Ecology: Patterns of Population Growth

Question 2

Population size is affected by 4 factors

Answer 2

Natality, mortality, emigration, immigration

Question 3

Density

Answer 3

of individuals per unit area/volume

Question 4

Density is measured by

Answer 4

Total counts and sub-sampling methods

Question 5

Patterns of dispersion

Answer 5

Clumped- discrete groupsUniform- minimum distance between indvRandom

Question 6

Type 1 age structure and what does the curve look like?

Answer 6

HumanQuarter circle downward hitting 0

Question 7

Type 2 age structure

Answer 7

BirdsLinear line downwards

Question 8

Type 3

Answer 8

Plants and fishDownward invert of humans

Question 9

All populations have the potential for exponential growth

Answer 9

False

Question 10

Requirements for exponential growth

Answer 10

Unlimited resources

Question 11

For a very short time some populations may grow at rates close to the intrinsic (max) growth rate

Answer 11

True

Question 12

Population dynamics

Answer 12

How population sizes change over time

Question 13

No natural populations can maintain exponential growth indefinitely

Answer 13

True

Question 14

Population density typically fluctuates around a constant # of individuals

Answer 14

True

Question 15

As population size increases, resources become limiting for growth and population

Answer 15

True

Question 16

In the population equations, logistic growth adds what variable?

Answer 16

K (carrying capacity)

Question 17

Carrying capacity is

Answer 17

The maximum population size an environment can support

Question 18

Population growth slows as density approaches what?

Answer 18

Carrying capacity

Question 19

When pop size is below (K) growth

Answer 19

Increases

Question 20

When pop size is near (K) growth

Answer 20

Decreases

Question 21

Logistic model fits well with what size organism?

Answer 21

Small

Question 22

Do populations stabilize at (K)?

Answer 22

Most don’t

Question 23

Logistic predictions are correct when

Answer 23

Environment is constantNo predatorsNo competition

Question 24

3 assumptions that make logistic growth not fit well

Answer 24

Each individual added has a negative effect on population growth

Question 25

The logistic curve is ____ shaped

Answer 25

S

Question 26

In density dependent curves the #killed is a ______ curve and the % mortality is a ________ curve

Answer 26

ExponentialIncreasing linear

Question 27

Density dependent examples

Answer 27

Predation, disease, competition

Question 28

In density-independent graphs the #killed is a _________ and the %mortality is a ______

Answer 28

Inclining linear curveHorizontal line

Question 29

Density-independent factors are

Answer 29

Abiotic

Question 30

Natural populations are a mix of density-dependent and independent factors

Answer 30

True

Question 31

Due to density-dependent control, over long time scales populations _______________ to (K)

Answer 31

Remain stable/close

Question 32

Short time fluctuations are due to

Answer 32

Density-independent factors

Question 33

Stable equilibrium means

Answer 33

Birth=deathIf disturbed it will go back to normalDensity-dependent control

Question 34

Unstable population

Answer 34

May never return to normalInverse density dependence with log time lags

Question 35

Metapopulation

Answer 35

A population thats divided into discrete sub-populations

Question 36

What connects sub-populations in a metapopulation?

Answer 36

Emmigration and immigration

Question 37

Dynamics of metapopulations

Answer 37

Growth in patches, migration and colonization

Question 38

Migration increase dampens what in metapopulations? Decrease does what?

Answer 38

Local population fluctuationEnhances local population fluctuation

Question 39

A medium rate of migration causes

Answer 39

A shifting “mosaic” of occupied and unoccupied patches (persistence)

Question 40

If immigration rate is high an extinction rate low, then

Answer 40

The fraction of occupied sites will increase with time, and vice versa