Chapter 6Sections 6.3 and 6.4

Stability in the Ecosystem

Stability• The measure of how easily an ecosystem is

affected by a disturbance and how quickly it returns to its original condition after a disturbance.

Equilibrium

• Is a state of balance.• The disrupted ecosystem will return

to this state of balance or equilibrium.

Disrupted Ecosystem

Natural Rule

• Species and whole ecosystems evolve and may die out, but new species and ecosystems can evolve to replace them.

Chaos Theory• Suggests that ecosystems

may be sensitive to very small changes, and that the initial state of an ecosystem is crucial to its later development.

Human Impacts• Habitat destruction.• Introduction of invasive

species.• Pollution of water, soil

and air.

Section 6.4Land Biomes

Biome• A major type of

ecosystem with distinctive temperature, rainfall, and organisms.

Biomes

• 8 Terrestrial • Aquatic

–Determined by water depth, nutrients, and nearness to land.

Desert Biome

• Very little water.• Covers 25 % of Earth’s

land surface.

Desert

Tundra

•Little water.•Cold.

Tundra

Forest Biomes

•Coniferous•Deciduous•Rain forest

Coniferous Forest

Deciduous Forest

Rain Forest

Grassland Biomes

•Steppe•Prairie•Savanna

Steppe

Prairie

Savanna

Review• What are some of the human

impacts on the environment?• Compare and contrast the

three different types of forests.