13.2 Biotic and Abiotic Factors

KEY CONCEPT Every ecosystem includes both living and nonliving factors.

13.2 Biotic and Abiotic Factors

MI State Standards

• L3.p2A Describe common relationships among organisms and provide examples of producer/consumer...

• L3.p2B Describe common ecological relationships between and among species and their environments.

• L3.p2D Explain how two organisms can be mutually beneficial and how that can lead to interdependency.

• L3.p3B Distinguish between the living (biotic) and nonliving (abiotic) components of an ecosystem.

13.2 Biotic and Abiotic Factors

An ecosystem includes both biotic and abiotic factors.

• Biotic factors are living things.– plants– animals– fungi– bacteria

plants

13.2 Biotic and Abiotic Factors

• Abiotic factors are nonliving things. – moisture– temperature– wind– sunlight – soil

moisture

sunlight

13.2 Biotic and Abiotic Factors

Changing one factor in an ecosystem can affect many other factors.

• Biodiversity is the assortment, or variety, of living things in an ecosystem.– Compare two plots of land:

• A 400 acre corn field, with over 1,500,000 corn plants.

• A small 1-acre wild plot with trees, shrubs, grasses, mosses, small mammals, birds, insects, etc., with many 2,000 organisms.

– Which has more biodiversity?

• Rain forests have more biodiversity than other locations in the world, but are threatened by human activities.

13.2 Biotic and Abiotic Factors

• A keystone species is a species that has an unusually large effect on its ecosystem.– The addition or removal of a keystone species has huge

environmental impacts on an ecosystem.

keystone

When sea otters near Russia were hunted to near extinction, they no longer ate the sea urchins, who then consumed all the sea kelp. The sea kelp were the breeding grounds for salmon, whose population dropped significantly.

13.2 Biotic and Abiotic Factors

• Keystone species form and maintain a complex web of life.

creation ofwetlandecosystem

increased waterfowlPopulation

increased fishpopulation

nesting sites for birds

keystone species

13.2 Biotic and Abiotic Factors

With the person next to you, discuss the previous slide, showing the family of beavers in their den.

1. How does dam building affect fish populations?

2. What effect does the increase in fish populations have on the pond?

3. What is the overall effect of damming?

13.2 Biotic and Abiotic Factors

With the person next to you, discuss the previous slide, showing the family of beavers in their den.

1. How does dam building affect fish populations?

The dam creates a pond from free-flowing water, which allows a greater number and variety of fish to live and reproduce in the water.

2. What effect does the increase in fish populations have on the pond?

Fish attract species to the pond that feed on them.

3. What is the overall effect of damming?

Increase in biodiversity.