Brainscape's Knowledge GenomeTM

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


See full index

BIOL 121 > 51 Population Ecology > Flashcards

51 Population Ecology Flashcards

1
Q

Population ecology

A

the study of how and why the number of individuals in a population changes over time and space

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

Range

A

geographic distribution of a species

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

What factors determine range?

A

abiotic factors (e.g. temperature, rainfall, geographical structures, large-scale historical processes like continental drift) and biotic factors (e.g. past and current presence of other species that provide habitat, food, or competition)

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

Population density

A

the number of individuals of a population per unit area

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

What are the types of arrangement of individual organisms within populations?

A

Random, clumped, uniform

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

Random arrangement

A

the position of each individual is independent of the others e.g. seeds dispersed by the wind

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

Clumped arrangement

A

the quality of the habitat is patchy or the organisms associate in social groups e.g. schools of fish

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

Uniform arrangement

A

negative interactions occur among individuals e.g. competition for space, water, or other resources

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

Metapopulation “beyond population”

A

a population made up of many small, physically isolated populations connected by migration; individuals from a species form many independent populations

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

How can the population size, density, or distribution pattern of individuals be determined?

A

sampling methods

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

Sampling method for sedentary or sessile (immobile) organisms

A

(1) Counting individuals that occur along transects or inside quadrats set up at random locations in the habitat (2) Counts are extrapolated to the entire habitat area to estimate population size (3) Counts are compared to later sampling efforts to document trends over time

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

Transects and quadrats

A

lines of known position and length; rectangular plots

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

Sampling method for mobile organisms

A

individuals can be captured and tagged to estimate the total population size by using mark-recapture

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

Mark-recapture study

A

(1) researchers catch individuals and mark them with leg bands, ear tags, or some other permanent/temporary identification (2) marked individuals are released and allowed to mix with those unmarked for a period of time (3) marked individuals are recaptured and recorded

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

What assumptions are made when estimating total population (N) in mark-recapture?

A

(1) Percentage of marked individuals (M) in the total population (N) = average percentage of marked individuals (m) found in each recapture sample (n); (2) Individuals are not moving in and out of study area; (3) Individuals mix between recaptures; (4) No bias regarding which individuals are recaptured; (5) Individuals do not learn to avoid or seek out traps after being caught; (6) Individuals do not change their behavior

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

What 4 processes do the number of individuals in a population depend on?

A

birth, death, immigration, and emigration

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

Immigration

A

the migration of individuals INTO a particular population from other populations

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

Emigration

A

the migration of individuals AWAY from one population to other populations

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

Demography

A

the study of factors that determine the size and structure of population through time

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

Age structure

A

the proportion of individuals in a population that are of each possible age

21
Q

Generation

A

the average time between a mother’s first offspring and her daughter’s first offspring

22
Q

Life table

A

a data set that summarizes the probability that an individual in a certain population will survive and reproduce in any given year over the course of its lifetime

23
Q

2 general approaches to collecting data for life tables

A

tracking individuals from short-lived species over time AND taking a snapshot of the age structure of a population from longer-lived species at one particular time

24
Q

Age class

A

all the individuals of a specific age in a population

25
Q

Cohort

A

a group of individuals that are the same age and can be followed through time

26
Q

Survivorship

A

on average, the proportion of offspring that survive to a particular age (the opposite of mortality); resistance to disease and predators

27
Q

Survivorship curve

A

a graph depicting the percentage of a population that survives to different ages, with the number of survivors in the y-axis and age on the x-axis

28
Q

Type 1 survivorship curve

A

survivorship throughout life is high and then drops dramatically in old age, indicating that most individuals approach the species’ maximum life span

29
Q

Type 2 survivorship curve

A

individuals have about the same probability of dying in each year of life

30
Q

Type 3 survivorship curve

A

extremely high death rates (low survivorship) for larvae or seedlings but high survival rates later in life

31
Q

Fecundity

A

the average number of female offspring produced by a single female in the course of her lifetime

32
Q

Age-specific fecundity

A

the average number of female offspring produced by a female in a certain age class

33
Q

Net reproductive rate (R₀)

A

the growth rate of a population per generation; equivalent to the average number of female offspring that each female produces over her lifetime; the sum of the products of survivorship and fecundity

34
Q

When is the population increasing or decreasing?

A

increasing when R₀ > 1 and decreasing when R₀ < 1

35
Q

Fitness trade-off

A

inescapable compromise between 2 traits that cannot be optimized simultaneously e.g. survivorship and fecundity

36
Q

Life history

A

sequence of events in an individual’s life from birth to reproduction to death, including how an individual allocates resources to growth, reproduction, and activities or structures related to survival

37
Q

Per capita “for each head” rate of increase (r)

A

or instantaneous rate of increase; the difference between the birth rate per individual and the death rate per individual

38
Q

Exponential population growth

A

the accelerating increase in the size of a population that occurs when the per capita growth rate (r) is constant and density independent; cannot continue indefinitely because resources are not infinite

39
Q

Intrinsic rate of increase (rmax)

A

the rate of increase of a population when conditions are ideal (birth rates per individual are as high as possible and death rates per individual are as low as possible)

40
Q

How is exponential growth density independent?

A

it’s a type of population growth that does not vary with population density (or size)

41
Q

What two types of circumstances is exponential growth common in?

A

(1) Colonization of a new habitat with plentiful resources (2) Recovery after a disaster

42
Q

Carrying capacity (K)

A

the maximum population size of a certain species that a given habitat can support over a sustained period of time; varies among species and populations and changes over time

43
Q

Logistic population growth

A

the density-dependent decrease in growth rate as population size approaches the carrying capacity

44
Q

What happens as population size approaches carrying capacity?

A

(1) Growth is exponential and r is constant (2) N increases to the point where competition for resources or other density-dependent factors occur and growth declines (3) Growth rate is 0 when population is at carrying capacity

45
Q

What factors regulate population size?

A

Density-independent factors and density-dependent factors

46
Q

Density-independent factors

A

alter birth rates and death rates irrespective of the number of individuals in the population, and usually involve changes in the abiotic environment (e.g. variation in weather patterns, catastrophic events)

47
Q

Density-dependent factors

A

change in intensity as a function of population size, and are usually biotic e.g. competition for resources (intraspecific), disease and parasitism (interspecific), predation (inter), toxic wastes, social behavior (intra)

48
Q

Population

A

group of individuals of the same species, in the same place

BIOL 121 (9 decks)

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