Ecology

Eco = houseLogy= study

• Ecosystem: A community of organisms and their environment

• Biosphere: the largest ecosystem (Ecosystems are threatened by pollution)

• Ecosystem: A community of organisms and their environment

• Biosphere: the largest ecosystem (Ecosystems are threatened by pollution)

Environmental factors• Abiotic factors: non-living factors that can

determine what type of organism can live in an environment.–Air and atmosphere• Plants need CO2 for photosynthesis. • Animals need oxygen for cellular respiration

–Water• Freshwater vs salt water

– Soil• Not all soil types are the same; some are rocky and others

are sandy.

Environmental factors– Sunlight

• Some plants need a lot of sun; some need a lot of shade

– Temperature • This is influenced by elevation and latitude

– Climate• The long-term weather conditions in a place.

• Biotic factors: living features of an

environment. Usually, what types of animals and plants live in a place.

Cycles in nature

• Nothing is ever created or destroyed; it only changes form.

• We have several cycles to show how materials move through the earth – Rock cycle– Water cycle– Nitrogen cycle– Carbon cycle

Energy Flow

• Energy moves through the earth as well. It is never created or destroyed but changes form often. – It can move through different animals as well

• Food Chains and Food Webs

Food Chains• Matter and Energy pass

between organisms in the Earth and are constantly changed and recycled. Neither matter or Energy are destroyed or created; they are continually changing form.– Food chains begin with a

producer– Primary consumers eat

producers– Secondary consumers eat

primary consumers

Sunproducers1st consumers2nd consumers

Other Terms• Producers can also be called

autotrophs• Consumers can be called

heterotrophs• Herbivores are animals that

eat plants• Carnivores are animals that

eat other animals• Omnivores are animals that

eat both plants and animals.

Lets practice making a food chain• Make a food chain with the following

organisms. Label each organism as a producer, 1st consumer or 2nd consumer:– Grass, sheep, wolf– Flower, hummingbird, snake– Algae, fish, bear

Lets practice making a food chain• Roll the dice to choose the animals to include

in your food chain• Roll 3 times. Choose one animal/plant from

each categoryRoll 0 1 2 3 4 5 6 7 8 9

Producers grass tree grass algae flower grass flower grass algae tree

1st Consumers cow sheep elephant mouse fish bee giraffe bird chipmunk skunk

2nd Consumers lion wolf hawk eagle bear wasp snake vulture bacteria mushroom

Food Webs

• Food chains don’t work well with more than 3 or four individuals in them

• For more complex interactions we use a food web

Lets practice making a food web• Roll the dice to choose the animals to include

in your food chain• Roll 7 times. Choose one animal/plant from

each categoryRoll 0 1 2 3 4 5 6 7 8 9

Producers grass

Apple tree

grass algae hibiscus grass flowers grass algae tree

Consumers cow sheep elephant mouse fish bee giraffe Song bird

chipmunk skunk

2nd consumers lion wolf hawk eagle bear wasp snake vulture bacteria mushroom

Energy Pyramid• Whenever energy is transformed,

part of it is lost as heat and entropy

• When a mouse eats a seed the energy stored in the seed is transformed into usable energy by the mouse and some of it is released as heat. There was more energy stored in the seed than can be used by the mouse because some was lost as heat when the energy was converted in the mouse.– This means that you always have

to have more producers than consumers. Otherwise there wouldn’t be enough energy for the consumers.

Ecology Quiz1. Define producers, primary consumers, secondary consumers,

autotrophs, heterotrophs, ecosystem, biosphere, carnivores, herbivores, omnivores.

2. Give an example of each of the above terms3. Make a 3-organism food chain. Label the producer, primary

consumer and secondary consumer. 4. Make a 6 organism food web. Label the producers, primary

consumers, secondary consumers5. GrasssheepwolfExplain what would happen to the wolf and grass population if a disease

killed off a lot of sheep6. What would happen to the grass population if there were very few

wolves?

Biodiversity

• Biodiversity is the variety of life in an ecosystem

• It is measured in species per area• Biodiversity increases the closer you get to the

equator

Why is biodiversity important?• Biodiversity gives us genetic

diversity– Species have a greater chance

of adapting– Hybrid vigor: individuals that

have more variety in their genes are healthier

• Biodiversity helps the stability of an ecosystem by giving enough variety to prevent extinction

Extinction• Mass extinction is when millions of plants and

animals die from a global catastrophy• Extinction is when a single species dies off • Endangered animals are in the process of

becoming extinct• Threatened animals are in the

process of becoming endangered

Threatenedendangeredextinct

What causes extinction

• Most modern extinctions are occurring because of humans– Divided habitats: humans build roads that go

through habitats – Habitat loss: humans build on top of animal habitats

and the animals must relocate– Introduced species: global travel has introduced

species from other parts of the world into habitats. Sometimes the exotic species are better adapted than the native species and the native species dies.

Human pollution

• Human pollution creates all the following environmental problems that can contribute to extinction:– Acid rain– Global warming– Ozone depletion

Population Ecology LabGeneration Number of

predators at startNumber of prey caught

Number of predators in next generation

1

2

3

trial Spoons Forks Knivesred black white spot red black White Spot Red Black White spot

1

2

3