Chapter 53: Population Ecology I Flashcards Preview

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Flashcards in Chapter 53: Population Ecology I Deck (27)
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1

Population (def.)

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)

2

Population dynamics (def.)

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

3

Key characteristics of populations

1) Dispersion
2) Density

4

Population ecology (def.)

Study of populations in relation to the environment

5

Dispersion (def.)

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

6

Factors that affect dispersion

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

7

General patterns of dispersion

- Clumped
- Uniform
- Random

8

Population density (def.)

Number of individuals per unit area or volume

9

Population size equation

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

10

Demography (def.)

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

11

Vital statistics (def.)

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

12

Life table useful for population ecologist?

- Age-specific summary of survival pattern of population

13

Survivorship curve (def.)

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

14

Type I (survivorship curve)

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

15

Type II (survivorship curve)

- Survival rate is constant over organism's life (gophers)

16

Type III (survivorship curve)

- Survival is low for young; mortality declines for survivors

17

Reproductive table

- Age-specific summary of reproductive rates in a population

18

Tradeoffs in patterns of reproduction?

- Many offspring = decreased survival probability
- Fewer offspring = increased survival probability

19

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

- Survival rate decreases with more involved parenting

20

Semelparity

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

21

Iteroparity

- Produces offspring repeatedly over course of life span
- Itero: Repeated

22

Growth rate + time equation

∆N / ∆t

23

Growth rate equation

bN - mN = N(b - m)
- b (birth), m (mortality rate)

24

Logistic population growth

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

25

Exponential growth

Constant rate of increase

26

Density dependence

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

27

Density dependent factors that influence birth and death rates?

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