1. Review of Ecology
Chap. 2.1 to 2.2

2. Biosphere Ecosystems Realm of ecology Communities Populations
Universe
Galaxies
Biosphere
Solar systems
Planets
Earth
Biosphere
Ecosystems
Ecosystems
Communities
Populations
Realm of ecology
Organisms
Communities
Organ systems
Organs
Figure 3.2
Natural capital: levels of organization of matter in nature. Ecology focuses on five of these levels.
Tissues
Cells
Populations
Protoplasm
Molecules
Atoms
Organisms
Subatomic Particles 2

3. Biotic vs. Abiotic Factors: Influences on each other
Biotic: Biological influences on organisms
Abiotic: Physical, non-living parts of an ecosystem

4. Levels of Organization of the Biosphere
Biosphere: All life on Earth and the parts of Earth that support life
Organized into specific levels

5. Biosphere organization: smallest to largest
Species: Similar organisms that can breed and produce fertile offspring
Population: Group of individuals of the same species that live in the same area

6. Biosphere organization
Community: Different populations that live in the same area
Ecosystem: All of the organisms that live in a place, together with their physical environment

7. Biosphere organization
Biome: a group of ecosystems that share similar climate and typical organisms
Biosphere: All life on Earth and parts of Earth that support life.

8. How this classroom fits in?
Species
Population
Community
Ecosystem
Biome
Temperate Deciduous
Biosphere

9. Interactions within Communities
Community: group of populations in a given place and time
Populations within a community can interact in manner that is beneficial or harmful

10. 6 Possible Interactions+
Mutualism
Both helped o
Commensalism
One helped; one neutral
Neutralism
Both neutral -
Amensalism
One harmed; one neutral
Predation
(Parasitism)
One helped;
one harmed
Competition
Both harmed

11. Symbiosis: “Living Together”
Close and established interactions among populations living in a community
Include:
Mutualism
Commensalism
Parasitism

12. Mutualism (+/+): Both benefit
Both species obtain a benefit from the relationship.
Obligatory: one species is totally dependent on other
Nonobligatory: can survive without relationship

13. Commensalism (+/o): One helped; One neutral
Can involve using another for:
transportation (remora eel and shark),
housing (Spanish moss on tree; hermit crab in old shell)
to obtain food (fish and shark)

14. Neutralism Neither affected by other Does not often occur in reality
Applies when interaction is negligible

15. Amensalism One species suffers while the other is neutral
Example: plant secretes chemical that inhibits growth around it (allelopathy)

16. Predation/parasitism (+/-): One is helped; one is harmed
Predator = organism that is capturing and eating another
Prey = organism being eaten

17. Predation/parasitism (+/-): Forms of Predation
Carnivory: Animal kills and eats animal
Parasitism: Predator lives within host, weakens it but doesn’t kill it
Parasitoidism: Lays eggs inside host and consume it as larvae grow
Herbivory: Foraging on plants

18. Predator-Prey Dynamics
Predators affect the size of prey populations and determine the places that prey can survive and grow.
Amount of prey determine how much predator population can grow.

19. Competition (-/-): Both harmed.
Competition occurs when organisms attempt to use the same limited ecological resource in the same place at the same time
Both end up in a more limited “niche” than may be possible for them without competition.

20. Niche: How an organism “makes a living”
Niche: full range of physical and biological conditions in which an organism lives and how it uses those conditions
One’s niche is determined first by tolerances and habitat
Tolerance: ability to survive in range of conditions
Habitat: species tolerance for specific conditions determine the general place where it can live -- its “habitat.”

21. Niches Physical Aspects: All abiotic factors needed for survival
Temperature, moisture etc.
Biological Aspects: All biotic factors needed for survival
How and when reproduce, food it eats, how it obtains food

22. Niche generalists vs. specialists
Generalists: Broad niches; can live in wide range of environments (cockroaches, mice, humans)
Specialists: Narrow niches; may have difficulties with environmental changes
Q: Which has the advantage in a stable ecosystem?

23. Niches and Competition
Competition can limit the niche that the species can occupy
Species may be able to survive and reproduce under larger range of conditions but is limited by competition

24. Competitive Exclusion Principle
No two species can occupy the same niche in the same habitat at exactly the same time
The better competitor excludes the weaker one

25. Dividing Resources Competition is niche overlap
Each species uses a portion not able to be used by another species.
Competition helps determine species and niches each species occupies.