1. Population and Community Ecology

2. Population & Community Ecology Learning Targets
Explain how nature exists at several levels of complexity
Discuss the characteristics of populations
Contrast the effects of density-dependent and density-independent factors on population growth
Explain the exponential growth model of populations, which produces a J-shaped curve
Describe how the logistic growth model incorporates a carrying capacity and produces and S-shaped curve
Compare the reproductive strategies and survivorship curves of different species
Explain the dynamics that occur in metapopulations
Identify and discuss species interactions that cause negative, neutral or positive effects on one or both species
Explain the role of keystone species
Explain the processes of primary and secondary succession
Explain the process of aquatic succession
Describe the factors that determine the species richness of a community

3. New England Forests Come Full Circle
Deforestation peaked in the 1800s due to agriculture.
Plants started to return such as goldenrod.
Eventually they were replaced with tree species.
Species interactions can alter species abundance.
Populations can increase and decrease dramatically over time.
Human activity can alter the distribution and diversity of species within an ecosystem

4. Case Study: New England Forests

5. Levels of Complexity in Nature
Species: most specific.
P???: same species found in the same area at the same time (can evolve).
C???: All the populations of organisms in the same area.
E??: all living and non-living components within an area.
B??: where live can exist.

6. Levels of Complexity in Nature
Species: most specific.
Population: same species found in the same area at the same time (can evolve).
Community: All the populations of organisms in the same area.
Ecosystem: all living and non-living components within an area.
Biosphere: where live can exisit.

7. Ecosystem: all living and non-living components within an area.
Biosphere: where live can exist.

9. Population Ecology
Population Ecology: the study of factors that cause populations to increase or decrease.
Which two factors control increases?
Which two factors control decreases?

10. Population Ecology
Population Ecology: the study of factors that cause populations to increase or decrease.

11. Population Characteristics
Population Size (N): total number of individuals within a defined area in a given time.
Population ?????: number of individuals per unit area.

12. Population Characteristics
Population Size (N): total number of individuals within a defined area in a given time.
Population Density: number of individuals per unit area.

13. Name this type of distribution?
Population Distribution: how individuals are distributed with respect to one another.
Name this type of distribution?

14. Population Distribution: how individuals are distributed with respect to one another.

15. Name this type of distribution?

17. Name this type of distribution?

19. Population Sex Ratio: the ratio between males and females.
Population Age Structure: how many individuals fit into particular age categories.

20. Factors That Influence Population Size
Name this concept
Density –Dependent Factors: influence an individual’s probability of survival and reproduction in a manner that depends on the size of the population.
Example: food available

21. Factors That Influence Population Size
Density –Dependent Factors: influence an individual’s probability of survival and reproduction in a manner that depends on the size of the population.
Example: food available

22. L??? Resource: a resource that a population cannot live without and which occurs in quantities lower than the population would require to increase in size.
???? (K): the limit of how many organisms an environment can contain.

23. Limiting Resource: a resource that a population cannot live without and which occurs in quantities lower than the population would require to increase in size.
Carrying Capacity (K): the limit of how many organisms an environment can contain.

25. Density-Independent Factors: Have the same effect on an individual’s probability of survival and amount of reproduction at any population size.
Examples: hurricanes, floods, fires, etc.
Name this concept

26. Examples: hurricanes, floods, fires, etc.
Density-Independent Factors: Have the same effect on an individual’s probability of survival and amount of reproduction at any population size.
Examples: hurricanes, floods, fires, etc.
Population Ecology Video Reviews
(Bozeman)
(Khan)
(Crash)

27. Growth Models Represent Population Changes
Exponential Growth Model
When populations are not limited by resources, their growth can be very rapid.
Creates a “?” shape curve.
Illustrates density dependent OR? independent growth pattern.

28. Growth Models Represent Population Changes
Exponential Growth Model
When populations are not limited by resources, their growth can be very rapid.
Creates a “J” shape curve.
Illustrates density independent growth pattern.

