1. REVIEW
Carrying capacity
Population dynamics
Fecundity
Biotic potential
Calculating Population change
Open population
Closed population
Three general survivorship patterns
3 growth models

2. Date of next test -
May 22nd – C-D, 23rd A-B

3. Pike Perch game answers
1.) Graph

4. 2.) Since pike eat a lot of perch there needs to be many more perch than pike in order for the pike to survive.
3.) The pike population responds to the population of perch. This means that an increase in perch population will cause an increase in pike populations and vice versa.

5. 4.) If there are no predators, the prey’s population would continue to increase until they run out of food or die from stress due to over-crowding or disease
5.) Predators are beneficial to prey because they can help control its population and prevent disease or over-crowding.

6. Read through population dynamics graphs and complete it.

8. Some key words used to describe population graphs
S Curve (Sigmoid) / logistic growth
Lag Phase
Log phase
Stationary phase/ Equilibrium
Exponential growth
Limiting factors
Density dependent/independent
Carrying capacity

9. Date of next test -
May 22nd – C-D, 23rd A-B

10. REVIEW
Carrying capacity
Population dynamics
Fecundity
Biotic potential
Calculating Population change
Open population
Closed population
Three general survivorship patterns
3 growth models

11. Factors Affecting Population Change & Interactions Within Communities

12. Density-Dependent Factors
Play a greater role in limiting population growth as the population increases in size
Ex. competition, predation, disease

13. Intraspecific competition
When the individuals of a population of the same species compete for the same resources
Growth rate slows as the population increases
Can reduce the number of offspring born

14. Density-Dependent Factors:
Predation
A predator catches, kills and consumes prey (of another species).
Helps to regulate the number of prey

15. Density-Dependent Factors
Disease
In dense or overcrowded populations, pathogens are able to pass more easily from host to host

16. Density-Dependent Factors
Allee Effect
When the population density is so low that the species cannot reproduce.
Mates are difficult to find since there are so few individuals
Population usually does not survive; especially harmful to threatened species

17. Density-Dependent Factors
Minimum viable population size
The smallest number of individuals needed to ensure a population can continue for a given period of time
Population can cope with variations in natality and mortality, as well as environmental changes or disasters
Population maintains enough genetic variation amongst its members

18. Density-Independent Factors
Play a role in limiting population growth regardless of population size
Ex. extreme weather, human intervention
Ex. Thrips (insect) have lower reproductive success at lower temperatures
Insecticide application (can result in death directly or through biomagnification)

19. Density-Independent Factors
Limiting Factor
Any essential resource that is in short supply or unavailable
Determines how much the individual or population can grow (affects the biotic potential)
Ex. light, space, water, nutrients

20. Complete p.g. 9 and first part of 10.

22. Bring laptops next class.
Test May 22nd/ 23rd

23. Review Density-Dependent Factors Allee Effect
Intraspecific competition
Predation
Disease
Allee Effect
Minimum viable population size
Density-Independent Factors
Limiting Factor
1.)Play a greater role in limiting population growth as the population increases in size
Ex. competition, predation, disease
2.) When the individuals of a population of the same species compete for the same resources
3.)A predator catches, kills and consumes prey (of another species).
Helps to regulate the number of prey
4.)In dense or overcrowded populations, pathogens are able to pass more easily from host to host
5.) When the population density is so low that the species cannot reproduce.
6.) Play a role in limiting population growth regardless of population size
Ex. extreme weather, human intervention
7.) The smallest number of individuals needed to ensure a population can continue for a given period of time
8.) Any essential resource that is in short supply or unavailable
Determines how much the individual or population can grow (affects the biotic potential)
Ex. light, space, water, nutrients

24. Using your textbook (P. g
Using your textbook (P.g ) and classmates help, come up with definitions to the following words for your notes.

