1. Chapter 2: Principles of Ecology

2. Ecology
The study of the interactions between organisms and their environment
Includes both Biotic (living) and abiotic (nonliving) factors
Abiotic factors might include:
Temperature
Water availability/quality
Terrain (mountains, flat land, etc.)
Soil chemistry
Etc.

3. Levels of Ecological organization
Individual
Population=members of same species in an area
Community=interacting populations
Ecosystem=communities and abiotic factors
Biosphere=portion of planet that supports life

4. Important!
Within populations and communities, there is competition for limited resources (i.e. food, water, shelter, etc.)

5. 2 types of ecosystems Terrestrial= on, under, or near land
Aquatic=in water
These ecosystems do occasionally overlap (pelicans, frogs, etc)

6. Habitat vs. Niche Habitat=where an organism lives
Niche=role or position of the organism in the habitat

7. Symbiosis Sym=together (think “symmetry”) Bio=life
Means “living together”
3 main types, defined by how they impact one another

8. Mutualism (+/+)
Both organisms are benefitted

9. Commensalism (+/0)
One organisms gets a benefit, the other is unaffected

10. Parasitism (+/-) One organism is benefitted, the other is harmed
Usually does not kill host, because it relies on it for survival

11. Nutrition and Energy Flow
Terms:
Autotroph: “Auto”=Self “troph”=nourishment
Makes its own energy (producers)
Typically photosynthesis, can also be chemosynthesis
Heterotroph: “Hetero”=other
A.k.a. consumers
Get energy from consuming other living matter (ex. Animals, fungi)
Decomposers/Detritivore/Scavengers (technically heterotrophs)
Break down dead/dying matter (ex. Fungi)

12. Types of Heterotrophs Herbivore-only eats plants
Carnivore=“only” eats other animals
Omnivore=eats plants and animals
Scavengers=consumes dead organisms
Detritivore=decomposes animal and plant pieces and feces (large)
Decomposer=Absorb and break down remains of dead organisms (small)

13. Trophic Levels Feeding step in energy chain Begin with autotrophs
1st order heterotroph (herbivore)
2nd order heterotroph (carnivore or omnivore)
3rd order heterotroph (carnivore or scavenger)
Decomposer (everything ends with decomposers!)

14. How energy moves through an ecosystem
Food chain-simple diagram showing where energy goes
Producer (Autotroph)→Primary Consumer (Herbivore)→Secondary consumer (carnivore)→Decomposer
NOTE: Arrows show where the ENERGY is going, not what is eating what

15. Food web More complex Shows “all possible” feeding relationships
More realistic, but seldom perfect

16. Energy Pyramids Recall, Law of Conservation of Energy
Cannot be created or destroyed
Can change forms
Model to show how much energy is available at each level
10% can move on
The rest is lost to the environment as heat (metabolism)
Biomass-mass of living matter at each level