29. ?? What’s the rest of the equation that represents this graph?

31. The Logistic Growth Model
Initial growth is exponential but slows as the population approaches the carrying capacity of the environment (K).
Creates an “?” shaped curve.
Density dependent type of growth.

32. The Logistic Growth Model
Initial growth is exponential but slows as the population approaches the carrying capacity of the environment (K).
Creates an “S” shaped curve.
Density dependent type of growth.

33. What does this line represent?

35. p. 199 25 reindeer introduced to St. Paul Island, Alaska in 1910
Animals exhausted the food supply
p reindeer introduced to St. Paul Island, Alaska in 1910

36. p. 199; Population oscillations- overshoots and die-offs around carrying capacity

37. Variations
Overshoots
Die offs

38. Hare and Lynx
Cyclic pattern
The lynx population peaks 1 or 2 years after the hare population peaks.
Isle Royale, Michigan
Wolves and moose
Wolf population declined drastically due to a virus.
Overpopulation of moose then they ran out of food and their population declined.

39. What caption goes here?
What caption goes here?

42. Reproductive Strategies and Survivorship Curves
?-Selected Species (large mammals, most birds)
Few number of offspring
Long life span
Long time to reproductive age
Size of offspring is large
Parental care present
Slow population growth rate
Density dependent
Stable, near carrying capacity

43. Reproductive Strategies and Survivorship Curves
K-Selected Species (large mammals, most birds)
Few number of offspring
Long life span
Long time to reproductive age
Size of offspring is large
Parental care present
Slow population growth rate
Density dependent
Stable, near carrying capacity

44. Reproductive Strategies and Survivorship Curves
K-Selected Species (large mammals, most birds)
Name 4 characteristics

45. r -Selected Species (mice, fishes, insects, weeds)
Name 4 characteristics

46. r -Selected Species (mice, fishes, insects, weeds)
Short life span
Short time to reproductive maturity
Many reproductive events
Many offspring
Small size of offspring
No parental care
Fast population growth rate
Density independent growth
Variable population dynamics

48. Survivorship Curves
Type 1?2? Or 3?: K-selected species. High survival rates throughout most of their lives. Die off as they get old (humans, whales, elephants).
Type 1?2?3?: R-selected species. Low survivorship at younger age, few reach adulthood (mice, weeds, frogs, fungi).
Type 1?2?3?: Constant decline in survivorship throughout their lives (squirrels, corals).

49. Survivorship Curves
Type 1: K-selected species. High survival rates throughout most of their lives. Die off as they get old (humans, whales, elephants).
Type 3: R-selected species. Low survivorship at younger age, few reach adulthood (mice, weeds, frogs, fungi).
Type 2: Constant decline in survivorship throughout their lives (squirrels, corals).

50. A???
B???
C???

52. Name this term
A group of spatially distinct populations that are connected by occasional movements of individuals between them.
Corridors: strip of habitat in which organisms can travel to one population to another.
Growing due to human intervention.
Maintain corridors is an important part to preserving biodiversity

53. Metapopulations
A group of spatially distinct populations that are connected by occasional movements of individuals between them.
Corridors: strip of habitat in which organisms can travel to one population to another.
Growing due to human intervention.
Maintain corridors is an important part to preserving biodiversity

54. Example:
Cougars (mountain lions, pumas)
Once lived throughout North America.
Population decreased due to habitat destruction and overhunting.
Now found in remote mountain ranges.
Each area is considered a population.
Corridors provide “connectedness”.
Important part of each population’s persistence.
Small populations subject to extinction and density independent factors (winters, hurricanes).

56. Community Ecology: Interactions Between Species
Competition
Predation
Symbiotic Relationships

57. Competition
The struggle of individuals to obtain a limiting resource.
?????????? Principle
Two species competing for the same limiting resource cannot coexist.
Resource P?????????????
Two species divide a resource based on differences in the species’ behavior or morphology.

