1. Ecosystems & The Organization Of Life
Chapters 4&5
Ecosystems
& The Organization
Of Life

2. Ecosystems: Everything is Connected
Chapter 4 Section 1
Ecosystems: Everything is Connected
Learning Target SEV1-4.a/5.a I can distinguish between biotic and abiotic factors in an ecosystem, describe how a population differs from a species, and explain how habitats are important for organisms, as well as compare and contrast producers and consumers and explain energy transfer in food webs and food chains.

3. 4.1 – Ecosystems: Everything is Connected
Defining an Ecosystem
Ecosystems are communities of organisms and their abiotic environment
Examples are oak forest or coral reef
Ecosystems do not have clear boundaries
Things move from one ecosystem to another. Pollen can blow from a forest into a field. Animals can migrate. Soil can wash from a mountain into a lake.

4. The Components of an Ecosystem
4.1 – Ecosystems: Everything is Connected
The Components of an Ecosystem
In order to survive, ecosystems need:
Energy
Mineral Nutrients
Water
Oxygen
Living Organisms
If one part of an ecosystem is destroyed, the entire system will be affected.

5. Biotic and Abiotic Factors
4.1 – Ecosystems: Everything is Connected
Biotic and Abiotic Factors
Biotic factors are environmental factors that are associated with or result from the activities of living organisms
Abiotic factors are environmental factors that are not associated with the activities of living organisms (include air, water, rocks and temperature); non-living

6. 4.1 – Ecosystems: Everything is Connected
Organisms
Organisms are living things that can carry out life processes independently.
Examples: humans, ants, plants, and bacteria living in your intestines.
Every organism is a member of a species
Species are groups of organisms that are closely related and can produce offspring.

7. 4.1 – Ecosystems: Everything is Connected
Populations
Populations are groups of organisms of the same species that live in a specific area and interbreed
The difference between Population and species is that species may not all live in the same place. (Field mice in Pennsylvania are a different population than field mice in Texas.

8. 4.1 – Ecosystems: Everything is Connected
Communities
Group of various species that live in the same area and interact with each other
A pond community would include all of the populations of fish, plants, and insects that live in or around the pond.

9. 4.1 – Ecosystems: Everything is Connected
Habitat
A habitat is the place an organism lives and includes all biotic and abiotic factors that the organism needs to survive.
Examples:
A cactus’s habitat is the desert
A polar bear’s habitat is the
arctic tundra

10. Chapter 5 Section 1 Energy Flow in Ecosystems
Life Depends on the Sun
Energy from the sun enters an ecosystem when plants use sunlight to make sugar molecules. (Photosynthesis)
6CO2 + 6H2O + solar energy  C6H12O6 + 6O2
When an animal eats a plant, energy is transferred from the plant to the animal.

11. Transfer of Energy Producer – Organism that makes its food.
5.1 – Energy Flow in Ecosystems
Transfer of Energy
Producer – Organism that makes its food.
Examples: grasses, ferns, flowering plants, trees, algae, and some bacteria
Consumer- Organisms that get their energy by eating other organisms
Examples: mice, starfish, elephants, turtles, humans, and ants

12. 5.1 – Energy Flow in Ecosystems

13. What Eats What Herbivore – eats plants only
5.1 – Energy Flow in Ecosystems
What Eats What
Herbivore – eats plants only
Examples: cows, sheep, deer, grasshoppers
Carnivore – eats other consumers (meat)
Examples: lions, hawks, snakes, spiders
Omnivore – eats plants and animals
Examples: bears, pigs, insects and humans

14. What did one mushroom say to the other?
5.1 – Energy Flow in Ecosystems
Decomposers
Organisms that get their food by breaking down dead organisms
Examples: bacteria and fungi
Decomposers allow the nutrients in the rotting material to return to the soil, air, and water.
What did one mushroom say to the other?
I’m a fungi

15. Food Chains and Food Webs
5.1 – Energy Flow in Ecosystems
Food Chains and Food Webs
A food chain is a sequence in which energy is transferred from one organism to the next as each organism eats another organism.
A food web shows many feeding relationships that are possible in an ecosystem

16. 5.1 – Energy Flow in Ecosystems

17. 5.1 – Energy Flow in Ecosystems
Trophic Levels
Each step through which energy is transferred in a food chain is known as a trophic level.
At each level, energy is lost as heat, and less energy is available to organisms at the next trophic level. (90% of the energy is lost at each level)
Because so much energy is lost at each level, there are fewer organisms at the top of the food chain.

18. 5.1 – Energy Flow in Ecosystems
Trophic Levels

19. The Cycling of Materials
Chapter 5 Section 2
The Cycling of Materials
Learning Target SEV1-5.b I can explain the cycling of carbon, nitrogen, and phosphorus and identify the role humans play in these cycles.
Refer to your cycles poster for more information on this section.

20. How Ecosystems Change Chapter 5 Section 3
Learning Target SEV2-5.c I can explain how a pioneer species contributes to an ecological succession, the events during old-field succession, and how lichens contribute to primary succession.

21. Ecological Succession
5.3 – How Ecosystems Change
Ecological Succession
Ecological Succession is the gradual process of change and replacement of some or all of the species in a community.
It may take hundreds or thousands of years.
Primary Succession occurs where no ecosystems existed before such as on rocks, cliffs, or sand dunes.

22. Ecological Succession
5.3 – How Ecosystems Change
Ecological Succession
Primary succession can occur :
on new islands created by volcanic eruptions
in areas exposed when a glacier retreats
on any other surface that has not previously supported life
Primary succession is much slower than secondary succession. This is because it begins where there is no soil.

23. Ecological Succession
5.3 – How Ecosystems Change
Ecological Succession
Steps for Primary Succession:
On new islands created by volcanoes, pioneer species such as bacteria and lichens begin to grow (without soil).
They break down the rock and cause cracks.
Soil slowly accumulates as dust particles settle in the cracks.
Mosses begin to grow, and when they die, the soil begins to pile up. This makes the area fertile for more advanced plant species.
Wind blows in seeds from other areas and succession continues.

24. Ecological Succession
5.3 – How Ecosystems Change
Ecological Succession
Secondary Succession occurs on a surface where an ecosystem has previously existed.
Secondary succession can occur in ecosystems that have been disturbed or disrupted by humans, animals, or by natural processes such as storms, floods, earthquakes, or volcanic eruptions.

25. Ecological Succession
5.3 – How Ecosystems Change
Ecological Succession
The first organisms to colonize any newly available area during secondary succession are called pioneer species.
These organisms will make the new area more habitable for other species.
Examples include: bacteria, lichens, and some grasses
A climax community is a final and stable community (like a mature forest). It will remain the same through time if not disturbed.

26. Ecological Succession
5.3 – How Ecosystems Change
Ecological Succession
Natural fires caused by lightning are a necessary part of secondary succession in some communities.
Minor forest fires remove accumulations of brush and deadwood that would otherwise contribute to major fires that burn out of control.
Some animal species also depend on occasional fires because the feed on the vegetation that sprouts after a fire has cleared the land.

27. Ecological Succession
5.3 – How Ecosystems Change
Ecological Succession
Old-field succession is a type of secondary succession that occurs when farmland is abandoned.
When a farmer stops cultivating a field, grasses and weeds quickly grow and cover the abandoned land.
Over time, taller plants, such as perennial grasses, shrubs, and trees take over the area.

28. Ecological Succession
5.3 – How Ecosystems Change
Ecological Succession