Population & Community Ecology Flashcards
1
Q
—: a group of individuals of a single species living in the same general area
*Defined by their — (natural or artificial) and their —
A
- Population
- Boundaries
- Size
2
Q
——: the study of population in relation to the environment
* Focuses in factors affecting —— over time
A
- Population Ecology
2. Population size
3
Q
—: the number of individuals per unit area or volume
A
Density
4
Q
—: the pattern of spacing among individuals within the boundaries of the population
A
Dispersion
5
Q
In most cases, it is impractical or impossible to — all individuals in a population
A
Count
6
Q
Sampling techniques can be used to estimate densities and total population sizes, for example by:
* Extrapolating from —— (e.g., number of trees in randomly located 100 x 100 m plots) * Using an indicator of —— (e.g., number of nests, burrows, tracks or fecal droppings) * ———
A
- Small samples
- Population size
- Mark-recapture method
7
Q
Mark Recapture Method:
Scientists —,—, & — a random sample of individual in a population
A
- Capture
- Tag
- Release
8
Q
Mark Recapture Method:
— individuals are given time to mix back into the —
A
- Marked
2. Population
9
Q
Mark Recapture Method:
A — sample of individuals are — and the number that are marked is notes
A
- Second
2. Captured
10
Q
Mark Recapture Method:
Population size is estimated by the equation: —=—/—
A
N= sn/x
S=individuals
n= second sample individuals
X= number marked
N= population size
11
Q
Density is the result of an interplay between processes that — & — individuals to/from a —
A
- Add
- Remove
- Population
12
Q
—: the influx of new individuals from other areas
A
Immigration
13
Q
—: the movement of individuals out of a population
A
Emigration
14
Q
Local densities within a population’s geographic range can — and create — of —
A
- Differ
- Patterns
- Dispersion
15
Q
Spacing can be influenced by both — and — factors
A
- Environmental
2. Social
16
Q
Individuals aggregate in —
A
Patches
17
Q
—— is the most common pattern
A
Clumped Dispersion
18
Q
Clumped Dispersion may be influenced by:
- — availability
- mating — & group —
A
- Resource
- Behavior
- Defense
19
Q
Uniform Dispersion:
Individuals are ——
A
Evenly distributed
20
Q
Uniform dispersion:
May be influenced by social interactions such as —, the defense of a bounded space against other individuals
A
Territoriality
21
Q
Random Dispersion:
Position of each individual is — of others
A
Independent
22
Q
Random Dispersion:
Occurs in Absence of strong — or —
A
- Attractions
2. Repulsions
23
Q
Patterns of Dispersion:
Dispersion patterns tend to be highly dependent on the —— of the observer
A
Spatial scale
24
Q
—: the study of the vital statistics of a population and how they change over time
A
Demographics
25
— and — factors influence birth, death, and migration rates of populations
1. Biotic
| 2. Abiotic
26
Life Tables:
An — specific summary of the survival and reproductive rates within a population
*Often made by following the fate of a —, a group of individuals of the same age, from birth until all have died
*— are often ignored when studying sexually reproducing species because only — produce offspring
*E.g., Belding’s ground squirrels
1. Age
2. Cohort
3. Males
4. Females
27
——:
Graphic way of representing the data in a life table
* Belding’s ground squirrels show relatively constant death rates
Survivorship Curves
28
Sensorship Curves:
| Type 1: — death rates during early and middle life, then an —in death rates among older age groups
1. Low
| 2. Increase
29
Survivorship Curves:
| Type 2: death rate is — over the organisms life span
Constant
30
Survivorship Curves:
| Type 3: — death rates for the young, then a — death rate for survivors
1. High
| 2. Slower
31
Survivorship Curves:
| Many species are — to the curves
Intermediate
32
Reproductive rate for sexual organisms, measured as the average number of — offspring produced by the — in an —group
1. Females
2. Females
3. Age
33
Age-specific reproductive rates — considerable by —
1. Vary
| 2. Species
34
2 models are commonly used by ecologists to estimate population growth under ideal or limiting conditions:
* —— describes population growth in an idealized, unlimited environment
* —— describes how a population grows more slowly as it nears its carrying capacity associated with limiting resources
1. Exponential model
| 2. Logistic model
35
Exponential growth Model:
Helps is understand the capacity of species to increase and the conditions that may facilitate this growth
* Population increases at an exponential rate(r), ————
* Results in a —— curve
1. Intrinsic rate of increase
| 2. J-shaped
36
Exponential Growth Model:
Characterizes some populations introduced in a new — or ——
* E.g. elephant population in South Africa grew exponentially after hunting was banned
1. Environment
| 2. Rebounding populations
37
Logistic Growth Model:
| Exponential growth cannot be — for — in any population
1. Sustained
| 2. Long
38
Logistic Growth Model:
| A more realistic population model limits growth by incorporating ——
Carrying capacity
39
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Carrying Capacity (K): — population size the environment can —
* varies with the abundance of ——
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1. Maximum
2. Support
3. Limiting resources
40
Rate of increase declines as —— is reached
| * Produces a — curve
1. Carrying Capacity (K)
| 2. Sigmoid (s-shaped)
41
The growth of laboratory populations of paramecium fits an —— curve
* these organisms are grown in a constant environment lacking — & —
1. S-shaped
2. Predators
3. Competitors
42
Some populations:
* overshoot K before settling down to a relatively stable —
* Fluctuate greatly, making it difficult to define —
1. Density
| 2. K
43
The logistic model fits few ——, but is useful as a starting point for thinking about how ——
1. Real populations
| 2. Populations grow
44
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Th logistic model and real populations:
Can be used to:
* Predict rates of ——
* estimate sustainable ——
* Estimate size below which population may become —
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1. Population recovery
2. Harvest rates
3. Extinct
45
An organisms —— comprises the traits that affect its schedule of reproduction and survival
Life history
46
Life history entails 3. Key components:
* The age at which — begins
* How much and how often an organism —
* Amount of investment in ——
1. Reproduction
2. reproduces
3. Parental care
47
—, or ———: produce many offspring once and die
* favored in highly variable or unpredictable environment where survival rates is —
* E.g. salmon, agave plant
1. Semelparity
2. Big-bang reproduction
3. Low
48
—-, or ——: produce offspring repeatedly
Z8Favored in more stable or predictable environments where survival is more —
E.g., sea turtle, bur oak
1. Iteroparity
2. Repeated Reproduction
3. Likely
49
Organisms vary widely in the number of offspring they —
Produce
50
Species that produce one or few offspring may — them better than species that produce many offspring
Provision
51
Organisms have — resources, which may lease to —— between survival and reproduction
* e.g. trade off between survival; and parental care in European kestrels
1. Finite
| 2. Trade-offs
52
—— can also influence trade off between number and size of offspring
Selective Pressure
53
If young are likely to —, may produce — small offspring
*Some plants produce a large number of small seeds, ensuring that at least some of them will grow and eventually reproduce
1. Die
| 2. Many
54
Greater —— in one or a few offspring enhances survival chances
* Some plants produce a moderate number of large seeds that provide a large store of energy that will help seedlings become established
Parental investment
55
——: selects for life history traits that are advantageous at high population densities
* Populations living at a density near carrying capacity, K
* E.g., mature trees in old growth forests
K-Selection
56
——: selects for life history traits that are advantageous at low population densities
* Populations living well below carrying capacity, such that the intrinsic rate of increase (r) is maximized
* E.g., weeds colonizing abandoned agricultural field
R-selection
57
2 important questions about regulation of population growth:
* What —— stop a population from — indefinitely?
* Why are some populations fairly — in —, while others are not?
1. Environmental Factors
2. Growing
3. Stable
4. Size
58
———: birth rate and death rate do not change with population density
Density-independent popualtions
59
———: birth rates fall and death rates increase with rising population density
density dependent populations
60
Population change and population density:
| — sometimes exist
Combinations
61
Density-dependent birth and death rates are an example of ——that regulates population growth and are affected by many factors, such as:
* Competition for —
* —
*—
* —
* — factors
* — wastes
1. Negative Feedback
2. Resources
3. Territoriality
4. Disease
5. Predations
6. Intrinsic
7. Toxic
62
In crowded populations, — population — intensifies competition for resources and results in a lower ——
1. Increasing
2. Density
3. Reproductive Rate
63
Territoriality:
| Can limits —— when individuals compete for limited space
Population density
64
Disease:
* Population density can influence the — and — of organisms
* In dense populations, — can spread more rapidly
1. Health
2. Survival
3. Pathogens
65
Predation:
| As a prey population build up, — may feed preferentially on that —
1. Predators
| 2. Species
66
Intrinsic Factors:
| For some populations, intrinsic(physiological) factors appear to regulate ——
Population size
67
Toxic Wastes:
| Accumulation of toxic wastes can contribute to —— regulation of population size
Density dependent
68
Population Dynamics:
| Focuses on the complex interactions between — and — factors that cause — in population size
1. Biotic
2. Abiotic
3. Variation
69
—: entry of individuals to an area
Immigration
70
—: exit of individual from an area
* Often increases when
~ a population becomes —
~ Competition for resources —
1. Emigration
2. Crowded
3. Increases
71
Metapopualtions:
Local populations that are linked by — and —
* Occupy patches of — habitat surrounded by — habitat
*Those lost through extinctions can be — by immigration from other patches
1. Immigration
2. Emigration
3. Suitable
4. Unsuitable
5. Recolonized
72
The Global Human Popualtion:
| Increase relatively — until about 1650 and then began to grow —
1. Slowly
| 2. Exponentially
73
The Global Human Population:
| No longer growing — but is still — rapidly
1. exponentially
| 2. Increasing
74
To maintain population stability, a regional human population can exist in one of 2 configurations:
* Zero population growth = — birth rate – — death rate
* Zero population growth =— birth rate – —death rate
1. High
2. High
3. Low
4. Low
75
——: the move from the first state to the second state
| *Associated with an increase in quality of —— and improved access to —
1. Demographic Transition
2. Health Care
3. Education
76
Global Carrying Capacity:
* Population ecologists predict a global population of ~— billion people in 2050
~ The carrying capacity of Earth for humans is —
1. 10
| 2. Uncertain
77
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Global Carrying Capacity:
Scientists have estimates on:
- — growth models
- area of ——
- — availability
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1. Logistic
2. Habitable Land
3. Food
78
Our carrying capacity could potentially be limited by —, —, —, nonrenewable resources, buildup of wastes, — change, plagues and war
1. food
2. water
3. Space
4. Climate
79
Unlike other organisms, we can regulate our population growth through ——
Social changes
