Unit 2: Population Ecology I and II Flashcards
Organismal Ecology
Organism’s interaction with environment (biotic and abiotic)
Population Ecology
interactions between members of the same species with each other and their environment
Community Ecology
interactions between populations and their environment
Ecosystem Ecology
interactions between communities and the climatic conditions of an entire region
Landscape Ecology
effects of spatial distributions in an area that can affect a species
What are the three key characteristics of population ecology?
- Range
- Spacing patterns
- Changes in size over time
Match the following with either an (A) abiotic factor or (B) biotic factor.
Sunlight
Bacteria
Rainfall
Zebras
Viruses
Sunlight (A)
Bacteria (B)
Rainfall (A)
Zebras (B)
Viruses (A)
What is the difference between a biotic component and an abiotic component?
Biotic components are living whereas abiotic components are non-living.
What are the two types of checks on populations?
Density-dependent and density-independent
Density-Dependent Factors
Checks on a population that are directly correlated to the size of a population
What are 4 examples of density-dependent factors?
Disease
Competition
Predation
Parasitism
Density-Independent Factors
Checks on a population that have no correlation to the size of a population
What are 3 examples of density-independent factors?
Weather and climate
Pollution
Rapid habitat loss
What are the three methods used by ecologists to study populations?
Demography
Population Growth
Population Dynamics
Demography
Study of factors that determine the size of populations through time
Population Dynamics
Interactions of demography and population growth
Population Growth
Change in the number of individuals in the population per unit time
What is the formula for population growth?
N/t = births - deaths
A population of snakes has a growth rate of r = -0.07. What is happening to the population?
The population is declining.
If r = 1.43, then the population is said to be _______.
Growing
If a population is not exhibiting change in rate, what is its growth rate?
r = 0.00
What are the characteristics of exponential growth?
- Population increases under ideal conditions
- Experiences rapid growth but this is not limitless as the carrying capacity will be reached
True or False: a higher r indicates that a population is growing more rapidly
True
A s-curve is indicative of which population growth curve?
Logistical
A s-curve is indicative of which population growth curve?
Logistical
In population ecology, N stands for what?
Population size
In population ecology, K stands for what?
Carrying capacity
Suppose a population has the following data. Calculate its logistical growth.
N = 1653
K = 1493
r = -0.97
-172
Match the following relation of N and K (letter) with its definition (number).
A) N –> K
B) N = K
C) N > K
1) Growth rate is zero
2) Population growth slows
3) Population decline until K
A - 2
B - 1
C - 3
What are r-selected populations?
Populations where:
- Age of first reproduction is early
- Life span is short
- Maturation time is short
- Mortality rate is high
- Number of offspring is high
- Number of reproductions per lifetime is low
- No parental care
- Size of offspring is often small
What are K-selected populations?
Populations where:
- Age of first reproduction is late
- Life span is long
- Maturation time is long
- Mortality rate is low
- Number of offspring is low
- Number of reproductions per lifetime is high
- Extensive parental care
- Size of offspring is often large
How do birth and immigration, as well as death and emigration, play a role in population dynamics?
Birth and immigration add individuals to a population, while death and emigration remove individuals from a population.
What do the different values of R (net reproductive rate) mean?
If R > 1, growth is occurring
If R < 1, decline is occurring
If R = 1, population is in equilibrium
A population has a higher proportion of its individuals living early on, not surviving late, reproducing early, and minimal parental care. Which type of survivorship best explains this?
Type III
Under the Mark-Recapture method, how is total population size deterimined?
[(# of marked individuals in 1st catch) x (total # in 2nd catch)] / (# of marked recaptures in 2nd catch)
What is an issue with the Mark-Recapture method?
Previously captured animals could learn to avoid traps or intentionally get caught to gain access to food
What are the three types of dispersion patterns?
Clumped spacing
Uniform spacing
Random spacing
Clumped Spacing
Most common dispersion pattern; resources tend to be clustered and social behavior may promote this pattern
Uniform Spacing
Uniform spacing between populations/resources; competition may cause this and it may result from social interaction
Random Spacing
Populations are randomly spaced and may occur where resources are common and abundant; rarest dispersion pattern
Where do metapopulations occur?
Areas where suitable habitat is patchily distributed and is separated by intervening stretches of unsuitable habitats.
Semelparity
All offspring are produced in a single reproductive event; individuals reproduce once before they die
Iteroparity
Reproduction takes place in successive years or breeding seasons
Human population best fits which growth model?
Exponential
True or False: in humans, the fertility rate is increasing
False
What is the main difference in human populations between developed and developing nations?
In developed nations, population is stabilized, while in developing nations the population is increasing
What sociopolitical impacts play a role in human population?
- Availability to resources
- Educations
- Healthcare
For humans, what is the average ecological footprint for one individual?
Roughly 5 acres
What is a life table?
Summarizes the probability that an individual
will survive and reproduce in any given year
over the course of its lifetime.
In a life table, what does nx mean?
Number alive
In a life table, what does dx mean?
Number dying
In a life table, what does lx mean?
Survivorship
Type I Species
Most individuals die late in life
Type II Species
Uniform birth and death rate over the entire lifetime
Type III Species
Most individuals die early in life
In a life table, what is mx?
Fecundity/Reproduction rate
