1. Chapter 13: Principles of Ecology

2. Section One: Ecologists Study Relationships
Ecology: the study of interactions among living things
Ecologists study the relationships between the levels of organization
Levels of Organization (ordered from smallest to largest)
Organism: an individual living thing
Population: a group of organisms of the same species that live in the same area
Community: a group of different species that live in the same area
Ecosystem: all organisms and abiotic factors in an area
Biome: major regional or global community of organisms

3. Section One: Ecologists Study Relationships
Ecologists use different tools to conduct research on these relationships
Observation
Experimentation ( in the lab or field)
Modeling
Computer and Mathematic Models

4. Section Two: Biotic and Abiotic Factors
Components of an Ecosystems
Biotic Factors: living things in an ecosystem
Abiotic Factors: nonliving things in an ecosystems such as temperature, sunlight, wind, and soil

5. Section Two: Biotic and Abiotic Factors
Everything is interconnected
If you change one thing in an ecosystem you change everything
Biodiversity: the variety of living things in an ecosystem

6. Section Two: Biotic and Abiotic Factors
Everything is interconnected
Keystone Species: a species that has an unusually large effect on the ecosystem

7. Section Three: Energy in Ecosystems
Energy Flow in Ecosystems
Producers: organisms that get their energy from nonliving resources and provide energy for other organisms in the ecosystem
Can also be called autotrophs
Consumers: organisms that get their energy by eating other living or once-living sources
Can also be called heterotrophs

8. Section Four: Food Chains and Food Webs
Food Chains: a sequence that links species by their feeding relationships
Always flows in one direction

9. Section Four: Food Chains and Food Webs
Types of Consumers
Herbivores: organisms that eat only plants
Carnivores: organisms that eat only animals
Omnivores: organisms that eat plants and animals
Detritivores: organisms that eat dead organic matter
Decomposers: detritivores that break down organic matter into simple compounds
Specialists: eats only one specific organism
Generalists: eats many different organisms

10. Section Four: Food Chains and Food Webs
Trophic Levels: the levels of nourishment in a food chain
Energy flows up the food chain from the lowest trophic level to the highest

11. Section Four: Food Chains and Food Webs
Food Web: a model that shows the complex network of feeding relationships and the flow of energy within an ecosystem
Flow many different ways

12. Section Five: Cycling of Matter
The Water Cycle
Also called the hydrologic cycle

13. Section Five: Cycling of Matter
The Oxygen Cycle
Most organism need oxygen to live

14. Section Five: The Cycling of Matter
The Carbon Cycle

15. Section Five: The Cycling of Matter
The Nitrogen Cycle
Most organism can only use nitrogen in two forms
Ammonium and Nitrate
Nitrogen Fixation: a process in which certain types of bacteria convert gaseous nitrogen in to ammonia

16. Section Five: The Cycling of Matter
The Phosphorus Cycle
Most of the cycle takes place underground
Phosphate is released by the weathering of rocks
Plants and fungi take up the phosphate

17. Section Six: Pyramid Models
Energy Pyramid: a diagram that compares energy used by producers, primary consumers, and other trophic levels
Biomass: the measure of the total dry mass of organisms in a given area
Biomass (or energy) is lost as you go up the pyramid