1. Introduction to Ecology
1. Ecology- is the study of how organisms survive and interact in their environment.

2. ECOLOGY
1. Ecology-Interaction of
living and non living factors
2. Biosphere- Zone of earth that supports life

3. ECOLOGY
Ecology actually means
“study of the environment,” so I guess you could say that ecologists study animal households!
3.Ecosystems-Refers to all of the living and nonliving factors in an environment

4. 4. Biotic factors - living things
5. Abiotic factors - nonliving things
6. Communities - all the living things in a certain area
7. Population - same species in the same area
8. Habitat- where an organism lives
9. Niche- role, what an organism does.

5. 10.Nitrogen fixation - bacteria transforms atmospheric nitrogen to a form usable to plants (lightning does this, too!) N2 --> NO3 -1
11.Denitrification – other bacteria break down nitrogen compounds and release nitrogen gas to the air
N2 – atmosphere
NO3 -1 – usable by plants (nitrate)

6. ENERGY AND THE ENVIRONMENT
Sunlight- major source of energy
Organisms are classed according to how they get food
Producers – (Autotrophs) Makes its own food. Ex: plants &
algae

7. Consumers – (Heterotroph) gets food from other sources. Ex: animals
Herbivores – eat plants (autotrophs)
Carnivores- eat meat (heterotrophs)
Omnivore- eats plants & animals (heterotrophs)

8. Primary Consumer – eats plants
Secondary Consumer – eats primary consumer
Tertiary Consumer – eats secondary consumer
Limiting Factor – The thing that is in short supply
Organisms may occupy several different feeding levels. Ex: Bear

9. Decomposers – (heterotroph) feed on dead organisms
Decomposers – (heterotroph) feed on dead organisms. They break down nutrients into compounds Ex: Bacteria & Fungi
Scavenger – Feed on the recently dead. Ex: Vulture, crows

10. Food Chain – Model of flow of energy through organisms of an ecosystem
Example of a food chain:
Sun  _____ _____ _____
Energy is not recycled. Therefore sunlight must continue to flow

11. Who’s the Greatest Carnivore ?
Food Web – combination of many food chains.
Best model of energy flow in an ecosystem
Draw an example of a food web on the back of your notes
Food Chain
Who’s the Greatest Carnivore ?

12. FOOD AND ENERGY LEVELS
Trophic Level = feeding level
Energy Pyramid – Animals only gain 10% of the energy from the food they eat . The rest is used by that animal for life processes or released as heat.

13. FOOD AND ENERGY LEVELS
bluejays 10
100
grasshoppers
grass
1000

14. RELATIONSHIPS IN AN ECOSYSTEM
Symbiosis = Interactions among different kinds of organisms
4 Types of Symbiosis
Predation –

15. RELATIONSHIPS IN AN ECOSYSTEM
Symbiosis = Interactions among different kinds of organisms
Predation – one kills another for food. Predator/Prey Ex: __________

16. 3 Types of Symbiosis
1. Parasitism – one benefits, one harmed. Parasite/Host
Ex: ______________

17. 2. Mutualism – Both benefit
Ex: ______________________
3. Commensalism – one benefits, one is unaffected (neither helped nor harmed)
Ex: ____________________

18. Population = same species in a given area
POPULATION GROWTH
Population = same species in a given area
Exponential Growth – (J- curve) Example: Human population
time 
Population 

19. LOGISTIC GROWTH (S-curve) Example: Deer populationB A
Time 
Steady State = Zero Population Growth

20. Carrying Capacity = # of organisms the environment can sustain
Limiting Factors – factors that control population growth
Example: food, water, habitat

21. Density-dependent limiting factors = affect large, crowded populations
Competition – compete for same resource
Predation predation
prey

22. Parasitism – crowding helps parasites travel from host to host
Crowding – restricts room to hunt nest. Increases fighting, causes stress. Stress weakens immune system
Density Independent Factors – affects populations regardless of their sizes. Ex: earthquakes

23. Section 4.1 Summary – pages 91-99
Predation affects population size
The data in this graph reflect the number of hare and lynx pelts sold to the Hudson’s Bay Company in northern Canada from 1845 through 1935.
Lynx and Hare Pelts Sold to the Hudson’s Bay Company
Lynx
Hare
Number of organisms(in thousands)
Times (in years)
Section 4.1 Summary – pages 91-99

24. Draw a population cycle

25. VANISHING SPECIES
Biodiversity – refers to the variety of life in an area * Large islands have greater biodiversity than small islands (if everything else is the same) Importance – Biodiversity brings stability
Species loss affects the existence of other species

26. LOSS OF BIODIVERSITY
Threatened species-species of declining numbers
Endangered species-numbers are very low, extinction is possible
Extinction – no longer exists

27. Threats to Biodiversity
*1. Habitat Loss - #1 threat Ex: rain forest becomes pasture
Habitat fragmentation- separation of wilderness areas from the rest Ex: roads

28. Threats to Biodiversity
*1. Habitat Loss - #1 threat Ex: rain forest becomes pasture
Habitat fragmentation- separation of wilderness areas from the rest Ex: roads

29. Threats to Biodiversity
3. Biotic Issues-some species need large spaces. Ex: migration
4. Abiotic Issues – climate can be changed with the removal of trees.

30. 5. Habitat degredation – damage to a habitat by pollution
a. Air pollution#1 source=burning fossil fuels
Acid rain = low pH from SOx (coal) and NOx (cars)
Ground Level Ozone & CFCs (chlorofluorocarbons) in refridgerators destroys atmospheric ozone

31. b. Water pollution  excess fertilizers, animal waste & silt
c. Land pollution  trash, pesticides (DDT banned in 1972)
Introduction of Exotic species – These are non-native species
Ex: rats, goats
*Rachel Carson-author of Silent Spring

32. Conservation of Biodiversity
Conservation Biology-explores ways to protect biodiversity
Legal Protection of species- U.S. Endangered Species Act protects threatened & endangered species

33. 2. Preserving Habitats- protecting entire ecosystems
2. Preserving Habitats- protecting entire ecosystems. May be best way to conserve species
First National Park 1872
6% of Earth is parks
Sustainable Use-philosophy of using resources in ways without harming the ecosystem

34. 4. Habitat Corridors-leaving natural strips that allows for migration & connects fragmented lands
5. Reintroduction programs-releasing species in an area where they once lived.
6. Captivity- species may survive by being kept by people.

35. Biomagnification

36. Biomagnification of Insecticides Biomagnification of Mercury
the accummulation and magnification of toxic materials at each step of a food chain. Ex: DDT & eagles
Biomagnification of Insecticides
Biomagnification of Mercury

37. THE END