Ecology is the study of the responses & interactions of living things with their environment. The word comes from the Greek word Ecos (home). The habitat where an organism lives must contain resources to provide energy, water, & gasses for survival. Organism must interact with their surroundings by responding to living (biotic) & nonliving (abiotic) parts of the environment in order to survive.

• Make a T-chart with the headings Biotic (living) and Abiotic (nonliving). Using the deciduous forest ecosystem picture, list as many items as you can under each heading.

• Following a class discussion, list 5 possible interactions between biotic and abiotic factors in the environment.

Organisms living together in the same ecosystem, interact with other organisms in many ways. Sometimes, organisms compete for the same resources to survive. Other organisms have a predator-prey relationship where one organisms eats the other to survive. A third type of relationship called symbiosis benefits one species while the other is benefitted, not affected, or harmed.

Food Chains• The sun is the source of energy that

supports all living things• A food chain shows the flow of

energy through an ecosystem• The arrows show the direction of the

energy flow through the system.

• Producers(Autotroph) – Use photosynthesis to make their own food (chemical energy).

• Consumers(Heterotroph) – Consume other organisms to get their needed energy.

Types of Organisms

Types of Consumers• Herbivores – Eat plants.

• Carnivore – Eat other animals.

• Omnivore – Eat plants or animals.

• Decomposers – Break down organic matter.

• Detritivore – Feed on detritus (plant and animal remains).

Complete the Food Chain

Food Chain Practice

Food Chain Activity• Use the list of organisms on the next

slide to create a food chain that would exist in an ecosystem. Be sure to:

–Include at least 4 organisms

–Draw arrows showing the flow of energy

–Label each organism as a producer, herbivore, omivore, or carnivore

• Bacteria

• Mullet fish

• Crab

• Grasshopper

• Fungus

• Grass

• Hawk

• Impala

• Hyena• Mushroom• Lion• Shark• Algae• Shrew• Worm• Water flea

Food Chain Resource• http://www.sheppardsoftware.com/content/

animals/kidscorner/games/foodchaingame.htm

Food Webs• Food webs show how different

food chains are actually linked together in an ecosystem .

• They show a more realistic picture of the paths energy takes as it flows through an ecosystem.

Food Web Activity

• http://www.gould.edu.au/foodwebs/kids_web.htm

Ecological Pyramids• The sun supplies a constant external

source of energy to the ecosystem.

• As energy moves through an ecosystem, much of it is transferred through the life processes (growth, repair, & reproduction) of living things.

• Only about 10% of the energy at one level is available to the next higher level.

10,000

1,000

100

10

1

100%

10%

1%

.1%

.01%

100

100,000

10,000

1,000

Variation of Pyramid of Numbers

Energy Pyramid Activity

• A single water flea must eat many phytoplankton to support itself.

• Only a portion of the energy present in the phytoplankton is available to the water flea. Most of the energy is transferred to the environment as heat.

• Record the numbers on the next slide on your energy pyramid.

Conclusion ?’s1. Based on your energy pyramid, how

many phytoplankton are necessary to provide energy for 10 sharks?

2. What percent of the energy in one level can be transferred to the next level?

3. List two ways the rest of the energy is transferred to the environment.

4. What percent of the energy at the phytoplankton level is available to the sharks? (show work)

5. If you had 5 million water fleas, how many mackerels could you have? (show work)

6. Which type of organism should be placed at the base of the pyramid? Explain your reasoning.

7. Which organisms in your pyramid are herbivores? Carnivores?

8. Describe how using an energy pyramid could be useful to a group of scientists establishing a wildlife refuge?

9. Create an energy pyramid for an African grassland using a lion, an acacia tree, and a giraffe.

10.Show how many lions could be supported and how many acacia trees are needed if there are 250 giraffes.

SYMBIOSIS• For each of the relationships on

the following slides, decide whether each organism in the pair benefits (+), is not affected (0), or is harmed (-).

–Mutualism = (+,+)

–Commensalism = (+,0)

–Parasitism = (+,-)

#1

• Barnacles often a attach themselves to whales, and filter food from the water as the whale swims. The barnacles do not affect the whale.

#2The desert yucca plant depends on moths to pollinate its flowers, and the moth depends on the yucca plant as a place to lay its eggs so the developing larva will have an available food source.

#3

A hermit crab uses the abandoned shell of snails as a home.

#4A tick burrows under the skin of a dog, and uses the dog’s blood as food.

#5

• A cowbird perches on the back of cows, and eats pesky insects off the cow’s skin.

#6

• Remoras are small fish that attach themselves to sharks, and eat leftover food when a shark eats another fish or animal. The sharks tough skin is not affected.