Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

General Ecology > Chapter 11 > Flashcards

Chapter 11 Flashcards

(100 cards)

Start Studying
1
Q

the distribution of populations is limited to

A

ecologically suitable habitats

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

what are population distributions characterized by

A
  1. range
  2. dispersion
  3. density
  4. abundance
  5. dispersal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

range

A

geographic distribution of the species

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

dispersion

A

spatial arrangement of individuals and habitats

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

density

A

number of individuals per unit of space

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

abundance

A

size of the population

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

dispersal

A

patterns of movement of individuals within and among populations

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

spatial structure

A

the pattern of density and spacing of individuals in a population

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

Fundamental niche

A

the range of abiotic conditions (e.g., temperature, humidity, salinity) under which a species can persist

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

what may prevent a population from persisting in an area

A

Competitors, predators, and pathogens

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

realized niche

A

the range of abiotic and biotic conditions under which a species can persist

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

geographic range

A

a measure of the total area covered by a population (e.g., temperature and drought define the range of sugar maple)

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

what do small-scale variation in the environment create

A

geographic ranges that are composed of small patches of suitable habitat

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

Ecological niche modeling

A

the process of determining the suitable habitat conditions for a species

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

Ecological envelope

A

the range of ecological conditions that are predicted to be suitable for a species (differs from the realized niche, which describes conditions in which a species currently exists).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

when is predicting the potential geographic range of a species difficult

A

when only a few individuals exist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what can ecological niche modeling predict

A

the expansion of pest species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Geographic Distribution (Range):

A

all the areas that a species occupies during

their life time. This might include rivers/ocean

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Endemic

A

species that live in a single, often isolated, location

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Cosmopolitan

A

species with very large geographic ranges that can span several continents. Cosmopolitan species: rock doves, house sparrows, peregrine falcons, killer whales, cattle egrets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Abundance

A

the total number of individuals in a population that exist within a defined area (e.g., total number of lizards on a mountain).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what does the total abundance of a population provide

A

a measure of whether a population is thriving or on the brink of extinction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

in a population, the number of individuals per unit area or volume; calculated by dividing abundance by area

A

density

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what happens if population density is greater than what the habitat can support

A

some individuals must leave or the population will experience lower growth and survival