58. Competition
The struggle of individuals to obtain a limiting resource.
Competitive Exclusion Principal
Two species competing for the same limiting resource cannot coexist.
Resource Partitioning
Two species divide a resource based on differences in the species’ behavior or morphology.

59. Competition for limiting resource; Gause grew 2 species of paramecium- separately- then together- demonstrate that two species competing for same limiting resource cannot coesist

60. 3 Types of Resource Partitioning
Name this word for different time periods
Name this word for area
Name this word for structure or change

61. 3 Types of Resource Partitioning
Temporal
Spatial
Morphological

65. Name this common word…P?
The use of one species as a resource of another species.

66. Predation
The use of one species as a resource of another species.

69. True Predators
Kill their prey and consume it.

70. Name this term Consume plants as prey.
Typically do not kill the plant.

71. Herbivores
Consume plants as prey.
Typically do not kill the plant.

72. S??? Relationship
A close relationship between two species.

73. Symbiotic Relationship
A close relationship between two species.

74. 1. Parasites Define Rarely OR Often? kill the host.
Parasites that cause disease are called p?.
include viruses, bacteria, fungi, protists and wormlike organisms called helminths.

75. 1. Parasites Live on or in the organism they consume, the host.
Rarely kill the host.
Parasites that cause disease are called pathogens.
Pathogens include viruses, bacteria, fungi, protists and wormlike organisms called helminths.

76. Parasitoids
Lay eggs inside other organisms.
Wasps and flies.

77. 2. Name this relationship term?
Both species benefit.
Examples:
Plants and pollinators.
Acacia trees and ants.
Algae and fungus (lichen).
Algae and coral.

78. 2. Mutualism Both species benefit. Examples: Plants and pollinators.
Acacia trees and ants.
Algae and fungus (lichen).
Algae and coral.

80. Acacia trees and Pseudomyrmex ants- thorns for nest sites; food in form of nectar; ants protect trees

81. Lichens- British soldiers- fungus and alga- fungus provides nutrients and alga provides carbohydrates through photosynthesis

82. 3. Name this relationship
One species benefits and the other is neither harmed nor helped.
Examples:
Barnacles on whales.
Birds perching on trees.
Fish using coral reefs in order to hide from predators.

83. 3. Commensalism
One species benefits and the other is neither harmed nor helped.
Examples:
Barnacles on whales.
Birds perching on trees.
Fish using coral reefs in order to hide from predators.

84. Name this concept/species
Plays a role in its community that is far more important than its relative abundance might suggest.
The most abundant species or the major energy producers are NOT keystone species.
They typically exist in LOW numbers.
Example:
Sea stars and mussels.
Example of predator-mediated competition.

85. Keystone Species
Plays a role in its community that is far more important than its relative abundance might suggest.
The most abundant species or the major energy producers are NOT keystone species.
They typically exist in LOW numbers.
Example:
Sea stars and mussels.
Example of predator-mediated competition.

88. Ecosystem Engineers Create or maintain a habitat for other species.
Example: Beaver

91. Changes in an Ecosystem
Ecological ????: the predictable replacement of one group of species by another group of species over time.

92. Changes in an Ecosystem
Ecological Succession: the predictable replacement of one group of species by another group of species over time.

93. P??? Succession
Occurs on surfaces devoid of soil.
Results in trees and shrubs.
Bare rock is colonized by lichens and mosses-- They break down the rock with acids--- The rock turns into soil---Grasses and shrubs colonize.
Usually occurs on lava!

94. Primary Succession
Occurs on surfaces devoid of soil.
Results in trees and shrubs.
Bare rock is colonized by lichens and mosses-- They break down the rock with acids--- The rock turns into soil---Grasses and shrubs colonize.
Usually occurs on lava!

96. Secondary Succession
Happens in disturbed areas that have not lost their soil.
Happens after an event that removes vegetation but not the soil.
P????? Species: able to colonize new areas rapidly and grow well in full sunshine.
Ends with a climax stage or climax forest.

