1. Ecology

2. Ecology…
The scientific study of interactions between organisms and their environment

3. Levels of Organization
Biosphere
= thin zone that contains ALL life of Earth

4. 2. Ecosystem
= a self supporting group of communities and their physical environment
Biotic factors: all the LIVING organisms that inhabit an environment
‘bio-’ = life
Abiotic factors: all the NONLIVING part of the environment
‘a-’ = without;
‘a’ ‘bio’tic = without life

5. rock, flower, sun, popcorn, grass, soil, water, animal, tree, carcass
Living
(biotic)
Nonliving
(abiotic)
Dead

6. Living (biotic) Nonliving (abiotic) Dead
Flower
Grass
Animal
Tree

7. Living (biotic) Nonliving (abiotic) Dead
Flower
Grass
Animal
Tree
Rock
Sun
Soil
Water

8. Living (biotic) Nonliving (abiotic) Dead
Flower
Grass
Animal
Tree
Rock
Sun
Soil
Water
Popcorn
Carcass

9. Levels of organization (continued)
3. Community
= all the living organisms in a specific area
(Ex. Pond, forest)

10. 4. Population:
= all the individuals of the same species living in the same area at the same time
5. Organism
= any living thing

11. BiosphereEcosystemCommunity PopulationOrganism
Overview: (largest  smallest)
BiosphereEcosystemCommunity PopulationOrganism
How to remember order?
Big Elephants Consume Peanuts Often

12. Habitat
= the place an organism lives
Niche
= the role (job) an organism has in it’s community

13. Species
= a group of like organisms that can reproduce AND have fertile offspring

14. NOT a species… Horse + Donkey = Mule
A mule is not fertile. In order to make more mules, there must be more (horse + donkey)

15. Lion + tiger = liger
Babies are sterile therefore NOT a species

16. Symbiotic Relationships
Symbiosis
= the relationship in which there is a close and permanent association between organisms of different species
3 types:

17. 1. Mutualism Relationship in which both organisms benefit
Organism 1 = = Benefit
Organism 2 = = Benefit

18. Example of mutualism
Ants and the acacia tree

19. 2. Commensalism
relationship in which one species benefits and the other is neither harmed nor benefited
Organism 1 = = benefit
Organism 2 = = no harm, no benefits

20. Example of commensalism
Spanish moss growing on trees

21. 3. Parasitism
Relationship in which one species benefits and the other is harmed
Organism 1 = = benefit
Organism 2 = = harmed

22. Example of parasitism
Tapeworms

23. Overview Relationship Organism 1 Organism 2 Mutualism Commensalism
Benefit
Commensalism
No benefit, not harmed
Parasitism
Harmed

24. Ecological Niches 1. Producers: Also called autotrophs ‘auto-’ = self
‘troph’ = feeding
These are organisms that make their own food
Ex. green plants

25. 2. Consumers:
Also called heterotrophs
‘hetero-’ = different
Organisms that can NOT make their own food
Three categories:
A. herbivores: eat plants (primary consumer)

26. B. carnivores: eat other consumers; eat meat (secondary/tertiary consumers)
C. omnivores: eat both plants and animals (tertiary consumers)

27. 3. Decomposers: break down organic matter and return it to the environment

28. Food Chains
The flow of energy and organic molecules from organism to organism
Energy for this system originates from the SUN
Food chains ALWAYS begin with a PRODUCER

30. Food Webs
Complex relationships formed by interconnecting and overlapping food chains

31. Food Pyramids
1. Pyramid of numbers
The higher up the food chain the lower the number of organisms

32. 2. Pyramid of energy
90% of the energy is lost to the environment at each level of the food chain
3. Pyramid of biomass
The amount of biomass decreases at each level of the food chain

33. Community Distribution
Limiting factor: any biotic or abiotic factor that restricts an organism’s ability to survive
Ex. Food supply, water supply, living space
Tolerance: the ability to withstand fluctuations in biotic and abiotic environmental factors

34. SUCCESSION the orderly, natural change in communities over time
Primary succession: development of living communities from BARE ROCK
NO soil present
Ex. Rock lichens moss ferns shrubs trees mature trees

35. Pioneer organism: the first organism to inhabit a community (ex
Pioneer organism: the first organism to inhabit a community (ex. lichens)
Climax community: a stable, mature community that undergoes little or no succession
Primary succession takes a relatively long time to reach this point

36. Secondary succession: the development of living communities that takes place when a community is disrupted by natural disasters or human impact Soil IS present Takes less time to reach climax community Ex. Abandoned farms, fires…

37. Population Growth
Exponential growth: when the number of organisms increases by an ever-increasing rate. 248163264128256etc J-shaped curve

38. Carrying capacity: the number of organisms of a population a particular environment can support over an indefinite period of time S-shaped curve

39. Factors that affect the size of populations
1. Birth rate
2. Death rate
3. Growth rate = birth rate – death rate
4. Immigration: movement INTO an area
5. Emigration: movement OUT of an area