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
where does the largest density of individuals typically occur
near the center of a population's geographic range
26
what happens near the edges of the range
conditions become less ideal and population densities decrease
27
the spacing of individuals with respect to one another within the geographic range of a population
dispersion
28
when individuals are aggregated in discrete groups (e.g., social groups or clustering around resources).
clustered (clumped) dispersion
29
when each individual maintains a uniform distance between itself and its neighbors (e.g., defended territories, croplands).
evenly spaced dispersion
30
when the position of each individual is independent of other individuals; not common due to non-random environmental heterogeneity
random dispersion
31
social antagonism
results in a spaced distribution
32
mutual attraction
leads to clumping
33
what happens in the absence of social antagonism or mutual attraction
individuals may distribute themselves randomly
34
individuals distribute themselves randomly
individuals are not influenced by the positions of others
35
since a random dispersion pattern implies that spacing is not related to a biological process
it is often used as the model against which an observed dispersion may be compared
36
probability theory
provides us with the tools to make such comparisons
37
poisson distribution
a probability distribution of discrete random variables (variables that can take on only a finite number of values)
38
expresses the probability of a number of events occuring in a fixed period of time and/or space if these events occur with a known average rate, and are independent of the time since the last event
poisson distribution
39
poisson distribution formula
P(x) = M^xe^-M/x!
40
M
the mean number of individuals per space
41
x!
the factorial of x
42
e
2.7183
43
when might an ecologist use the Poisson distribution
to make a quantitative determination of the pattern of dispersion
44
how does an ecologist use the poisson distribution to make a quantitative determination of the pattern of dispersion
by comparing the mean (M) of our distribution with the variance (V)
45
the variance of a random variable
a measure of the spread about the mean of the distribution of that variable
46
dispersal
the movement of individuals from one area to another (away from their birth place or away from centers of high population)
47
migration
the seasonal movement of individuals back and forth between habitats
48
what is the mechanism by which individuals can move between suitable habitats
dispersal
49
allows species to colonize areas outside of their geographic ranges
dispersal
50
a way to avoid areas of high competition or high predation risk
dispersal
51
when are barriers to dispersal revealed
when species are introduced to new areas/regions
52
census
counting every individual in a population
53
what do scientists conduct when a census is not feasible
survey
54
survey
count a subset of the population
55
area and volume based surveys
define the boundaries of an area or volume and then count all of the individuals in the space
56
what is the size of the defined space related to
the abundance and density of the population
57
what is possible by taking multiple samples
it is possible to determine how many individuals are in an average sample
58
line-transect surveys
surveys that count the number of individuals observed as one moves along a line
59
what can line-transect survey data be converted into
area estimates of a population (detection probabilities)
60
mark-recapture survey
a method of population estimation in which researchers capture and mark a subset of a population from an area, return it to the area, and capture a second sample of the population after time has passed
61
the population size is estimated by assuming that:
initially captured individiuals/population size = marked recaptured individuals/total individuals captured in 2nd sample
62
how can we estimate population densities
mark and recapture
63
mark and recapture studies
some individuals from a population are initially captured, marked, and released back into the population
64
M/N=
R/C
65
M
number initially captured and marked
66
N
number in population
67
C
total number captured on 2nd attempt
68
R
number of recaptures on 2nd attempt
69
N=
MC/R
70
how can dispersal be quantified
measuring how far individuals travel from a single source location, marked and recaptured, radio transmitters
71
lifetime disperal distance
the average distance an individual moves from where it was born to where it reproduces
72
what does lifetime disperal distance provide an estimate for
how fast a population can increase its geographic range
73
dispersal can cause a geographic range to expand rapidly if
a few individuals can disperse much farther than the average individual
74
Populations with high abundance also have large
geographic ranges
75
what may cause the relationship between population abundance and range
resource availability; species are likely to cover the area that contains the resources that they require
76
what may cause the large amount of variation in the abundance-range size regression
fluctuations within a geographic range
77
what does the regression caused by fluctuations suggest
reducing the range of a population will reduce the size of that population
78
how is the density of a population correlated to the body size of the species
negatively
79
what can we expect from the relationship between population density and body size
a given plot of habitat to support fewer large individuals than it does small individuals
80
what is essential to colonizing new areas
dispersal
81
dispersal limitation
the absence of a population from suitable habitat because of barriers to dispersal
82
barriers
large expanses of inhipitable habitat that an organism can't cross
83
human barriers for dispersal
roads, forest clearings
84
habitat corridor
a strip of favorable habitat located between two large patches of habitat that facilitates dispersal (narrow band of trees that connects forests)
85
what habitats do individuals choose
those that provide the most energy
86
what happens as individuals move to a high-quality habitat
resources must be divided among more individuals (reduced per capita benefit)
87
per capita benefit can fall so low that
an individual would benefit by moving to the low-quality habitat
88
ideal free distribution
when individuals distribute themselves among different habitats in a way that allows them to have the same per capita benefit; assumes perfect knowledge of habitat variation
89
why do individuals in nature rarely meet the expectations required by the ideal free distribution
- they may not be aware that other habitats exist - fitness is not solely determined by maximizing resources - presence of predators or territory owners
90
what can the ideal free distribution allow
populations in low-quality habitats to persist over time
91
subpopulations
when a large population is broken up into smaller groups that live in isolated patches
92
when individuals frequently disperse among subpopulations
the whole population functions as a single structure; all subpopulations increase and decrease in abundance synchronously
93
when disperal is infrequent
each subpopulation fluctuates independently
94
basic metapopulation model
decribes a scenario in which there are patches of suitable habitat embedded within a matrix of unsitable habitat; all suitable patches are assumed to be of equal quality
95
source-sink metapopulation model
builds upon the basic metapopulation model and accounts for the fact that not all patches of suitable habitat are of equal quality
96
source subpopulation
in high-quality habitats, subpopulaitons that serve as a source of dispersers within a metapopulation
97
sink subpopulations
in low-quality habitats, subpopulations that rely on outside dispersers to maintain the subpopulation within a metapopulation
98
landscape metapopulation model
considers both differences in the quality of the suitable patches and the quality of the surrounding matrix
99
represents the most realistic and most complex spatial structure of populations
landscape metapopulation model
100
habitat patchiness has led to 3 models of population
1. metapopulation model 2. source-sink model 3. landscape model

General Ecology (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions