Populations - Distribution and Growth

Question 1

What are the properties of populations (5)?

Answer 1

Geographic range, abundance, density, dispersion, dispersal

Question 2

How are populations measured?

Answer 2

Census, quadrat, mark-recapture

Question 3

What are the types of population growth models?

Answer 3

Density independent (exponential) and density dependent (logistic)

Question 4

Why are population dynamics important for conservation and resource management?

Answer 4

If how populations change in response to their conditions is understood, then populations can be managed by manipulating the conditions

Question 5

How can you distinguish individuals from populations?

Answer 5

Can be difficult to distinguish, so must be defined by the study.

Genetically identical individuals may be linked by runners. Genets are composed of ramets.

Question 6

What can the spatial distribution of a population tell us about its behaviour and ecology?

Answer 6

Spatial distribution tells us where the specie’s favourable habitats are - favourable as in close to good foraging spots, protected, beneficial interactions with other species.

Question 7

Populations can be either ________ or ________, and measured at ________ or ________ time intervals.

Answer 7

Populations can be either open or closed, and measured at discrete or continuous time intervals.

Question 8

Density-independent

Answer 8

Exponential growth, population size limited by chance abiotic factors (ex. flooding, fire)

Question 9

Density-dependent

Answer 9

Logistic growth, population size limited by competition for resources

Question 10

Population

Answer 10

Individuals of the same species co-occurring in time and space, dynamic

Question 11

Population dynamics

Answer 11

Models that predict how populations will change over time and space

Question 12

Genet

Answer 12

Genetically distinct individual, composed of ramets

Question 13

Ramet

Answer 13

Genetically identical sub-individuals of a genet

Question 14

Geographic range

Answer 14

Area encompassing all individuals of a species. Limited by temperature, rainfall, geographic boundaries (ex. mountains, oceans)

Question 15

Geographic range: distribution

Answer 15

Presence or absence of a species depending on environmental conditions

Question 16

Geographic range: scale

Answer 16

Spatial extent that is relavent to study

Question 17

Abundance

Answer 17

Count of individuals (function of density)

Question 18

Density

Answer 18

Abundance per unit of area

Question 19

Dispersion

Answer 19

Spacing of individuals in relation to one another in response to abiotic/biotic factors

Question 20

Types of dispersion (3)

Answer 20

Random, clumped, uniform

Question 21

Dispersal

Answer 21

Movement of individuals between places… but not migration

Question 22

Census

Answer 22

Counting every individual

Question 23

Quadrat

Answer 23

Count every individual in a smaller area

Question 24

Mark-recapture

Answer 24

Number of recaptures proportional to the population size

N = (M x C) / R

population estimate = (1st captures x new captures) / recaptures

Question 25

Define these equation terms:
N =
b =
d =
t =
i =
e =

Answer 25

N = number of individuals
b = number of births
d = number of deaths
t = time
i = immigrants (entering)
e = emigrants (leaving)

Question 26

Closed population

Answer 26

Isolated from other populations. Only affected by b and d

Question 27

Open population

Answer 27

Individuals may leave, enter, or stay in the population. Affected by births, immigration, deaths, and emigration.

Question 28

Is it reasonable to assume a closed population?

Answer 28

Usually, yes. Emigration and immigration are tiny factors compared to births and deaths.

Question 29

Continuous time scales

Answer 29

Births and deaths are recorded all the time

Question 30

Discrete time scales

Answer 30

Births and deaths are recorded at discrete intervals

Question 31

Intrinsic growth rate

Answer 31

r
Ideal/maximum growth rate

Question 32

Density independent model

Define the two types

Answer 32

Exponential, ideal growth rate, determines doubling rate, J-shaped curve

r is used in continuous time models, and lambda is used in discrete time models (accounts for seasonal effects)

Question 33

Density dependent model

Answer 33

Logistic, limited by carrying capacity (k), S-shaped curve