1. Unit 2 Ecology

2. Characteristics of Life
How do you know if something is ALIVE???

3. 1. All organisms are made of cells
Cells are the smallest unit of life

4. 2. All organisms need energy
Any living organism needs energy to live
They take in and use energy.

5. 3. All organisms respond to the environment
What happens to an organism depends on the environment they are living in.

6. 4. All organisms reproduce
Living organisms can make more of themselves
Two types:
asexual
sexual.

7. 5. All organisms grow and develop
Get bigger as they get older.

8. 6. All organisms have genetic information (DNA)
Carry their own genetic code
Traits are passed to offspring

9. 7. Internal Balance (Homeostasis)
Living things maintain stable internal conditions
Examples
Temperature
Water Balance
Heart Beat

10. Matter cycles, energy flows
ECOLOGY
Key Knowledge:
Matter cycles, energy flows
Abiotic factors cause changes in biotic factors in a ecosystem

11. Ecosystem
Structure

12. Abiotic: Non-living parts of the environment
Soil
Sunlight
Climate
Temperature
Rainfall
Nutrients

13. Biotic: living parts of the environment
Plant
Animals
Decomposers (Bacteria and Fungus)

14. General Organization A. Organism= any individual living thing
B. Population= Individual organisms of a single species in one area.
C. Community= more than one population living in the same area.

15. More Organization vocabulary:
D. Ecosystem= All the populations and abiotic factors in an area.
E. Habitat = the environment that a particular species prefers within an ecosystem
F. Niche= the role that an organism fills “job”
G. Biomes= Ecosystems with similar characteristics.

17. Example of a Community Different species of fish
Different species of corals (animals)
Starfish (animal)
Example of a Community
Algae
(microscopic plants)

18. Give an example of a population:
Give an example of an organism:
List what would be in an Ecosystem:

19. How would the Habitat of an owl differ from that of a rabbit in the North American Forrest?
What Niche does the owl fill?
What niche does the rabbit fill?

21. Characteristics of a Biome
No distinct boundaries
Defined by types of plants
Similar climate conditions, but may be located in a totally different part of the world (Africa and Asia)
Classification of biomes:
land biomes
water biomes (marine or freshwater)

23. Where in the world is a biome similar to ours here in the Southwest?

24. How Organisms Gain Energy!!
How an organism generates it’s energy determines it’s place in the ecosystem!!

25. AKA: Primary Producer/PLANTS & Algae
Autotroph
Self
Feeding
Can make their own food through energy from the sun or inorganic substances
AKA: Primary Producer/PLANTS & Algae

26. What kinds of organisms are producers???????
Producers are the BASE of ALL ecosystems!!

27. AKA: Consumers Heterotroph Many Feeding
Obtains energy by eating other organisms,
AKA: Consumers

28. Types of Consumers Primary consumers: eat producers (herbivores)
Secondary consumers: eats both producers & consumers (omnivores)
Tertiary consumers: top predator (carnivore)

29. We can visualize this feeding structure by drawing Pryamid structures:
These show Trophic levels. These show what kinds of food an
organism uses.
1st trophic level= primary producers
2nd trophic level= primary consumers
3rd trophic level= secondary consumers
4th trophic level= tertiary
consumer

30. Decomposers & Scavengers
Decomposers feed on wastes & dead material from all trophic levels
Ex: bacteria, fungi
Scavengers are consumers that eat dead animals (like road kill) found in
all tropic levels except for 1st.
Ex: vulture

31. Energy in an ecosystem is transferred (flows)through the trophic levels of that ecosystem

32. Biomass and Energy Transfer
Biomass- total mass of living material in an area
Biomass and energy transfers at the lowest trophic levels determines the carrying capacity of each ecosystem
1 hawk
10 snakes
100 mice feed
1000 plants feed
Rule of 10****-
Only 10% of the energy is transferred to the next organism.

33. This shows a food chain

34. Why do you think there are more 1o consumers than 3o consumers??

35. Very few animals feed on only one food source, food webs are a more accurate picture of how animals feed.

36. Biological Magnification
The build-up of toxins in living organisms with movement up the trophic levels .
The toxins collect in organisms at the top of food web because top consumers eat so much.
Examples:
Methyl Mercury
DDT

37. DDT: Dichlorodiphenyltrichloroethane
Developed during WWII as a pesticide
Very high levels of DDT were found in top consumers.
DDT is stored in fat.
Organisms died or had reproductive problems
Banned in US and Canada during the 70’s.
Still found in almost all living things
Developing countries are still use DDT