97. Secondary Succession
Happens in disturbed areas that have not lost their soil.
Happens after an event that removes vegetation but not the soil.
Pioneer Species: able to colonize new areas rapidly and grow well in full sunshine.
Ends with a climax stage or climax forest.

99. Aquatic Succession
Happens near the ocean shore or in ponds or small lakes.

102. Species Richness of a Community is Influenced by Many Factors
Declines as we move from the equator toward the North or South Pole.
2. T?
The longer it has been around the more opportunity for speciation.

103. Species Richness of a Community is Influenced by Many Factors
1. Latitude
Declines as we move from the equator toward the North or South Pole.
2. Time
The longer it has been around the more opportunity for speciation.

104. Habitat Size and Distance: The Theory of Island Biogeography
3. Larger or smaller? habitats typically contain more species.
4. The farther or?? closer “islands” are to other natural areas the greater the species richness.
Islands can be considered on land masses as well such as National Parks!

105. Habitat Size and Distance: The Theory of Island Biogeography
3. Larger habitats typically contain more species.
4. The closer “islands” are to other natural areas the greater the species richness.
Islands can be considered on land masses as well such as National Parks!

107. Black-footed ferret- once critically endangered; rebounding because of conservation efforts

108. Learning Check for Ch. 6 Community Ecology
A trophic cascade is the effect of ___ on ___
flooding; terrestrial ecosystem
Detritivores; decomposers
Producers; first=-level consumers
Top predators; one another
Tertiary consumers; the abundance of primary consumers

109. Learning Check for Ch. 6 Community Ecology
A trophic cascade is the effect of ___ on ___
flooding; terrestrial ecosystem
Detritivores; decomposers
Producers; first=-level consumers
Top predators; one another
Tertiary consumers; the abundance of primary consumers

110. Learning Check for Ch. 6 Community Ecology
The Hawaiian honeycreeper’s specific biotic interactions, including the abiotic factors in its high-altitude forest environment, are collectively referred to as its
Trophic level
Consumption rate
Habitat
Symbiotic placement
Ecological niche

111. Learning Check for Ch. 6 Community Ecology
The Hawaiian honeycreeper’s specific biotic interactions, including the abiotic factors in its high-altitude forest environment, are collectively referred to as its
Trophic level
Consumption rate
Habitat
Symbiotic placement
Ecological niche

112. Learning Check for Ch. 6 Community Ecology
A keystone species
Is most often dominant in numbers in their ecosystem
When removed, causes the removal of a trophic level in the ecosystem
Is most likely a top predator
Is most likely to be a producer on which all species ultimately depend
Feeds upon a variety of species in several different trophic levels

113. Learning Check for Ch. 6 Community Ecology
A keystone species
Is most often dominant in numbers in their ecosystem
When removed, causes the removal of a trophic level in the ecosystem
Is most likely a top predator
Is most likely to be a producer on which all species ultimately depend
Feeds upon a variety of species in several different trophic levels

114. Learning Check for Ch. 6 Community Ecology
The level of ecological organization described by ecologists when studying multiple interacting species that live in the same area is
The habitat
Energy flow
The population
The community
The ecosystem

115. Learning Check for Ch. 6 Community Ecology
The level of ecological organization described by ecologists when studying multiple interacting species that live in the same area is
The habitat
Energy flow
The population
The community
The ecosystem

116. Learning Check for Ch. 6 Community Ecology
Characteristics that contribute to the vulnerability of a species becoming endangered include which of the following?
Having low genetic diversity
Having a generalist habitat
Being a keystone species
Being r-selected
(A) I only (B) II only (C)III only
(D) III and IV only (E)I and IV only

117. Learning Check for Ch. 6 Community Ecology
Characteristics that contribute to the vulnerability of a species becoming endangered include which of the following?
Having low genetic diversity
Having a generalist habitat
Being a keystone species
Being r-selected
(A) I only (B) II only (C)III only
(D) III and IV only (E)I and IV only