1. Ecosystems and Community
Chapter 4
Unit 2

2. Biotic and Abiotic Factors
Biotic: the biological influences on organisms within an ecosystem
Abiotic: physical or nonliving factors that shape ecosystems

3. Biotic:
Abiotic:

4. Habitat The area in where an organism lives
Includes both abiotic and biotic factors
Animals address

5. The Niche
The full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions
The animals occupation
Includes:
Type of food the organism eats
How it obtains food
Which other species use the organism as food
Physical conditions organism requires to survive
When and how it reproduces

6. A bear’s niche Type of food it eats: How it obtains food:
Who uses the organism as food:
Physical conditions required to survive:
When and how does it reproduce:

7. Competitive Exclusionary Principle
No two species can share the same niche in the same habitat
EX: 3 species of birds live in the same spruce tree but feed at different elevations and in different parts of the trees. Each warbler has a different niche within the forest

8. Community Interactions
Competition: when organisms of the same or different species attempts to use the same source in the same place at the same time
EX: plants competing for sunlight
Predation: One organisms captures and feeds on another organism

9. Community Interactions
Symbiosis: any relationship in which two species live closely together
Mutualism: both species benefits from the relationship
Commensalism: one member benefits and the other is neither helped nor harmed
Parasitism: one organism lives on or inside another organism and harms it

11. Ecological Succession
Series of predictable changes that occurs in a community over time
Primary Succession:
Occurs on surfaces where no soil exists
Pioneer species: first species to populate the area

13. Secondary Succession:
When a disturbance of some kind changes an existing community without removing the soil
Ex: fires, farming

14. Biomes
Terrestrial communities that cover a large area and is characterized by:
certain soil
climate conditions
particular plants and animals
Tolerance: ability to survive under different conditions that differ from their optimal conditions

16. Biomes and Climate
Microclimate: climate in a small area that differs from the climate around it

17. Aquatic ecosystems Determined by
depth, flow, temperature, and chemistry of water
Grouped according to the abiotic factors that influence them

18. TUNDRA
GRASSLAND
DECIDUOUS FOREST
CONIFEROUS FOREST

19. TAIGA
DESERT
RAIN FOREST
DESERT

20. Freshwater ecosystem
Two main types:
Flowing-water
Standing-water

21. Aquatic Ecosystems Photic zone: well-lit upper layer
Aphotic zone: below photic zone where light cannot penetrate