1. Chapter 3: The Biosphere
What is ecology?

2. Ecology
Ecology –study of interactions among organisms, between organisms, and their environment
Interdependence – Life depends on other living things and natural resources (air, water, land)

3. Levels of Organization 1. Species
Individual living thing

4. Levels of Organization 2. Population
Groups of individuals of same species in an area.

5. Levels of Organization 3. Community
Different populations that live together in an area.
Several populations interacting together.

6. Levels of Organization 4. Ecosystem
Collection of all organisms (biotic) in a particular place together with the abiotic (physical) environment.

7. Levels of Organization 5. Biomes
Groups of ecosystems with similar climate and communities.

8. Levels of Organization 6. Biosphere
The highest level of organization.
The portion of
the Earth
that supports life.

9. BIOSPHERE
BIOME
ECOSYSTEM
COMMUNITY
POPULATION
SPECIES

10. Levels of Organization
BIOSPHERE
BIOME
ECOSYSTEM
POPULATION
SPECIES
COMMUNITY

11. Biotic and Abiotic Factors
Biotic – living
Plants, Animals ,Mold, Fungi, Bacteria, Protist
Abiotic – Nonliving
Sunlight, soil, wind, water, temperature

12. Ecological Methods Observation – 1st step to designing an experiment
Experiment – test hypotheses
Modeling – make models based on observation & experiment
Helps make future predictions

13. 3.1 Review Many populations together is called a…
Combination of biotic and abiotic factors in an environment make up the…
What’s the different between biotic and abiotic?
Community
Ecosystem
Biotic – living factor
Abiotic – nonliving factor

14. 3.1 Review Picture
Pick any animal you want and draw a picture similar to the one below. Include “species, population, community, and ecosystem”

15. 3.2 ENERGY FLOW (Autotrophs and Heterotrophs)
One of the most important factors to determine capacity to sustain life is Energy Flow

16. Autotrophs (producers)
Trap light energy to produce food
Plants
Some protists
Some bacteria
Photosynthesis – Converts light into chemical energy
6CO2 + 6H2O C6H12O6 + 6O2
Chemosynthesis – Converts chemical energy into carbohydrates
SUN

17. Heterotrophs (consumers)
Must acquire energy from consuming other organisms
Herbivores – plants
Carnivores – animals
Omnivores – both
Detritivores – eat dead plants & animals
Decomposers – break down organic matter

18. 3.2 Review Another name for autotroph is…
What are the two processes autotrophs use to make energy?
What are the four types of –vores?
Producer
Photosynthesis and Chemosynthesis
Carnivore, herbivore, omnivore, detritivore

19. 3.3 Energy Flow in Ecosystems
Food Chains and Food Webs

20. Food Chains and Food Webs
SUN Autotrophs Heterotroph
Food Chain – shows simple energy transfer
Food Web – shows possibilities of energy transfer
Food Chain – energy trapped by producers passed on when organisms eat and are eaten

21. Trophic Levels T Level 2 T Level 3 T Level 1
Trophic Levels – each step in a food chain/web
T Level 4?
T Level 2
T Level 3
T Level 1

22. Ecological Pyramids
Ecological Pyramids – shows relative amount of energy at each level (10% rule)
Biomass – total amount of living tissue within a trophic level

23. 3.3 Review Which is more complex – food chain or web?
Grass  rabbit  fox  alligator – Which is T2?
What is biomass?
Food web
Rabbit
Amount of living tissue in each trophic level

24. 4.2 Niches and Community Interactions

25. Tolerance
Species ability to survive and reproduce under a range of environmental circumstances.
Intolerance Zone
Zone of Tolerance
Optimal Range (center) organisms most likely to be most abundant
Physiological stress zone (edges of curve) organisms stressed and numbers decline
Expend more energy to maintain homeostasis
Less energy available for growth and reproduction
Zone of Intolerance
Outside tolerance zone; No organisms

26. Habitat General place an organism lives.
Determined by species tolerance.

27. Niche
Range of physical and biological conditions in which a species lives and the ways the species obtains what it needs to survive and reproduce.
How a species interacts with its environment and resources to survive.

