Changes in Environments

Unit 9

It’s All Around You

• Learning Goal:

I will understand how environmental changes affect organisms.

Pictures

• Please cut out pictures of ANY animals, plants, flowers, insects, etc. that you like! – You can get these pictures from

magazines or print them (in color) from the internet.

– The more pictures that we have the better the activity!

It’s All Around You

• Environment – is all of the living and nonliving things in nature.

• We depend on the environment for:

• Food• Air• Water• shelter

It’s All Around You• Examples of

nonliving things found in Earth’s environment:

•water• air• sunlight• land

It’s All Around You

• Ecosystem – a community of living things and nonliving things around them that interact with each other.

It’s All Around You

• Brain Pop!

http://www.brainpop.com/science/ecologyandbehavior/ecosystems/

It’s All Around You• Together lets

make a list of everything in your environment.

• Now draw a picture of you local environment on page 395.

It’s All Around You

1. Can the nonliving parts of the environment affect each other?

2. What are some ways that living things in an ecosystem interact?

3. What is the difference between an environment and an ecosystem?

4. Name four living and four nonliving things in the school ecosystem?

Change Comes Naturally• In the pictures

on page 396 and 397, what changes have happened because of natural events?

• How might some of these changes affect the ecosystem?

Change Comes Naturally

• Natural events that affect our environment:– Events that occur quickly

• floods• earthquakes• volcanic eruptions• droughts • forest fires• Hurricanes

– Events that occur slowly• ice age• volcanic eruptions

Change Comes Naturally

• Climate is a long-range average of weather.

Change Comes Naturally• Drought is a long period of time

during which there is less-than-normal rainfall.– Rain falls unevenly across the land (think

climate zones) and a drought is rainfall over a long period of time at the low end of that average.

• Ice Age – occurs when Earth has colder-than-normal temperatures for a very long time.

• Volcanic eruption – causes rapid changes when the hot flowing lava scorches the land. – It can also cause changes over time

because it sends gases and dust high into the air which blocks sunlight from reaching earth’s surface.

– This can cause temperatures to drop for months or years.

Change Comes Naturally

1. What effect might drought have on an ecosystem, including humans?

2. Why might a volcanic eruption cause long-term changes in an ecosystem?

3. Look at the map of the Ice Age on page 396. What kinds of living things might be affected by advancing ice.

4. How might an overall drop in temperature over many years affect Earth’s environment?

5. Why are forest fires both bad and good for the ecosystems?

Animal Architects

• Beavers may be small but they can have a huge impact on the environment:

1. Beavers build a dam in a stream

2. trees are harmed

3. ponds and wetlands form

4. Stream organisms move out or die

5. pond organisms move in

Animal Architects

• What are some ways that dam building by beavers might negatively affect organisms in the ecosystem?

• In what ways might dam building benefit organisms in the ecosystem?

• Can plants cause changes to environments?

• What are some other ways in which living things change their environment?

Animal Architects

• Invasive animal or plant – a plant or animal that is not native to the region. – Fire ants accidentally came to

the US. They spread rapidly.– Harvester ants are native ants

they eat seeds. Fire ants began to eat these ants.

– Horned lizards are native to this region and eat harvester ants. What will eventually happen to these lizards if the fire ants continue to grow in population?

Animal Architects

• List several examples of organisms that depend on each other for food, beginning with plants and organisms that eat plants.

• MAKE A MODEL• Get out the pictures that

you have been collecting.– Glue them down on

your poster.– Use sharpies or yarn

to connect each organism to the food that it eats.

Animal Architects

1. What does the structure that you have built look like?

2. What happens if the number of plants decreases?

3. How would horned lizards be affected if they had food sources other than harvester ants to eat?

4. How could a decrease in the number of predators negatively affect the prey?

5. Give me and example of an invasive animal we read about. Why are they considered invasive?

Humans Change the Environment• Some human activities that are harmful to

our environment:

– mining – people mine coal to get energy to power homes and businesses. • Open-pit mining kills all the plants living in the

area. • Burning coal for energy is harmful to the our

air.

– Cutting down trees – people use the wood for items or to clear space for homes. • Organisms that usually live in the forest must

move or die, this effect is called habitat destruction.

– Waste – people produce a large amount of waste. This waste ends up in landfills. If the landfills are not built the wastes can pollute soil and water. • Pollution is any harmful substance that gets

into the environment. • Pollution can kill organisms or cause

diseases.

Humans Change the Environment

• Conservation - protecting ecosystems and the organisms that live in them.

• Ways people try to help the environment:

– replanting trees– cleaning up pollution– removing invasive

plants and animals– caring for animals

injured or orphaned by natural disasters.

Humans Change the Environment

• Brain Pop!

http://www.brainpop.com/science/ourfragileenvironment/

humansandtheenvironment/

Humans Change the Environment

1. How can people solve the environmental problems listed below?– Coal mining can harm habitats and cause

pollution– Cutting a forest destroys habitats and

can lead to soil erosion.– Waste from garbage in landfills can enter

the ground and pollute soil and water.

Teachers pg. 410

Humans Change the Environment

1. What do the three pictures on pages 400 have in common?

2. How do the pictures on this page contrast with those on page 401?

3. What are three things that would be important in the habitat of an animal?

4. How does clearing and paving land for buildings and roads change the environment?

5. Does replanting trees that are cut down immediately solve the problem of habitat destruction in an area? Explain your answer.

Living Things Change

• Activity: hunting for beans (flip chart pg. 37)

• Imagine that you are a hawk. What would make you notice prey in a field of grass?

Living Things Change

1. Why is variation in a population beneficial?

2. When an environment changes, why do some individuals survive while other die?

3. Suppose less rainfall was received than normal. Which plants would be more likely to survive?

4. Infer – Do you think that all variations that individual organisms have can be seen? Why or why not?

Gone!• Extinction – the death of

all organisms of a species– Many causes:

• Climate changes • Amount of food available

decreases • Increase in human

population that takes over environment

• Giant reptiles like the Tyrannosaurus rex could not survive a cooler environment and became extinct.

• The Tasmanian wolf is extinct because of too much hunting.

Gone!• Some scientists

estimate that 35-150 species become extinct each day. – most live in

tropical rain forests

– majority are insects or plants that were not yet discovered by humans

– Most are the result of forest clearing and other human disturbances

Gone!

• Brain Pop!

http://www.brainpop.com/science/ourfragileenvironment/extinction/

Gone!

• Could the extinction of the dodo bird have been prevented? –Why or why

not?

Gone!

1. How might human actions lead to extinction?

2. What are some ways to help an endangered species recover?

3. What steps lead to the extinction of a certain type of organism? (sequence)