Chapter 53: Population Ecology I

Question 1

Population (def.)

Answer 1

Group of individuals of a single species living in the same general area (real on same resources, influenced by same environment, interact and breed with one another)

Question 2

Population dynamics (def.)

Answer 2

Examine characteristics of populations and how they change over time and space

Question 3

Key characteristics of populations

Answer 3

1) Dispersion

2) Density

Question 4

Population ecology (def.)

Answer 4

Study of populations in relation to the environment

Question 5

Dispersion (def.)

Answer 5

• Pattern of spacing among individuals
• Reflects environmental conditions and interactions
• Clumped, uniform, random

Question 6

Factors that affect dispersion

Answer 6

• Food, predators, competitors, microclimate, reproduction, age/sex

Question 7

General patterns of dispersion

Answer 7

• Clumped
• Uniform
• Random

Question 8

Population density (def.)

Answer 8

Number of individuals per unit area or volume

Question 9

Population size equation

Answer 9

N = B + I - D - E

- N (population), B (births), I (immigrants), D (deaths), E (emigrants)

Question 10

Demography (def.)

Answer 10

Study of vital statistics of a population and changes in these values over time

Question 11

Vital statistics (def.)

Answer 11

Factors that affect present and future population size (e.g. births, deaths)

Question 12

Life table useful for population ecologist?

Answer 12

• Age-specific summary of survival pattern of population

Question 13

Survivorship curve (def.)

Answer 13

• Graphical representation of a life table; changes in survival over maximum life span

Question 14

Type I (survivorship curve)

Answer 14

• Survival is high in early/middle life; survival decreases as organism gets older
• Elephant

Question 15

Type II (survivorship curve)

Answer 15

• Survival rate is constant over organism’s life (gophers)

Question 16

Type III (survivorship curve)

Answer 16

• Survival is low for young; mortality declines for survivors

Question 17

Reproductive table

Answer 17

• Age-specific summary of reproductive rates in a population

Question 18

Tradeoffs in patterns of reproduction?

Answer 18

• Many offspring = decreased survival probability

- Fewer offspring = increased survival probability

Question 19

Degree of parental care in relation to survival rate of parent?

Answer 19

• Survival rate decreases with more involved parenting

Question 20

Semelparity

Answer 20

• Big-bang reproduction (1x)
• Salmon, annual plants
• Semel: One time

Question 21

Iteroparity

Answer 21

• Produces offspring repeatedly over course of life span

- Itero: Repeated

Question 22

Growth rate + time equation

Answer 22

∆N / ∆t

Question 23

Growth rate equation

Answer 23

bN - mN = N(b - m)

- b (birth), m (mortality rate)

Question 24

Logistic population growth

Answer 24

• Exponential growth cannot be sustained for long in any population; population is limited by resource
• Growth rate changes as it approaches (K-carrying capacity)

Question 25

Exponential growth

Answer 25

Constant rate of increase

Question 26

Density dependence

Answer 26

Factors where effects on size or growth of population vary with density of population itself

Question 27

Density dependent factors that influence birth and death rates?

Answer 27

- Competition - Territoriality - Disease (pathogens easier to spread with larger population) - Predation