Population Ecology

Question 1

What is a population’s geographic range?

Answer 1

overall part of the world that the species inhabits

Question 2

What is a population’s habitat?

Answer 2

specific environment where the species lives

Question 3

Give an example showing the difference between a population’s range and habitat?

Answer 3

range of giraffe is central, eastern, and southern africa

habitat of giraffe is grasslands

Question 4

What is the optimal zone for the range of tolerance curve?

Answer 4

the central part of the curve that has conditions that favour maximal reproductive success and survivability

Question 5

What are the zones of stress for the range tolerance curve?

Answer 5

regions outside the optimal zone where organisms can survive but with reduced reproductive success

Question 6

What are the zones of intolerance for the range tolerance curve?

Answer 6

outermost regions where organisms cannot survive

Question 7

What effect does resource partitioning/niche partitioning have on biodiversity?

Answer 7

increases biodiversity

(partitioning means dividing up resources)

Question 8

What is the fundamental niche?

Answer 8

the full range of environmental tolerances a species could occupy if there was no competition

Question 9

What is the realized niche?

Answer 9

range of tolerance that is restricted by other species, the space a species occupies given competition

Question 10

What are invasive species?

Answer 10

non-native species that cause social, economic, or environmental harm, spreads rapidly and has no native predators

Question 11

What is a type 1 survivorship curve?

Answer 11

high survivorship throughout their life until they reach old age (curve starts off high and remains consistent until old age when it steeply drops)

Question 12

What is a type 2 survivorship curve?

Answer 12

constant mortality rate regardless of age (negative linear slope)

Question 13

What is a type 3 survivorship curve?

Answer 13

high mortality at a young age (looks like negative exponential function) lower after they reach established age

Question 14

In a mark-recapture study what indicates a larger population?

Answer 14

smaller amount of marked individuals being recaptured

Question 15

When is estimating population size using direct counts useful?

Answer 15

large organisms that are easy to see and that are in small areas

Question 16

For mobile organisms what do we use to estimate population size?

Answer 16

mark-recapture studies

Question 17

What is the formula for determining the total population using a mark-recapture study? What do the variables represent?

Answer 17

M/N=R/T–>N=MT/R

N is total population size, M is marked individuals, T is amount recaptured, and R is # of marked that were recaptured

Question 18

How are population dynamics determined?

Answer 18

births, deaths, immigration, emigration

Question 19

What is a closed population? When does population size increase/decrease?

Answer 19

isolated from other populations

N increases when births(M)>deaths(D)
N decreases when M<D

Question 20

What is an open population?

Answer 20

individuals may enter, leave, or stay in the population

N increases when births(M) + immigration(I)>deaths(D) + emigration(E)
N decreases when M+I<D+E

Question 21

What is the population growth rate?

Answer 21

r=m-d, determined by deaths and births

Question 22

What is the population change over time determined by?

Answer 22

r and N (growth rate and population size)

deltaN/detlat=rN

Question 23

When does exponential growth occur?

Answer 23

when r does not change over time, but the instantaneous growth rate increases as the population increases

Question 24

What is rmax?

Answer 24

when the birth rates are as high as possible and the death rate is as low as possible

Question 25

what happens to the population if r<0? What about r=0? What about r>0?

Answer 25

shrinks, stable, grows

Question 26

What are limiting factors?

Answer 26

biotic or abiotic factors that regulate the size of a population

Question 27

What are the two types of limiting factors?

Answer 27

density-dependent and density-independent

Question 28

What is the carrying capacity?

Answer 28

the number of organisms of one species that an environment
can support indefinitely

Question 29

What is logistic growth?

Answer 29

when the population increases rapidly and then levels out at the carrying capacity

Question 30

What is true for logistic growth when N is small?

Answer 30

(K-N)/K is close to 1 and the growth rate is high

K is carrying capacity

Question 31

What is true for logistic growth when N is large?

Answer 31

(K-N)/K it gets smaller and the growth rate is low

Question 32

What is true for logistic growth when N is equal to K?

Answer 32

(K-N)/K is 0 and carrying capacity is reached, growth rate is zero

Question 33

What are the three stages of density dependent growth?

Answer 33

1. initially, growth rate is exponential
2. growth rate starts to decline
3. growth rate is 0

Question 34

What does density indepedent growth curves look like?

Answer 34

a series of j-shaped growth curves

Question 35

What does it mean when a j-shaped curve becomes an s-shaped curve?

Answer 35

the carrying capacity was reached

Question 36

What would happen if a population exceeds its carrying capacity?

Answer 36

the growth rate would become negative until the population is within its carrying capacity