39. Current Chemicals of Concern
DDT ( soil )
Almost 40 years later!
Methyl Mercury ( Fish)
Current Chemicals of Concern
PCB's ( industrial waste)
Polychlorinated Biphenyl
Dioxin (plastic)

40. How do all these populations interact with each other?

41. Community
Interactions

42. Community Interactions
In order to sustain an environment, organisms and abiotic factors interact
EXAMPLES:
Symbiosis
Succession

43. Forms of Species Interaction
A. Symbiotic relationships: relationships between two species (3 types)
1. Parasitism: one organism benefits at another’s expense (humans and tape worm)
2. Commensalism: one organism benefits while the other is unaffected (anemone and clown fish)
3. Mutualism: both organisms benefit from the interaction (rhino and bird)

44. Forms of Species Interaction Continued
B. Competition: two species are fighting for the same resources
C. Predator/Prey: one species hunts the other Prey:

45. How does the environment cycle through changes?

46. Ecological succession: change in the types of species in a community observed over time

47. Why does succession happen?
It is because Communities & environments change over time

48. When communities form in brand new areas (usually rocky)
1) Primary Succession
When communities form in brand new areas (usually rocky)
Ex: volcanoes, rocks, etc

49. Steps of Primary Succession
A. Pioneer species appear  lichens
(grow on rock & turn it into soil)
Pioneer Species: the first organisms to occupy an area
B. Grass & small plants appear
C. Weeds & shrubs
D. Shallow trees (ex: pine trees)
E. Climax community  stable & final stage (ex: deciduous trees)

50. So What is a Lichen? Symbiotic Relationship between a
Fungus (provides shelter)
Algae (provides food)

51. 2) Secondary Succession
Occurs in areas that were cleared by disturbance (fire, tornado, floods, etc)
faster than primary (soil already formed)
Same as primary except pioneer species are grasses instead of lichens

52. Climax Community
A community that has achieved stability and species diversity

53. Ecological Succession leads to…..
Population Growth

54. FACTORS THAT AFFECT POPULATION GROWTH
Birth Rate
Death Rate
Immigration (movement into an area)
Emigration (Movement, exiting an area)

55. TYPES OF
POPULATION GROWTH

56. Exponential Growth
J-shaped curve on a graph
Population doubles every generation
Humans are reproducing this way!
Humans - Trouble ahead? What will happen to our resources?

58. Logistic Growth S–shaped curve on graph How real growth looks
Populations grow fast early, then slow down, as we get closer to CARRYING CAPACITY

59. Biomass and
energy transfer
at the lowest
trophic level determines
the carrying capacity of
the ecosystem.
All has to do with how many producers are there to support the consumers!

60. Carrying Capacity Maximum # of individuals a population can support
Populations will increase to carrying capacity, and they decrease again once they have reached it.

61. What affects the size limit of populations???

62. Limits to Pop. Growth
1. Density-dependent limiting factors – Factors that reduce population growth; that depends on current population size
Affect crowded populations
Disease
Competition (for shelter, food, water)
Predation (predator eats prey)

63. Think about it……
How might the bubonic plague have been different if the medieval populations didn’t live so close to each other?

64. Affect all populations (crowded or not)
2. Density-independent limiting factors – environmental factors affecting a population regardless of size
Affect all populations (crowded or not)
Weather
Natural disasters (fire, etc)
Human activities

65. Think about it……
Would the physical effects of hurricane Katrina be any different in a town of 100, then in a town of 100,000?
New Orleans, LA
Gulf Port , MS

66. VII. AKA: Nutrient Cycles
Matter Cycles!
VII. AKA: Nutrient Cycles
All matter essential for life moves in cycles between living things & the environment
Examples of cycles:
carbon cycle
water cycle
nitrogen cycle

67. 1. Why is carbon important to us?
Carbon Cycle
1. Why is carbon important to us?
1) Carbon is used to make hair, muscle, & skin
2) Carbon stores energy so living things can think, move, etc
3) Fossil fuels (gas, coal, oil) are made from carbon

68. 2. Where is carbon found in the environment?
atmospheric gas (CO2)
rocks (limestone, diamonds)
fossil fuels (oil, coal, etc.)

69. 3. How does carbon enter living things?
1) CO2 gas enters plants
2) Photosynthesis allows plants to change CO2 into a sugar
3) Animals then get carbon by eating the sugar found in plants

70. 4. How does carbon get back into the environment?
1. Plants & animals release CO2 during respiration
2. Burning of wood & fossil fuels
3. Using electricity, (most power plants use fossil fuels)
4. Cow farts (seriously) CH4
5. Decomposition when bacteria and fungus break down tissue of dead things

71. 5. How are fossil fuels formed? Fuel is fossilized Carbon!!!
When living things die & fall to the bottom of water, they are buried & compressed 
They eventually form coal, petroleum, or natural gas

72. 6. So …. There are 2 main steps to recycling Carbon.
the 2 main steps are photosynthesis & respiration!

