Population Growth and Regulation

Question 1

Population

Answer 1

Group of individuals of the same species

Question 2

Population Growth Rate

Answer 2

The number of new individuals produced per unit of time minus the number that die

Question 3

Population ecology is…

Answer 3

Conservation of threatened species. Control of over abundant pest and invasive species. Responsible management of invasive population

Question 4

Log b^y=d same thing as

Answer 4

b^d=y

Question 4

Log functions reverse

Answer 4

exponential functions

Question 4

E (Eulers Number)

Answer 4

2.718. Exponential function with e. Mathematically convenient in population dynamics

Question 5

The natural log

Answer 5

e and In

Question 5

(Loge)^y can also be said as

Answer 5

(In(^y

Question 6

Nile Perch Population Growth

Answer 6

Population grew exponentially and contributed to extinction or near extinction of more than 200 species.

Question 7

Exponential Growth Model

Answer 7

Nt=Noe^rt

-Population growth under “ideal” conditions. -Relative growth rate is constant.
-r is a constant rate specific to the population
-the observed rate changes
-highest observed growth rate

Question 8

The actual observed rate of a populations growth at any specific point in time

Answer 8

DN/dt=rN

Question 9

Intrinsic Growth Rate (R)

Answer 9

Highest possible per capita growth rate for a population. “Instantaneous growth rate”

Question 10

R=Births(b)-Deaths(d)=Immigration(I)-Emmigration(E) or in shorter terms…

Answer 10

R=b-d

Question 11

if b>d then…

Answer 11

positive growting population

Question 12

Geometric Growth Model

Answer 12

Nt=N0lambda^t
-like the exponential growth model but discrete
-compares population size at regular time intervals

Question 13

Lambda

Answer 13

Discrete population growth rate

Question 14

Lambda=

Answer 14

Nt/Nt-1

Question 15

Geometric growth model accounts for

Answer 15

Seasonal births, and breeding periods common in nature

Question 16

t2 =

Answer 16

The time required for a population to double in size

Question 17

For continuous growth (exponential), t2 is

Answer 17

loge^2/r

Question 17

For discrete growth (geometric) t2 is

Answer 17

loge2/logelambda

Question 18

Exponential and geometric models are

Answer 18

density independent (assumes constant birth and death rates)

Question 19

Indefinite growth is not possible because of

Answer 19

resource limitation, epidemics and other natural enemies, environmental change and natural disasters

Question 20

Limits to population growth

Answer 20

Density independent factors and density dependent factors

Question 21

Density independent factors

Answer 21

Not related to populations density. Often abiotic (floods temperature)

Question 22

Density dependent factors

Answer 22

Related to density. Often biotic (disease, competition for food and space)

Question 23

Negative Density Dependance

Answer 23

High population density leads to negative population growth from competition (intraspecific) and disease. Birth rates increase death rates decrease

Question 24

Positive Density Dependance

Answer 24

Low population density. Low even negative population growth. Inability to find mates or forage successfully

Question 25

Population Regulation

Answer 25

Often involves positive and negative density dependence. Increased densities with abundant resources. Above some density resources become limiting

Question 26

Negative Density Dependence depends on a

Answer 26

carrying capacity (K)

Question 27

Carrying Capacity (K)

Answer 27

the maximum population supported by the environment

Question 28

Above K means

Answer 28

low reproduction and survival cause negative population. Often treated as a constant but can vary with environmental conditions. Often treated as constant but can vary in environmental conditions.

Question 29

Logistic model of population growth

Answer 29

Describes slowing growth of population at high densities. Represented by rate of growth with carrying capacity factors added to it. dN/dt=rN(1-N/K) (r is still intrinsic rate of increase)

Question 30

Inflection Point

Answer 30

Maximum observed growth rate (dN/dt) when N=k/2

Question 31

Populations can overshoot K sometimes resulting in

Answer 31

extinction

Question 32

Density Independent Limitation

Answer 32

Birth and death rates unaffected by population size. Does not mean infinite growth. (not be sustainable). Many factors can prevent populations from ever reaching K (disturbance, climate, fire, specialist predation)