1. 4-2 What Shapes an Ecosystem?
Ecosystems are shaped by Biotic (living) & Abiotic (nonliving) factors.
Biotic factor=living organisms in the ecosystem
Abiotic factors= physical (nonliving) components of the ecosystem & how the organism uses these components.
Area where an organism lives=habitat

2. Biotic Factors
Abiotic and Biotic Factors
Abiotic Factors
ECOSYSTEM

3. The Niche
Niche-the combined physical and biological conditions in which organisms live & how the organism uses these conditions.
A Niche includes:
The food type, method to obtain it and competition for the food.
Temperature and water content.
Reproductive time and location

4. Community Interaction:
Competition- a conflict for the same resource in a habitat at the same time.
Resource- any necessity for life.

5. Predation occurs when one species (predator) captures & feeds on another species (prey).

6. Symbiosis: two organisms living close together. There are three types.
1) Mutualism
2) Commensalism
3) Parasitism

7. Symbiosis: Mutualism: both species benefit. Water buffalo and cowbird
Crocodiles and plover birds

9. Symbiosis:
Commensalism: One member benefits & one is neither helped nor harmed.
Flatworm on horseshoe crab
Barnacles on a whale

10. Symbiosis:
Parasitism: One organism (parasite) lives on or in another organism (host) and harms it.

11. Symbiosis: = 1 species Type of relationship Species harmed
Species benefits
Species neutral
Commensalism
Parasitism
Mutualism
= 1 species

12. http://www. cstephenmurray

13. Ecological Succession
Ecosystems & communities are ALWAYS changing!
Ecological Succession=
a series of predictable
changes in a community.
1) Primary succession
2) Secondary succession

14. Ecological Succession
Primary succession: occurs in areas with no soil.
Example= Volcanic eruptions, glacial melts.

15. Ecological Succession
Secondary succession: succession following a disturbance that destroys a community without destroying the soil.
Ex: destructed through fire, natural disasters, or clearing of land

16. Chapter 5-1: How Populations Grow
Populations have 3 characteristics:
-- Geographic distribution
-- Population Density
-- Growth rate.

17. Characteristics of a Population
Geographic Distribution (range) is the area a population inhabits. (Where it lives.)

18. Characteristics of a Population
Population Density is the number of individuals in a given area.

19. Characteristics of a Population
Growth rate is the rate at which members are added or removed from the population.

20. Population Growth Three factors affect population size:
birth rate, death rate, and migration.
Growing population= a higher birth rate than death rate.
Shrinking populations= a higher death rate than birth rate
Stable populations have equal birth & death rates

21. Two Types of Growth Patterns
1. Exponential
2. Logistic

22. Exponential Growth
Individual organisms reproduce at a constant rate

23. Logistic Growth Population’s growth slows down or stops
Carrying Capacity: the largest number of individuals a given environment can hold

24. Population Growth Immigration = movement into a population
Emigration = movement out of a population

25. 5-2 Limits to Growth
A Limiting Factor causes a population to decrease.
Example: Panda & Bamboo

26. Density Dependent Factor
A limiting factor that depends on the population size= Density Dependent Limiting Factor.
Types of Density Dependent Factors:
--Competition
--Predation
--Parasitism & Disease

27. Density Dependent Factor
1) COMPETITION:
Competition is when organisms use the same resources

28. Density Dependent Factor
2) PREDATION:
Predation creates the predator-prey relationship. 60 50 40 30 20 10
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
1600
1200
800
400
2400
Moose
Wolves

29. Density Dependent Factor
3) PARASITISM & DISEASE
Parasitism & Disease harms the host

30. 6-3 Biodiversity Variety= Diversity
Biodiversity- the sum total of the variety of organisms in the biosphere.
Human activity can reduce biodiversity by altering habitats:
1) Hunting species to extinction
2) Introducing toxic chemicals into food webs

31. Pollution DDT= one of the first widely used pesticides. GOOD BAD Cheap
Remains active for a long time
Kills many different insects
Controls agricultural pests.
Non biodegradable
Organisms can NOT remove it from their bodies.
DDT gets stored in organisms (producers & consumers bodies)

32. How DDT gets into the Environment

33. Pollution
As you move up trophic levels in a food chain the amount of DDT consumed increases GREATLY!
Biological Magnification- concentrations of a harmful substance increases at higher trophic levels.
Plants pick up
DDT from water
& store it
Herbivores eat
plants and store some DDT
Carnivores eat
herbivores and store more DDT → →

34. DDT 10,000,000 1,000,000 100,000 10,000 1000 1 Fish-Eating Birds Large
Small Fish
Zooplankton
Producers
Water