25. Interactions Within Communities
Community
Interspecific competition
Ecological Niche
Fundamental Niche
Realized Niche
Symbiosis
Community
Made up of all populations of different species within an ecosystem
Interspecific competition
When the individuals of different species compete for the same resources
Restricts population growth
A driving force for populations of species to evolve adaptations to continue to use resources
Ecological Niche (organism’s “occupation”)
An organism’s biological characteristics, including the use of, and interaction with abiotic and biotic resources in its environment
Fundamental Niche
An organism’s biological characteristics and the set of resources individuals in the population are theoretically capable of using under ideal conditions
Ex. If resources were abundant and no competition existed
Realized Niche
An organism’s biological characteristics and the set of resources individuals in the population actually use under existing environmental conditions
Symbiosis
Two species maintain a close, usually physical association
At least one of the species benefits
Includes mutualism, commensalism and parasitism

26. Interspecific competition
Community
Made up of all populations of different species within an ecosystem
Interspecific competition
When the individuals of different species compete for the same resources
Restricts population growth
A driving force for populations of species to evolve adaptations to continue to use resources

27. Ecological Niche (organism’s “occupation”)
An organism’s biological characteristics, including the use of, and interaction with abiotic and biotic resources in its environment
Fundamental Niche
An organism’s biological characteristics and the set of resources individuals in the population are theoretically capable of using under ideal conditions
Ex. If resources were abundant and no competition existed
Realized Niche
An organism’s biological characteristics and the set of resources individuals in the population actually use under existing environmental conditions

28. Symbiosis Two species maintain a close, usually physical association
At least one of the species benefits
Includes mutualism, commensalism and parasitism

29. Interactions Within Communities
Types of Symbiotic Relationships:
Mutualism (+/+)
Both organisms benefit
Neither organism is harmed
Obligatory mutualism: neither species can survive without the other
Ex. bacteria in our intestinal tract (they get nutrients from the food we consume and produce vitamins that we need)
Ex. pollination (insects and animals ingest pollen/nectar, and pollen stuck to bodies of insects and animals gets spread to other flowers)

30. Interactions Within Communities
Commensalism (+/0)
One organism benefits and the other organism is unaffected
Ex. remora (small fish) attach themselves to sharks and feed on small pieces of the shark’s prey and get free transportation

31. Host is harmed but is usually not killed
Parasitism (+/-)
One organism (parasite) benefits at the expense of the other organism (host)
Host is harmed but is usually not killed
~1/4 animal species is thought to be a parasite
Ex. Plasmodium (malaria), tapeworms, fleas, lice
Social parasite: manipulates the social behaviour of their hosts to complete their life cycle (ex. cowbirds use nests of smaller birds and these smaller bird newborns are usually killed)

32. Symbiosis worksheet

34. Interactions Within Communities
Types of Interspecific Competition
I. Interference competition: fighting over shared resources

35. II. Exploitative competition: consumption of shared resources

36. Interactions Within Communities
Interspecific Competition
Niche overlap means more competition.
Competition declines because:
Population size of the weaker competitor declines
One species may adapt.
Migration
One species may change its behaviour so that it survives on different resources
Individuals of one population may migrate to another habitat where resources are more plentiful

37. Interactions Within Communities
Resource partitioning
Avoidance of, or reduction in, competition for similar resources by individuals of different species occupying different non-overlapping ecological niches
Ex. Anolis lizards
Ex. plants
Ex. Anolis lizards partition their tree habitats by occupying different perching sites
Ex. plants differing in their root systems to allow them to acquire water and mineral ions from the same environment

39. Interactions Within Communities
Predation
interspecific interaction
If other prey is available, it alters this cyclical relationship
Population density of one species (predator) increases while the population density of the other species (prey) decreases

40. Interactions Within Communities
Canadian lynx-snowshoe hare cycle (10 years)

41. Complete first ½ of p.g. 10, matching

42. Defense Mechanisms

44. Interactions Within Communities
Defence Mechanisms
Plants: morphological defences (thorns, hooks, spines, needles) and chemical defences (distasteful, toxic)
Insects: some use chemicals produced by their food as protection from their
predators (ex. monarch butterfly)

45. Interactions Within Communities
Passive Defence Mechanisms
Ex. Hiding
Ex. Camouflage
Ex. Visual warning to predators of chemical defences (poisons)
Ex. Mimicry
Batesian: a harmless species mimics a harmful species

46. Interactions Within Communities
Active Defence Mechanisms
Ex. Fleeing from predators
Ex. Alarm calls
More costly in terms of energy required

48. Interactions Within Communities
Introduction of Exotic (non-indigenous) Species
Can disrupt ecosystems’ dynamic equilibrium and displace indigenous species to such a degree that they impact on the biodiversity in that ecosystem
Since non-indigenous species often have few predators in that area, they can reduce or eliminate indigenous species by outcompeting them for food and habitat, or by preying on them
Ex. European rabbit in Australia (page 686)
Ex. West Nile virus (from Uganda) is believed to have been introduced into North America accidently via an exotic frog species

49. Complete pages 10 – 11 in your population ecology package.