1. 4-6 Species Role in Ecosystems

2. Concept to Understand
• Each species plays a specific
ecological role called its niche.

3. Ecological Niche
• Every species occupy unique niches and play specific
roles in an ecosystem

4. Ecological Niche
• Generalist species – can live many different places,
eat many things, tolerate wide variety of
environmental conditions
▫ Examples: people, mice, cockroaches

5. Cockroach Information
• Existed for 350 million years – 3,500 known species
• Highly adapted, rapidly producing generalists
▫ Consume almost anything
▫ Endure food shortage
▫ Survive everywhere except polar regions
▫ Avoid predation
• Carry human diseases

6. Ecological Niche
• Specialist species – can only survive in very specific
habitat
▫ Examples: most salamanders, giant pandas

7. Ecological Niche
• Native species – naturally found in that ecosystem
• Nonnative species – invasive, alien, exotic
• Spread to new ecosystems (because of humans)
• Problems:
• 1. No predators
• 2. Kill native species
which lack adaptation

8. Indicator Species
• Indicator Species - Early warning
system, damage to the environment
causes this species population decline.

9. Keystone Species
• Keystone Species - Significant role in
ecosystem food web: large affect on other
species in an ecosystem.
• Ex. Algae

10. Keystone Species
• Elimination may
alter structure
and/or function
of ecosystem
• Pollinators –
bees, butterflies,
hummingbirds,
bats

11. Keystone Species
• Top predators – alligator, wolf, lion,
sharks

12. Keystone Species
• Keystone species create habitat/
ecosystem & help to keep it
functioning.

13. Foundation Species
• Create habitats and ecosystems
• Ex. Beavers, Elephants, Seed dispersers