1. Principles of Ecology

2. What is ecology?
The study of the interactions between organisms and their environments.

3. Biosphere The part of the earth that supports life Air (Atmosphere)
Water (Hydrosphere)
Land (Lithosphere)
Variety of organisms in a wide range of conditions that they are adapted to survive in

4. Biotic vs. Abiotic Biotic factors: living factors in an environment
Ex:
Abiotic factors: nonliving factors in an environment
Ex:

5. Levels of Organization
Organism
Population
Biological Community
Ecosystem
Biome

6. Population- All members of a species living in the same location at the same time
Individuals must compete to survive
What limits the size of a population?
Organism- One member of a species
The lowest level of organization that ecologists study

7. Community- A group of populations that interact in the same location at the same time
Includes all plants, animals, bacteria, fungi, and protists
May or may not compete for resources

8. Ecosystem- A biological community and all the biotic and abiotic factors that affect it
Boundaries are defined by scientists
Can change
Can overlap

9. Biome- A large group of ecosystems that have
the same climate
similar types of communities

10. Ecosystem Interactions
Habitat: an area where an organism lives
Tree
Grove of trees
Niche: the role an organism has in its environment
How it meets its need for
Food
Shelter
Survival
Reproduction

11. Community Interactions
Each organism depends on and competes with other organisms.
Competition: occurs when organisms need to use same resource at the same time
Food
Water
Space
Light

12. Symbiosis: relationship in which two organisms live in close association to each other
Mutualism: Two species live together and benefit from each other
Ex: Termite and protozoa in stomach
Commensalism: One organism is helped and the other is not helped or harmed
Ex: Remora and whale sharks
Parasitism: One organism is helped and the other is harmed
Ex: Mosquitoes and humans

13. Symbiosis Oxpecker and Cattle (and ticks)
White winged dove and Saguaro Cactus

14. Energy in an Ecosystem
Autotrophs: organisms that get energy from sunlight or inorganic substances to produce food
Producers
Heterotrophs: organisms that obtain energy by consuming other organisms
Consumers

15. Consumers Herbivore: Consumes only plants
Ex: cows, rabbits, grasshoppers
Carnivore: Eats other heterotrophs
Ex: lions, wolves
Omnivore: Eat both plants and animals
Ex: humans, bears, mockingbirds
Detritivore: Eats dead things and return nutrients to the environment
Ex: hyenas, vultures, fungi, bacteria
Why are they important? What would happen without them?

16. Food Chains Shows how energy flows through an ecosystem
Flow on energy is one way into the consumer

17. Food Web Shows feeding relationships in an ecosystem
Contains several food chains

18. Pyramid of Energy Shows energy flow by trophic levels
Indicates the amount of energy available to next level (~10%)

19. Pyramid of Biomass
Shows the amount of biomass consumed by the level above it
At each level there is less energy available to support organisms

20. Nutrient Cycles producer  consumer detritivore  environment
Nutrients cycle through biosphere
Needed for organisms to survive
Water
Carbon
Nitrogen
Phosphorous
producer  consumer detritivore  environment

21. Communities, Biomes, and Ecosystems

22. Limiting Factor
Any factor that restricts the numbers, reproduction, or distribution of organisms
Sunlight
Climate
Water
Fire
Space
Other plant or animal species
Factors that limit one species might enable another

23. Range of Tolerance
Upper and lower limit of tolerance that an organism can survive when exposed to certain factors
Optimum zone: range that is best suited for the organism
Zone of physiological stress: zone between optimum zone and tolerance limits

24. Range of Tolerance

25. Succession

26. Ecological Succession
Primary Succession
Secondary Succession
Begins with bare rock
Ex: lava flow forms rock
Pioneer Species: the first organisms to appear
Lichen- creates soil to support other life
Might take hundreds of years for ecosystem to balanced
Climax Community: a stable, mature community; little change in number of species
Scientists now reject – always changing
Begins with disrupted community; soil present
Fire, flood
Over time species belong to community are likely to return
Pioneer communities quickly progress
Ends in climax community
The process of one community replacing another as a result of changing factors

27. 1 2 3 Primary Succession Bare rock with lichen Grasses and shrubs
Forest community 3

28. Secondary Succession of an abandoned farm field in North Carolina

29. Secondary Succession - Fire
Primary Succession

30. Succession in a Pond Eventually the pond fills in with soil
Some last only a couple weeks others for thousands of years
Ponds go from:
Oligotrophic (nutrient poor) to
Eutrophic (nutrient rich)

31. Biomes Land Aquatic Tundra Taiga (Boreal Forest)
Temperate Deciduous Forests
Grasslands
Deserts
Savannas
Tropical Rain Forests
Fresh Water
Transitional
Marine

32. You are going to get to do Biome Projects next week!