28. Niches Resources – Things needed for life
Plants- sunlight, water and soil nutrients
Animals- nesting, space, shelter, food, places to feed
Physical resources– Abiotic factors required for survival.
Ex- amphibians lose and absorb water through skin::must live in moist places.
Biological resources– Biotic factors required for survival.
E.g. when/how reproduces, food, way obtains food.
such as food, water, light, nutrients or space.

29. Competition Different organisms attempting to use essential resources.
Same resources at same time and place = competition
Intraspecific competition-same species competing
Interspecific competition- different species competing
What do you think these two males are fighting over?

30. Competitive Exclusion Principle
-No two species can occupy exactly the same niche at the same time. -One species will win and survive. -One will lose and die.
Competition = almost always a winner and loser (losing species dies out)
-exactly the same habitat at

31. Dividing Resources
Helps determine the number and kinds of species in a community and the niche each species occupies.
What would happen if two of the warlber species tried to occupy the same niche in the same tree at the same time?

32. Review so far… (14 points)
Pick an animal. Any animal.
On a blank piece paper draw or write a paragraph using COMPLETE SENTENCES:
It’s habitat
Some things that would give it optimal tolerance.
Some things that would cause the habitat to be intolerable.
It’s niche (list two physical and two biological factors it interacts with)
When might it come into competition?
What could it do to divide resources with competition?
Frog – Habitat: pond in a warm environment.
Optimal: warm, lots of water, many insects.
Intolerable: Cold, no insects, not a lot of water, lots of predators
Niche physical: Water, temperature
Niche biological: Predators, prey, plants to hide in and eat.
Competition with fish for food.
Divide resources: eat at different times, different parts of pond.

33. Predation, Herbivory, and Keystone Species

34. Predation
Where one animal (the predator) captures and feeds on another animal (the prey)

35. Predation
Predators affect size of prey population and determine the places prey can live.
E.g. birds can play important role in regulating mouse population sizes

36. Herbivores Herbivory - Animal (herbivore) feeds on producers (plants)
Affect size and distribution of plants.
E.g- Many white-tailed deer are eliminating their favorite food plants across US.
Determine the places that certain plants can survive and grow
-Why hunting is important – but over-hunting is bad. Everything is moderation.

37. Keystone Species
A single species that can dramatically change in a community
Ex- Sea otters eat large amounts of sea urchins, which eat kelp.
Sea otters almost eliminated by hunting; urchins population increased; ate all the kelp.
Other organisms also disappeared.
Sea otters went on endangered species, populations recovered

38. Symbioses Any relationship in which two species live closely together
Three main classes:
Mutualism
Parasitism
Commensalism

39. Mutualism Relationship in which both species benefit
E.g. – Sea anemone and clownfish
Sea anemone-offers shelter; clownfish protects for preditors.

40. Parasitism
Relationship where one organism lives inside or on another organisms and harms it.
Parasites obtains all or part of its nutritional needs
Parasites weaken but generally do not kill hosts.

41. Commensalism
Relationship where one organism benefits and the other is neither harmed or helped
E.g. Grey whale and barnacles-
Grey whale not harmed and no benefits
Barnacles- benefit from flow of water from moving whale that provides food

42. 4.2 Review
What could be a physical and biological resource for a flower?
When does competition occur?
Ants protecting a tree that gives the ants shelter is an example of…
Phys – Sun Bio – Roots, insects, etc.
Need for same resources at same time
Mutualism

43. Symbiosis Review
A : Find an example of each type of symbiosis and explain why it is that type.
B: Draw a picture of one type of symbiosis.

44. Chapter 5 Populations
5-1
How Populations Grow

45. How Populations Grow Characteristics of Populations
4 important characteristics of a population
Geographic distribution
Density
Growth rate
Age structure

46. Geographic Distribution
Geographic distribution – Area inhabited by a population.
Ranges can vary enormously in size

47. Population Density
Population Density - number of individuals per unit area.
This picture shows the population density of people.

