Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Ecology > Ch. 9 Exam 3 > Flashcards

Ch. 9 Exam 3 Flashcards

1
Q

Population abundances and distributions can be estimated with..

A

Area-based counts, distance methods, mark-recapture methods, and niche modeling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Relative population size

A

Number of individuals in one time period or place relative to the number in another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Relative population size

Estimates are based on data presumed to be related to absolute population size, such as..

A
  • number of animal tracks or road kills in an area

- number of fish caught per unit of effort

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Relative population example

A

Ride down road and count roadkill

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Absolute population estimates examples

A

Area-based counts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Area-based counts

A

Counts individuals in a given area or volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Area-based counts used to..

A

Estimate the abundance of immobile organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Belt transects

A

Band of area in which organisms are counted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Quadrats

A
  • standardized sampling areas of specific size

- counts are used to estimate population size or density

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Quadrat locations are selected at ___ or on a ___.

A

Random; regularly spaced grid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How many quadrats should be used?

A

Use species-area curve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Species-area curve

A

Helpful in determining point of diminishing returns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Distance methods

A

Distances of individuals from a line or point are converted into estimates of abundance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Line transects

A

Observer travels along line and counts individuals and their distance from the line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Mark-recapture methods

A
  • used for mobile organisms
  • a subset of individuals is captured and marked/tagged in some way, then released
  • at a later date, individuals are captured again
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Ratio of marked to unmarked individuals in a second sample are used to estimate what?

A

Population size

17
Q

Lincoln-Petersen method is used for ___ populations.

A

Closed

18
Q

Closed population

A

No immigration

19
Q
  • To estimate total population size
A

N = (M*C) / R

Total population size = (marked * captured) / recaptured

20
Q
  • Lincoln-Petersen estimate
A
  • marked individuals behave as unmarked (random sampling)
  • marking method does not affect “catchability”
  • marks last throughout study period
21
Q

Hantavirus study

A
  • carried by deer mouse
  • outbreak of disease in 1993
  • deer mouse specimens indicated the virus had been present for 10 years
  • why did outbreak occur in 1993?
  • because density of species increased between 1992 and 1993
  • precipitation data and satellite photos showed that high rainfall led to more plant growth, which provided seeds, nesting material and shelter for rodents
  • high mouse densities increased changes of them coming in contact with humans
22
Q

Ecologists often wish to predict the future distribution of a species .. why?

A
  • pest species or disease carriers

- species distributions may also change with global warming

23
Q
  • Ecological niche
A

Abiotic and biotic conditions that a species needs to grow, survive, and reproduce

24
Q
  • Niche model
A

Predictive tool that models environmental conditions occupied by a species based on conditions at localities it is known to occupy

25
Q

GARP

A

Genetic algorithm for rule-set prediction

26
Q

___ works by changing habitat rules in a way that mimics the occurrence of genetic mutations and natural selection.

A

GARP

27
Q

Detritus

A

Recently dead or partly-decomposed organisms

28
Q

Test hypothesis

Sea otters control population size of urchins, and thus the distribution of kelp forests

A
  • compare sites with and without otters

- at sites newly colonized by sea otters, urchins virtually disappeared within 2 years, and kelp densities increased

29
Q

Recent sea otter decline may be due to predation by killer whales

A
  • whaling may have reduced preferred prey

- reduced fish populations reduced seal and sea lion populations

30
Q

Example of top-down control

A
  • killer whales turned to otters as prey
  • as otter density decreased, sea urchin rebounded
  • with increased urchin biomass, urchin grazing on kelp increased
  • increased grazing on kelp led to decrease in kelp density

Ecology (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions