Brainscape's Knowledge GenomeTM

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


See full index

Ecology > Lecture 14: Population spatial structure > Flashcards

Lecture 14: Population spatial structure Flashcards

1
Q

Ecologists try to understand what factors determine

A

the distribution and abudance of species

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

Population

A

group of individuals of the same species that live within a particular area and interact with one another

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

When species interact, it means

A

compete, share pathogens, reproduce

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

Distribution

A

Geographic area where individuals of a species occur

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

Abundance

A

Number of individuals in a given area

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

Measure of population abundance

A
  1. population size (individuals)
  2. population density (individuals/area or individuals/volume)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Genetic population

A

group of individuals that mate with one another and produce offspring; group of individuals that exchange genes

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

Ecological population

A

group of individuals of the same species that compete for same resources, share pathogens, parasites, predators, and mutualists
they are linked together by ecological processes

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

What is the spatial extent of genetic population vs. ecological population?

A

Think about conifers are all wind pollinated
In this case, Genetic population is much larger because of the genetic connectivity (gene flow) provided by long distance pollen dispersal

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

Dispersion of individuals within a population =

A

spacing with one respect to one another

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

Dispersion of individuals can be described as 3 distributions:

A
  1. Regular distribution
  2. Random distribution
  3. Clumped distribution
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

From regular –> random –> clumped distribution is

A

overdispersed –> regularly dispersed –> underdispersed

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

Causes of overdispersed (even spacing) distribution

A

Animals defending territories (overdispersion at individual level and group level)

In plants: resource limitation (ex. water limitation)

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

Causes of underdispersed (clumped) distribution

A

Animals: animal flocks, cooperative breeding
Plants: heterogenous (=patchy) physical environment

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

Spatial structure may vary by

A

scale

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

Ex of how herbacceous has spatial structure varrying by scale

A

patchy at large scales (limestone meadows)
more random/uniform at smallest scales

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

Dispersal limitation

A

absence from suitable habitat due to limited dispersal
-particularly annoying to theoreticians
can be easy to test for

Ex. Hawaiian islands only have one native terrestrial mammal, hoary bat

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

Measuring a population

A

Measuring subsamples for sessile organisms
Mark-Recapture for motile organisms

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

Area based counts of a subsample

A

individuals in a given area of volume are counted
Used to estimate abundance of sessile organisms like plants
Individuals are counted in several quadrats; counts are averaged to estimate population size

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

Quadrats

A

sampling areas of specific size

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

Distance methods

A

distance 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
22
Q

Line transects

A

observer travels along a randomly placed line, counts individuals and determine distance from the line
used for sessile organisms (trees)

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

Mark Recapture studies

A

Measure population abundance for mobile organisms
A subset of individuals are captured and marked or tagged, then released
Those released individuals mix evenly with rest of population
At later date, individuals are captured again and proportion of previously marked individuals is noted

24
Q

For mark-recapture studies, the proportion of marked individuals in recaptured population should equal

A

the original proportion of the population caught during the first sampling

25
Q

Variables for measuring population size (N) with mark recapture

N is ____
A=
B=
R=
A/N=
R/B=

A

N is unknown
A= # in 1st sample = # marked
B= # of 2nd sample
R=# of recaptured in 2nd sample
A/N= true proportion marked
R/B= observed proportion marked in 2nd sample

26
Q

Assuming no bias, equation R/B __ A/N

A

equal

27
Q

N=

A

N= (A * B) / R

28
Q

Geographic ranges vary in

A

size

Ex. many tropical plants live in small ranges vs. coyotes live all over North American continent

29
Q

Endemic species

A

occurs in one location only, and no where else on Earth

30
Q

Geographic range includes

A

all the areas a species occupies during all life stages

31
Q

Really important to think about geographic range and distribution pattern for species that

A

mirgate and whose biology is poorly understood

32
Q

Within a species’ range, not all habitats are ___ so distributions are ____

A

suitable, patchy

33
Q

Some species have very specific _____ others tolerate ______

A

habitat requirements, a broader range

Ex. Creosote bush tolerates both dry and cold vs. saguaro cactus can tolerate only dry but not cold

34
Q

Habitat suitability determines

A

distribution and abundance

35
Q

Habitat suitability/ species distribution influenced by

A

abiotic factors: moisture, temperature, pH, light, nutrients
biotic factors: herbivores, predators, competitors, parasites, and pathogens
disturbance

36
Q

Disturbance

A

events that kill or damage some individuals, creating opportunities for other individuals to grow and reproduce
Ex. Fires
Influence species distribution

37
Q

Species distribution models

A

Attempt to determine climatic rules determining a species’ abundance
Apply those rules to predict distribution as climate changes

38
Q

Why are species distribution models useful

A

You don’t know the whole range of a species, but have samples of its presence
Predicting spread of pest species
Predicting shifts with climate change

39
Q

Chameleons in Madagascar Species Distribution Model Example

A

Models predicted distributions from known climatic associations
Able to see where species was found not known before

Use known samples with climate change

Not perfect!

40
Q

Large scale spatial structure

A

Effects of climatic change on geographic ranges

41
Q

Map Climate velocity

A

The distance needed to move to maintain the same climate
Can be done for different details of climate

42
Q

Population dynamics

A

the study of population size over time

simple assumptions about individuals
assume all individuals are the same

43
Q

Use of population dynamics

A

Predator-prey cycles
Disease dynamics
Population viability analyses

44
Q

If △N > 0

A

population is increasing

45
Q

If △N < 0

A

population is decreasing

46
Q

△N =

A

births - # deaths + # immigrants -# emigrants

47
Q

Population dynamics models used to answer questions:

A

How does the population size change over time?
What determines whether a population is increasing or decreasing?

48
Q

Assumptions in Population Dynamic model 1

A

Births per unit time of the population are constant (B)
Deaths per unit time of the population are constant (D)
Immigration = Emigration

49
Q

Population Dynamics model 1

A

Linear increase/decrease in population size
Constant population growth

50
Q

Assumptions in Population Dynamic model 2 = Discrete model

A

All of the individuals are the same
Each individual gives birth at the same rate (b)
Each individual has same chance of dying (d)
Immigration and emigration are equal

51
Q

per capita

A

rate of change in population size
per capita = per individual

52
Q

λ

A

Geometric rate of increase

53
Q

Conditions of geometric growth

A

Unlimited Resources
Often: small population size and rapidly growing organisms (time lags)
Good “null” model for comparison: If there are no changes to per capita births, deaths, and immigration = equal emigration

54
Q

Ex of geometric growth

A

Bacteria in petri dish with abundant food, invasive species, global human populations

55
Q

Discrete geometric growth model

A

Time is discrete
The per-capita rate of change in population size is constant.
▪ Each individual contributes the same amount to the change in
population size over time.
▪ This means the population will rapidly increase or die out
▪ Or stay the same if lambda = 1.
Good null model to figure out if the per-capita rate of change
in population size is changing.

Ecology (16 decks)

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