48. Populations Growth Three factors affect population size:
number of births
number of deaths
number of individuals that enter or leave the population.
* Simply put, a population will increase or decrease in size depending on how many individuals are added to it or removed from it

49. Immigration & Emigration
movement of individuals into an area
causes growth.
Emigration
movement of individuals out of an area
causes decrease.
Immigration is formed from the Latin prefix in-, meaning “in,” and migrare, meaning “to move from one place to another.
If the Latin prefix e- means “out,”

50. Age Structure
Number of males and females of each age a population contains.
Age structure greatly effects reproduction

51. Exponential Growth
Exponential growth – When the offspring generation is larger than the generation before.
Population size will increase if there is abundant space and food, and protected from predators and disease
Under ideal conditions with unlimited resources.
Exponential growth - When the size of each generations’ offspring is larger than the generation before it.
Exponential growth occurs when the individuals in a population reproduce at a constant rate.

53. Logistic Growth
Logistic growth- occurs when growth slows or stops following a period of exponential growth.
As resources decrease, the growth of a population slows or stops.

54. The general, S-shaped curve of this growth pattern, is called logistic growth.

55. Carrying Capacity
Maximum number of individuals of a particular species that a given environment can support.
Things that will decrease pop size – resources (food, space), predators, disease

56. Review 5.1 List the four characteristics of population.
What factors can change a population's size?
What is carrying capacity?
Geographic distribution, population density, growth rate, age structure
Birthrate, death rate, immigration and emigration
Max number of a population an environment can support

57. 5.2 Limits to Growth
Limiting factor – factor that controls the growth of a population.
Density dependent
Density independent
Limiting factors determine the carrying capacity of an environment for a species.

58. Density- Dependent Factors
Limit size when the number of individuals reach a certain level
Competition for food, water, space, sunlight, etc.
Predation and Herbivory – populations cycle up and down

59. Wolf/Moose graph
Pred-prey relation fluxuates
Moose
Wolves

60. Density- Dependent Factors Continued
3. Disease – the denser the population, the easier it spreads
4. Stress from overcrowding – can lower birth rates, higher death rates, can cause parents to neglect young, lead to emigration

61. Density -Independent Factors
Affect all populations regardless of size and density
Weather, natural disasters, seasonal change, human interventions (dams, logging, housing developments)
Populations usually decrease dramatically after such an event
Can be permanent + cause extinction

62. Review 5.2 What are the two types of limiting factors?
What are the four density-dependent factors?
Define density-independent factors.
Density-dependent, density-independent
Competition, predation, disease, stress
Affect population regardless of size.

63. 5.3 - Historical Overview
For most of human existence, the population grew slowly because life was harsh. Food was hard to find. Predators and diseases were common and life-threatening.

64. Historical Overview
Limiting factors kept human death rates high. Until fairly recently, only half the children in the world survived to adulthood.
Because death rates were so high, families had many children, just to make sure that some would survive.

65. Exponential Human Population Growth
As civilization advanced, life became easier, and the human population began to grow more rapidly.
What types of things made life easier?
That trend continued through the Industrial Revolution in the 1800s.

66. The Predictions of Malthus
Exponential growth cannot continue
Two centuries ago, English economist Thomas Malthus suggested that only war, famine, and disease could limit human population growth.
Malthus’s work was vitally important to the thinking of Charles Darwin.
Malthus thought that human populations would be regulated by competition (war), limiting resources (famine), parasitism (disease), and other density-dependent factors.

67. The Demographic Transition
Three stages
Stage I, birthrates and death rates are high for most of history.

68. The Demographic Transition
In Stage II, advances in nutrition, sanitation, and medicine lead to lower death rates.
Birthrates remain high
Births exceed deaths
Population increases exponentially.

69. The Demographic Transition
During Stage III, as education and living standards increase, families have fewer children; population growth slows.
When the birthrate meets death rate, growth stops.

70. The Demographic Transition
So far, the United States, Japan, and Europe have completed the demographic transition.
Parts of South America, Africa, and Asia are passing through Stage II.
A large part of ongoing human population growth is happening in only ten countries, with India and China in the lead.

71. Review 5.3
What are three things Malthus suggested would decrease population size?
Which demographic stage has advances that result in higher birthrates and lower death rates?
In Stage III, why would families have fewer children?
War, famine, and disease
Stage II
Higher education and living standards