or even kill off local species.

� FACT: All ecosystems are in a constant state of change.

How do people affect the environment? pgs 68-69

� The things people do every day affect the environment. Pollution is a harmful change to the natural environment.

� Pollution occurs because Earth’s land, water, and air have a limited capacity to absorb wastes and to recycle them naturally.

Affects on Land Affects on Water Affects on AirStrip-mining, some farming practices, growth of urban areas which increases transportation- new roads, vehicles emitting gases and leaking oil, clearing trees for houses

Bathing, washing clothes, and flushing toilets could send harmful residues into water, some factories dump wastes and chemicals, oil leaks from ships (also harming animals), fertilizers and pesticides

Burning fuels to power factories, heat homes, or driving vehicles, smog (smoke and fog) coming from urban or industrial areas, acid rain (formed by nitrogen, sulfur gases and water vapor)

BrainPop- Air Pollution and Water Pollution National Geographic Site

How does waste affect the land? pgs 70-71

� People use large quantities of garbage every day. Most of this garbage ends up in landfills, which are specially designed places where garbage is deposited into lined pits.

� BrainPop- Waste Management � Some garbage is biodegradable, or able to break down

naturally over a short period of time… like the banana. � Other materials, such as foam cups and plastic

containers are nonbiodegradable. � Industrial materials and waste may contain poisonous

chemicals and metals. Toxic waste, a collection of poisonous materials, must be disposed of carefully so it does not pollute soil, groundwater, rivers, and lakes.

How does waste affect the land? pgs 70-71

� Recycling (8:53)

What happens when ecosystems change?pgs 72-73

� Organisms must respond to or adapt to changes in the ecosystem. Some respond by migrating to a place they are more likely to survive. Other organisms respond by adapting to ecosystem changes.

� If an organism does not respond, the individual members of that species begins to die.

� When the last member of a species dies, the species becomes extinct.

� Extinction (6:12)- animals that came back from extinction

What happens when ecosystems change?pgs 72-73

� When a species is in a danger of becoming extinct, it is called an endangered species. Endangered species today include the pitcher plant, the hawksbill sea turtle, the Karner blue butterfly, the flying squirrel, and many others.

� Species with low numbers that could become endangered are called threatened species. The gray wolf, and manatee, and many others are threatened species.

� Each endangered and threatened organism is at risk for different reasons. Pollution, overhunting or over collecting, disease, and competition can all cause a species to die out. The biggest threat is habitat loss.

Organisms either adapt to changes in ecosystems or their species dies out.

Changes to ecosystems affect the organisms within that ecosystem.

What happens when ecosystems change?

Help the Tigers EcoKids ARKive GamesSave the Beach

How do ecosystems come back?

� The process of one ecosystem changing into a new and different ecosystem is called succession. During succession, an area is changed as a certain species is replaced by other species over time.

� Primary succession takes place in a community where few, if any, living things exist, or where earlier communities were wide spread.

� The first organisms are pioneer, the first species living in an otherwise lifeless area. The pioneer organisms create the pioneer community, the first living community in an otherwise lifeless area.

Click to watch the video on succession.

� Primary and Secondary Succession (6:25)� Primary Succession (3:30)� Secondary Succession- Forest Born by Fire (5:45)� Primary and Secondary Succession (2:29)� Succession- animation (2:33)

How do ecosystems come back?

� The process of succession is…¡ The lichens and the mosses break down the rock and form

soil. The lichens and mosses will die off and decomposers will go to work.

¡ The decomposing adds nutrients to the soil helping to support the growth of larger plants. Insects and spiders begin to colonize.

¡ The process continues with richer soil that is capable of supporting larger plant species and flowering plants, which attracts insects birds and small mammals.

¡ After many years, this community may become a grassland or prairie.

¡ If enough moisture is present, small birch trees will begin to grow. This enables other seedling to grow like pine trees and then hardwoods.

¡ As these trees fill in the forest, they form a climax community.

How do ecosystems come back?

� A climax community is the final stage of succession. Unless the community is disturbed by some natural disaster or human activity, the climax community will remain.

Ecosystems can gradually change over time. Succession happens when one ecosystem eventually changes into a new and different ecosystem.

bare rock lichens and mosses

small plants, lichens, grasses

and shrubs

shrubs and poplar, pine, and willow

trees

maple and beech trees

How do ecosystems come back?

Succession Facts

Secondary succession is the beginning of a new community where a community had already existed.

Secondary succession occurs faster than primary succession, but happens in the same way as primary succession.

What is secondary succession?

Examples of Secondary Succession

Review

� Review Crossword Puzzle� Environmental Kids

Review

1. To increase crop production while practicing conservation, a farmer might

a. use crop rotationb. use chemical fertilizersc. introduce a new species into his field to

control pestsd. remove all trees surrounding his field

Review

2. Which of these most likely happened in an secondary succession after a volcanic eruption?

a. Animals move out of ecosystem.b. Flood waters destroy a natural habitatc. Small plants begin to grow.d. Trees cast shade over small plants.

Review

3. Small plans and shrubs have begun to grow on a stone cliff. This is an example of which one of the following?

a. environmental successionb. ecological changec. secondary successiond. primary succession

Review

4. Which of these natural disasters can actually help maintain the health of an ecosystem?

a. earthquakeb. volcanoc. fired. flood

Review

5. What is a pollutant?a. a substance that increases nutrientsb. a substance that reacts with waterc. a substance that causes pollutiond. the release of nutrients into the soil

Review

6. What is deforestation?a. clearing land for the construction of

new homesb. using paper products in a businessc. clearing a forest to use trees for lumberd. polluting a forest

Review

7. What is an example of a natural disaster?

a. a volcanic eruptionb. a ship spilling oil into the seac. pollution from the burning of fuelsd. dumping of garage into a stream