73. A. The Carbon Cycle The movement of carbon through the environment
Photosynthesis- plants and algae(producers) take up CO2 from the air or water to make sugar
Cellular Respiration- consumers use sugar for energy and release CO2 into the air or water

74. Due to humans using more fossil fuels, more CO2 is released each year
7. Future Predictions
Due to humans using more fossil fuels, more CO2 is released each year
this may result in global warming since CO2 traps heat (remember the greenhouse effect)

75. What is global warming?

76. Facts about Nitrogen 78% of air is nitrogen gas (N2)
Living things can’t use nitrogen when it’s a gas (N2)

77. Why do living things need Nitrogen?
To make amino acids & proteins
To make DNA

78. Nitrogen gas (N2) is found in the atmosphere
B. The Nitrogen Cycle
Step #1
Nitrogen gas (N2) is found in the atmosphere

79. Step #2
”Nitrogen Fixation”: Bacteria living at the roots of plants change the N2 gas into a usable form like ammonia or nitrates
Lightning also “fixes” nitrogen
Atmospheric Fixation
The enormous energy of lightning breaks nitrogen molecules and enables their atoms to combine with oxygen in the air forming nitrogen oxides. These dissolve in rain, forming nitrates, that are carried to the earth.
Atmospheric nitrogen fixation probably contributes some 5– 8% of the total nitrogen fixed.

80. Step #3 Step #4 Plants then use the ammonia or nitrates in the soil
Animals get nitrogen from plants by eating them

81. This is done by denitrifying bacteria
Step #5
When plants & animals die, the nitrogen in their bodies is changed back into (N2)
This is done by denitrifying bacteria
Step #6
Nitrogen gas is released back into the atmosphere

82. What are the two process that are responsible; for cycling Carbon in the environment? What things add carbon? Which things take it away?
Photosynthesis and Cellular Respiration
Photosynthesis : take it away
Cellular Respiration, Fossil Fuels and Decaying organisms add it.

83. Breaking the Water Cycle
The only way for water to get back to the atmosphere is through transpiration (plant sweating)
When we cut down trees they no longer transpire
So water does not get into the air to become rain
The area becomes a desert in a very short time period
Really bad in rainforest regions, because the soil is so shallow

84. VIII. HUMAN IMPACT
A Sad True Story

85. Invasive Species
A species that is brought by HUMANS into a new environment and outcompetes the ones already there.
They have no competitors, no diseases so they outgrow other populations
Example: Africanized honey bees, which will take over the hive of the honey bees.
Example: Zebra mussels attach to boats and cover piers within months 85

86. Keystone Species A species that plays a key role in the ecosystem
Increases biodiversity by keeping the number of each species in balance
Examples
Sea otter in the kelp forests
Beavers in rivers
Beaver
Sea Otter

87. An Ecological Mystery
Long term study of sea otter population along the Alaskan and Aleutian Islands
1970: Sea Otters healthy and populations growing
1990: Sea Otter #’s declining
Maybe due to emigration, not deaths
1993: 800 km area in Aleutian Islands studied
Sea Otter #’s reduced by 50%

88. Vanishing Sea Otters 1997: Study of area repeated
Sea Otter pop. had declined by 90%
1970: > 53,000 Otters in the study area
2012: < 2800
Why?
Reproductive issues
Starvation, pollution, disease?

89. Cause of the Decline
1991: one researcher observed an orca whale (killer whale) eating a sea otter.
Sea lions or seals are the normal prey of orcas.
Decline in usual prey led to feeding shift.
Single orca could consume 1,825 otters/year.
Clam Lagoon (CONTROL GROUP), which was not accessible to orcas, had no decline in otter population

90. No Big Deal.. Right?
Declines in ocean fish due to over fishing and climatic changes led to a reduction in food for sea lions & seals, so their #’s decreased
This forced the orcas to enter into the coastal waters where they consumed sea otters.
Sea otters normally feed on sea urchins. As sea otters decreased, the urchins numbers increased.

91. Urchins eat kelp, and the large numbers of urchins damaged kelp forests.
The decline in the kelp forests has had an impact on many others species because of the decrease of oxygen and an increase in carbon dioxide in the water.
Other Species Affected
Bald Eagle
Mussel
Sea Stars
Seagulls